Abstract:
Mango mealybug Drosicha mangiferae (Pseudococcidae: Hemiptera) is one of the most damaging insect pests of a wide range of horticultural crops. This sap-feeding insect pest causes substantial loss to different fruit crops, particularly to citrus. For its management, citrus farmers rely on extensive and irrational applications of synthetic insecticides. Due to which, D. mangiferae have attained resistance against most these chemicals. This laboratory study was aimed to determine the toxicity of some selected conventional insecticidal formulations concurrently being used by the farmers against D. mangiferae infestation. Using standard twig-dip method, toxicity bioassays were conducted against 2nd instar nymphs of D. mangiferae. Treatments included nine conventional synthetic insecticides from three insecticidal groups. Results revealed that both treatments i.e. insecticidal formulations (F9,245 = 93.05, P < 0.001) and time intervals (F4,245 = 158.72, P < 0.01) and their interaction (F36, 245 = 5.73, P < 0.001) had a significant impact on the mortality of 2nd instar mealybug nymphs. The most effective synthetic insecticides against D. mangiferae individuals were lambda-cyhalothrin, methidathion, profenofos and deltamethrin with mean mortality and LT50 values of 45.00±4.57% and 49.01 h, 44.67±3.96% and 49.83 h, 40.00±4.07% and 58.98 h and 35.67±4.11% and 74.86 h, respectively. These insecticides may be incorporated in future pest management programs against D. mangiferae mealybugs.
Page(s):
159-163
DOI:
DOI not available
Published:
Journal: Pakistan Entomologist, Volume: 41, Issue: 2, Year: 2019
Keywords:
comparative toxicity
,
Citrus mealybug
,
pyrethroids
,
Drosicha mangiferae
,
Organophosphates
,
Conventional insecticides