Effects of temperature on host plant selection by a tropical butterfly species

In this study, we examined whether female Bicyclus anynana butterflies can enhance their reproductive performance by modifying host plant use in response to challenging temperature regimes. We investigated (1) whether exposure to variable thermal conditions affected reproductive output when females had access to only one host plant, and (2) whether this in turn affected the oviposition preference for host plants of different quality under laboratory conditions. We expected hot conditions to reduce the reproductive performance (egg number, offspring survival and performance) of butterflies. Such deleterious effects may, however, be counterbalanced by a higher selectivity for high-quality plants when females have simultaneous access to plants of different quality. We found that the reproductive performance of butterflies was indeed reduced when they experienced hot conditions. These temperature effects were only observed when butterflies only had access to a low-quality plant. However, individuals did not increase their selectivity towards the higher-quality host plant in response to hot conditions, possibly because of fecundity costs associated with increased choosiness.

本研究旨在探究雌性安纳纳眼蝶（Bicyclus anynana）能否通过调整寄主植物利用策略，以应对挑战性温度环境，进而提升自身繁殖性能。我们开展了两项相关实验：(1) 当雌性蝴蝶仅能接触单一寄主植物时，可变温度暴露是否会影响其繁殖产出；(2) 该暴露情况是否会进一步影响实验室环境下雌性对不同品质寄主植物的产卵偏好。我们推测高温环境会降低蝴蝶的繁殖性能（包括产卵量、后代存活率与后代生长表现）。不过，当雌性蝴蝶可同时获取不同品质的寄主植物时，其对高品质植物的选择偏好提升或许能抵消这类有害效应。研究结果表明，当蝴蝶暴露于高温环境时，其繁殖性能确实出现下降。且仅当蝴蝶仅能接触低品质寄主植物时，才会观测到温度带来的上述影响。然而，蝴蝶并未因高温环境而提升对高品质寄主植物的选择偏好，这一现象可能源于提升选择严格性所伴随的繁殖成本。