Efficacy of some new insecticides against mango shoot gall psylla.
Singh S. S., Yadav S. K.
Author Affiliation: Horticulture Research and Krishi Vigyan Kendra, G.B. Pant University of Agriculture & Technology, Dhakrani, Dehradun, Uttrakhand, India.
Indian Journal of Horticulture 64 : 359-361
Abstract : A study was conducted to evaluate a wide range of insecticides for the control of shoot gall psylla (Apsylla cistellata) on mangoes (cv. Dashahri) grown in Uttaranchal, India during 2005-06. Treatments comprised: quinalphos, monocrotophos, methyl-demeton [demeton-methyl], profenofos + cypermethrin, profenofos, carbosulfan, spinosad, imidacloprid, thiomethoxam, acetamiprid, cypermethrin, alfamethrin [alpha-cypermethrin] and diafenthiuron. All treatments were superior to the untreated control throughout the period of experimentation in terms of gall formation. All 13 insecticides were effective when sprayed during the second fortnight of August, while only thiomethoxam, imidacloprid, methyl-demeton, quinalphos, spinosad and monocrotophos caused effective nymphal mortality. In mid-August, the nymphs remained exposed to the insecticides and had direct contact with the chemical. However, in November, they lived inside the hard conical galls and were protected. Thus, during this period, the aforementioned insecticides with only systemic and fumigant effects were effective but these insecticides were more effective when applied in August. Hence, spraying should be done thrice at 12-day intervals from the second fortnight of August instead of November. Thiomethoxam and acetamiprid were the most effective, containing promising molecules for minimizing gall formation and nymphal population. It is recommended that mango growers apply thiomethoxam, acetamiprid and imidacloprid in August at 12- to 15-day intervals for effective and ideal management of shoot gall psylla.