Combined Efficacy of Aliphatic Hydrocarbons with Neonicotenoids against Phenacoccus solenopsis (Hemiptera: Pseudococcidae) under Controlled Conditions

Phenacoccus solenopsis appeared as a major pest in recent years and caused huge losses to cotton. Control of cotton mealybug is difficult because of the waxy covering on the body which prevents penetration of insecticides in nymph and adult stages. Present study was carried out under laboratory conditions to evaluate the synergistic effects of minerals oil (Diver®) on the toxicity of diafenthiuron, nitenpyram and thiacloprid against different instars of cotton mealybug. Diafenthiuron, nitenpyram and thiacloprid alone demonstrated mortality in the range of 10.3-46.0%, 13.3-50% and 10.30-46.70% in 1st instar, 8.00-42%, 10.30-44% and 6.60-42.3% in 2nd instar while 7-38%, 7.30-38% and 3.3-32% in adult female of P. solenopsis, respectively. Admixing of 500 ml of Diver® with diafenthiuron administered 65.2-332.7% and 114.6-602.8%; 78.0-428.8% and 128.6-750.0%; and 94.6-457.1% and 147.3-852.9% increase in mortality of 1st instar, 2nd instar and adult female stages of P. solenopsis, respectively. Similarly, fraternization of 1000 ml of Diver® with diafenthiuron administered 42.0-202.6% and 100.0-490.2%; 60.6-261.4% and 127.3-600.2% and 79.8-336.6% and 154.4-854.9% increase in mortality of 1st instar, 2nd instar and adult female stages of P. solenopsis respectively. However, thiacloprid, when admixed with 500 ml and 1000 ml of Diver®, explained 16.7-114.3% and 114.3-633.3%; 24.9-103.6% and 132.3-900.9%; and 0.0-303.9% and 191.7-1990.9% increase in mortality of 1st instar, 2nd instar and adult female stages of P. solenopsis, respectively. In conclusion, Diver® can be exploited as synergist for resistance management of insecticides against P. solenopsis.