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Chilicola setosicornis Packer, n. sp.
No full textChilicola setosicornis Packer, n. sp. (Figs. 16 A–O) Diagnosis. This is a somewhat isolated species, perhaps most closely related to Toro and Moldenke’s Heteroediscelis (Packer, in press). It can be most readily separated from all other Chilicola in the male, by the long setae towards the apices of the apical flagellomeres (Fig. 16 A). The form of the hind trochanter is also unique (Fig. 16 D and E). Females differ from other Chilicola with apical hair patches on the metasomal terga and unmodified hind tibial spurs by the comparatively deep depressions dorsal of the antennal socket, which seem to house the scape. Only one other species matches this description, and Chilicola neffi Toro and Moldenke, has deeper and narrower frontal depressions but the females can be instantly differentiated by the maroon coloured metasoma of C. neffi, as well as by the latter species’ smaller size and location in coastal Chile rather than montane northwest Argentina. Description. Male: Length 6.0mm, forewing length 4.0mm, head width 1.4mm. Colouration: Black-brown with following parts yellow: Basal portion of labrum (rest dark brown), mandible (apex dark brown), clypeus except adjacent to epistomal suture, mark on lower paraocular area up to level of ventral margin of supraclypeal area, apicoventral spot on hind tibia. Following parts orange: Ventral surface of antennal flagellum, dorsal and anterior surfaces of foretibia, forebasitarsus, forepretarsus, S 2 and S 3 orange anterior to submarginal zone and all of S 6. Wing veins and tegula dark brown. T 1 and T 2 dark brown, narrowly orange anterior to translucent amber apical impressed areas. Surface Sculpture: Labrum shining with dense punctures basally (i~d) sparsely punctate apically (i= 2– 3 d). Clypeus with punctures small and dense apically (i~d), sparser towards base. Supraclypeal and lower and upper paraocular areas with strongly imbricate microsculpture, appearing almost granular and with small, sparse, irregularly spaced punctures (i = 1–5 d). Upper paraocular area with larger punctures. Frons with punctures crowded and sharp edged, very variable in size; area immediately below lateral ocelli with few, large punctures. Vertex behind ocelli rugose, laterally with dense punctures. Genal area with weak, elongate punctures on longitudinally microstriate background, shiny. Pronotum and metanotum roughly and densely punctate (id. Pubescence: Hairs short and sparse, except on gena, frons, mesopleuron and lateral surface of propodeum 1–2 MOD. Scopal hairs of hind tibia 2 MOD. Sparse basal hair bands on T 2 and T 3 and apicolaterally on T 2 – T 4. Scopa of S 2 corbiculate, hairs long 2.5 MOD, with branches only on anterior surface, scopal hairs of S 3 somewhat shorter 2 MOD. Structure: Maxillary palpus with segments increasing in length and decreasing in breadth from first to last, 0.7 X as long as prementum. Prementum 0.4 X as broad as long, with fovea covering most of ventral surface, margins strongly carinate. Lacinia an elongate triangle, 4 X as long as greatest breadth. Lorum poorly sclerotised, less than 0.33 X as long as cardo. Clypeus with transverse apical depression for middle half of its width, extending one third below lower ocular tangent. Compound eyes less convergent below (Fig. 16 C), UOD:LOD 52: 40. IOC:OOC 17: 14. Frons swollen midway between lateral ocelli and antennae, swellings delimiting medial margin of supra-antennal depression. Dorsal surface of propodeum shorter, ratio of length to scutellum, 18: 22. Apical lunule of S 5 broadly U-shaped, 2 X as broad as long. Sting apparatus: As in Fig. 16 K–O. Lateral portion of marginal ridge of hemitergite 7 with two obtuse angles, one where margin of apodemal region meets ridge, second one just anterior to origin of lateral process; apodemes to spiracular atrium large (Fig. 16 K). Hemitergite 8 with plate and apodeme subequal in size, anterior ridge of apodeme slightly sinuate, junction between plate and apodeme straight (Fig. 16 L). First valvifer with dorsal and ventral processes equal in length. Second valvifer with pars articularis acutely angled, incisura postarticularis narrow and parallel-sided. Base of sting shaft with processus medianus moderately developed ventrally (Fig. 16 M). Furcula with ventral arms somewhat narrow, widely spaced forming broad U; dorsal arm comparatively broad, abruptly narrowing to apex; sinuate and narrow in side view (Figs. 16 N and O). Material studied. Holotype male, allotype female, one male and four female paratypes: ARGENTINA: Salta, Cuesta de Obispo, 1km E. of Piedra de Molina, 25 o 11 ’ 152 ” S 0 65 o 51 ’ 236 ”W, 3340m, 20.iv. 2003, L. Packer; one female paratype, Salta, Cuesta Obispo, iii. 1997, Fritz. All specimens except the one collected by Fritz were found as adults in hollow stems of an unidentified shrub except both males and one female that emerged later the same year from nests obtained at the site. The holotype, allotype and one female paratype are at MACN, the remaining paratypes are at PYU except Fritz’s specimen, which is at AMNH. Etymology. The specific epithet refers to the setation on the more apical antennal flagella of the male. Comments. This species generally agrees with that section of Toro and Moldenke’s subgenus Heteroediscelis that was subsequently sunk within Oediscelis by Michener, (1995), (i.e. those species possessing a highly modified hind femur and tibia in the males). It can be differentiated from these species by the long antennal flagellomeres and form of the hind tibia, which is considerably expanded, but unlike Heteroediscelis with an expanded hind tiba, it lacks an incision just before the apex. The antennae are more reminiscent of C. (Oediscelis) vernalis Philippi and C. (O.) lonco Toro & Moldenke, although these latter two species lack the setation. It would seem to be somewhat isolated morphologically. This is another interesting new species of Chilicola discovered in and primarily known from specimens obtained from nests. Other examples of species known only from nests include several species of the subgenus Oroediscelis (Michener 2000; L. Packer unpublished data), C. venticola Packer (Packer 2004), C. (Anoediscelis) paramo González and Michener (González and Michener 2004) and also an undescribed species with affinities to C. inermis and C. mailen, known from a single gynandromorph collected by the senior author at the same locality and in stems of the same shrub that yielded the type series of C. setosicornis. Undescribed species in the subgenera Oroediscelis and Anoediscelis were also found in the same stems.Published as part of Packer, Laurence & Genaro, Julio A., 2007, Fifteen new species of Chilicola (Hymenoptera: Apoidea; Colletidae), pp. 1-55 in Zootaxa 1468 on pages 47-50, DOI: 10.5281/zenodo.17662
Chilicola chubutense Packer, n. sp.
No full textChilicola chubutense Packer, n. sp. (Figs. 6 A–F) Diagnosis: Extremely similar to the previous species, but with forefemur and hind tibia almost entirely dark, pubescence on metasomal sterna longer, the carina on the inner surface of the hind tibia more basal in position (Fig. 6 C) and penis valves with two membranous lobes (Fig. 6 F). Thus, the combination of forefemur dark except for narrow apical ring; hind tibia entirely dark, laterally compressed except at extreme apex (Fig. 6 B) with single carina on inner surface (with base of carina much closer to base of tibia than the apex of the carina is to the apex of the tibia) (Fig. 6 C), two membranous lobes on the penis valves (Fig. 6 F) plus S 2 –S 5 with posteromedially directed patches of suberect pubescence approximately 1.5 MOD in length is sufficient to separate this species from all other Chilicola known to us. Details of S 7 are also unique (Fig. 6 D). The female is unknown. Description. Male: body length 4.2mm, wing length 3.0mm, head width 1.1mm. Colouration: As for C. unicarinata except facial markings paler, anterior yellow stripe on scape narrow, spot on pedicel small, hind tibia entirely dark except at extreme base and narrowly at extreme apex; tegula transparent, posterior 0.33 X and anterior spot cream; wing veins amber except for costa and 2 nd abcissa of M+Cu brown and stigma testaceous. Surface sculpture: As for C. unicarinata except punctures deeper, more distinct and slightly denser throughout, except on metasoma; dorsolateral area of propodeum more coarsely rugose. Pubescence: As for C. unicarinata except S 2 –S 5 with longer posteromedially directed hairs, longest laterally ~ 1.5 MOD, shorter medially 0.75 MOD, longest hairs subequal in length on all sterna, sparser on S 5. Structure: As for C. unicarinata except as follows: Head: Clypeus longer than broad (11: 10) (Fig. 6 A), with weak broad incomplete median longitudinal depression. Supraclypeal area broader, length to breadth 17: 10. Flagellomeres slightly shorter, for F 8, length:breadth 9: 8. Mesosoma: Dorsal surface of propodeum shorter than scutellum, ratio of scutellum:metanotum:propodeum 37: 20: 33. Hind femur slightly narrower, length to depth of femur 10: 3 (Fig. 6 B). Hind tibia with oblique carina on inner surface more basal in position than in previous species, distance from base of tibia to base of carina almost 2 X distance from apex of carina to apex of tibia (Fig. 6 C). Basal vein curved near middle; stigma shorter in relation to marginal cell, ratio 53: 76, stigmal margin on marginal cell more evenly convex. Metasoma: As in C. unicarinata. Terminalia: S 7 with one pair of well developed lateral lobes; dorsal lobes subparallel to one another, hairs finer than in previous species; remnant of ventral lobe as short as in C. unicarinata but extending posteriorly as short, twisted extension (Fig. 6 D). S 8 with lateral lobes shorter and broader and apical lobe broader than in C. unicarinata (Fig. 6 E). Penis valve with one membranous lobe longer than in previous species (Fig. 6 F). Material studied. Holotype male and one paratype: ARGENTINA, Chubut, 8km S, of Rada Tilly, 45 ° 59 ’043S, 72 ° 36 ’ 322 W, 30m, 24.xi. 2003, L. Packer; the paratype bears an additional blue label: VOUCHER SPECIMEN DNA EXTRACTION E.A.B. Almeida # 67 extraction date: 7 / 2004. The holotype is at MACN; what remains of the paratype is at PYU. Comments. The only known specimens of this species were collected in scrub habitat close to the edge of a small pond just to the west of the coastal highway. The paratype was used for DNA extraction and is missing most of the mesosoma.Published as part of Packer, Laurence & Genaro, Julio A., 2007, Fifteen new species of Chilicola (Hymenoptera: Apoidea; Colletidae), pp. 1-55 in Zootaxa 1468 on pages 16-17, DOI: 10.5281/zenodo.17662
MARKET POWER IN BEEF PACKING: FEEDLOT "CAPTURE" AND ITS CAUSES
No full textConcentration in the beef packing industry has been rising for the past 25 years. Many studies of market power in beef packing are based on the conjectural variations framework, which depends on accurate estimates of packer input and processing costs. We propose an alternative measure of packer behavior which does not rely on estimates of packer costs. We also suggest how this measure could be used to draw tentative conclusions regarding packer behavior.Agribusiness, Marketing,
Liphanthus centralis Sharifi & Graham & Packer 2019, sp. nov.
No full textLiphanthus centralis Mir Sharifi & Packer, sp. nov. urn:lsid:zoobank.org:act: CA74085B-1BEA-42A4-AD12-BA43AE76AADA Figs. 7–9, 41–51, 139, 167, 171–172, 177–178, 183–184. Diagnosis: Males of this species can be differentiated from all others of the genus except L. discolor and L. domeykoi by the combination of two submarginal cells, pronotal lobe yellow, metatibial spurs straight, S2 and S3 with posterior margin straight (Fig. 44). It can be differentiated from these two species by IAD equal to AOD (16:16) (Fig. 42) and face above antenna (Fig. 43) and mesoscutum weakly imbricate, shiny whereas IAD> AOD in both the other species (15:10 and 19: 16 in L. discolor and L. domeykoi respectively) both of which have the face and mesosoma minutely tuberculate (as in Fig. 1) and dull (Figs. 32 & 35). Females of this species can be differentiated from all others in the genus by the combination of two submarginal cells, pronotal lobe yellow, metatibial spurs straight (Fig. 50), clypeus dark (Fig. 49) and face and mesoscutum distinctly and densely punctate (i~d) (Figs. 49 & 50). The most similar species in the female is L. tregualamensis sp. nov. which shares the first four characteristics but is sparsely and obscurely punctate (Figs. 109 & 111). Description. Holotype Male: Dimensions: Approximate body length: 4.69mm; head width: 1.44mm, wing length: 2.96mm, intertegular width: 0.78mm. Coloration: Black to dark brown with following parts yellow: labrum, mandible (apex orange-red), clypeus, lower paraocular area from just above midlength of compound eye, subantennal sclerite (except extreme base), pronotal lobe, broad apical ring on all femora, all tibiae (except brown mark on anterior surface of protibia and posterior surface of mesotibia), all tarsi (except all tarsomeres 4 and 5 yellow-brown). Ventral surface of F3–F11, T6–T7 and S6 red-brown. Sculpture: Microsculpture absent on whole body except as stated otherwise. Basal 2/3 of clypeus and subantennal sclerite punctures minute, dense, i≤d, apical 1/3 of clypeus punctures larger, irregularly spaced, i=1–3d; lower paraocular area punctures small irregularly spaced, i=1–4d above, larger, more evenly spaced below, i=1–2d; upper paraocular, frontal and vertexal areas punctures small, dense, i2d. Pubescence: White, somewhat plumose and short; ≤1.5 MOD on head, sides of mesosoma and scutellum except 2d, moderately sparsely punctate posteriorly, i=1.5–3d, denser on S4 and S 5 i =1–2d. Pubescence: Longest hairs often longer than in male, mostly ≤2 MOD, ≤3 MOD on sides of mesosoma; scopal hairs strongly curved, simple, ~2.5 MOD. Prepygidial fimbria pale brown, dense and ~2–2.5 MOD. Structure: Head: 1.2 X as wide as long (77:64). Mandible 2.1 X as long as basal depth (52:25), apex rounded. Labrum less than twice as broad as long (34:20), raised area sides convergent below, apical margin weakly biconvex. Clypeus ~ 2.5 X as wide as long (90:37). Anterior tentorial pit just above junction of outer subantennal and epistomal sutures. Frontal line a row of slightly depressed punctures, briefly deep below midlength. IAD2.6 X as long as greatest width (35:13), longer than pedicel and F1 combined (24). Pedicel and F1 as long as wide, both 12:12; F2 shorter than wide (8:12), remaining flagellomeres with length and width subequal except F10 ~1.5 X as long as wide (21:14). Mesosoma: Mesoscutum shorter than wide, 81:91. Length of scutellum: metanotum: metapostnotum:32:22:14. Marginal cell slightly shorter than distance between its apex to wing tip (80:85). Tarsal claws with short teeth. Metasoma: Metasoma widest at midlength of T3, sterna unmodified. Pygidial plate triangular, sides straight, forming angle of ~70˚, apex moderately rounded, broadly raised medially. Material studied: Holotype male, allotype female, 25 male and 23 female paratypes as follows: Holotype male, allotype female and 2 male paratypes: CHILE, Region Metro {politana}, Valle Nevado, 2596m, -33.34111, -70.29497, 9.i.2009, L. Packer. One paratype male and one paratype female: CHILE, Region Metro {politana}, Farellones, -33.35627, -70.32478, 2179m, 9.i.2009, L. Packer. Six males: CHILE, Valparaiso: W of Cuesta Colliguay, x.5.1969, Rozen & Peña. Five males, one female: CHILE, Region V, Caleu, NW of Tiltil, 9.xi.1997, L. Packer. Eleven males and 21 females: CHILE, R.M, Chacabuco Caleu, nr. Cerro del Roble {= Cerro El Roble}, -33.0136, -70.983, 30.xi.2004, J. S. Ascher, A. Y. Kawahara, C. Espina. The holotype, allotype and paratypes from Valle Nevado and Farellones and paratypes from Caleu are at PCYU except one male at PUCV (the holotype and allotype will be sent to MNHN), the remaining specimens are at the AMNH. Etymology. The specific epithet refers to the geographic range of the species in Central Chile. DNA barcodes. One full length (from the allotype) and one partial sequence are available for this species, they differ by 0.53% and the nearest neighbor is L. pilifrons Ruz & Toro 1983 from which the sequences differ by 10.08%, although L. centralis does not cluster with this species. Its BIN is AAV8032 and the one sequence on genbank noted by Packer and Ruz (2017) is KX820707. Comments. Treating it as if it had three submarginal cells, using the key in Ruz and Toro (1983) males of this species fail at couplet 10 which contrasts different forms of process on S2: L. centralis has no process on S2. Females fail at couplet 35 where they would key out to L. (Leptophanthus) anacanthus Ruz & Toro 1983 based on clypeal coloration but have the facial fovea shorter than the scape as for L. (Lpt.) alicahue Ruz & Toro 1983. The specimens from Cerro El Roble and Caleu are from moderate altitude in the coastal mountain range and those from Cuesta Colliguay are from lower elevations further west, whereas those from Valle Nevado and Farellones are from the Andes range proper. We found no consistent differences among specimens between the two mountain ranges. The structures associated with the penis of this species are remarkably complex. It seems as if the penis valves proper are quite simple, short and not curved ventrally towards the apex but the endophallus is considerably elaborated. No other Liphanthus known to us has such an elaborate endophallus. This species has been collected in reasonably large numbers from areas that have long received considerable attention from melittologists yet with only one specimen found before 1997. The locality referred to on data labels as “Farellones” is one of steep and strongly curved roads (leading Monckton, 2016 to name a new species from this area as Chilicola curvapeligrosa) where numerous interesting bees have been found including the aforementioned Chilicola Spinola 1851 species, Xeromelissa farellones (Toro and Moldenke) (Toro and Moldenke, 1979) and close to where Eucerinoda gayi Michener and Moure 1957 was recently rediscovered (Vivallo, 2009).Published as part of Sharifi, Negar Mir, Graham, Liam & Packer, Laurence, 2019, Fifteen new species of Liphanthus Reed (Hymenoptera: Andrenidae) with two submarginal cells, pp. 1-80 in Zootaxa 4645 (1) on pages 21-24, DOI: 10.11646/zootaxa.4645.1.1, http://zenodo.org/record/334544
Chilicola (Stenoediscelis) denisii Packer, n. sp.
No full textChilicola (Stenoediscelis) denisii Packer, n. sp. (Figs. 13 A–H) Diagnosis: On the basis of numerous characteristics this species is clearly a member of Toro and Moldenke’s subgenus Stenoediscelis, subsumed within Anoediscelis by Michener (1995), but deserving of subgeneric status based upon phylogenetic analysis (Packer, in press). Synapomorphies for Stenoediscelis include, for both sexes, the previously unnoticed notched parascutal carina (Fig. 13 D); in the male, the form of the hind tibia and basitarsus, both of which are slightly outwardly concave (Fig. 13 E), and the terminalia with a particularly characteristic S 7 (Fig. 13 F); and in the female the subapical mandibular tooth, which is as long as, or almost as long as, the apical tooth and the presence of a medial angulation basal to the subapical tooth (Packer, in press). Males of Chilicola denisii can be differentiated from the two described species of Stenoediscelis, C. inermis (Friese) and C. mailen Toro and Moldenke, on the basis of its almost entirely dark hind tibia. Two additional undescribed species are known from the same geographic region as the type locality for C. denisii in Patagonian Argentina. One can be differentiated from C. denisii on the basis of size; it is less than 3.5mm in length whereas C. denisii is 4.5 –5.0mm, as well as having narrow pale rings on the base and apex of the hind tibia. The remaining species is as large as C. denisii and like it has an entirely dark hind tibia, but has the ventral surface of the hind femur angulate at the base so that it attains its maximum depth in its basal quarter. The hind femur of C. denisii is not swollen basally and attains its maximum depth near midlength (Fig. 13 E). Females of the new species can be differentiated from C. inermis and C. mailen by their generally sparse and irregular mesoscutal punctation, with i= 1–5 d as opposed to i= 1–2 d. The smaller of the undescribed species noted above also has irregular and sparser punctation but can be differentiated readily on the basis of size as noted. Description. Male: body length 5.0mm, forewing length 3.0mm, head width 0.9mm. Colouration: Black, with following parts yellow: Labrum, mandible (except apex red-brown), all of clypeus, lower paraocular area extending to half distance between anterior tentorial pit and upper margin of clypeus. Following parts orange or yellow-orange: Pedicel and flagellum, apical spot on fore- and midfemur, anterodorsal surface of foretibia, foretarsus, basal and apical rings on midtibia. Following parts testaceous: Mid- and hindtarsi and apical ring on hindfemur. Posterior surface of flagellum brown. Tegula translucent dusky brown. Wing veins dark brown, tending to testaceous towards base. Apical impressed areas of metasomal terga translucent dusky brown. Surface Sculpture: Labrum coarsely and irregularly punctate (id, becoming sparser on more posterior terga, apical impressed areas impunctate with weaker microsculpture. Pubescence: White, short and sparse, not especially plumose; longest on genal area (2 MOD), of intermediate length on legs and ventral surface of mesosoma. Without apico-lateral hair patches on metasomal terga and no specialized hair patches on metasomal sterna. Structure: Head: Longer than broad, length to width 13: 12 (Fig. 13 A). Labrum 2 X as broad as long, apical margin slightly produced medially. Mandible length:basal depth ~ 2: 1. Clypeus shorter than broad 38: 45, lower one quarter extending beyond lower ocular tangent, lacking median longitudinal groove (Fig. 13 A). Epistomal suture expanded below anterior tentorial pit into elongate comma, pit adjacent to suture. Subantennal sutures weakly concave outwardly. Supraclypeal area somewhat protuberant dorsally, flat below, length:breadth 25: 21. Frons lacking swellings or depressions. Frontal line raised for lower 0.4 X distance between supraclypeal area and median ocellus, replaced by narrow depression for remaining 0.6 X. Facial fovea present but extremely weakly developed as comparatively shiny area with weak wrinkling in surface above and below. Inner margin of compound eye weakly emarginate, strongly convergent below (Fig. 13 A), UOD:LOD 77: 48. OOC: IOC 22: 28. Lateral ocellus separated from compound eye by slightly less than 2 X its diameter. Vertex rounded in frontal view, slightly longer than LOL in dorsal view. Upper ocular tangent approximately 0.6 MOD below lower margin of median ocellus. Scape slightly shorter than pedicel+F 1 +F 2 combined, almost 3 X as long as broad; F 1 slightly broader than long; F 2 –F 10 almost 2 X as long as broad; F 11 0.75 X as long as F 10; flagellum not markedly increasing in breadth from F 1 to F 11; flagellomeres lacking unusual patterns of setation or structural modifications. Genal area narrower than compound eye (28: 40) (Fig. 13 B). Malar space linear such that presence or absence of malar suture indetectable. Mesosoma: Elongate, approximately 2 X as long as greatest depth. Pronotal collar short, subequal to LOL. Mesoscutum with parascutal carina notched (Fig. 13 D). Episternal groove complete; scrobal groove weakly defined posterior to scrobe, absent anteriorly. Propodeum elongate, dorsal surface as long as posterior depth and subequal to length of scutellum (scutellum:metanotum:propodeum 30: 15: 23), propodeal sulcus absent, area outside of dorsal triangle of propodeum swollen, and dorsal and posterior surfaces at angle of 135 º to each other. Hind trochanter unmodified. Hind femur 2.5 X as long as greatest depth, convex ventrally. Hind tibia laterally compressed, narrow basally, gradually expanding to apical third, somewhat parallel sided to apex, length to greatest depth 90: 23, attaining base of trochanter when folded, lacking angles or carinae (Fig. 13 E). Hind tibial spurs somewhat short but not robust, strongly curved or sclerotised. Hind basitarsus very slightly concave outwardly and slightly downcurved, 5.5 X as long as greatest depth (Fig. 13 E). Hind tarsal claws bifid. Basal vein weakly curved near base; distal stigmal perpendicular crossing near middle of second submarginal cell; stigma shorter than length of marginal cell on wing margin; stigmal margin on marginal cell angularly convex; first recurrent vein apical to first submarginal cross vein. Metasoma: Length and apical width of T 1 subequal; T 2 and T 3 with weak basal depressions; apical impressed area approximately 0.25 X length of tergum. Metasomal sterna unmodified except S 1 concave subapically in profile. Terminalia: S 7 with ventral lobe L-shaped and posteriorly directed, bearing row of long hairs in basal half of outer surface and a few short hairs at extreme apex, dorsal lobe short and flat (Fig. 13 F). S 8 with apical lobe narrowly joined to rest of sternum, apex concave. Gonobase with lateral projection of ventroapical process broadly rounded (Fig. 13 G). Volsella with outer margin angularly and deeply concave before apex. Gonoforceps elongate, gonostylus poorly demarcated from gonocoxite, elongate and narrow. Penis valve with two long membranous lobes, medial one dorsally oriented, lateral one bent inwardly at right angles over medial lobe (Fig. 13 H). Female: Body length 4.5mm, wing length 2.6mm, head width 1.0mm. Colouration: Entirely dark brown-black except anterior surface of F 4 –F 10 pale orange and apical impressed areas of metasomal terga amber. Surface Sculpture: As in male except as follows: Labrum with large dense punctures, i<d. Clypeus with punctures more distinct, i= 1–4 d. Lower paraocular area regularly punctate, i=d; upper paraocular area with shiny almost impunctate area. Frons more regularly punctate, i= 2 d. Vertex with weak transverse wrinkles. Genal area with distinct punctures anteriorly, i~d. Hypostomal area shiny lacking microsculpture with few minute punctures. Mesoscutum with punctures irregular, i= 1–5 d. Metanotum with punctures more distinct and regular than in male, i~d; Pubescence: Longest hairs on frons <1.5 MOD; on genal area, <2 MOD; on lateral surface of thorax 1 MOD. Hind trochanter, femur and tibia with sparse scopal hairs <2 MOD. Metasomal terga lacking apicolateral hair patches. S 2 with long scopal hairs forming corbicula, <4 MOD, with widely spaced, short branches on anterior surface. Structure: As in male except for usual secondary sexual characteristics and as follows (mouthparts and sting apparatus not dissected in sole female specimen): Head longer, length to width 13: 11 (Fig. 13 C). Labrum 2.5 X as wide as long, with circular apicomedial ridge, bearing tuft of setae. Mandible with subapical tooth as long as apical one and with mesal angulation basal to subapical tooth. Frons lacking swellings or depressions. Frontal line raised for lower 0.6 X distance between supraclypeal area and median ocellus. Facial fovea absent but represented by shiny almost impunctate area. OOC: IOC 24: 26. Upper ocular tangent approximately 1 MOD below lower margin of median ocellus. Gena shorter than width of compound eye (30: 36). T 1 broader, length to width 60: 85. S 5 with apical lunule 0.75 X as long as apical width. Material studied. Holotype male: ARGENTINA, Santa Cruz, 20km E. of Los Antiguos, 46 o 36 ’ 595 ” S 0 71 o 21 ’ 472 ”W 17.xi. 2003, pan trap, L. Packer; allotype female: same except 0.5km E. of Los Antiguos, 46 ° 33 ’ 500 ” S 071° 35 ’ 507 ”W, 237m, 17–19.xi. 2003, pan trap, L. Packer. Both known specimens will be housed at MACN. The holotype bears a blue label that states: VOUCHER SPECIMEN DNA EXTRACTION E.A.B. Almeida # 58 extraction date: 7 / 2004. Etymology. This species is named, with gratitude and affection, after the senior author’s father, who ensured that the senior author was not afraid of insects as a child. Comments. The genitalia of this species are very similar to those of C. inermis and particularly, C. mailen, but the outer margin of the ventral lobe of S 7 is straighter and the whole lobe more L-shaped, whereas in the other two species the outer margin is rounded and the whole lobe more lunate. In C. inermis the ventral lobe of S 7 is also more gradually narrowed to the apex and the basal bare area longer than in the other two species.Published as part of Packer, Laurence & Genaro, Julio A., 2007, Fifteen new species of Chilicola (Hymenoptera: Apoidea; Colletidae), pp. 1-55 in Zootaxa 1468 on pages 37-41, DOI: 10.5281/zenodo.17662
Calliopsis (Liopoeum) rigormortis Dumesh and Packer, new species
No full textCalliopsis (Liopoeum) rigormortis Dumesh and Packer, new species. (Figs. 1-12) Diagnosis. The female can be differentiated from those of other Chilean Calliopsis by the color of the metasomal terga, particularly the more apical terga which are entirely pale. The only other Chilean Calliopsis species with yellow markings (Calliopsis trifasciata) has the apical terga entirely dark with relatively narrow, medially interrupted bands on T 2 –T 4. The male can be differentiated from other Chilean Calliopsis males by its largely dark lower face (supraclypeal area entirely black, clypeus mostly black) and presence of an interrupted yellow band on T 1. Calliopsis trifasciata and C. hirsutula males have the lower face entirely yellow and T 1 entirely black. Description. Female. Figs. 1, 3– 6. Body length 7.6–7.8mm, forewing length 4.7 mm, head breadth 2.0 mm. Coloration: Black, with yellow as follows: labrum apicomedially, mandible middle third (black basally, dark red apically), irregular marking on apical margin of clypeus, supraclypeal area apical 1 / 5, lower paraocular area and adjacent to inner margin of lower half of compound eye; mesocoxa ventrally, meso- and metatrochanters, protrochanter ventrally, profemur basally, meso- and meta femora (except for dark dorsal surface), pro- and meso tibiae (except dark posterior spot), metatibia ventrally, entire probasitarsus (tarsus apically darkened); terga mostly yellow with sublateral dark spots (decreasing apically), T 1 dark with pale yellow lateral areas, T 2 –T 4 pale yellow, medially orange, apically dark with dark areas decreasing on more apical terga, T 5 entirely pale yellow; sterna with dark basomedial markings. Surface sculpture: Body mostly dull due to imbricate microsculpture, face above antennal sockets and mesosomal dorsum more coarsely sculptured, granulose; following areas weakly imbricate, shiny: labrum, clypeus, supraclypeal area below, lower paraocular area, meso- and metapleuron, and metasomal sterna; labrum with weak transverse striae basally and metapostnotum with short irregular basal striae and a raised midline; clypeal punctures coarse and irregularly spaced on disc, fine and dense laterally and on supraclypeal area below (i 4 d), T 5 –T 6 very sparsely punctate. Pubescence: White long hairs less dense; mesosomal venter with sparse short hairs, metatarsus very sparsely pubescent, longest hairs as long as or only slightly longer than metatarsus; S 5, S 6 and S 8 with dense long hairs apically. Structure: Head: frontal line not as strongly impressed; compound eyes convergent below (UOD:LOD 1.2mm:1.0mm); scape about 2 X as long as apical breadth, most flagellomeres longer than broad, F 2 –F 3 shortest. Mesosoma: meso- and metatibial spurs short, ~ 0.33 X as long as basitarsus, microserrate; mesobasitarsus parallelsided and slender, 4 X as long as broad; total length of tarsomeres 1–3> 1.5 X length of tarsomere 4, b:l for tarsomeres 1–3: 0.8, 1.5, and 1.75, respectively; tarsal claw with subapical tooth. Metasoma: T 7 apically rounded and medially impressed; S 5 with apical margin produced medially (Fig. 8); S 6 with basal margin concave, apex produced as two acute processes (Fig. 8); S 7 with dorsally oriented lateral lobe sclerotised basally, membranous apically, sclerotised portion with posterior acute process (Fig. 9); S 8 with basal margin only weakly concave (Fig. 10); genital capsule with gonocoxite rounded dorsomedially, penis valve pointed at apex with sparse hairs on inner surface (Fig. 11). Notes. Color variation has been observed in the female metasoma, where the dark tergal bands range from complete (Fig. 3) to only lateral dark marks (Fig. 4). T 1 coloration ranges from almost entirely dark (Fig. 3) to mostly orange (Fig. 4). Figure 1 shows the intermediate state of the holotype. Material examined. Holotype female and paratype female: CHILE: Region VII, W of Laguna del Maule, S 35.96901 W 70.56940 1982m L. Packer; allotype male with same locality except: S 35.99909 W 70.42668 2205m; two paratype females and four paratype males with same locality except: S 35.99711 W 70.56071 2165m 3.i. 2009; paratype male with same locality except: S 36.00163 W 70.27328 2227m 5.i. 2009. Material at PCYU except one male and one female paratype at PUCV. Floral host. All specimens were collected from, or flying over, an unidentified species of Adesmia (Fabaceae). Etymology. The species is named because of its death posture, with the head oriented upwards such that the face is horizontal and on the same plane as the dorsal surface of the mesoscutum (Fig. 6).Published as part of Dumesh, Sheila & Packer, Laurence, 2011, The Calliopsis (Hymenoptera; Andrenidae; Panurginae) of Chile with the description of a new species, pp. 64-68 in Zootaxa 2908 on pages 65-67, DOI: 10.5281/zenodo.27778
Chilicola obesifrons Packer, n. sp.
No full textChilicola obesifrons Packer, n. sp. (Figs. 2, 3A–M) Diagnosis. Chilicola obesifrons and its close relatives (all of which are undescribed, but include this and the following species) are among the smallest bees in the genus. As a group, they can be differentiated from any of the named subgenera of Chilicola on the basis of the shape of the pronotum, the collar of which is moderately long, not strongly convergent anteriorly but angulate at the anterolateral corners (Fig. 3 E). A new subgenus is being described for this group of species (Packer, in press). Other unusual characteristics are the lack of an emargination on the inner margin of the eye (Figs. 2, 3A and C) (shared only with some species of the subgenus (Prosopoides)) and the comparatively coarse punctation of the thoracic dorsum (Fig. 3 F). The frons is at least slightly expanded around the median ocellus and just mesad of the upper portion of the compound eye (Figs. 2, 3A and C) in all of the species in the group with the exception of the next species to be described (C. catamarcense Packer, n. sp.). These expanded areas are comparatively impunctate but bear strongly imbricate microsculpture appearing almost granular, some species of the subgenus Prosopoides also share this condition. The membranous lobes of S 7 are unique (Fig. 3 H) in form, colouration and setation among related species, including the subgenus Prosopoides. These other taxa have much more robust lobes that usually bear long and/or thick, capitate setae. Chilicola obesifrons can be differentiated from other members of its group by the following characters: the head of both sexes in profile has the median ocellus entirely hidden by frontal swellings and the vertex is flat around the lateral ocellus (Figs. 3 B and D). This feature combined with the anterolateral corners of pronotum approximately right-angled serve to identify the male (Fig. 3 E). For the female, the comparatively small mesoscutal punctures, with space for approximately 12 between the median and parapsidal lines, separate this species from others with a swollen frons and flat vertex. Other species with the median ocellus hidden in profile either have males with the head angularly produced in front of the lateral ocellus in profile (an undescribed species known only from the male from Neuquen, Argentina) or anterolateral corners of pronotum acutely angled (a Bolivian species) and females with larger mesoscutal punctures such that at most 9 would fit in the space between admedian and parapsidal lines (both an additional northern Argentinian species and the Bolivian one). Description. Male: Body length 3.2mm, forewing length 2.0mm, head width 0.8mm. Colouration: Black, with following parts yellow: labrum, mandible (except apex red-brown), most of clypeus, spot on lower paraocular area, anterior mark on scape. Pedicel and flagellum orange. Legs with yellow-orange as follows: anterior surface of foretibia, outer surface of forebasitarsus, apical rings on all femora; basal and apical rings on all tibiae. Tarsi pale brown. Tegula and apical impressed areas of metasomal terga pale amber. Wing veins orange-brown. Surface Sculpture: Microsculpture strongly imbricate almost throughout. Labrum deeply, coarsely and densely punctate (i<d) on shining background. Clypeus dull with sparse, irregular and obscure punctures, i= 1– 4 d. Supraclypeal and lower paraocular areas somewhat shiny with punctures more distinct and somewhat more dense, i= 1–3 d. Frons with larger, denser punctures, i~d, with impunctate swellings around median ocellus and laterad of lateral ocellus. Vertex with transverse wrinkles among punctures. Hypostomal area irregularly punctate, i= 1–4 d. Pronotum, mesoscutum and scutellum (Fig. 3 F) dull with dense punctures that are large for size of insect, i<d; sparser on scutellum, i~d; metanotum duller than mesoscutum, punctures i<d. Mesopleuron somewhat shiny, irregularly punctate, i<1–3 d. Dorsal surface of propodeum with disk slightly depressed, weakly rugosoreticulate on either side of median carina, dorsolateral area roughened. Metasomal terga with weak microsculpture, sparse shallow obscure punctures, anterior portions of terga not differently sculptured from disks, apical impressed areas impunctate with very weak microsculpture. Pubescence: White, short and sparse, not especially plumose; lacking long erect hairs on hypostomal area. Without apicolateral hair patches on metasomal terga. No areas of specialized pubescence on metasomal sterna or legs. Structure: Head: Longer than broad, length to width 62: 53 (Fig. 3 A). Labrum 2 X as broad as long, apex almost straight. Mandible short and broad, length:basal depth ~ 2: 1. Clypeus with length and breadth subequal, lower one third extending beyond lower ocular tangent, lacking median longitudinal groove; epistomal suture expanded below anterior tentorial pit almost to laterally reflexed portion of suture, pit not separated from suture (Fig. 3 A). Subantennal suture curved inward from near origin on antennal socket, otherwise straight; supraclypeal area (Fig. 3 A) long and narrow, length to breadth <2: 1, weakly produced and poorly demarcated from frons above. Frons greatly swollen around median ocellus and mesad of upper inner margin of eye such that median ocellus not visible in profile; swellings causing head to be flat dorsally in profile (Fig. 3 B). Frontal line distinct to median ocellus. Facial fovea broadly oval, shiny and shallow (Fig. 2). Inner margin of compound eye not emarginate (Fig. 3 A) making UOD difficult to assess, but eyes strongly convergent below (Fig. 3 A); OOC subequal to IOC. Lateral ocellus separated from compound eye by more than 2 X its diameter. Vertex slightly longer than lateral ocellus, abruptly rounded onto occipital region. Upper ocular tangent passing well below lower margin of median ocellus by more than MOD. Scape 3 X longer than greatest breadth, much longer than pedicel (Fig. 3 A) and F 1 –F 3 combined; F 1 broader than long, F 2 4 X broader than long (Fig. 2); middle flagellomeres with length and breadth subequal; F 11 slightly longer than F 10; flagellum gradually increasing in breadth from F 1 to F 11; flagellomeres lacking unusual patterns of setation or structural modifications. Genal area approximately one third as long as eye (Fig. 3 B). Malar space linear such that presence or absence of malar suture indetectable. Mesosoma: Elongate, length more than 2 X its greatest depth (17: 7). Pronotal collar long, slightly more than ½ as long as scape and approximately 1.5 LOL, laterally weakly concave, anterolateral corners forming right angle (Fig. 3 E). Episternal groove complete, sharply curved anteriorly below. Scrobal groove weakly defined posterior to scrobe. Propodeum elongate, dorsal surface as long as posterior depth and subequal to length of scutellum (scutellum:metanotum:propodeum 24: 15: 25); propodeal sulcus marked by shallow pits becoming more distinct posteriorly. Hind leg not strongly modified; trochanter lacking modifications; femur 3 X as long as greatest depth, convex ventrally; tibia gradually expanding from base to apex, somewhat more strongly so in basal half, length 3.5 X greatest depth, lacking angles, carinae or ridges (Fig. 3 G); hind tibial spurs long and not strongly curved or sclerotised; hind basitarsus 6 X longer than greatest depth, parallel sided; hind tarsal claws bifid. Basal vein evenly curved; distal stigmal perpendicular crossing near apex of second submarginal cell, stigma shorter than length of marginal cell on wing margin, stigmal margin in marginal cell convex; first recurrent vein and first submarginal crossvein approximately interstitial on Rs+M. Metasoma: Length and apical width of T 1 subequal. T 2 and T 3 with weak basal depressions; apical impressed area approximately 0.33 X length of tergum. Metasomal sterna unmodified except S 1 slightly swollen at apex, gradulus of S 2 with long posteriorly directed lateral portion, gradulus missing on S 3 –S 6. Terminalia: S 7 with one pair of lateral lobes, ventral lobe broad, membranous, dusky pigmented except for basal and apical extremities; dorsal lobe reduced to narrow lamella with acute dorsolaterally oriented angulation (Fig. 3 H). S 8 with apical process elongate; widest at apex; emarginate apically (Fig. 3 I). Ventroapical process of gonobase broad with comparatively long lateral projections. Volsella kidney-shaped; gonostylus not clearly demarcated from rest of gonoforceps. Gonoforceps with medioventral lobe approximately right-angled. Penis valve with pair of subapical membranous lobes, both oriented dorsally (Fig. 3 J). Female: Body length 3.3mm, wing length 2.0mm, head width 0.8mm. Colouration: As in male except as follows: Labrum, mandible and anterior surface of flagellum orange. Clypeus and lower paraocular area lacking pale markings. Legs with marking darker orange; rings on femora and tibiae narrower. Metasomal sterna dark brown. Wing veins pale amber. Surface Sculpture: As for male except as follows: Somewhat less dull throughout due to slightly weaker microsculpture. Spacing of punctures on supraclypeal area less regular, i= 1–5 d. Scutellum with space for approximately 12 punctures between admedian and parapsidal line. Metanotum no duller than scutellum. Mesopleural punctures finer. Lateral sulcus of propodeum very weak. Pubescence: As in male except as follows: Comparatively sparse scopa on hind leg, with hairs on femur and tibia <3 MOD. Metasomal scopal hairs with short branches on anterior side of rhachis, well developed corbicula on S 2, <5 MOD; scopal hairs on S 3 <4 MOD; apical row of hairs on S 4 <3 MOD; Structure: Maxillary palpus unmodified, somewhat less than 0.5 X as long as prementum. Prementum 4 X longer than greatest width; premental fovea large, carinate laterally. Lacinia an elongate triangle, more than 3 X as long as greatest breadth. Lorum weakly sclerotised except towards apex, 0.33 X as long as cardo. Rest of body as in male except for usual secondary sexual characteristics and as follows: Facial fovea larger (Fig. 3 C). Frons less strongly swollen around median ocellus and dorsally along inner margin of eye, median ocellus not visible in profile, area around it somewhat flattened (as in Figs. 3 C and D), region between medial and lateral swellings concave. Supraclypeal area shorter than in male (Fig. 3 C). Gena more than 0.5 X as long as width of compound eye (Fig. 3 D). Apical lunule of S 5 forming approximately equilateral triangle. Sting apparatus: Hemitergite 7 (Fig. 3 K) with lateral portion of marginal ridge thick almost to apex with obtuse angle at base of lateral process; lateral lamella approximately triangular, medial portion of marginal ridge concave; spiracle closer to lateral portion of marginal ridge than to apex of lamina spiracularis, set in shallow depression; apodeme poorly developed; posterior margin of lamina spiracularis obtusely excised. Hemitergite 8 (Fig. 3 H) with anterior ridge strongly developed to apex, straight except slightly produced anteriorly at apex; margin of plate and junction of apodeme and plate both slightly sinuate. First valvifer comparatively long and parallel-sided with short dorsal and ventral processes. Second valvifer with apodemal ridge slightly convex, apical process weakly developed, pars articularis narrowly rounded, incisura postarticularis moderately broad, portion of plate basal to gonostylus membranous, gonostylus somewhat parallel-sided. Sting shaft with basal bulb 2 / 3 as long as stylet, ventral surface slightly concave; processus muscularis and processus medianus not strongly developed (Fig. 3 M). Furcula with ventral arms narrow apically considerably broadened near basal one third, in lateral view strongly reminiscent of a cheese knife with ventral margin of dorsal arm strongly convex. Material studied. Holotype male and allotype female, ARGENTINA, Catamarca, 17km N. of Andalgala, 14–15.ii. 2003, L. Packer, pan traps; all paratypes are also from Catamarca province and are as follows: 25km N. of Andalgala, 14.ii.03 L. Packer, six females (one in glycerin); 20km N. of Andalgala, 27 o 29 ’ 477 ”S, 0 66 o 23 ’006”W, 1736m, 14.ii.03, L. Packer, three females; Los Nacimientos de Abajo, 16–31.i. 1969 Willink, Torán & Stange, malaise trap, [Entomofauna Subandina], one female; 6km N. of Belén, 1240m, 16–31.i. 1969 Willink, Torán & Stange, malaise trap, [Entomofauna Subandina], one female; Punta Balasto, i. 1997, Arriagada, one female; San Fernando, 7.iii. 1990, Rozen and Roig, on Sclerophyllax gilliesii (Sclerophyllaceae), six females. The holotype and allotype will be housed at MACN pending completion of revisionary studies of the group; the Willink, Torán, Stange females are at IML, Arriagada’s and Rozen and Roig’s specimens are at the AMNH, the remaining paratype females are at PYU. Etymology. The specific epithet refers to the large swellings around the median ocellus and just mesad of the upper portion of the eye. Comments. The type series collected by the senior author was found on the roadside between Andalgala and Capillitas in an area that was substantially moister than were the surrounding areas. The two specimens collected by Duckworth have the propodeal sulcus more strongly developed than in the others and approach several undescribed species in the group in this regard. Two females from Sumalao, Salta Province, Argentina (AMNH), collected by Fritz in January 1996 may be attributable to this species.Published as part of Packer, Laurence & Genaro, Julio A., 2007, Fifteen new species of Chilicola (Hymenoptera: Apoidea; Colletidae), pp. 1-55 in Zootaxa 1468 on pages 5-10, DOI: 10.5281/zenodo.17662
Chilicola tricarinatoides Packer, n. sp.
No full textChilicola tricarinatoides Packer, n. sp. (Figs. 11 A–C) Diagnosis: This species can be differentiated from all other Chilicola by the form of the hind tibia and the punctures on the frons separated by somewhat less than their diameters, as opposed to being crowded and sharp edged as they are in related species. Females are unknown. Otherwise, this species is very similar to C. tricarinata from which it can be differentiated based upon the characteristics listed in the diagnosis for that species. Description. Male: Body length 4.3mm, forewing length 3.0mm, head width 1.0mm. Colouration: Black with following parts yellow: Labrum, mandible (except apex red), large inverted Tshaped mark on clypeus, apical half of anterior surface of scape, spot on pronotal lobe, basal spot on tegula and ventral-most portion of apical swelling of hind tibia. Following parts orange or orange-testaceous: Anterior surface of pedicel and flagellum, apical ring on foretrochanter, anterior surface of fore and mid femora except for dark basal ring; fore and midtibia except for most of outer surface, spot on apex of hind coxa, most of ventral surface of hind trochanter, oval spot on outer surface of hind femur, ventral portion of apical expanded region and narrow apical ring and externoventral margin of hind tibia. All tarsi dusky brown. Wing veins red brown. Tegula clear transparent. Apical impressed areas of metasomal terga pale amber. Metasomal sterna brown. S 6 suffused with testaceous. Surface sculpture: As for C. tricarinata except as follows: Microsculpture sparser making surface somewhat shinier except clypeus duller. Punctation somewhat denser and less regular on clypeus, supraclypeal area and lower paraocular area, i= 0.5–2.5 d. Frons with punctures separated by somewhat less than their diameters. Vertex rugulose. Genal area with weak striae and shallow obscure punctures. Pronotum, mesoscutum and scutellum irregularly punctate i= 0.2–2 d. Dorsal surface of propodeum rugoso-reticulate, lateral surface with only strong microsculpture below, dorsolateral area rugose. Mesopleuron irregularly punctate, i= 1–3 d. T 1 –T 2 densely punctate i~d; punctures smaller, more irregular and shallower on more apical terga; basal depressed portions of T 2 –T 3 transversely microstriate; apical impressed areas impunctate. Pubescence: As in C. tricarinata except as follows: Genal beard shorter, 1.5 MOD posteriorly; T 1 –T 3 with apicolateral hair patches sparse; S 2 with sparser and shorter erect pubescence <1 MOD; remaining sterna lacking specialized pubescence although with subapical transverse row <0.75 MOD on S 3 –S 5. Structure: Head (Fig. 11 A): As in C. tricarinata except as follows: Clypeus shorter, length to breadth (38: 45). Supraclypeal area less than 1.5 X as long as apical width (27: 20). IOC 2 X OOC (34: 17). Scape narrower, length to apical breadth 33: 13; flagellomeres broader, length to breadth of F 8 16: 10. Gena longer in comparison to compound eye (20: 48). Mesosoma: As in C. tricarinata except as follows: Hind basitarsus 5 X as long as greatest depth. Dorsal area of propodeum shorter, propodeum:metanotum:scutellum, 22: 18: 30; propodeal sulcus broader, pits clearly transverse throughout. Stigmal margin on marginal cell angularly convex. Metasoma: Subpetiolate, T 1 proportionately longer than in C. tricarinata (90: 65). Terminalia: S 7 as in C. tricarinata except membranous lobe with apicolateral margin broadly rounded with longer setae and anterior laterally directed hair bearing area more extensive (Fig. 11 B). S 8 with apical process comparatively broader and shorter than in C. tricarinata, more strongly broadened towards apex (Fig. 11 C). Genital capsule as in C. tricarinata except: gonobase with ventral process somewhat longer and penis valve with membranous lobe slightly larger. Material studied. Holotype and eight male paratypes (one in glycerin), ARGENTINA: Chubut, 8km S. of Rada Tilly, 45 ° 59 ’043S, 72 ° 36 ’ 322 W, 30m, 24.xi. 2003, L. Packer. The holotype and 3 paratypes are at MACN, the remainder at PYU. One paratype bears a blue label stating: VOUCHER SPECIMEN DNA EXTRACTION E.A.B.Almeida # 62. Comments. This species was collected at the same locality as C. chubutense described above.Published as part of Packer, Laurence & Genaro, Julio A., 2007, Fifteen new species of Chilicola (Hymenoptera: Apoidea; Colletidae), pp. 1-55 in Zootaxa 1468 on pages 33-34, DOI: 10.5281/zenodo.17662
THE EFFECTS OF INDUSTRY STRUCTURE ON PRICE: A CASE IN THE BEEF INDUSTRY
No full textThis study estimates the influence of concentration and other structural variables on the price of slaughter cattle. Cross-sectional data were used to estimate a single equation model which included, in addition to traditional factor demand variables, packer concentration and a measure of market power exerted by feedlots. Results suggest that packer concentration has had a significant and increasing negative impact on fed cattle prices during the years of analysis, 1972 and 1977.Industrial Organization, Livestock Production/Industries,
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