1,720,983 research outputs found
Differing morphology and ultrastructure of the male copulatory apparatus in species-groups of Anagrus Haliday (Hymenoptera: Mymaridae)
No full textMale genitalia of thirteen members of the mymarid wasp genus Anagrus have been studied: Anagrus (Anagrella) mymaricornis (Bakkendorf), Anagrus (Paranagrus) unilinearis Soyka, A. (Anagrus) ustulatus Haliday, A. (A.) erythroneurae Chiappini & Trijapitzin, A. (A.) atomus (Linnaeus), A. (A.) aegyptiacus Soyka, A. (A.) vilis Donev, A. (A.) sensillatus Viggiani and Jesu, A. (A.) breviphragma Soyka, A. (A.) incarnatus Haliday, A. (A.) obscurus Förster sensu Soyka, A. (A.) fennicus Soyka and A. (A.) avalae Soyka. Taxonomically significant differences between subgenera and the atomus and incarnatus species groups are described. The functional significance of various features, and in particular, the arrangment of sensilla are discussed
Flagellar sensilla of Quadraspidiotus perniciosus Comstock (Rhynchota: Diaspididae) male
No full textThe flagellar sensory structures of Quadraspidiotus perniciosus Comstock (Rhynchota: Diaspididae) male have been investigated, using scanning and transmission electron microscopy.
Five categories of sensilla have been identified: three types of sensilla trichodea, a sensillum coeloconicum and a sensillum basiconicum. The possible function of sensilla is discussed, considering their location, morphology and ultrastructure.
No gustatory sensilla have been detected. All the setae (sensilla trichodea) present on the flagellomeres, except for the three ‘knobbed’ ones that are mechanosensilla, are cuticular components of olfactory structures. These olfactory sensilla are of two distinct types, having fluted or smooth hairs; furthermore, the fluted ones present different typologies for a varied number of dendrites. They are conceivably used for perceiving female sexual pheromone. It might be that each of the different components of the female sexual pheromone is perceived by a specific sensillum.
Two types of supposed thermo-hygroreceptors have been found, one sensillum coeloconicum and two sensilla basiconica
Preliminary data on Stegobium paniceum (L.) larval head sensilla
No full textSensory structures of Stegobium paniceum (L.) head have been investigated under Scanning and Transmission Electron Microscopes and described.
Their possible function is hypothesized
Trisopsis sp. (Diptera: CecidomyIidae): un predatore presente nei prosciuttifici. Osservazioni preliminari.
No full textI Cecidomyiidae, probabilmente la famiglia più numerosa dei Ditteri, comprendono specie galligene di interesse economico perché dannose alle piante coltivate, ma anche numerose specie zoofaghe, sia predatrici sia endoparassitoidi, importanti per il ruolo ecologico di limitatori naturali di afidi, cocciniglie, psille, aleirodidi e acari.
La famiglia si suddivide in diverse sottofamiglie: ai Cecidomyiinae appartiene il genere Trisopsis, descritto da Kieffer nel 1912 (Harris e Dorchin, 2012).
Di questo genere si conosce poco, in particolare non è noto molto della sua biologia: si sa che si tratta di un genere a cui appartengono anche specie predatrici di altri artropodi come afidi, cocciniglie, acari (Crosby, 1986).
Il presente lavoro riguarda individui catturati in un prosciuttificio nel Parmense, presenti sul pavimento dello stabilimento all'interno del "ruffino", dove è stata messa in evidenza un’entomofauna piuttosto ricca. Su questo pabulum sono state trovate larve di Trisopsis sp., stadi preimmaginali di Rincoti Antocoridi, anch'essi predatori, oltre ad acari dei salumi.
Gli esemplari di Trisopsis sp., rinvenuti nel prosciuttificio, sono stati allevati e i vari stadi inviati al Prof. Solinas e al Prof. Harris per l’identificazione della specie. In base ai dati morfologici, gli esemplari studiati appartengono a un’unica specie del genere Trisopsis, vicina a Trisopsis tyroglyphi Barnes. Nel presente contributo si riporta quindi una brevissima descrizione morfologica dei vari stadi della specie, corredata di fotografie al microscopio elettronico a scansione, e si descrivono comportamenti di adulti e larve.TRISOPSIS SP. (DIPTERA: CECIDOMYIIDAE): A MITES PREDATOR PRESENT IN HAM FACTORIES. PRELIMINARY OBSERVATIONS
The Cecidomyiidae, probably the largest family of Diptera, include gall midge species of economic interest, being harmful to cultivated plants, but also many zoophagous species both predators and endoparassitoids, important as natural control agents of aphids, mealy bugs, psyllids, aleyrodids and mites.
The family is divided into several subfamilies: the genus Trisopsis, described by Kieffer in 1912, belongs to that of Cecidomyiinae (Harris and Dorchin, 2012). Little is known of this genus, particularly of its biology: it includes species which are predators of other arthropods such as aphids, mealy bugs, mites (Crosby, 1986).
This contribution concerns specimens collected in a ham factory in Parma, on the debris present on the floor, where a quite rich fauna is present. On this pabulum Trisopsis sp. larvae, preimaginal stages of Hemiptera Anthocoridae, also predators, as well as ham mites were found.
Specimens of Trisopsis sp., collected on the ham debris, were bred and the various stages were sent to Prof. Solinas and Prof. Harris for species identification. On morphological data bases, the specimens studied belong to a single species of the genus Trisopsis, close to Trisopsis tyroglyphi Barnes.
In this paper a brief morphological description of the various stages of the species, illustrated with Scanning Electron Microscope photographs, together with an account of adults and larvae behavior, is given
Mortality of Tribolium confusum J. du Val (Coleoptera: Tenebrionide) in modified atmosphere at different oxigen percentages
No full textSince the 1990s an ecologically friendly alternative to insecticide treatments for controlling stored-product insect pests has been available: the methods of modified and controlled atmospheres, which involve reducing the quantity of oxygen (O2) in the air in order to kill insects by anoxia. This study examines the effect of treatments with controlled atmospheres, considering the time necessary to obtain total mortality of insects at percentages of O2 higher than those normally used in controlled atmospheres and estimating the possible positive influence of a temperature increase in order to compensate for the effects of the reduced anoxia. Adult populations of Tribolium confusum J. du Val were treated at various O2 percentages (1, 3, 5, 6, 7, 8 and 10%) and temperatures (23, 26, 29, 32, 35, 37 and 40 °C). The relative humidity was very low (<18%) in all the treatments considered. Lethal exposure times varied from less than one day to a week (longer times were not considered). A multiple regression procedure was applied to the experimental data, considering the time necessary to obtain total mortality as the dependent variable. The analysis provided a good fit to the experimental data and indicated a positive correlation with the percentage of O2 and an inverse one with temperature
Morphological and physiological adaptations of wood-boring beetle larvae in timber
No full textBeetles which develop boring tunnels inside and feed on seasoned wood
present morphological and physiological adaptations related to the specific activities of their larvae in such a peculiar substrate. As far as protection of antiquarian goods made of wood is concerned, we are dealing mainly with three Coleoptera families, namely Lyctidae, Anobiidae, and Cerambycidae, which include species
with wood-boring larvae. The adaptation to wood-boring and wood-feeding activities in beetle larvae was reached independently by phyletic lines not closely related, as a convergent evolution due to feeding behaviour.
Among these adaptations, the following are examined with reference to the three
families mentioned above. The conformation and activity of the larval mandibles and their possible correlations with the characteristics of the wood attacked are considered together with the presence of body structures for anchoring the larvae to the wood substrate inside the tunnel during the gnawing action. Intracellular
endosymbiosis (endocytobiosis) with yeasts or bacteria, capable of supplementing larval diets lacking in some essential nutrients, and its main features are summarized.
Last, structural and functional characteristics are discussed as regards
tracheal spiracles, provided with filter devices important for preventing intrusion of wood powder into tracheae from larval tunnels as well as useful for avoiding dehydration
Wood preservative composition
No full textThe invention relates to a preservative composition comprising a polyamidoamine polymer dissolved or dispersed in an aqueous solvent and/or in an organic solvent, and its use for coating wood, paper, stone and lithoid construction materials (for ex-ample travertine, calcareous stones etc.). The preservative composition, which may envisage the addition of metal cations or metal nanoparticles or boric acid, has biocidal properties (anti-fungal, anti-insect, antibacterial, anti-mould) and allows the material to which it is applied to be protected and consolidated
Preliminary observations on the use of low temperatures in the cultural heritage protection
Full text linkEach insect species has different temperature optima: the more this
parameter deviates from these values the more the insect suffers negative consequences, up to the death. Temperature can be easily editable. Therefore, the application of low temperatures may represent a physical method for the protection of valuable cultural objects, alternative, for example, to chemical ones.
In this paper we report laboratory tests results, carried out on Trogoderma inclusum LeConte (Coleoptera: Dermestidae), a species harmful to leather items such as bindings of books and mummies, in order to reach its control by applying low
temperatures. The tests were conducted using specimens obtained from laboratory breeding blocks maintained at 27 ± 2°C and 75 ± 5% R.H., in a temperature controlled room of the Institute of Entomology and Plant Pathology, Piacenza. The aim of the tests was to determine the time necessary to obtain the total mortality
of the different instars of development at temperatures of -10°C and -20°C. The
insects, in the various instars of development of egg, larva, pupa and adult, were treated with low temperatures in two different ways:
- inserting the Petri dishes containing the insects directly in the freezer without any protection, in order to obtain an immediate lowering of the temperature, and inserting the Petri dish in a niche carved in an old book so that the lowering of the temperature is gradual. In some cases the insects were kept at +4°C for a time before the test to determine whether exposure to low temperature before treatment
could induce a resistance to it.
The results show that the method can be validly applied for cultural heritage objects protection, attacked by the species concerned
Preliminary data on cellulase encoding genes in the xylophagous beetle, Hylotrupes bajulus (Linnaeus)
No full textHylotrupes bajulus (Linnaeus) (Coleoptera, Cerambycidae), a wood-boring beetle attacking softwood,
utilises both wood starch and cellulose as food. The fibre is digested in variable percentages, depending
on the starch content. A role for symbiotic bacteria was presumed as well as the presence of endogenous
cellulases. The aim of our investigation was to verify the presence of endogenous endoglucanase genes in
H. bajulus larvae. After performing an online search, three sequences for the endoglucanases of the class
GHF5 and four for the endoglucanases of the class GHF45 were recovered and aligned in order to develop
some primers on the most conserved regions and try the amplification of the genes in H. bajulus. Seven
degenerated primers for GHF5 endoglucanase and five for GHF45 endoglucanase were tested. By using
two different primer combinations we obtained two fragments: both of them showed homology with
significant identity with insect endoglucanases of the GHF45 family available online, and one also with
microbial cellulases. The first fragment is undoubtedly of endogenous origin while we cannot exclude
that the second one is of microbial origin. No results were obtained for the endoglucanase of the class
GHF5
Polyamidoamines (PAAs) functionalized with siloxanes as wood preservatives against fungi and insects
No full textA novel treatment based on polyamidoamines (PAAs) for the preservation of wood against fungi and insects with a broad protection functionality, low effective concentration, and low environmental impact has been developed. PAAs were synthesized by nucleophile addition of ethanolamine (EtA) and/or 3-aminopropyltriethoxysilane (APTES) to N,N′-methylene-bisacrylamide (MBA). The molar ratios in the tested formulation were: I) MBA:EtA=1:1; II) MBA:APTES=1:1; III) MBA:EtA:APTES=1:0.5:0.5. These formulations, characterized by ESI-MS, NMR, FT-IR, were tested against: (a) the wood decay fungi (Coniophora puteana, Coriolus versicolor, and Poria placenta); (b) the subterranean termite Reticulitermes lucifugus, and the drywood termite Kalotermes flavicollis; (c) the woodborer Stegobium paniceum. Tests in combination with leaching showed that formulation II and III can be utilized as fungal wood preservatives for use classes 2–3 (EN 335:2013). In addition, all PAAs formulations were equally effective in preserving wood against the subterranean termite, and formulation II was most effective against drywood termite. On the other hand, the formulation I showed good efficacy against S. paniceum
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