The effects of temperature on interference competition in the regal jumping spider Phidippus regius Koch, 1846 (Araneae: Salticidae)

It is well known that spiders exhibit a broad variety of agonistic behaviours towards their conspecifics during interference com petition. However, it remains unclear how much these behav iours shift/alter as a coping mechanism in response to changing abiotic factors such as temperature. Therefore, the present study examined the effects of temperature (20°C, 25°C, 30°C, and 35°C) on different agonistic behaviours between individuals of male jumping spiders (Phidippus regius) during interference competition. It was hypothesized that the frequency of competi tive behaviours of P. regius would increase as the temperature increased. The results revealed that the presence of a conspecific had a statistically significant impact on the frequency of all behaviours recorded except resting. The most frequently observed behaviours in the presence of a conspecific comprised leg extensions and palpal drumming. The effects of temperature change were less well defined. All behaviours, except leg exten sions, increased in frequency with temperature but the increases were not statistically significant. Statistically significant nega tive relationships were found between the extension of one or two front legs and temperature. With respect to variability among the spiders tested, coefficients of variation ranged from approximately 30% to 350% across all recorded behaviours. While the results of this study indicate that certain competitive behaviours in male P. regius are influenced by temperature, that the substantial behavioural plasticity observed among individu als suggests that jumping spiders may be well equipped to cope with varying thermal conditions.