Search
Search Results
-
Some microbial treatments against the tomato leaf miner; Tuta absoluta (Merick) under natural field conditions
81-84.Views:171In an attempt to find more effective methods and safety to control the tomato leaf miner, Tuta absoluta, this research was conducted to study the efficacy of the four bio-treatments ; two bacterial isolates (Bacillus subtilis. and Pseudomonas Fluorescence), one fungal isolate Trichoderma viride) and Spinosad as a microbial insecticide compared with the most common insecticides used against the dipterous and lepidopterous leaf miners in Egypt; Profenofos and Aphox. In the two successive seasons; 2011 and 2012, the fungal isolate Trichoderma viride achieved the lowest infestation(numbers of infested leaflets, mines, infestation percentages) which were 167, 195, and 21.9% resp.in season 2011 and 198, 222 and 26.2% resp. in season 2012. While the highest infestation was occurred in case of using the insecticides, Aphox (423, 559 and 55.9% resp.& 384, 839 and 72.2%. and Prohpenofos (436, 562 and 57.7% &391, 534 and 51.7% resp.).during 2011 and 2012 respectively. The other treatments occupied the intermediate levels. On the other hand, the yield of tomato fruits was increased by 75% over the check in case of plants treated with Trichoderma viride isolate, but the pesticide treatment given weak or no impact in increasing tomato crop. In season 2012, the infested tomato fruits percentages with T. absoluta larvae and Rhizoctonia soil rot disease(that Frequently observed incidentally) were recorded the minimum levels obtained by spraying Trichoderma viride isolate(21.38 and 10.32% resp.). In contrast, the maximum levels were recorded in Prophenofos (44.87 and22.78% resp.) and Aphox treatments(47.22 and 27.78% resp.).
-
The effects of spinosad insecticide to adults of Apis mellifera, Megachile rotundata and Nomia melanderi (Hymenoptera: Apidae)
93-97.Views:252The toxicity of spinosad to adult female bees tended to be least to the honey bee (Apis mellifera L.) (LD50 = 0.078 pg/bee), intermediate to the alkali bee (Nomia melanderi) (0.065 pg/bee), and greatest to the alfalfa leafcutter bee (Megachile rotundata (F.)) (0.058 pg/bee), both in topical drop tests and in tests involving spinosad residues on alfalfa (Medicago sativa) foliage. For the calculated LD50 pg/g, the honey bee (LD50 = 0.612 pg/g) was the most susceptible followed by the alkali bee (0.773 pg/g) and the leafcutter bee (1.908 pg/g). The honey bee oral LD50 was 0.063 pg/bee and the calculated LD50 0.492 pg/g. Adding an adjuvant to spinosad sprays did not change the toxicity of spinosad to bees in residue bioassay studies. Spinosad at as high as 500 ppm in feeders containing a sucrose/honey syrup caused no significant reduction in honey bee visitation or total syrup consumed.