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The pea leafminer, Chromatomyia horticola (Goureau) (Diptera: Agromyzidae) is a polyphagous and serious pest of peas. In India, this pest is attacked by many parasitoids and among them Diglyphus horticola Khan (Hymenoptera: Eulophidae) is an important one, however, demographics and pest-kill potential of this parasitoid has not been studied so far. This study presents the first report on its demographics and pest-kill potential on C. horticola. The parasitoid showed three modes of host-killing behaviour viz. host-feeding, parasitism and host-stinging. The parasitoid females killed more number of hosts by parasitism than host-feeding or host-stinging. The pre-adult survival, net reproductive rate, intrinsic rate of increase (rm) and finite rate of increase (λ) were higher on the 5-days old host larvae than those reared on the 3-days old larvae. Demographics and pest-kill parameters of D. horticola were also better on 5-days old host larvae than on 3-days old host larvae. Based on the study, D. horticola appeared to be a promising biocontrol agent for the suppression of C. horticola in peas and could be promoted through conservation biological control. Further studies are required to standardize the mass production protocol and release rates to use the parasitoid by augmentation. [ABSTRACT FROM AUTHOR]

The experiment was conducted at experimental farm situated at 30°5'N latitude and about 77°11'E longitudes, an elevation of 1260 m above mean sea level of Department of Environmental Science, Dr YS Parmar University of Horticulture and Forestry Nauni, Solan, Himachal Pradesh during 2014 and 2015, to study the effect of elevated CO2 (eCO2) and elevated temperature (eT) on growth, development and nutritional indices of Spodopteralitura on bell pepper plant. Feeding trials with foliage feeding insect S. litura was conducted using foliage of bell pepper plants grown under four concentrations of CO2 and temperature, viz. three Open Top Chambers, (T1: OTC eCO2 550±10 ppm; T2: OTC with elevated temperature 1°C higher and eCO2 550±10 ppm; T3: OTC with ambient temperature and CO2 and T4: natural ambient air and temperature in open. Biochemical analysis of foliage revealed that plants grown under elevated CO2 had lower nitrogen. The larvae fed on eCO2 as well as eCO2 and temperature foliage exhibited greater consumption compared to the larvae fed on foliage under ambient CO2. Larval duration also increased by two days. The eCO2 and eCO2 and temperature foliage was more digestible with higher values of approximate digestibility. The relative consumption rate increased whereas the efficiency parameters, viz. efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and relative growth rate (RGR) decreased in eCO2 and eCO2 and temperature. The consumption and weight gain of the larvae were negatively and significantly influenced by leaf nitrogen. [ABSTRACT FROM AUTHOR]

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]

The present study deals with the impact of temperature on development, survival, reproduction and population growth of a recently invaded and the most destructive pest of tomato, Tuta absoluta (Meyrick) with the aim to understand its possible expansion in different agro-climatic zones. Though T. absoluta was able to develop between 15° and 35°C, temperature around 25°-30°C was more suitable. Survival and fecundity were highest at 25°C and lowest at 35°C. Developmental threshold for different developmental stages of the pest varied from 6.2 to 9.5°C, while the thermal constant required by the insect to complete the development from egg to adult emergence was 500 degree-days. Population growth parameters were also influenced significantly by the rearing temperature. Intrinsic rate of increase, net reproductive rate and finite rate of increase was higher at 25° and 30°C as compared to other temperature regimes. The study concludes that T. absoluta can be a serious pest of tomato in mid-hills of north-western Himalayan region and the southern plains of India where temperatures varies between 15-35°C. Furthermore, the developmental threshold values indicate that the pest can develop and survive at temperatures as low as 6-9°C without entering the diapause as long as the food is available. [ABSTRACT FROM AUTHOR]