Department of Entomology and Agricultural Zoology, Rajendra Agricultural University, Pusa-848 125, District Samastipur, Bihar (India).
*A part of approved M.Sc. thesis submitted by Md. Monobrullah to the Rajendra Agricultural University, Pusa-848 125, District Samastipur, Bihar (India).
Each of the nine insecticides, viz, quinalphos 25 EC, phosalone 35 EC, phosphamidon 85 EC, methyl parathion 50 EC, fenitrothion 50 EC, monocrotophor 36 EC, dichlorvos 100 EC, formothion 25 EC and dimetboate 30 EC were sprayed at 0.05% concentration to evaluate their effectiveness against the mango shoot gall, Apsylla cistellata Buckton. All the treatments were effective in reducing the gall formation, when sprayed thrice at fortnightly intervals commencing from tbe 2nd fortnight of September. The lowest number of fully formed galls were obtained on mango trees treated with phosphamidon (6.4 galls/10 twigs) followed by methyl parathion (7.1 galls/10 twigs), fenitrothion (7.3 galls/10 twigs) and monocrotophoa (9.7 galls/10 twigs), whereas tbe highest number of galls was in dichlorvos treated trees (17.5 galls/10 twigs). Spraying during mid-November revealed that only five insecticides, viz, phosphamidon, monocrotophos, dimethoate, formothion and dichlorvoa reduced the nymphal population. Among these, phosphamidon exhibited the maximum mortality of nymphs (63.1%) followed by monocrotophos (58.8%) and were significantly different from dimethoate (53.4%), formothion (40.4%) and dichlorvos (19.9%). The remaining treatments were practically ineffective as compared to control. The most ineffective insecticides like fenitrothion (9.9%) followed by phosalone (10.1%), methyl parathion (10.4%) and quinalphos (10.8%) tended to increase the population of this psyllid pest.
