Developmental Biology of Pulse Beetle, Callosobruchus chinensis (L.) on Lentil under Laboratory Conditions

Abstract

Aims: The present investigation was conducted to study the developmental biology of pulse beetle, Callosobruchus chinensis (L.), on lentil under laboratory conditions. Study design: The experiment was laid out in a Completely Randomised Design (CRD) with five replications. Place and Duration of Study: The study was carried out in the Storage Laboratory, Department of Entomology, S.K.N. College of Agriculture, Jobner, Rajasthan, from November 2024 to October 2025. Methodology: Freshly emerged adults (0–24 h old) of C. chinensis were released on lentil seeds for oviposition. Seeds containing freshly laid eggs were kept individually under laboratory conditions maintained at 29 ± 1.5 °C and 75 ± 5 per cent relative humidity. Observations were recorded on the incubation period, egg hatchability, larval and pupal duration, adult emergence, fecundity, adult longevity, sex ratio and total life cycle. Results: The results showed that the incubation period of C. chinensis on lentil was 4.00 ± 0.32 days, with 67.33 ± 2.49 per cent egg hatchability. The first, second, third and fourth larval instars lasted for 4.20 ± 0.58, 5.20 ± 0.74, 5.50 ± 0.60 and 6.30 ± 0.72 days, respectively, with a total larval duration of 21.20 ± 0.61 days. The pre-pupal and pupal periods were 3.80 ± 0.13 and 6.40 ± 0.79 days, respectively. Adult emergence was 53.33 ± 3.36 per cent, and the total developmental period was 36.30 ± 1.16 days. Fecundity was 67.30 ± 4.12 eggs per female, with a female-to-male sex ratio of 1:0.71. Male and female longevity were 9.40 ± 0.58 and 11.60 ± 1.05 days, respectively. Conclusion: The study of the biology of pulse beetle, C. chinensis, on lentil provides information on its developmental and reproductive behaviour under storage conditions. The findings identify vulnerable stages during the developmental period, which may help determine suitable intervention periods and formulate effective management strategies against this storage pest.