CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
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DESCRIPTION OF GONATOPUS XUISP. N. FROM INDIA (HYMENOPTERA DRYINIDAE)
Get PDFA new species of Dryinidae (Hymenoptera: Chrysidoidea) is described from India: Gonatopus xuisp. n. It is thefirst species of Dryinidae reported from Himachal Pradesh. The new species belongs to group 7 of Gonatopus. The key tothe females of the Oriental species of Gonatopusgroup 7 is modified to include the new taxon. The new species is namedafter the late Professor Zaifu Xu, from Guangzhou (China), well-known specialist of Chinese dryinids
Effect of the few-branched-1 (Fbr1) tassel mutation on performance of maize inbred lines and hybrids evaluated under stress and optimum environments
No full textYield can be increased under stress conditions by manipulating the traits that limit yield under these conditions. Tassel size is one such trait. A few branched-1 mutation (Fbr1) was introduced into the maize breeding programme of CIMMYT as a strategy to improve drought tolerance. The aim of this study was to evaluate yield performance of Fbr1 maize lines and hybrids under optimum and stress environments, and to determine associations between tassel size and grain yield under stress and optimum environments. Genotype effects were highly significant for all traits and genotype by environment (GxE) interaction effects were significant for all traits except for kernel row number and anthesis silking interval. Generally Fbr1 x Fbr1 hybrids had lower grain and pollen yields, and were less adapted to abiotic stress conditions. Positive relationships between grain yield components and pollen yield components were found except for association of prolificacy with tassel branch number and total tassel length under drought stress and optimum conditions. We were expecting that the Fbr1 genotypes could potentially in- crease grain yield under drought stress. It seems that grain yield improvement and stress tolerance is determined by multiple factors, which, when put together can additively contribute to increased yield performance. Although reduction in tassel size could be one of these many factors that contribute to improved grain yield under stress conditions, the factor cannot bring significant improvement on its own. Our results show that the Fbr1 trait reduce pollen production in genotypes with few tassel branches resulting in reduced kernel set and the problem worsens under drought and low N stress. We recommend selection for shorter and lighter tassels to improve grain yield without compromising on tassel size to ensure sufficient pollen availability, especially under stress environments
PHYLOGENETIC PLACEMENT OF THE WHITE COCONUT SCALE, PARLAGENA BENNETTI WILLIAMS (HEMIPTERA DIASPIDIDAE)
Get PDFParlagena bennetti Williams (Hemiptera: Diaspididae) is commonly known as the coconut scale and has only been collected in some islands in the Caribbean, Central America and the northernmost countries of South America. The species P. bennetti has been placed in Parlagena, a genus of few species currently considered as closely related to Parlatoria Targioni Tozzetti, but it has never been involved in molecular phylogenetic analysis. Here we include data from three genes of P. bennetti with 32 other armored scale insects and one outgroup to determine the correct placement of this species among armored scale insects. Both combined analysis and individual genealogies demonstrate the probable placement of this species in the subfamily Diaspidinae, likely as part of the tribe Lepidosaphidini
Assessing the mechanical stability of trees in artificial plantations of Pinus nigra J. F. Arnold using the LWN tool under different site indexes
Get PDFIn young black pine plantations, the most valuable and interesting thinning scheme is mainly based on the positive selection of dominant and well-shaped trees to be candidates for carbon sequestration, timber production and natural regeneration. The mechanical stability of candidate trees is here a fundamental skill that must be taken into account and the slenderness ratio (HD) is one of the main indicators. HD has been recently proved to be correlated to the living whorl number (LWN) by Cantiani & Chiavetta (2015). In this study, the statistical model was re-calibrated in order to study the influence of soil fertility on the HD - Living whorls number (LWN) relationship.The fertility-balanced models estimated a different LWN threshold. The model for the highest fertility class (Site index 24) estimated 12 LWN (RMSE of 20%). Similarly, a lower value were detected for the other two fertility classes, SI20 and SI16, where 10 LWN were considered enough with an associated RMSE of 16% and 17% respectively. Compared to the general model provided by Cantiani & Chiavetta (11 LWN with 18% of RMSE) the site index approach improved the accuracy and reliability
BIOLOGICAL CONTROL OF ACLEES SP. CF. FOVEATUS AND FIRST RECOVERY OF AN ASSOCIATE BEAUVERIA BASSIANA STRAIN
Get PDFAclees sp. cf. foveatus (Coleoptera: Curculionidae) is spreading in Central Italy, causing severe infestation on fig trees. There are very few information for this pest and no natural enemy is reported. Here, we report the first recovery of a natural enemy associated with this invasive weevil, a strain of the entomopathogenic fungus Beauveria bassiana. The potential use of entomopathogenic fungi and nematodes as biocontrol agents was tested against adults in laboratory trials. In agree with the detection in nature, only treatments with B. bassiana were able to control the insects. This result opens new frontiers for the environmental friendly control strategies against this weevil
NEW INDONESIAN COUNTRY RECORDS AND SPECIES INFORMATION FOR MEALYBUGS (HEMIPTERA PSEUDOCOCCIDAE) IN WIRJATI’S HISTORIC COLLECTION
Get PDFBetween 1955 and 1960, a collection of slide-mounted mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) was prepared by Mrs Wirjati, using samples collected between 1916 and 1960 from a variety of hosts in Indonesia. The collection is a record of which species were established in the country in 1960. The slides, deposited at the Indonesian Ministry of Agriculture in Java, are the earliest material in the national mealybug collection. There are 181 temporary slide mounts of unstained, waxy mealybugs mounted in agar or gum chloral media that have dried out to varying degrees. Specimens were retrieved from 50 representative slides and re-mounted as stained, archival mounts in Canada balsam. The method used to retrieve the specimens from the old mounts is described. The re-mounted specimens were re-identified using up-to-date, published identification keys, resulting in new identities for most of the specimens. Fifteen species belonging to 12 genera were identified, however specimens from four of the slides could not be identified beyond genus level. The Wirjati slides of Antonina thaiensis Takahashi, Hordeolicoccus nephelii (Takahashi) and Paraputo corbetti (Takahashi) are new country records. The differences between the fauna in Wirjati’s collection and that found in Indonesia today are discussed
KNOWN DISTRIBUTION AND PEST STATUS OF FLUTED SCALE INSECTS (HEMIPTERA MONOPHLEBIDAE ICERYINI) IN SOUTH AMERICA
Get PDFCurrent information on the known distribution of all 18 species (12 species of Crypticerya Cockerell and 6 species of Icerya Signoret) of fluted scale insects (Hemiptera: Monophlebidae: Iceryini) found in South America is provided. A list of known host plants and natural enemies of these species is given and their pest status in South America is discusse
Effects of potting mixture on the growth of seedlings of Entandrophragma cylindricum (SPRAGUE) and Tamarindus the Growth of Seedlings of Entandrophragma cylindricum (SPRAGUE) and Tamarindus indica L
Get PDFThe study describes the effects of biochar and NPK fertilizer on Entandrophragma cylindricum and Tamarindus indica seedlings in the nursery of the Department of Forestry and Wildlife, University of Benin, with a view to evaluating the seedling growth response to the quantity of biochar and the level of fertilizer applied. The potting mixtures used were soil only which is the control, mixture of soil and biochar, mixture of soil, biochar and fertilizer, mixture of soil and fertilizer. The seeds of Entandrophragma cylindricum and Tamarindus indica were sourced for and planted. Transplanting was carried out for germinated seeds until the required number of seedlings needed for the experiment was obtained. Measurements were taken at one week interval. Seedlings were evaluated for ten weeks for different growth variables. The experiment was a completely randomized design. Result indicates that there was no significant difference in the growth variables except for stem height of Entandrophragma cylindricum at 5% level. Although, there were marginal differences in the growth variables recorded. Other silvicultural practices that would promote the growth of Entandrophragma and Tamarindus should be considered. Few problems were encountered especially those of insect and pest infestation
DESCRIPTION OF TYLENCHORHYNCHUS IRANENSIS SP. N. (NEMATODA TELOTYLENCHIDAE) FROM IRAN
Get PDFA new species of stunt nematodes, Tylenchorhynchus iranensis sp. n. is described from the rhizosphere of faba bean (Vicia faba L.), from material collected in the Khuzestan province, southwestern Iran. The new species is characterized by the following combination of features: lateral fields with four non areolated incisures, cephalic region continuous to slightly offset and conformed by 6-7 fine annuli, stylet 15-18 µm long, post-anal intestinal sac extends into the entire tail cavity, epiptygma present, tail sub-cylindrical with a hemispherical to sub-hemispherical smooth terminus, 46-65 μm long and composed by 46-49 annuli. Molecular analysis based on 28S rRNA gene sequences placed T. iranensis sp. n. within a clade that contained representatives of the genus Tylenchorhynchus with high support
IBIZELLA BALEARICA N. GEN., N. SP. (ASTIGMATA CANESTRINIIDAE) FROM BALEARIC ISLANDS, SPAIN
Get PDFIbizella balearica n. gen., n. sp. from Ibiza, Balearic Islands is described and illustrated, based on female, male and protonymph. All specimens were collected on undetermined Blaps sp. (Coleoptera: Tenebrionidae). Canestrinia samsinaki known from Bulgaria and Cyprus is included to the new genus Ibizella