Laboratory of Evolutionary Ecology, Graduate School of Environmental Science, Okayama University, Okayama City, Okayama 700-8530, Japan.
J Econ Entomol. 2010 Oct;103(5):1564-8. doi: 10.1603/EC09420.
The use of flightless strains of the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), established via artificial selection, can be highly effective as a biological control agent for aphids. However, flightless H. axyridis must depend on walking for dispersion. Therefore, data on the walking activity levels in flightless strains are important for the development of effective methods when releasing these agents in the field. Results of measurement of walking activity levels using an infrared actograph showed that walking activity levels during the daytime (but not nighttime) in both sexes of pure flightless strains tended to be lower than those of control strains. We also found that walking activity levels during the daytime for the F1 generation of hybrid strains, produced by reciprocal crossing between two pure flightless strains, were approximately equal to those of pure strains; the reduction in walking activity levels was not recovered by hybrid vigor. Our results indicate that the reduction in walking activity levels in the pure flightless strains was not caused merely by inbreeding depression stemming from the artificial selection process. Instead, potentially flight ability and walking activity levels in this species may be controlled by the pleiotropic effect of a gene.
利用经过人工选择培育的无飞行能力的多色亚洲瓢虫（Harmonia axyridis）（鞘翅目：瓢虫科）可以非常有效地作为蚜虫的生物防治剂。然而，无飞行能力的 H. axyridis 必须依靠行走来扩散。因此，关于无飞行能力的品系的行走活动水平的数据对于开发在田间释放这些剂的有效方法非常重要。使用红外动作记录仪测量行走活动水平的结果表明，无论是雄性还是雌性，纯无飞行能力品系的日间（而非夜间）行走活动水平往往低于对照品系。我们还发现，由两个纯无飞行能力品系相互杂交产生的杂交品系的 F1 代的日间行走活动水平与纯品系大致相同；杂种优势并没有恢复行走活动水平的降低。我们的结果表明，纯无飞行能力品系行走活动水平的降低不仅仅是由人工选择过程引起的近交衰退所致。相反，该物种的潜在飞行能力和行走活动水平可能受到一个基因的多效性影响。
