Developmental Nutrition Affects the Structural Integrity of a Sexually Selected Weapon.
Developmental Nutrition Affects the Structural Integrity of a Sexually Selected Weapon.
复制标题
发育营养影响性选择武器的结构完整性。
DOI：
10.1093/icb/icab130
复制
发表时间：
2021
影响因子：
2.6
通讯作者：
Woodman TE
中科院分区：
文献类型：
--
作者：
Woodman TE
许多物种中的雄性为了获得配偶而进行身体上的战斗，性选择导致了武器的进化，以提高竞争的表现。众所周知，这些精心制作的结构的大小对营养非常敏感。然而，我们对营养对动物武器的其他属性的影响程度知之甚少，这些属性对战斗至关重要。在这项研究中，我们调查的影响，自然饮食变化的武器结构完整性的战斗昆虫，纳尼亚femorata（半翅目：Coreidae）。这种物种的雄性向其他雄性展示它们扩大的、多刺的后腿，这些腿在攻击性的身体竞赛中充当武器，用来打击和挤压对手。femorata以仙人掌果为食，并在这种植物上建立领地。在佛罗里达中北部，多刺的梨在四月和五月开始结果。femorata有多个，重叠的世代，而绿色果实在接下来的几个月里慢慢成熟。我们研究了昆虫在这个范围内，6月和7月，在两个附近的时间点达到成年，以测试成熟的绿色仙人掌果实提供的营养对武器大小和抗穿刺能力的影响。我们还提出了昆虫仙人掌红色，成熟的果实进行比较。我们发现仙人掌果实的物候对武器有显著的影响。用更成熟的绿色果实饲养的昆虫（第二队列中的那些）比用早期绿色果实饲养的昆虫（第一队列中的那些）具有71%的更大的武器面积和4.4倍的更大的穿刺阻力。与此相反，在红色成熟果实上饲养的昆虫大小适中，具有高的抗穿刺性，并且它们从第一至第二队列的表型变化不大。后股骨武器结构完整性的增加与更好的营养带来的身体尺寸的增加有关。这种模式突出表明，武器越大，表皮厚度越厚，或其材料特性发生变化。重要的是，营养对穿刺阻力的影响也超越了大小。同样大小的昆虫，如果得到上级营养，则结构完整性更高。性选择的武器通常被用作战斗前同种的视觉信号，这项工作暗示，当营养可变时，武器的大小可能是武器性能的不良信号。
Males in many species engage in physical combat over access to mates, and sexual selection has led to the evolution of weapons to enhance contest performance. The size of these often-elaborate structures is known to be exquisitely sensitive to nutrition. However, we know very little about the degree to which nutrition affects other attributes of animal weapons that can be crucial to fighting. In this study, we investigated the impact of natural dietary variation on weapon structural integrity in a fighting insect,Narnia femorata(Hemiptera: Coreidae). Males in this species display their enlarged, spiny hind legs to other males, and these legs serve as weapons in aggressive physical contests where they are used to strike and squeeze opponents.N. femoratafeeds on the fruit of prickly pear cactus and sets up territories on this plant. In North Central Florida the prickly pearOpuntia mesacanthassp.latablooms and begins to produce fruits in April and May.N. femoratahas multiple, overlapping generations while the green fruits slowly ripen over the next several months. We examined insects reaching adulthood at two nearby time points in this range, June and July, to test the influence of the nutrition provided by ripening green cactus fruit on weapon size and its ability to resist puncture. We also raised insects on cactus with red, ripe fruit for comparison. We found a striking effect of cactus fruit phenology on weapons. Insects raised with the more mature green fruit (those in the second cohort) had 71% larger weapon area and 4.4 times greater puncture resistance than those raised on the early green fruit (those in the first cohort). In contrast, insects raised on red, ripe fruit were moderate in size, had high puncture resistance, and they changed little phenotypically from the first to second cohort. Increased structural integrity of the hind femur weapon was associated with the increased body size that came with better nutrition. This pattern highlights that cuticle thickness increased or its material properties changed when weapons were larger. Importantly, effects of nutrition on puncture resistance also transcended size. Insects of the same size had greater structural integrity if they received superior nutrition. Sexually selected weapons are often used as visual signals to conspecifics before fights, and this work hints that the size of the weapons may be a poor signal of weapon performance when nutrition is variable.