Yadav, D. N.PATEL, VIRENDRA G.2018-06-292018-06-291988http://krishikosh.egranth.ac.in/handle/1/5810055590The studies on biology of three species of white grub viz./ Holotrichia consanguinea Blanch., H. serrata P. and H. fregei Mittel were made at average temperatures of 22.15 to 35.26°C and 58 to 87 per cent RH. In addition to this, their population density and natural enemies were also studied during 1985, 1986 and 1987. The pest was observed to aestivate in its adult stage and emerge during June between 7.45 to 8.00 p.m. after first heavy showers. Their emergence was largely governed by the amount of rainfall. Rainfall of 5 to 50 mm was sufficient to trigger emergence of the adults. The most emergence took place during first fifteen days of the monsoon showers. The adults after emergence fly to the near by host trees such as neem, drumstick and ber, where they mate, feed on leaves and then return to soil before dawn for oviposition. The emerging pattern, feeding, mating and ovipositing behaviour of all the three species was observed to be similar. The difference was only in respect to fecundity, larval duration and adult longevity.enAGRICULTURAL ENTOMOLOGYA STUDYThesis