Bacillus thuringiensis toxin proteins are deployed in transgenic plants for pest management. The present studies were aimed at characterization of gut bacterial proteases involved in activation of inactive Cry1Ac protoxin (pro-Cry1Ac) to active toxin in Helicoverpa armigera. Bacterial strains were isolated from H. armigera midgut and screened for their proteolytic activation toward pro-Cry1Ac. ...

Food characteristics strongly regulate digestive enzymatic activity of insects through direct influences on their midgut mechanisms. Insect performance is better on diets that contain nutrients in proportions that fit its digestive enzymes. Little is known about the influences of rearing history on parasitism success of Habrobracon hebetor Say. This research focused on the effect of nutrient re...

Although there is a significant knowledge about mammalian metallocarboxypeptidases, the data available on this family of enzymes is very poor for invertebrate forms. Here we present the biochemical characterization of a metallocarboxypeptidase from the insect Helicoverpa armigera (Lepidoptera: Noctuidae), a devastating pest spread in subtropical regions of Europe, Asia, Africa and Oceania. The ...

Chemosensory proteins (CSPs) are soluble proteins found only in arthropods. Some of them fill the lumen of chemosensilla and are believed to play a role similar to that of odorant-binding proteins in the detection of semiochemicals. Other members of the CSP family have been reported to perform different functions, from delivery of pheromones to development. This report is focused on a member (C...

A co-occluded binary mixture of Helicoverpa armigera nucleopolyhedrovirus genotypes HearSP1B and HearLB6 at a 1:1 ratio (HearSP1B+HearLB6) was selected for the development of a virus-based biological insecticide, which requires an efficient large-scale production system. In vivo production systems require optimization studies in each host-virus pathosystem. In the present study, the effects of ...

This study deals with Insecticide Resistance Management of cotton bollworm Helicoverpa armigera to five commonly used insecticides on cotton were carried out during 2008. In August, LD value for 50 chlorpyriphos varies from 0.046μg/larva in Parbhani district to 0.172 mg/larva during October in Aurangabad district. Resistance to chlorpyriphos was highest in Aurangabad district (3.65-8.25 fold) f...

Jasmonic acid (JA) and salicylic acid (SA) are important phytohormones involved in plant resistance against insect herbivory and pathogen infection. Application of JA and SA induces several defensive traits in plants. Here we investigated the effect of JA and SA on trichome density in five groundnut genotypes [ICGV 86699, ICGV 86031, ICG 2271, ICG 1697 (resistant) and JL 24 (susceptible)]. The ...

High diversity of digestive proteases is considered to be the key factor in the evolution of polyphagy in Helicoverpa armigera. Serine proteases (SPs) contribute ~85% of the dietary protein digestion in H. armigera. We investigated the dynamics of SP regulation in the polyphagous pest, H. armigera using RNA interference (RNAi). HaTry1, an isoform of SP, expressed irrespective of the composition...

INTRODUCTION Cicer arietinum is an important self-pollinated diploid crop 2n=2x=16 with genome sized approximately 931 Mbp (Arumuganathan and Earle 1991). India is the largest producer of chickpea, contributing with about 66% of the total global production, followed by Turkey, Pakistan and Mexico (Thangwana and Ogola 2012). It is a major source of protein (12.4-31.5%), energy, fiber, vitamins, ...

According to the previous research of our group, we found compound ZQ-8 ((1S,2R,4S)-1,3,3-trimethylbicyclo [2.2.1]heptan-2-yl-4-(tert-butyl)benzoate). This showed a strong growth inhibitory effect on Helicoverpa armigera by inhibiting chitinase 2 and endochitinase. To further understand mechanism interfering with development H. armigera, ultra-high performance liquid chromatography-mass spectro...