Multiparasitism of stink bug eggs: competitive interactions between Ooencyrtus pityocampae and Trissolcus agriope
Females of Trissolcus agriope (Platygastridae) avoid host (Brachynema signatum) eggs parasitized by conspecifics or Ooencyrtus pityocampae (Encyrtidae), but females of the latter species will superparasitize and multiparasitize, although they mostly attack unparasitized eggs. Females of T. agriope were more efficient in the laboratory and parasitized more hosts in 24 and 48 h. In multiparasitized hosts, O. pityocampae was a superior larval competitor and could complete also development as a facultative hyperparasitoid. When females of both species foraged together, T. agriope parasitized significantly more than O. pityocampae, about 50 % in both cases, although O. pityocampae almost doubled its parasitism rate as the exposure period was lengthened from 24 to 48 h. When O. pityocampae followed T. agriope in sequential foraging bouts, the former species successfully parasitized more hosts than the latter. The advisability of co-releases of both species to improve biological control of first generation B. signatum in Iranian pistachio orchards is discussed.
KeywordsBiological control Brachynema signatum Interspecific competition Intraguild interactions Encyrtidae Scelionidae
The authors gratefully acknowledge the Pistachio Research Institute of Iran, Rafsanjan, Iran, for the provision of services and facilities essential to completion of this work.
- Correa-Ferreira SB (1986) Natural occurrence of the egg parasitoid complex of stink bugs on soybean in Parana, Brazil. An Soc Entomol Bras 5:189–199Google Scholar
- Grenier S (1994) Rearing of Trichogramma and other egg parasitoids on artifical diets, pp. 73–92. In: Wajnberg E, Hassan SA (eds) Biological control with egg parasitoids. CAB International, Wallingford, UK, p 286Google Scholar
- Hashemi Rad H (1999) Identification of egg parasitoid wasps of the green stink bugs (Brachynema spp. and Acrosternum spp.) and study of biology of Trissolcus agriope (Hym.: Scelionidae) in Rafsanjan. M.Sc. thesis, Shahid Chamran University of Ahvaz, Ahvaz, IranGoogle Scholar
- Hashemi Rad H (2009) Study on egg parasitoids (T. agriope and Psix sp.) using eggs of four bug species in laboratory conditions. V International Symposium on Pistachios and Almonds 912, Sanliurfa, TurkeyGoogle Scholar
- Hoffmann MP, Davidson NA, Wilson LT, Ehler LE, Jones WA, Zalom FG (1991) Imported wasp helps control southern green stink bug. Calif Agric 45:20–22Google Scholar
- Mehrnejad M (2001) The current status of pistachio pests in Iran. Cahiers Options Méditerranéennes 56:315–322Google Scholar
- Michailides T, Morgan DP, Doster MA (1994) Diseases of pistachio in California and their significance. Acta Hortic 419:337–344Google Scholar
- Shepard BM, Elsey KD, Muckenfuss AE, Justo HD Jr (1994) Parasitism and predation on egg masses of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), in tomato, okra, cowpea, soybean, and wild radish. J Agric Entomol 11:375–381Google Scholar
- Tiberi R, Niccoli A, Roversi PF, Sacchetti P (1991) Laboratory rearing of Ooencyrtus pityocampae (Mercet) on eggs of Nezara viridula (L.) and other pentatomids. Redia 74:467–469Google Scholar
- Tiberi R, Niccoli A, Sacchetti P (1994) Thaumetopoea pityocampa egg parasitism: modifications resulting from Ooencyrtus pityocampae augmentation. Atti XVII Congresso Nazionale Italiano di Entomologia, Udine, Italy, pp 13–18Google Scholar