Mating interactions are rife with conflict because the evolutionary interests of males and females seldom coincide. Intersexual conflict affects sexual selection, yet the proximate factors underlying male coercive ability and female resistance are poorly understood. Male combat outcomes are often influenced by bite force, with superior biters being more likely to achieve victory over poorer biters in a range of species, including crickets. If good performers also achieve mating success through sexual coercion, then bite force might play a role in intersexual conflict as well. We tested the capacity of bite force to influence mating interactions in house crickets both directly by measuring bite forces of males and females and by altering male bite capacity through neuropharmacological manipulation. In addition, the invertebrate neurotransmitter octopamine both mediates aggression and underlies motivation to bite in male house crickets. By blocking octopamine receptors through the application of an antagonist, epinastine, we tested the effects of reduced bite force on male mating success. Our results show that male bite capacity, in combination with body size, influences both the likelihood and the outcomes of mating interactions, whereas treatment of males with epinastine eliminates motivation to mate. Our results suggest a functional role for bite force in affecting both sexual conflict and sexual selection and expand our knowledge of the influence of biogenic amines on reproductive behaviour.

中文翻译：

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咬合力、体型和章鱼胺介导家蟋蟀（Acheta Domesticus）的交配相互作用。

交配互动充满了冲突，因为雄性和雌性的进化利益很少一致。两性冲突影响性选择，但男性强制能力和女性抵抗力背后的直接因素却知之甚少。雄性的战斗结果往往受到咬合力的影响，在包括蟋蟀在内的一系列物种中，咬合力强的咬合者更有可能战胜咬合力差的咬合者。如果优秀的表演者也通过性胁迫实现交配成功，那么咬合力也可能在两性冲突中发挥作用。我们通过直接测量雄性和雌性的咬合力以及通过神经药理学操作改变雄性咬合力来测试咬合力影响家蟋蟀交配相互作用的能力。此外，无脊椎动物神经递质章鱼胺既介导攻击性，也是雄性蟋蟀咬人动机的基础。通过使用拮抗剂依匹斯汀阻断章鱼胺受体，我们测试了减少咬合力对雄性交配成功率的影响。我们的结果表明，雄性咬合能力与体型相结合，影响交配相互作用的可能性和结果，而用依匹斯汀治疗雄性则消除了交配动机。我们的结果表明咬合力在影响性冲突和性选择方面发挥着功能性作用，并扩大了我们对生物胺对生殖行为影响的认识。