Abstract

Long-term mass rearing of parasitoids under laboratory conditions may affect their quality. We studied the quality of Habrobracon hebetor (Say) (Hymenoptera: Braconidae) reared for more than 20 generations (G) using two-sex life table parameters. We found that G2 had the longest pre-adult development time (12.4 d) and the highest fecundity (1304.00 eggs/female) compared with the other generations. While no significant differences in the intrinsic rate of increase (r) and net reproductive rate (R₀) were found among G4, G6, G8, G15, and G20, the highest values of r (0.3273 day⁻¹) and R₀ (436.28 eggs/individual) as well as the shortest mean generation time (T) were observed in G10. In addition, significant differences in sex ratio (F/F + M) were observed among different generations, ranging from 17% in G2 to 60% in G10. These results suggest that up to a certain number of generations (G10), the quality of H. hebetor significantly increased without adding field-collected parasitoids or changing the factitious host. To maintain the quality of the colony beyond this point, it should be rejuvenated by periodically adding field-collected individuals.

摘要

在实验室条件下长期大规模饲养寄生蜂可能会影响其质量。我们使用两性生活表参数研究了饲养超过 20 代 (G)的Habrobracon hebetor (Say) (Hymenoptera: Braconidae) 的质量。我们发现，与其他世代相比，G2 的成年前发育时间最长（12.4 d）和最高的繁殖力（1304.00 个卵/雌）。虽然G4、G6、G8、G15 和 G20的内在增长率 ( r ) 和净繁殖率 ( R _{0 ) 没有显着差异，但}r (0.3273 天^-1 ) 和R ₀ ( 436.28个鸡蛋/个体）以及最短的平均世代时间（T ) 在 G10 中观察到。此外，性别比（F/F+M）在不同代之间存在显着差异，从 G2 的 17% 到 G10 的 60% 不等。这些结果表明，直到一定数量的世代（G10），H. hebetor的质量显着提高，而无需添加现场采集的寄生蜂或改变人为宿主。为了在这一点之后保持群体的质量，应该通过定期添加野外采集的个体来使其恢复活力。