The susceptibility of olive cultivars to the olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae),\ud
has seldom been studied. This article examines factors associated with olive fruit fly infestation\ud
of 16 commonly planted Sicilian olive cultivars. Total infestation data were simultaneously correlated\ud
with categorical and quantitative factors using ordinal logistic regression. When all factors were\ud
included in the analysis, year, sampling date, cultivar, and fruit color were highly significant, but the\ud
quantitative factors fruit volume, fruit elongation, and fruit hardness were not. When the analysis\ud
was repeated excluding cultivar, all quantitative factors were significant, and elongation and volume\ud
were highly significant. Spherical, large, and hard fruit seemed to be preferred by B. oleae over fruit\ud
that are elongate, small, and soft. Therefore, fruit color, elongation, volume, and hardness provide\ud
useful information regarding the susceptibility of cultivars. In both organic and conventional olive\ud
cultivation, information about olive cultivar susceptibility to olive fruit fly will help orchard managers\ud
to produce quality oil and table olives while reducing treatments for olive fruit fly control
Accurate identification of parasitoids is crucial for biological control of the invasive brown marmorated stink bug, Halyomrpha halys (Stål). A recent work by Talamas et al. (2017) revised the Palearctic fauna of Trissolcus Ashmead, egg-parasitoids of stink bugs, and treated numerous species as junior synonyms of T. semistriatus (Nees von Esenbeck). In the present paper, we provide a detailed taxonomic history and treatment of T. semistriatus and the species treated as its synonyms by Talamas et al. (2017) based on examination of primary types, molecular analyses and mating experiments. Trissolcus semistriatus, T. belenus (Walker), T. colemani (Crawford), and T. manteroi (Kieffer) are here recognized as valid and a key to species is provided. The identification tools provided here will facilitate the use of Trissolcus wasps as biological control agents and as the subject of ecological studies.
This study shows that the pathogenicity of wild isolates of B. bassiana differs among the tested R. ferrugineus instars. The low mortality of treated adults supports their use as vectors of B. bassiana as a potential tool for reducing R. ferrugineus populations.
Leptoglossus occidentalis (Heteroptera, Coreidae), a Nearctic species, was accidentally introduced into Northern Italy in the late 1990s, from where it has spread throughout Europe. The bug causes abortion of immature cones of Pinus pinea L., with economic impact on the pine‐nut industry. As part of a pest control research program, the egg parasitoid Gryon pennsylvanicum Ashmead (Hymenoptera, Platygastridae) was collected from British Columbia, Canada, and legally introduced to a quarantine climatic chamber in Florence, Italy. The egg parasitoid will be tested against native non‐target heteropterans, an environmental impact assessment will be conducted, and a mass rearing method will be developed if appropriate. The ultimate goal is to release G. pennsylvanicum into Italian P. pinea forests for classical biological control of L. occidentalis.
Wild and cultivated olives harbor and share a diversity of insects, some of which are considered agricultural pests, such as the olive fruit fly. The assemblage of olive-associated parasitoids and seed wasps is rich and specialized in sub-Saharan Africa, with native species possibly coevolving with their hosts. Although historical entomological surveys reported on the diversity of olive wasp species in the Western Cape Province of South Africa, no comprehensive study has been performed in the region in the molecular era. In this study, a dual approach combining morphological and DNA-based methods was used for the identification of adult specimens reared from olive fruits. Four species of Braconidae and six species of Chalcidoidea were identified, and DNA barcoding methodologies were used to investigate conspecificity among individuals, based on randomly selected representative specimens. Morphological identifications were congruent with DNA data, as NJ and ML trees correctly placed the sequences for each species either at the genus or species level, depending on the available taxa coverage, and genetic distances strongly supported conspecificity. No clear evidence of cryptic diversity was found. Overall seed infestation and parasitism rates were higher in wild olives compared to cultivated olives, and highest for Eupelmus spermophilus and Utetes africanus. These results can be used for early DNA-based detection of wasp larvae in olives and to further investigate the biology and ecology of these species.Résumé : Les olives sauvages et cultivées abritent et partagent une grande diversité d'insectes, dont certains sont considérés comme des ravageurs, comme la mouche de l'olive. Il existe une riche diversité de parasitoïdes et de guêpes séminivores spécialisés associés aux oliviers en Afrique subsaharienne, dont plusieurs espèces indigènes qui auraient co-évolué avec leurs hôtes. Bien que des enquêtes entomologiques historiques aient rapporté la diversité des guêpes de l'olive dans la province du Cap-Occidental en Afrique du Sud, aucune étude approfondie n'a été réalisée dans cette région depuis l'avènement de méthodes moléculaires. Dans ce travail, une approche double combinant des méthodes morphologiques et basées sur l'ADN ont été employées pour identifier des spécimens adultes élevés sur des olives. Quatre espèces de Braconidae et six espèces de Chalcidoidea ont été identifiées sur la base de la morphologie et des méthodes de codage à barres de l'ADN ont été employées pour étudier la conspécificité chez des individus choisis au hasard parmi des spécimens représentatifs. Les identifications morphologiques étaient en accord avec les données moléculaires car les arbres NJ et ML ont correctement placé les séquences de chacune des espèces, soit en fonction du genre ou de l'espèce selon la couverture des taxons, et les distances génétiques ont fortement supporté la conspécificité. Aucune évidence claire de diversité cryptique n'a été trouvée. Globalement, les niveaux d'infestation des graines et les taux de parasitisme...
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