Bioefficacy and Persistent Toxicity of Different Insecticides and Neem Derivatives against Cucurbits Fruit Fly, Bactrocera cucurbitae. Coq. on Summer Squash

A field experiment conducted at the College of Agriculture, CSKHPKV, Palampur, H.P. during 1999–2000 revealed that the synthetic pyrethroid treatments viz., deltamethrin (37.5 g ai ha⁻¹), cypermethrin (75 g ai ha⁻¹) and fenvalerate (75 g ai ha⁻¹) gave significantly less fruit infestation of cucurbit fruit fly, Bactrocera cucurbitae Coq. upto 14 days of spray on summer squash compared to malathion (375 5 ai ha⁻¹). The neem derivatives namely Achook, Econeem and Neemjeevan although were statistically superior over untreated check but were less effective than synthetic insecticides in suppressing the infestation. Maximum yield was observed in deltamethrin treatment (205.61 q ha⁻¹) followed by cypermethrin, fenvalerate, malathion, deltamethrin + achook, deltamethrin + Neemjeevan, Achook, Neemjeevan and Econeem. The synthetic pyrethroids had the higher persistent toxicity (PT 7 days) compared to malathion or the neem derivatives (PT 3 days or less).