Graziosi Ignazio, Rieske Lynne K
Department of Entomology, University of Kentucky, S225 Ag North, Lexington, KY 40546-0091, USA.
Environ Entomol. 2014 Aug;43(4):1053-8. doi: 10.1603/EN14047. Epub 2014 Jul 7.
Fecundity is a key factor in modulating population growth rate, and is of particular significance when considering the invasiveness of introduced species. In insects, fecundity is affected by body size, age, and nutrition. We investigated the potential fecundity of the invasive Asian chestnut gall wasp Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), an introduced parthenogenetic gall former of Asian origin and a global pest of chestnut (Castanea spp.), to better understand its invasiveness. We compared ovarian, egg, and body metrics of adult wasps of different age. We evaluated insect weight, body length, mesosomal and metasomal lengths and widths, hind femur length, number of eggs, and size of eggs in wasps from four age cohorts. Adult weight and metasomal width were positively correlated with number of eggs. Egg load decreased with wasp age, and egg size initially increased before decreasing. Our findings suggest that adult D. kuriphilus, previously reported as proovigenic, may be resorping eggs in the absence of suitable hosts, and reallocating nutritive resources for body maintenance and egg quality to increase fitness, implicating a plasticity in its reproductive strategy. D. kuriphilus may be able to vary its potential fecundity in response to nutrition and host availability, thus increasing its invasiveness.
繁殖力是调节种群增长率的关键因素，在考虑外来物种的入侵性时具有特别重要的意义。在昆虫中，繁殖力受体型、年龄和营养的影响。我们研究了入侵性亚洲栗瘿蜂Dryocosmus kuriphilus Yasumatsu（膜翅目：瘿蜂科）的潜在繁殖力，它是一种原产于亚洲的孤雌生殖瘿蜂形成者，也是全球栗树（Castanea spp.）的害虫，以更好地了解其入侵性。我们比较了不同年龄成年雌蜂的卵巢、卵和身体指标。我们评估了四个年龄组的雌蜂的体重、体长、中躯和后躯的长度和宽度、后股骨长度、卵的数量和卵的大小。成年雌蜂的体重和后躯宽度与卵的数量呈正相关。卵的负载量随雌蜂年龄的增长而减少，卵的大小最初增加，然后减少。我们的研究结果表明，先前被报道为先行产卵型的成年栗瘿蜂在没有合适宿主的情况下可能会吸收卵，并重新分配营养资源用于身体维持和卵的质量，以提高适应性，这意味着其繁殖策略具有可塑性。栗瘿蜂可能能够根据营养和宿主可用性改变其潜在繁殖力，从而增加其入侵性。
