查看更多>>摘要：The western flower thrips, Frankliniella occidentalis (Pergande), is a widespread and serious agricultural pest. Controlling F. occidentalis is difficult because it rapidly develops resistance to many insecticides. To assess the development status (2016-2018) of insecticide resistance of F. occidentalis and to improve resistance management, we determined the susceptibility levels of field populations in China to seven commonly used insecticides (spinosad, spinetoram, abamectin, emamectin-benzoate, chlorfenapyr, thiamethoxam and 13-cypermethrin). The results showed that F. occidentalis developed resistance to spinosad, spinetoram, abamectin, emamectinbenzoate, thiamethoxam and 13-cypermethrin, and except for spinetoram and thiamethoxam, the resistance of southern populations to the other four insecticides was higher than that of northern populations. A population from Changping, Beijing, had the highest resistance level and its spinetoram resistance ratio was 16,972 (susceptible reference strain LC50 = 0.001 mg/L). Susceptibility to spinosad and abamectin varied greatly among the populations (LC50 values ranged from 0.006 mg/L to 9.943 mg/L for spinosad and from 1.071 mg/L to 939.410 mg/L for abamectin). The use of non-chemical control methods and IPM should be considered for the sustainable management of F. occidentalis populations.
Gad, Hassan A.Atta, Ayman A. M.Abdelgaleil, Samir A. M.
6页
查看更多>>摘要：The insecticidal efficacy of abamectin (AB) and three inert dusts, diatomaceous earth (DE), zeolite (ZE) and kaolin (KA), was evaluated alone and in binary mixtures as stored cowpea protectants against Callosobruchus chinensis. Inert dusts (DE, ZE and KA) were tested at 100, 500 and 1000 mg/kg (ppm), and abamectin was applied at 0.1, 0.25 and 0.5 mg/kg (ppm). Adult mortality of C. chinensis was evaluated after 3 and 7 days of treatment, while progeny production and cowpea seed weight loss were recorded for all tested treatments after 60 days. The mortality of adults in the binary treatments was higher than the individual treatments of inert dusts or AB. Combined treatments of AB at 0.5 mg/kg with DE, ZE or KA at 500 and 1000 mg/kg led to 100% mortality after 7 days of treatment. Moreover, combined treatments of AB (0.25 mg/kg) with KA (1000 mg/kg), AB (0.25 mg/kg) with ZE (1000 mg/kg) and AB (0.5 mg/kg) with KA (100 mg/kg) caused 100% mortality of adults after 7 days of treatment. After 3 days, the binary mixture of AB (0.5 mg/kg) with KA (1000 mg/kg) was the only treatment inducing 100% adult mortality. All treatments with inert dusts, AB, and their binary mixtures caused significant decrease in progeny production of C. chinensis after 60 days of exposure. In particular, treatments with high concentrations induced strong progeny reduction and led to complete protection of cowpea seeds against weight loss and damage caused by C. chinensis after 60 days. Furthermore, no adverse effect on germination was observed in cowpea seeds treated with the highest application rates of inert dusts, AB, and their mixtures. Our findings demonstrated that binary mixtures of inert dusts with abamectin could be successfully used as potential protectants for cowpea seeds against C. chinensis.
Baena, RayneAraujo, Emily S. S.Bischoff, Joao P. A. M.Bischoff, Adelia M. L....
11页
查看更多>>摘要：Drosophila suzukii (Diptera: Drosophilidae) is an invasive polyphagous pest that causes economic losses in berry production worldwide. Its damage is caused by the ovipositor used to lay eggs into fruits, which also introduces microorganisms that hasten fruit spoilage and serve as food for larvae, leading to non-marketable fruits. Strawberry cultivars more resistant to D. suzukii can help in the management of this pest. Therefore, the aim of this study was to compare the susceptibility of Albion, Monterrey, and San Andreas, worldwide important strawberry cultivars, to D. suzukii harvested at three ripening stages (epidermis with 50%, 75%, and 100% of red surface). Moreover, fruit volatile compounds and their effect over D. suzukii female and male attraction were identified. Free-choice and non-choice bioassays were carried out to check oviposition preference. Fruit trait effects on oviposition preference were determined. Additionally, the volatile organic compounds active in D. suzukii antennas, and their contribution to pest attraction were analyzed. Both, cultivar and ripening stage affected fruit choice in the free-choice bioassay (p < 0.001). More mature fruits (sweeter and less firm) were more oviposited. However, in the no-choice bioassay neither the cultivar nor the ripening stage affected the oviposition choice (p = 0.998). Total amount of volatiles did not explain the oviposition choice, suggesting the relevance of specific volatiles. (+/-)-Linalool affected D. suzukii females (p = 0.0053) behavior and needs further investigation for being used as an attractant in mass-capture lures, monitoring and toxic baits, and assisting in oviposition control.
NSTL
Elsevier