Social conditions can alter the allocation of resources to reproductive traits. For example, an increase in social density during development is frequently associated with an increase in the testes mass of males. Sperm competition theory assumes that increased investment in testes should come at the expense of investing into precopulatory traits, such as sexually selected weaponry. However, much remains unknown about the role of the social context on the concurrent, relative investment in both testes and weapons. We found that the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae), grew nearly 20% larger testes when raised in high social densities. In addition to manipulating social density, we used autotomy (limb loss) to limit investment in their hindlimb weapon during development. At low densities, we found that those that lost a weapon during development grew larger testes by adulthood, supporting previous work demonstrating a weapons-testes trade-off. However, at high social densities, males that dropped a hindlimb did not grow larger testes, though testes were already large at this density. These results underscore the importance of the social context to resource allocation patterns within the individual.

中文翻译：

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在较高的社会密度下，武器与睾丸之间的权衡并不明显。

社会条件可以改变对生殖特征的资源分配。例如，在发育过程中社会密度的增加通常与男性睾丸质量的增加有关。精子竞争理论认为，增加对睾丸的投资应以投资于交配前的性状为代价，例如性选择的武器。但是，关于社会背景在同时进行相对睾丸和武器投资方面所起的作用，仍然知之甚少。我们发现，以高社交密度饲养时，带叶仙人掌的臭虫纳尼亚·费莫拉塔（Haniaptera：Coreidae）的睾丸长了近20％。除了控制社会密度之外，我们还使用自动截肢（肢体丧失）来限制他们在开发过程中对后肢武器的投资。在低密度下 我们发现，那些在开发过程中丢失武器的人到成年后会长出更大的睾丸，从而支持先前的工作，证明了武器与睾丸之间的权衡。但是，在较高的社会密度下，掉落后肢的雄性不会长出更大的睾丸，尽管在这种密度下睾丸已经很大。这些结果强调了社会环境对个人内部资源分配模式的重要性。