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Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive invasive pests of tomato worldwide. To improve biological control of T. absoluta, we studied the functional response of Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae) to T. absoluta. Under laboratory conditions, N. formosa parasitised and host-fed on the first three larval instars, while the fourth instar was not selected for oviposition or feeding. The logistic regression analyses yielded significantly negative linear coefficients, confirming a type II functional response of the parasitoid to each host stage. Irrespective of the mode of host-killing, the attack rate was the highest and the handling time the lowest on the second instar host larvae. The theoretical maximum numbers of host larvae that a single mated female N. formosa could parasitise, host-feed or host-kill over a 24 h foraging period are 2.82, 2.87 and 5.66 (first instar); 3.50, 5.99 and 9.05 (second instar); and 2.28 1.71 and 3.38 (third instar), respectively. In conclusion, the parasitoid may enhance the augmentative and/or conservation biological control of T. absoluta under Indian conditions. [ABSTRACT FROM AUTHOR]

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most serious pests of tomato, capable of causing 100% crop losses under favourable conditions. We studied the effect of different host plants on developmental and population parameters of this pest at 25 ± 0.5 °C temperature, 70 ± 5% relative humidity and 12 L: 12D photoperiod. Host plant had significant effect on the developmental biology and the population growth parameters of the pest. The leafminer developed fastest on tomato leaves and slowest on potato tubers. Population growth parameters like intrinsic rate of increase, net reproductive rate, finite rate of increase, doubling time and weekly multiplication rate of T. absoluta were highest on tomato leaves and lowest on potato tubers. Mean generation time was minimum on tomato leaves and maximum on potato tubers. Females developed on tomato leaves were more fecund than other hosts. Though, tomato was found to be the most suitable host plant of T. absoluta, yet, the pest developed and grew successfully on other alternate hosts like potato (Solanum tuberosum L.), brinjal (Solanum melongena L.) and pepino (Solanum muricatum Aiton). These hosts can, therefore, play an important role in the survival, population build up and overwintering of the miner. Further, under favourable conditions the miner can become a serious pest on these crops and need to be monitored on these crops as well. [ABSTRACT FROM AUTHOR]