Toxicity of Neem seed Azadirachta indica Juss (Meliaceae) different solvents extracts against cotton mealybug Phenacoccus solenopsis Tinsley (Sternorrhyncha: Pseudococcidae) under Laboratory conditions

This study investigated the toxicity of neem treatments in comparison with Confidor 20% SL against cotton mealybug Phenacoccus solenopsis Tinsley. The experiments were laid out under completely randomized design (CRD) with six main treatments including untreated check under laboratory conditions at Agricultural research Institute Tarnab, Peshawar-Pakistan during 2012/2013. Results indicated that Confidor 20% SL and neem seed extracts (acetone and n-hexane extracts) caused 100 % mortality of P. solenopsis after 48 hrs and one week duration respectively. Over all after a week exposure, mortality trend was recorded as 100%, 97%, 88% and 67% by Neem seed n-Hexane extracts, Neem seed Acetone extracts, Neem oil and Neem seed water extracts respectively for 3% concentration. Similarly for 2% concentration it was recorded as 87%, 84%, 74% and 46% and for 1% concentration the mortality trend was noted as 68%, 62%, 56% and 29% in n-Hexane, Acetone, Neem oil and Neem seed water extracts respectively. The neem extracts and oil bioassay revealed that % mortality of P. solenopsis was dose and time dependent. These findings provide clear indication that n-Hexane and Acetone are good solvents for neem seed extracts preparation to be used against cotton mealybug in Pakistan. However further study needs to be conducted to know the compatibility of these extracts against the natural enemies in field as well as in laboratory conditions.