Study on lethal effects of Diazinon and Imidaclopride on fourth instar larvae and adult Cryptolaemus montrouzieri Mulsant (Col., Coccinellidae) under laboratory condition
Subject Areas : entomology and othea arthropods
S. Aghabaglou
1
(Department of Entomology, Agriculture Faculty, Islamic Azad University, Arak Branch, Arak, Iran)
Sh. Goldasteh
2
(Department of Entomology , Faculty of Agriculture, Islamic Azad University, Arak Branch, Arak, Iran)
Z. Rafiei Karahroudi
3
(Department of Entomology , Faculty of Agriculture, Islamic Azad University, Arak Branch, Arak, Iran)
Keywords:
Abstract :
Cryptolaemus montrouzieri Mulsant is one of the important predators of the citrus mealybug, Planococcus citri (Risso). This study was carried out to investigate the effects of Diazinon and Imidaclopride in direct (spraying) and indirect methods (prey treated with insecticide) on larvae and adults of the ladybird.The experiment was conducted in 5 treatments and 4 replications under 25±1° C and 65±5% RH. Each replicate included 25 larvae and adults. Mortalities were recorded 72 h after treatment. The results indicated that Diazinon and Imidaclopride were moderate toxic (33-66%) to adult stage of C. montrouzieri (according to IOBC standard method) in direct spraying method The corrected mortalities of fourth instar larvae of C. montrouzieri by field recommended doses were lower than 30% (slightly harmful). The corrected mortalities of pesticides with different dosages on fourth instar larvae were lower than 10% (harmless pesticide). In other experiment, the realative toxicity of Diazinon on adult stage of C. montrouzieri in indirect method (prey treated with insecticide) was ranged between (66-100%) and Imidaclopride which was lower than 30% (slightly harmful). The corrected mortalities of pesticide induced by different dosages varied dosages on adult stage of C. montrouzieri was lower than 20% (harmless). Relative toxicity of tested pesticides on fourth instar larvae C.was lower than 20% (harmless).