Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, USA.
J Econ Entomol. 2021 Aug 5;114(4):1517-1522. doi: 10.1093/jee/toab108.
Flexibility in oviposition site selection under temporally shifting environmental conditions is an important trait that allows many polyphagous insects to flourish. Population density has been shown to affect egg-laying and offspring fitness throughout the animal kingdom. The effects of population density in insects have been suggested to be mutualistic at low densities, whereas intraspecific competition is exhibited at high densities. Here, we explore the effects of adult crowding and spatial resource variation on oviposition rate in the invasive pest Drosophila suzukii (Matsumura). In a series of laboratory experiments, we varied the density of adult males and females while holding oviposition substrate availability constant and measured per female oviposition rate using high and low-quality substrates. We found that oviposition behavior was affected more by substrate than adult density, though both variables had significant effects. When we varied the spatial arrangement of whole raspberries, we observed differences in oviposition rate and egg distribution between the grouped and solitary female treatments. Our results suggest that social interactions encourage oviposition, especially when exposed to unfamiliar or unnatural substrates. These results highlight the compensating effect of increased oviposition rate per female as adult populations decline. They will help researchers and crop managers better understand in-field population dynamics throughout the season as population densities change.
在随时间变化的环境条件下，产卵地点选择的灵活性是许多多食性昆虫得以繁荣的重要特征。种群密度已被证明会影响整个动物界的产卵和后代适应性。昆虫种群密度的影响在低密度时被认为是互利的，而在高密度时则表现为种内竞争。在这里，我们探讨了成虫拥挤和空间资源变化对入侵害虫果蝇（Drosophila suzukii）（松村）产卵率的影响。在一系列实验室实验中，我们在保持产卵基质可用性不变的情况下，改变了成年雄性和雌性的密度，并使用高质量和低质量的基质来衡量每个雌性的产卵率。我们发现，尽管两个变量都有显著影响，但产卵行为受基质的影响大于成虫密度。当我们改变整个覆盆子的空间排列时，我们观察到成群和单独的雌性处理之间在产卵率和卵分布上的差异。我们的结果表明，社会互动促进了产卵，尤其是在接触不熟悉或不自然的基质时。这些结果突出了随着成虫种群数量的减少，每个雌性产卵率增加的补偿效应。它们将帮助研究人员和作物管理者更好地了解整个季节田间种群动态随种群密度变化的情况。
