Factors affecting egg-laying behavior and fecundity of Callosobruchus chinensis (L.) (Coleoptera : Bruchidae) infesting stored pulses

Effects of physico-chemical parameters in large gardenpea (Pisum sativum L, , cv Pusa-257; 48.3 +/- 0.4 mm(2)/seed), chickpea (Cicer arietinum L., cv P usa-256; 45.6 +/- 0.2 mm(2)/seed), and small lentil (Lens esculenta Moench, ev B-256; 16.7 +/-: 0.2 mm2/seed) on the host preference, egg-laying behav ior and fecundity of Callosobruchus chinensis (L.) were investigated in the laboratory at 27 +/- 2.5 degreesC temperature, 70 :+/- 10% relative humidi ty and 12 :+/-: 1.8 L natural photoperiod. The shape, colour and size of pu lse seeds, and the texture and thickness of the seed-coat affected egg-layi ng. Firstly mated female deposited more eggs in no-choice experiments than in co-choice ones. Eggs deposited on a gardenpea seed were Significantly (P < 0.05) greater than those deposited on a chickpea or a lentil seed. The f emale discriminated among these pulse seeds, and deposited greater number o f eggs on occupied hosts than on unoccupied ones (paired-t = 2.39 - 3.77, P <0.05). Females exhibited significant (P < 0.05) choice of gardenpea or ch ickpea seeds for egg laying. Levels of proteins and phenols in the seed-coa t were lowest in gardenpea, and highest in lentil. Moisture contents in len til seeds differed significantly (P < 0.05) from those in gardenpea or in c hickpea ones, and these affected (P < 0.05) egg-laying and fecundity of the female. The penetration capacity of the neonate larvae was inversely relat ed to phenol contents of the seed and the capacity was highest (72.3%) for gardenpea and lowest (41.8%) for lentil seeds. The biomass (mg dry or mg as h-free) of these pulse seeds differed significantly (P < 0.05), as did the energy contents (J/ash-free seed). The realized fecundity of the female off ered gardenpea was 19 or 101% greater than that of the female offered chick pea or lentil, respectively.