Kim Jong-Yoon, Thorp Robbin W
Department of Farm Mechanization, National Agriculture Research Center, Laboratory of Biomicromachine, 3-1-1 Kannondai, 305-8666, Tsukuba, Japan.
Department of Entomology, University of California, 95616, Davis, CA, USA.
Oecologia. 2001 Feb;126(3):451-456. doi: 10.1007/s004420000540. Epub 2001 Feb 1.
Maternal investment in offspring size and number differed between spring- and summer-emerging individual females of Megachile apicalis, a solitary multivoltine bee. Data from experimentally initiated female populations indicated that spring-emerging females produced a relatively large number of progeny but allocated a small amount of food to each, resulting in small progeny. Adult females of larger body sizes provisioned food at a greater rate than did smaller females, and this body-size effect was significant in spring-emerging females. The large body size of these females allowed them to increase the number of progeny produced under the abundant floral resources that occurred during the spring. Conversely, summer-emerging females produced fewer progeny under the diminishing resources for brood production, but allocated each with more food, producing larger progeny, most of which emerged in the spring of the following year. Field data using trap-nests also indicated the same pattern of seasonal offspring size allocation found in the experimental populations. This maternal investment strategy entails a trade-off between the size and number of progeny, so that the daughters upon emergence can best perform in their brood production under the seasonally variable environments where they reproduce.
对于独居多化性蜜蜂顶切叶蜂（Megachile apicalis）而言，春季羽化和夏季羽化的雌蜂在对后代大小和数量的亲代投资上存在差异。来自实验性组建的雌蜂群体的数据表明，春季羽化的雌蜂会产生相对较多的后代，但为每个后代分配的食物量较少，导致后代个体较小。体型较大的成年雌蜂比体型较小的雌蜂提供食物的速度更快，这种体型效应在春季羽化的雌蜂中尤为显著。这些雌蜂体型较大，使它们能够在春季丰富的花卉资源条件下增加后代数量。相反，在育雏资源逐渐减少的情况下，夏季羽化的雌蜂产生的后代较少，但为每个后代分配了更多食物，从而产生体型较大的后代，其中大多数在次年春季羽化。使用诱捕巢获得的野外数据也表明，实验群体中发现的季节性后代大小分配模式与之相同。这种亲代投资策略需要在后代的大小和数量之间进行权衡，以便羽化后的雌蜂女儿们能够在它们繁殖的季节性变化环境中，在育雏过程中表现得最为出色。
