The immune response can be costly. Studies in several arthropod species have indicated a trade-off between immunity and other life-history traits, including reproduction. In sexually dimorphic species in which females and males largely differ in their life history strategies and related energetic demands, we can expect to find sex differences in immune functions. Sex differences in immunity are well documented in vertebrates; however, we largely lack data from invertebrate systems. Lytic activity, the immune system’s ability to lysate bacteria and viruses, has been widely used as a proxy for the strength of the immune response in several invertebrates. With this in mind, we used the burrowing wolf spider Allocosa senex to test differences in lytic activity between females and males. We also studied whether digging behavior affects the immune responses in this species. While females of A. senex construct simple refuges where they stay during the day, males construct deep burrows, which they donate to females after copulation. In accordance with our hypothesis, females showed higher lytic activity compared with males, and those males who dug showed higher levels of lytic activity than those that did not dig. Furthermore, male body condition and lytic activity did not correlate with burrow length, a trait under female choice in this species. Our results show sexual dimorphism in lytic activity responses, which are likely related to differences in life-history strategies and energetic requirements of each sex in A. senex spiders.

免疫反应可能代价高昂。对几种节肢动物物种的研究表明，在免疫力和其他生命历史特征（包括生殖）之间要进行权衡。在雌雄两性生活史策略和相关能量需求差异很大的有性双态物种中，我们可以期望发现免疫功能存在性别差异。免疫力方面的性别差异已在脊椎动物中得到充分证明。但是，我们在很大程度上缺乏无脊椎动物系统的数据。免疫系统具有溶解细菌和病毒的能力，即裂解活性，已被广泛用作几种无脊椎动物免疫反应强度的代表。考虑到这一点，我们使用了穴居狼蛛Allocosa senex测试女性和男性之间溶血活性的差异。我们还研究了挖掘行为是否会影响该物种的免疫反应。仙鹤草（A. senex）的雌性在白天居住时会建造简单的避难所，而雄性则建造深的洞穴，它们在交配后捐献给雌性。根据我们的假设，与男性相比，雌性显示出更高的溶胞活性，而挖出的雄性比未挖出的雄性显示出更高的溶胞活性。此外，男性的身体状况和溶菌活性与洞穴长度不相关，而洞穴长度是该物种雌性选择的特征。我们的研究结果表明，在裂解活动反应中存在性二态性，这可能与生活史策略的差异以及每种性别对女性的能量需求有关。A. senex蜘蛛。