The cowpea weevil, Callosobruchus maculatus (F.) (Col.: Bruchidae) is a cosmopolitan field-to-store pest ranked as the major post-harvest pest of cowpea in tropical regions. The cold tolerance of an insect species can vary as a result of abiotic features including food resources. In this study, C. maculatus larvae were fed with proline and trehalose (10, 20, and 40 mmol) treated cowpea seeds to determine the effects of these potential cryoprotectants on the supercooling (SCP) and cold hardiness of the upcoming adult beetles. The SCPs of the control, proline-fed and trehalose-fed adults non-significantly changed from −18.2 °C for the control to −17.2 °C for trehalose-fed adults. The cold hardiness (24 h at 0, -5.0, −7.5, −10.0, and −12.5 °C) of the adults was almost the same for control and treatments. Median lethal times (LT₅₀; lethal time for 50% mortality) were 6.3, 6.0, and 5.4 h, respectively. Moreover, feeding the larvae with proline and trehalose-treated seeds did not affect the proline and trehalose contents of the adult beetles. Our results showed that C. maculatus could not tolerate subzero temperatures well above their SCP, indicating that this species might be a chill-susceptible insect.

豇豆象鼻虫Callosobruchus maculatus (F.) (Col.: Bruchidae) 是一种世界性的从田间到商店的害虫，被列为热带地区豇豆主要的收获后害虫。由于包括食物资源在内的非生物特征，昆虫物种的耐寒性可能会有所不同。在这项研究中，C. maculatus用脯氨酸和海藻糖（10、20 和 40 mmol）处理过的豇豆种子喂养幼虫，以确定这些潜在的冷冻保护剂对即将到来的成年甲虫的过冷 (SCP) 和耐寒性的影响。对照、脯氨酸喂养和海藻糖喂养的成年人的 SCP 从对照的 -18.2 °C 到海藻糖喂养的成年人的 -17.2 °C 无显着变化。成虫的抗寒性（0、-5.0、-7.5、-10.0 和 -12.5 °C 下的 24 小时）与对照和治疗几乎相同。中位致死时间（LT ₅₀；50% 死亡率的致死时间）分别为 6.3、6.0 和 5.4 小时。此外，用脯氨酸和海藻糖处理过的种子喂养幼虫不会影响成年甲虫的脯氨酸和海藻糖含量。我们的结果表明，C. maculatus 无法忍受远高于其 SCP 的零下温度，这表明该物种可能是一种对寒冷敏感的昆虫。