Jai Research Foundation, P.B. No. 30, G.I.D.C., Vapi-396195, Gujarat, (India).
Address for correspondence: Dr. S. Selvakumaran, Plot No. 148, Kambar Street, E.B. Colony, Ayyer Baingalow, Madurai-625 017, Tamil Nadu, (India)
1Present address: Section of Entomology, Indian Institute of Spices Research, Marikkunnu, Kozhicode-673 012. District Calicut, Kerala, (India).
Life table for the cardamom whitefly, Kanakarajiella cardamomi (David and Subramaniam) was constructed during July–August, September–October and November–December, 1991 for three consecutive generations. The highest cohort loss was 66, 63 and 47 per cent during the egg stage followed by 13, 18 and 32 per cent during first instar stage. Whereas, a cohort loss respectively 7, 8 and 6 per cent and 5, 7 and 6 per cent was observed for the second and third instar stage for the three generations. During pupal stage, a cohort loss was respectively 6.1, 1.4 and 3.1 per cent for the three generations. The large proportion of mortality observed during the egg and first instar was due to the predatory mites (? Amblyseius sp.), non-viability of eggs, and failure of the first instar to locate proper feeding site. Mortality during the second and third instar was due to the predatory mites and entomopathogenic fungus, Aschersonia placenta Berk & Br. The cohort loss due to predatory mites could not be quantified but the loss due to A. placenta was 0.4, 0.2 and 0.2 per cent only. Population density reduced during the pupal stage was mainly due to parasitization of the aphelinid wasp, Encarsia septentrionalis Hayat and Encarsia dialeurodis Hayat, which accounted 1.6, 0.5 and 0.7 per cent cohort loss. A positive trend index approximately of 2.2, 2.4 and 2.4 per cent and survival rate of 8.7, 9.7 and 7.1 were observed for the three generations, respectively. In spite of positive trend Index, low survival rate may be due to the high reproductive rate of K. cardamomi.
