Studies on biology and host preference of South American Leaf Miner, Phthorimaea absoluta Meyrick (Lepidoptera: Gelechiidae)

Abstract

The invasive South American Leaf miner, Phthorimaea (=Tuta) absoluta Meyrick (Lepidoptera: Gelechiidae) is now getting a status of key pest in India. Biology studies carried out on tomato revealed that the P. absoluta had four larval instars. The total life cycle of P. absoluta lasted for 20.62 ± 0.66 days with an egg, larval and pupal periods of 2.54 ± 0.15, 9.54 ± 0.31 days and 8.54 ± 0.20 days, respectively. The longevity of female (40.00 ± 0.49 days) was found longer than the males which lasted for 36.45 ± 0.21 days. The biology studies carried out at different temperature conditions revealed the lowest egg (3.00 ± 0.24), larval (10.00 ± 0.27), pupal (9.00 ± 0.27) period, high fecundity (211.00 ± 2.54/female), highest female (40.00 ± 0.49) and male (36.45 ± 0.21) longevity at 30o C. Studies
on the spatial distribution of eggs by P. absoluta revealed that the P. absoluta adults mostly preferred to lay the eggs on upper leaf surface (6.07 eggs) followed by lower surface of leaves (5.79 eggs). Ovipositional preference studies on different solanaceous crops viz., tomato, brinjal, potato, chilli and European black nightshade revealed that the adults of P. absoluta highly preferred tomato (233.70 and 326.00 eggs plant-1) followed by potato (95.90 and 143.20 eggs plant-1) both under free and no choice conditions, respectively. Biology of P. absoluta on other solanaceous crops revealed that the total life cycle was the shortest on tomato (22.00 ± 0.61) followed by European black nightshade (27.75 ± 0.84 days). However, no eggs hatched on chilli.