Management of false wire worm, Gonocephalum beetle (Tenebrionidae: coleoptera) in chickpea raised under residual moisture conditions

False wire worm, Gonocephalum indicum, incidence was observed for the first time in severe form in Rabi 2008-09 on chickpea, confined to saline tracts of Vidarbha (MS). Gonocephalum adults inflicts injury near collar region of chickpea resulting in collapsing and drying of plants translating into re-sowing of crop due to poor plantstand. Field study revealed 5.8 – 32.3% damaged plants with lowest damage in Module 9 (Seed treatment with clothianidin 2 gm/kg seed + spaying of chlorpyriphos 2 ml/liter water 20 days after crop emergence), Module 10 (Application of phorate granules 10 kg/ha at sowing + spraying of chlorpyriphos 2 ml/liter water 20 days after crop emergence) and Module 11(Seed treatment with clothianidin 2 gm/kg seed + application of clothianidin granules 200 gm/ha 20 days after crop emergence) with 5.8, 6.2 and 8.7% affected plants. The % drying of plants due to injury was in the range of 4.3 – 21.6 % with lowest in Module 11, Module 10 and Module 9 with 4.3, 6.0 and 6.2 % drying of plants, respectively. Superiority of Module 9 (20.4 q/ha) and Module 11 (19.7 q/ha) was evident in yield, whereas, lowest yield was observed in control plot (13.2 q/ha). Module 9 and Module 11 registered higher net returns of Rs. 13887 and Rs. 9948 per ha, respectively, whereas, Module 9 and Module 10 had highest ICBR of 1: 6.0 indicating the suitability of modules in terms of bioefficacy and cost effectiveness for the management of Gonocephalum in problematic area

Toxicological studies on Helicoverpa armigera in pigeonpea growing in Vidarbha region of Maharashtra, India

Insecticide resistance level in pigeonpea pod borer, Helicoverpa armigera (Hubner) to technical grade insecticides collected from major pigeonpea growing districts of Vidarbha viz., Akola, Amravati, Buldhana, Yavatmal and Washim was worked out. LDP indicated LD50 of Cypermethrin in the range of 1.402 to 9.209 ppm with maximum in Yavatmal (9.209 ppm); LD90 within range of 6.021 to 18.427 ppm. LD50 of Quinalphos in the range of 1.303 to 4.789 ppm with maximum in Yavatmal (4.789 ppm); LD90 within range of 3.150 to 14.194 ppm.LD50 of Methomyl in the range of 1.297 to 3.792 ppm with maximum in Yavatmal (3.792 ppm); LD90 within range of 4.993 to 16.737 ppm.LD50 of Indoxacarb in the range of 0.521 to 2.709 ppm with maximum in Yavatmal (2.709 ppm); LD90 within range of 2.819 to 20.947 ppm.LD50 of Spinosad in the range of 0.713 to 2.408 ppm with maximum in Buldhana (2.408 ppm); LD90 within range of 6.413 to 18.349 ppm. The resistance level is visibly high in cypermethrin, moderate to indoxacarb, quinalphos, spinosad and low to methomyl; Yavatmal and Washim strains expressed higher resistance level to cypermethrin, quinalphos and methomyl, whereas Yavatmal and Buldhana strains expressed higher resistance level to indoxacarb and spinosad. The investigation will help to track resistence level in Helicoverpa armigera to different groups of insecticides

Impact of Bt transgenic cottons and insecticides on target and non-target insect pests, natural enemies and seedcotton yield in India

Genetically engineered cottons expressing ä-endotoxins from Bacillus thuringiensis have been adopted on a largescale worldwide. Therefore, we studied the efficacy of Bt cottons for the management of bollworms, their effects on nontarget insects, and seedcotton yield under insecticide protected and unprotected conditions. Helicoverpa armigera and Earias vittella damage was significantly lower in Bt than in non-Bt cottons, while no significant differences were observed in egg-laying by H. armigera. The populations of major non-target sucking insect pests such as Amrasca biguttula biguttula, Bemisia tabaci, Aphis gossypii, Oxycarenus laetus, Dysdercus koenigii and Nezara viridula and the generalist predators, viz Cheilomenes sexmaculatus, Chrysopa spp., and spiders did not differ significantly between Bt and non-Bt cottons. Insecticide application resulted in resurgence of cotton aphid and whitefly, possibly because of elimination of natural enemies or better growth of plants uder protected conditions. Abundance of bollworms, non-target pests, and generalist predators was significantly greater before insecticide sprays than after insecticide application, except in a few cases. Bollworm damage was lower and seedcotton yields higher in Bt than in non-Bt cottons. The present studies indicated that Bt cotton hybrids are effective for the management of bollworms and yield more, and do not have any adverse effects on the abundance of generalist predators

Expression of Tolerance to Pod Borer, Helicoverpa armigera (Lepidoptera: Noctuidae) in Relation to Biochemical Content of Chickpea Leaves

The pod borer (Helicoverpa armigera) is one of the most serious pest of chickpea and plant resistance is an important component for managing this pest. To develop cultivars with resistance to insects, it is important to understand the role of different components associated with resistance to insects. Therefore, in this study we characterized RIL’s (recombinant inbred lines) population for total phenol content leaves and organic acid profiles in the leaf exudates which are associated with tolerance to H. armigera. Chickpea leaves contained phenol and five major organic acids, which were identified as malic acid, oxalic acid, acetic acid, citric acid, and fumaric acid. The high performance liquid chromatography (HPLC) profiles of the leaf exudates of 196 RIL’s exhibited amounts of all organic acids were negatively correlated with egg count, larval incidence and with pod damage. Total phenol levels were negatively associated with egg count, larval incidence and pod damage percentage

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> Cytochrome oxidase I sequence of <i style="">Helicoverpa</i> (Noctuidae: Lepidoptera) species in India—Its utility as a molecular tool </smarttagtype></smarttagtype>

195-199 The genus Helicoverpa comprises of 2 species in India—H. armigera and H. assulta. This paper compares partial CO-1 sequences of the two-field-collected species with a laboratory strain of H. armigera and Drosophila yakuba whose entire mitochondrial genome has been sequenced. The region sequenced in the study corresponds to 2111 to 2601 bp sequence of D. yakuba mitochondrial genome, i.e mid to near terminal segment of the CO-I region. When analyzed, at least 18 nucleotide and 8 amino acid substitutions were observed between the two species. Using this information, a specific PCR-RFLP tool was designed that distinguishes between the two species at the egg stage itself, thus, influencing pest control options significantly, especially in areas and crops where the two may occur simultaneously. </smarttagtype