Laboratory tests using the dry film method were conducted to assess the toxicity of different commonly used insecticides and insect growth regulators to Bracon brevicornis. The carbamate insecticide, carbosulfan, was highly toxic to B. brevicornis with a LC50 value of 0.0001 mg a.i./l, whereas pymetrozine and buprofezin had LC50 values of 0.1056 and 0.0374 mg a.i./l, respectively. Among the three neonicotinoids, acetamiprid showed the highest toxicity to B. brevicornis with a LC50 of 0.0041mga.i./l followed by thiamethoxam and imidacloprid. The order of toxicity based on the LC50 values was: carbosulfan > lambdacyhalothrin > bifenthrin > indoxacarb > acetamiprid > thiamethoxam > imidacloprid > buprofezin>pymetrozine. Pymetrozine showed slight to moderate toxicity to B. brevicornis, with a risk quotient (RQ) of 1420, while the RQ value for all other insecticides were dangerously toxic to B. brevicornis. The mean activity of cytochrome P450 in B. brevicornis was 4.2817 nM/mg protein with a frequency distribution ranged from 3.001 to 5.446 nM/mg protein. The mean activity of acetyl choline esterase in B. brevicornis was 1.7056 nM/Min with a frequency destitution ranged from 0.7572 to 3.1951 nM/Min. The mean activity of carboxylesterase was 37.5 mOD/Bracon/min with a frequency destitution ranged from 27.8 to 47.1 mOD/Bracon/min. Use of selective insecticides to conserve B. brevicornis may improve the compatibility of biological control with the IPM programme.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 25 • No. 2