Premium
Parasitic castration of Plutella xylostella larvae induced by polydnaviruses and venom of Cotesia vestalis and Diadegma semiclausum
Author(s) -
Bai Sufen,
Cai Dongzhang,
Li Xin,
Chen Xuexin
Publication year - 2009
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.20279
Subject(s) - biology , plutella , diamondback moth , larva , zoology , host (biology) , parasitoid , andrology , instar , botany , ecology , medicine
Abstract In the present study, we used γ‐ray to irradiate the female parasitoids to make wasp eggs infertile, resulting in pseudoparasitization, which allowed the analysis of maternal secretions such as polydnaviruses (PDVs) and venom in the absence of larval secretions or teratocytes by the growing parasitoids. We then investigated the spermatogenesis and components of testicular proteins of male Plutella xylostella larvae pseudoparasitized by two endoparasitoids ( Cotesia vestalis and Diadegma semiclausum ). The results showed that pseudoparasitism by the two endoparasitoids at the early third instar host larvae both induced smaller testes in size than those of nonparasitized host larvae. Both of them caused parasitic castration, and the degree of castration is almost as severe as in naturally parasitized hosts. This suggested that PDVs and venom played a major role in the degeneration of host testes. There are significant differences in the degree of castration induced by the two endoparasitoids, with respect to testicular growth, testicular protein concentrations, and histological changes of germ cells. Cotesia vestalis bracovirus always has a significantly stronger effect on host testicular growth and development than D. semiclausum ichnovirus. SDS‐PAGE analysis indicated that synthesis of P 65 and P 67 proteins were clearly inhibited in testes of hosts that were pseudoparasitized by C. vestalis while reduction in synthesis of other proteins was not evident. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley‐Liss, Inc.