CABI

About: CABI is a nonprofit organization based out in Wallingford, United Kingdom. It is known for research contribution in the topics: Population & Introduced species. The organization has 789 authors who have published 1759 publications receiving 73843 citations. The organization is also known as: Centre for Biosciences and Agriculture International.

Adult reproductive diapause in Drosophila suzukii females

Abstract: Drosophila suzukii (Diptera: Drosophilidae) is an emerging pest of soft fruits, but in this species diapause has not been thoroughly explored. We examined the effects of different temperatures and photoperiods on diapause induction and termination under laboratory conditions. There was variation in the ovarian development and oviposition rate under different photoperiods at 10 ± 1 °C, and the percentage of adults with immature ovaries was higher during the short photoperiod (8L:16D) than other photoperiods at 10 ± 1 °C. Adults were most sensitive to photoperiod within 3 days of eclosion. The optimal combination of photoperiod and temperature for diapause termination was a long photoperiod (16L:8D) at 25 ± 1 °C. The supercooling point was significantly reduced in reproductive diapause females, and trehalase, pyruvate kinase, sorbitol dehydrogenase, hexokinase and phosphofructokinase enzyme activities were significantly reduced (36.46, 57.85, 32.64, 54.68 and 24.59 %, respectively); glycogen and triglyceride levels were significantly increased (42.17 and 120.36 %). We conclude that D. suzukii is typical of short-day diapause species within a certain photoperiod range. This information might contribute to a more fundamental understanding of adult reproductive diapause for this important pest.

Native egg parasitoids recorded from the invasive Halyomorpha halys successfully exploit volatiles emitted by the plant–herbivore complex

Abstract: When an accidentally introduced pest establishes in the invaded area, native natural enemies may adapt to the new host. A decade after the accidental introduction of the brown marmorated stink bug, Halyomorpha halys, in Europe, two generalist native egg parasitoids, the eupelmid Anastatus bifasciatus and the encyrtid Ooencyrtus telenomicida, have been recorded from this invasive agricultural pest in the field. Both species are able to complete development to the adult stage within the new host. Trissolcus basalis (Platygastridae = Scelionidae), which is not associated with H. halys in the field, was reared from freeze-killed sentinel eggs placed on soybean plants in central Italy. We tested in a Y-tube olfactometer the behavioural responses of these egg parasitoids to volatiles from H. halys adults and from Vicia faba plants attacked by H. halys. Both A. bifasciatus and O. telenomicida positively responded to adult H. halys male volatiles and to H. halys-induced plant volatiles, indicating ability to exploit cues associated with the new host for egg location, whereas T. basalis only reacted to female volatiles. A. bifasciatus and O. telenomicida are generalist egg parasitoids, showing a much wider host range when compared to T. basalis. On the other hand, platygastrid egg parasitoids from the native area of H. halys, considered for classical biological control, may be too risky due to the possibility of attacking non-target species, including predaceous stink bugs. Therefore, indigenous A. bifasciatus and O. telenomicida are presently under evaluation for augmentative biological control of H. halys in Europe.

The impact of invasive species on social-ecological systems: Relating supply and use of selected provisioning ecosystem services.

Abstract: Understanding the sustainability of social-ecological systems requires quantifying the relationships between ecosystem service supply and use. However, these relationships, and the influence of environmental change on supply and use, are poorly known. Here we apply a nested sampling design to analyse supply-use relationships in ten administrative units in each of two Eastern African regions undergoing invasion by an alien tree, Prosopis juliflora. Ecological data on supply of two key provisioning services, woody and herbaceous biomass, were collected in field plots and the use, defined here as income and livestock numbers, was assessed using household surveys. Supply and use were then up-scaled to the level of the smallest administrative unit. High Prosopis cover affected the supply of both services, with increased woody biomass but reduced herbaceous biomass. We found that supply of woody biomass was positively associated with income from wood sales. Prosopis invasion reduced income from livestock and slightly decreased cattle numbers over the past ten years. We propose that biophysical and socio-economic data collected at the same scale can help to determine supply-use relationships for ecosystem services and we discuss how integration of supply-use data can inform sustainable management of social-ecological systems in the context of environmental change.