The sterile insect technique (SIT) involves periodically releasing artificially sterilized insects to inhibit normal mating between wild insect pests, ultimately resulting in the eradication of wild pest populations. It has often been discussed whether releasing either one sex, mainly males, of sterile insects (i.e., a unisexual release) can enhance the pest-control effect of the SIT more than releasing both sexes (i.e., a bisexual release). We constructed a mathematical model to examine the contribution of sterile males and females to the pest-control effect and the synergy between them. We consider that males seek out and court females in accord with their own female searching ability and preference, and that females subsequently choose one male from among males courting them in accordance with their own preference. Using this model, we compared the pest-control effect of bisexual and unisexual release, focusing on the difference in mating systems of the targeted insects. We showed that for swarm-type mating systems (with few courtship chances with higher encounter rates), bisexual release was the most effective, irrespective of the relative female searching ability between wild and sterile males. In this case, sterile females indirectly reduce wild females mating with either male by absorbing courtship from both wild and sterile males. By contrast, bisexual release is the most effective for scramble-type mating systems (more courtship chances with lower encounter rates) only when the female searching ability of sterile males is lower than that of wild males. In this case, sterile females absorb courtship from males with higher searching abilities. Therefore, the net impact of sterile females depends on the difference in sexual performance between wild and sterile males. Because the sexual performance of sterile insects is often degraded during the process of sterilization, we suggest that bisexual release can be a compatible measure to efficiently suppress wild pest populations.

昆虫不育技术（SIT）涉及定期释放人工灭菌的昆虫，以抑制野生害虫之间的正常交配，最终消灭野生害虫种群。人们经常讨论释放不育昆虫的任一性别（主要是雄性）（即单性释放）是否比释放两性（即双性释放）更能增强 SIT 的害虫防治效果。我们构建了一个数学模型来检查不育雄性和雌性对害虫防治效果的贡献以及它们之间的协同作用。我们认为，雄性会根据自己对雌性的搜索能力和偏好来寻找和追求雌性，而雌性随后会根据自己的喜好从雄性中选择一名雄性来向自己求爱。使用这个模型，我们比较了双性和单性释放的害虫控制效果，重点关注目标昆虫交配系统的差异。我们表明，对于群型交配系统（很少有求偶机会，遇到率较高），无论野生雄性和不育雄性之间的相对雌性搜索能力如何，双性释放是最有效的。在这种情况下，不育雌性通过吸收野生和不育雄性的求爱，间接减少了与雄性交配的野生雌性。相比之下，只有当不育雄性的雌性搜索能力低于野生雄性时，双性释放对于争夺型交配系统（更多的求偶机会，较低的相遇率）才是最有效的。在这种情况下，不育雌性从具有更高搜索能力的雄性那里吸收求爱。所以，不育雌性的净影响取决于野生雄性和不育雄性之间的性能力差异。由于不育昆虫的性性能在绝育过程中往往会下降，我们建议双性释放可以作为有效抑制野生害虫种群的兼容措施。