Interspecific interaction between Aphidius matricariae and Praon volucre (Hym., Braconidae), the parasitoids of Myzus persicae (Hem., Aphididae)
عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران
نویسندگان
چکیده
Biological control agents are frequently used in combination against one pest in greenhouses, which result in interspecific interaction and it may affect their demographic parameters. Aphidius matricariae Haliday and Praon volucre (Haliday) (Hymenoptera: Braconidae) are two main parasitoid wasps of Myzus persicae (Sulzer) (Hemiptera: Aphididae) in many parts of the world and Iran. In this research, life table parameters of A.matricariae and P. volucre (before and after combination) was investigated on M.persicae on pepper (Marqueza variety) at 25±1°C, 60±5% RH and a photoperiod of 14L:10D hours. To investigate daily fecundity of A. matricariae and P. volucre (before and after combination), a pepper leaf with 100 third instar nymphs of M. persicae was exposed to pairs of each parasitoid species (<24h old) (before combination) and both parasitoids (after combination) in plastic container (50×130×150 mm). After 24h, parasitoids were transferred into new container with above condition. The experiments continued until the death of the female parasitoid in before parasitoids combination. After combination, when adult female of each species died before the other, experiments continued until to death other parasitoid female. After mummification, numbers of mummified aphids were counted for each female individual at each day. Daily fecundity of 62 and 41 females of A. matricariae and P. volucre, respectively (before combination) and at least 40 females of parasitoid species (after combination) was investigated. Comparison of demographic parameters of each parasitoids before and after combination was done by t-test (P<0.05). When parasitoids foraged alone, mortality rate of pupa of A. matricariae and P. volucre were 6% and 34%, respectively. But when host were parasitized simultaneously by both wasp species, it was increased to 17% and 39% for A. matricariae and P. volucre, respectively. The intrinsic rate of increase of A.matricariae significantly decreased from 0.414 to 0.282 (day-1) and for P. volucre decreased from 0.154 to 0.126 (day-1) as a result of interspecific interaction between parasitoid wasps. The net reproduction rate (R0) of A. matricariae was 134.32 and 35.62 and for P.volucre was 20.64 and 14.18 (females/female/generation time) before and after combination, respectively. The generation time (T) and doubling time (DT) of both parasitoid wasps were affected by interspecific interaction between parasitoids. When of A. matricariae and P. volucre acting together on M. persicae, they spend more energy to find host, therefore their efficiency reduce. The results of this study may be useful for management of M. persicae on pepper in greenhouses in Iran.
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