The noctuid pod borer, Helicoverpa armigera, is one of the most important pests of pigeonpea, and plant resistance is an important component for minimizing the extent of losses caused by this pest. To develop insectresistant cultivars, it is important to understand the contributions of different components of resistance, and therefore, we studied the antixenosis mechanism of resistance to H. armigera in a diverse array of pigeonpea genotypes under no-choice, dual-choice, and multi-choice conditions. Antixenosis for oviposition was observed in case of ICPL 187-1, ICP 7203-1, ICPL 88039, T 21, ICPL 84060, and ICPL 332 under no-choice, dual-choice and multi-choice conditions. However, the number of eggs laid on ICPL 88039, T 21 and ICP 7203-1 did not differ significantly from those on ICPL 87 under dual-choice conditions. The susceptible check, ICPL 87 was highly preferred for oviposition. The genotypes ICP 7203-1, ICPL 187-1, T 21, ICPL 332, and ICPL 84060 can be used as sources of non-preference mechanism of resistance in pigeonpea improvement programs to breed for resistance to H. armigera.

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Levels of cyclodiene pesticides (aldrin, α-endosulfan, β-endosulfan, endosulfan sulfate and heptachlor) residues in muscle, liver and kidney tissues of buffalo were estimated. The effects of common cooking methods (microwave cooking, boiling, broiling and pressure cooking) on the levels of endosulfan were determined. Aldrin and total endosulfan (α-endosulfan, β-endosulfan, endosulfan sulfate) residues were found in 42.86 and 64.29% of buffalo tissue samples, with overall mean residual concentration of 0.013 and 0.055 ppm, respectively. However, the levels of these residues were well below the maximum residue limit (MRL: aldrin 0.2 ppm; endosulfan 0.1 ppm) specified by national and international regulatory bodies. Cooking of endosulfan (Endoin 35 EC) spiked meat resulted in 58.33-64.59% reduction in α-endosulfan and 55.93-61.60% reduction in β-endosulfan. Among the cooking methods, pressure cooking was most effective in reducing both α- and β-endosulfan.

Analysis of ovipositor washings from virgin female Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae) of Indian origin by linked gas chromatography and electroantennography indicated the presence of three electrophysiologically‐active compounds. These were identified on the basis of their gas chromatographic retention times and mass spectra as (Z)‐11‐hexadecenyl acetate, (Z)‐13‐octadecenyl acetate and (Z)‐13‐octadecen‐1‐ol with (Z)‐13‐octadecenyl acetate present in amounts of between 0.25 and 1.5 ng per ovipositor and the other two components at less than 10% of this. Trace quantities of octadecyl acetate were identified by mass spectrometry but no electroantennographic responses were observed to this compound. Field trials conducted with a range of blends of the three electrophysiologically‐active compounds showed that blends containing between 5% and 30% (Z)‐11‐hexadecenyl acetate in (Z)‐13‐octadecenyl acetate dispensed from either white rubber septa or polythene vials were more attractive to male moths than a virgin female moth. Addition of (Z)‐13‐octadecen‐1‐ol reduced attractiveness to male moths in the blends and concentrations tested.