Regular Papers
A comparative study on development and reproduction of the parasitoid Lysiphlebus japonicus (Hymenoptera: Aphidiidae) in symbiotic and aposymbiotic host aphids
2004 年 39 巻 2 号 p. 243-248
詳細
2004 年 39 巻 2 号 p. 243-248
The development and reproduction of the braconid wasp, Lysiphlebus japonicus Ashmead, parasitizing either symbiotic or aposymbiotic aphids, were investigated. In order to obtain aposymbiotic aphids, the black bean aphid, Aphis craccivora Koch, was fed at birth with Vicia faba dipped in 200 μg/ml rifampicin. Transmission electron microscopy revealed that the intracellular symbiotic bacteria (Buchnera) began to degenerate 2 days after the antibiotic treatment. Bacteria-free aposymbiotic aphids exhibited a reduced growth rate, adult size and reproduction rate. The development and reproduction of the parasitoids were clearly affected by the rifampicin treatment of the aphid host. The larval size and the growth rate of the parasitoids were reduced, and the emergence rate and the body weight of the wasps decreased by 13% and 54%, respectively. The number of progeny produced by the wasps that emerged from aposymbiotic aphids decreased by 25%. Possible factors involved in the effects of aposymbiosis on the parasitoids are discussed.
