SELECTIVITY OF CERTAIN INSECTICIDES FOR CONTROLLING THE CABBAGE APHID Brevicoryne brassicae (L.) And Their Effect On Some Predatory Insects On CAULIFLOWER FIELDS IN EL-MINIA REGION-UPPER EGYPT.

Abstract

The relative toxicity of Thiamethoxam, lambda-cyhalothrin, dimethoit, chlorpyrifos and (lambda-cyhalothrin + chlorpyrifos) were tested against the Cabbage aphid, Brevicoryne brassicae (L.) on Cauliflower in EL-Minia regon during 2015 season. The population of Cabbage aphid on Cauliflower plants was nearly the same in all the treat plants before application with insecticides in 2015 season. The population density of Cabbage aphid was strongly decreased in all treated plots after 3 days from insecticides application compared with control. The average reduction of all compounds during experiment were 86.8 and 76.1for Thiamethoxam and (Chlorpyriphos + lambda-cyhalothrin), respectively. Also, the results revealed that all compounds differed significantly in their toxicity except Lambda-cyhalothrin , Dimethoit and Chlorpyrifos (no significant difference between for their toxicity, which were 64.3, 66.5 and 62.3 percent reduction, respectively). In general, data showed that superiority of Thiamethoxam as systemic insecticides activities than nonsystemic insecticides in their toxicity after 3,7 and 15 days. On the other hand, the average reduction of all compounds during experiment to Coccinella undeciumpunctata L. were 45, 38.3, 38, 37.3 and 30.7, for (Chlorpyriphos + lambdacyhalothrin), Chlorpyriphos , Lambda-cyhalothrin, Dimethoit and Thiamethoxam, respectively. The degree of selectivity to all compounds was selectivity but Thiamethoxam was the highest. Also, Thiamethoxam was good selectivity on Scymuns spp. and all compounds were selectivity and the average reduction to all compounds during experiment to Scymuns spp were 41.7, 35, 31.4, 31 and 16 percent reduction for (Chlorpyriphos + lambda-cyhalothrin), Lambda-cyhalothrin, Dimethoit , Chlorpyriphos and Thiamethoxam, respectively. In general, data showed the tested compounds did not completely eliminate the beneficial arthropods. The superiority of Thiamethoxam as systemic insecticides activities than non-systemic.

Toxicity of Certain Chemical Compounds Against Aphids, Leafhoppers AND Related Predators on Faba Bean Fields

“…Date indicated that there was a highly decrease in the predator's numbers on faba bean plants. That results were similar to Ali et al (2015) they showed that the tested compounds did not completely eliminate the beneficial arthropods. The superiority of thiamethoxam as systemic insecticides activities than non-systemic insecticides in their selectivity to C. undeciumpunctata and Scymuns spp after 3,7 and 15 days in Cauliflower field.…”

Toxicological Effects of five Insecticides on Cabbage Aphid, Brevicoryne brassicae (L.) (Homoptera: Aphididae) and its Parasitoid Aphelinus sp. (Hymenoptera:Aphelinidae)

“…Cabbage aphids feed on the underside of the leaves and on the center of the cabbage head and they prefer feeding on young leaves and flowers and often go deep into the heads of brussels sprouts and cabbage (Natwick 2009;Hines & Hutchison, 2013). Adults and nymphs feeding cause direct damage like leaves yellowing, curling, wilting, and stunting of plants, resulting in plant deformation (Ali & Zedan, 2015). In this interim, it causes indirect damage by honeydew through cornicles which stick to leaves and causes sooty mold to develop, which ultimately renders photosynthesis death and decay of leaf (Griffin & Williamson, 2012) or by transmission of viruses (Lashkari et al, 2007).…”

“…In addition, it is a vector of 20 virus diseases in a large range of plants including important viruses like cauliflower and turnip mosaic viruses (Ellis et al, 1998). Interestingly, cabbage aphid has a great reproduction capacity and may have up to forty-five generations per year (Ali & Zedan, 2015).…”