Sex Allocation and the Evolutionary Transition between Solitary and Gregarious Parasitoid Development

1998 ◽  
Vol 152 (5) ◽  
pp. 757-761 ◽  
Author(s):  
Paul J. Ode ◽  
Jay A. Rosenheim
2009 ◽  
Vol 5 (2) ◽  
pp. 197-199 ◽  
Author(s):  
Shingo Tanaka

Parasitoid wasps lay female eggs or a high proportion of female eggs in favourable host insects because female wasps require many more resources during their development. Many studies have tested the effects of host physiological status on the sex allocation of parasitoids, but few have attempted to test the effects of host behavioural traits. Cotesia glomerata is a gregarious parasitoid wasp that lays eggs in caterpillars of pierid butterflies. The brood sex ratio in C. glomerata females that attacked aggressive host caterpillars was compared with that in females that attacked less aggressive hosts. The male ratio was higher when C. glomerata attacked aggressive Pieris brassicae caterpillars than when it attacked less aggressive Pieris rapae crucivora caterpillars. However, when C. glomerata females were induced to oviposit in anaesthetized P. brassicae caterpillars, the male ratio in their offspring was significantly lower than when they attacked unanaesthetized caterpillars. C. glomerata was attacked by aggressive host caterpillars during oviposition bouts. It is likely that this aggressive host behaviour disturbed the fertilization process in ovipositing C. glomerata females. These results suggest that a behavioural defence by host caterpillars affects sex allocation in the parasitoid wasp C. glomerata .


2013 ◽  
Vol 20 (3) ◽  
pp. 386-390
Author(s):  
Ge Xingyue ◽  
Zhu Biru ◽  
Liao Wanjin
Keyword(s):  

Author(s):  
Fazila Yousuf ◽  
Peter A. Follett ◽  
Conrad P. D. T. Gillett ◽  
David Honsberger ◽  
Lourdes Chamorro ◽  
...  

AbstractPhymastichus coffea LaSalle (Hymenoptera:Eulophidae) is an adult endoparasitoid of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera:Curculionidae:Scolytinae), which has been introduced in many coffee producing countries as a biological control agent. To determine the effectiveness of P. coffea against H. hampei and environmental safety for release in Hawaii, we investigated the host selection and parasitism response of adult females to 43 different species of Coleoptera, including 23 Scolytinae (six Hypothenemus species and 17 others), and four additional Curculionidae. Non-target testing included Hawaiian endemic, exotic and beneficial coleopteran species. Using a no-choice laboratory bioassay, we demonstrated that P. coffea was only able to parasitize the target host H. hampei and four other adventive species of Hypothenemus: H. obscurus, H. seriatus, H. birmanus and H. crudiae. Hypothenemus hampei had the highest parasitism rate and shortest parasitoid development time of the five parasitized Hypothenemus spp. Parasitism and parasitoid emergence decreased with decreasing phylogenetic relatedness of the Hypothenemus spp. to H. hampei, and the most distantly related species, H. eruditus, was not parasitized. These results suggest that the risk of harmful non-target impacts is low because there are no native species of Hypothenemus in Hawaii, and P. coffea could be safely introduced for classical biological control of H. hampei in Hawaii.


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