A study was conducted to test the hypothesis that Diadegma semiclausum is one of the factors involved in horizontal transmission of the microsporidial disease of the diamondback moth (DBM), Plutella xylostella L. Results showed that 41% of the larvae exposed to presumably microsporidia contaminated the adult D. semiclausum died before pupation, and all of the dead larvae were observed to have abundant microsporidia spores. None of the DBM larvae in the control treatment died before pupation. The microsporidia spores were detected on the body of the parasitoid adults (D. semiclausum) of both sexes, indicating that the parasitoid get contaminated with spores during eclosion or host finding bout. The spores were also detected within parasitoid`s body (abdomen) of both sexes, and within the sex organ of the adult parasitoid female. This suggests that parasitoid is infected with the disease during immature stages. The presence of spores within female sex organ (plus ovipositor) could explain why many larvae died before pupation as the parasitoid oviposition (parasitism) behaviour indirectly transmit the disease spore to the host (DBM) larvae.
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Idris A. B., B. A. H. Zainal-Abidin, I. Noraini and A. K. Hussan, 2001. Diadegma semiclausum as a Possible Factor for the Horizontal Transmission of Microsporidial Disease of Diamondback Moth, Plutella xylostella L. Pakistan Journal of Biological Sciences, 4: 1353-1355.
- Biever, K.D., R.L. Chauvin, G.L. Reed and R.C. Wilson, 1992. Seasonal occurrence and abundance of lepidopterous pests and associated parasitoids on collards in the Northwestern United States. J. Entomol. Sci., 27: 5-18.
- Bolter, C.J. and J.E. Laing, 1983. Competition between Diadegma insulare (Cresson) (Hymenoptera: Ichneumonidae) and Microplitis plutellae (Muesbeck) (Hymenoptera: Braconidae) for larvae of the diamondback moth, Plutella xylostellae (L.) (Lepidoptera: Plutellidae). Proc. Entmol. Soc. Int., 114: 1-10.
- Geden, C.J., S. Long, D.A. Rutz and J.J. Becnel, 1995. Nosema disease of the parasitoid Muscidifurax raptor (Hymenoptera: Pteromalidae) Prevalence, patterns of transmission, management and impact. Biol. Control, 5: 607-614.
- Idris, A.B. and E. Grafius, 1999. Sources of possible inoculum for horizontal transmission of Nosema bombycis in diamondback moth, Plutella xylostella (L.). Sains Malaysiana, 28: 39-47.
- Orr, D.B., L. C.Lewis and J.J. Obrycki, 1994. Behaviour and survival in corn plants of Ostrinia nubilalis (Lepidoptera: Pyralidae) larvae when infected with Nosemci pyrausta (Microspora: Nosematidae) and Parasitized by Macroscentruss grandii (Hymenoptera: Braconidae). Environ. Entomol., 23: 1020-1024.