تاثیر دما بر رشد و نمو سوسک چهار نقطه‌ای حبوبات، Callosobruchus maculatus F. (Col.: Bruchidae) با تغذیه از میزبان‌های مختلف

The cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae), is one of the most important storage pests of legumes, causing considerable damage to products such as beans, lentils, mung beans, fava beans, and chickpeas in various parts of the world. The larvae of this pest, by feeding on the legumes, not only reduce seed weight but also decrease seed germination potential, nutritional value, and product marketability. In this study, to investigate the effect of temperature and host on its development and survival, these parameters were examined by feeding on two hosts, cowpea and chickpea, at eight constant temperatures including 15, 18, 21, 24, 27, 30, 33, and 36 ˚ C. To initiate the experiment, 400 seeds of the host were placed inside transparent plastic containers (5×15×12 cm); 50 pairs of less than five-day-old adults were released into each container for oviposition. After 24 hours, adults were removed, and the seeds were checked using a stereomicroscope. Seeds containing one egg were placed in plastic containers with similar dimensions and incubated in a controlled environment at the specified temperatures, with a relative humidity of 60 ± 5% and complete darkness. The containers were inspected daily, and adult insects were sexed and weighed upon emergence. After 9 months, no adult beetles emerged at 15 ˚C in either host. The statistical analysis indicated that the effects of temperature (F = 5838.39, P < 0.001 for development; F = 31.1, P < 0.001 for adult weight) and host (F = 8583.03, P < 0.001 for development; F = 82.87, P < 0.001 for adult weight) were statistically significant on the developmental time and adult weight. The insect developmental time at temperatures 18-36 ˚ C was 117.02, 70.75, 38.59, 34.96, 26.56, 25.46, and 25.95 days on chickpea, and 104.41, 63.72, 35.19, 33.17, 24.55, 21.9, and 22.99 days on cowpea, respectively. The highest and lowest percentage of mortality on chickpea was obtained at temperatures of 36 ˚C (41.09%) and 27°C (21.48%), respectively; on cowpea these parameters were observed at temperatures of 36 ˚C (45.38%) and 24°C (20.69%), respectively. The heaviest and lightest adult insects on chickpea were at temperatures of 18°C (6.279 ± 0.007 mg) and 30°C (4.613 ± 0.012 mg), respectively, while on cowpea, they were at temperatures of 18°C (5.182 ± 0.012 mg) and 36 ˚C (4.225 ± 0.007 mg). The findings of this study can be used to calculate thermal requirements, temperature thresholds, thermal constants, and the number of generations of this pest per year, for providing integrated management approaches.