Abstract: The wide dispersal of aphid parasitoids is most likely related to the flight of parasitized alates. This hypothesis was examined via simulated flight and post-flight colonization of green peach aphid, Myzus persicae (Sulzer) alates parasitized individually by a common obligate aphid parasitoid, Aphidius gifuensis Ashmead. Data grouped by flight time (h) and flight distance (km) were analyzed using one-way ANOVA procedure, and for all the variables, a stepwise procedure of polynomial regression analysis was used. The results showed that a total number of 378 alates flew successfully in different batches, and among them, 239 alates were mummified finally. Mummified alates flew for an average time and distance of 2.63 h and 2.16 km, respectively, survived for an average time of 6.11 d, and laid 8.5 nymphs and 162 nymphs per alate during a 6-day and 14-day post flight period, respectively. The non-mummified alates did not differ significantly in these statistics from the mummified alates. Associated parasitoids successfully developed in the mummified alates, and eventually a total of 205 mummified alates emerged as adult wasps (85.8%) with a sex ratio of 1∶5.2. We so conclude that host dispersal flight is utilized by aphid parasitoids for their own dispersal. The results highlight the significant role of aphid dispersal flight in disseminating parasitoids.

Key words: Aphid; Myzus persicae, Aphidius gifuensis, parasitoid, flight dispersal, simulated flight