Maxwell Michael R, Frinchaboy Caylin
Department of Mathematics and Natural Sciences, National University, 11255 North Torrey Pines Road, La Jolla, CA 92037, USA.
Environ Entomol. 2014 Feb;43(1):91-101. doi: 10.1603/EN12310. Epub 2013 Dec 16.
Body size is an important feature of organisms, influencing many components of life history and fitness, such as feeding success and reproductive output. Body size is considered especially salient for solitary predators, whose food intake hinges on individual predation success, which in turn is often driven by the relative sizes of predator and prey. The current study examined intraspecific variation in adult female length and its fitness consequences in a solitary predator, the praying mantid Stagmomantis limbata Hahn. Through a 5-yr integration of observational and experimental work in the field and captivity, we investigated the relationship between female pronotum length and prey size, diet breadth, male attraction, and measures of egg production (fecundity and ootheca mass). We found that longer females ate longer prey in the field and showed greater breadth of prey size than shorter females. Longer females did not necessarily feed at higher rates in the field, as measured by the rate of abdominal expansion. Female length failed to show significant effects on male attraction or on the incidence of cannibalism. Longer females had higher fecundity (mature eggs in body at death) and laid heavier oothecae than shorter females. In nature, longer females consistently emerged as adults earlier in the season than shorter females. Shorter female adults emerged when feeding rates were higher in the field, suggesting an incidental ecological benefit of shorter adult size.
体型是生物体的一个重要特征,影响着生活史和适合度的许多方面,如捕食成功率和繁殖产出。体型对于独居捕食者来说尤为显著,它们的食物摄入量取决于个体的捕食成功率,而捕食成功率又常常由捕食者和猎物的相对体型所驱动。本研究调查了独居捕食者缘纹巨斧螳螂(Stagmomantis limbata Hahn)成年雌性体长的种内变异及其适合度后果。通过在野外和圈养环境中进行为期5年的观察和实验工作相结合,我们研究了雌性前胸背板长度与猎物大小、食性广度、雄性吸引力以及产卵量(繁殖力和卵鞘质量)之间的关系。我们发现,在野外,体型较长的雌性捕食的猎物更长,并且与体型较短的雌性相比,其猎物大小的范围更广。以腹部扩张率衡量,体型较长的雌性在野外的进食速率不一定更高。雌性体长对雄性吸引力或同类相食的发生率没有显著影响。体型较长的雌性比体型较短的雌性具有更高的繁殖力(死亡时体内的成熟卵数量),并且产下的卵鞘更重。在自然界中,体型较长的雌性成虫在季节中出现的时间始终比体型较短的雌性成虫更早。体型较短的雌性成虫在野外进食速率较高时出现,这表明较短的成虫体型具有附带的生态益处。