BioControl (2013) 58, 27-36

Ting-Hui Chen, Min Li, Ji-Hong Wang, Fan Zhang and Yuan-Xi Li (2013)
Vulnerability window for laying male eggs and superparasitism in producing female offspring of Encarsia sophia on Bemisia tabaci B biotype
BioControl 58 (1), 27-36
Abstract: Encarsia sophia (Girault and Dodd) (Hymenoptera: Aphelinidae) is an autoparasitoid that produces male offspring by laying unfertilized eggs in conspecific or heterospecific immature parasitoids at a particular stage of development known as the "vulnerability window". In the work discussed in this paper, the early vulnerability window in which parasitoid wasps lay unfertilized eggs was determined by exposing parasitized Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) nymphs to female E. sophia wasps at 12-h intervals. Because superparasitism affected the results of mass-rearing of parasitoids, especially for autoparasitoids, the effects of superparasitism on development time for female offspring were investigated. Furthermore, the effects of the ratio of wasps to nymphs and the effects of inoculation interval on superparasitism were also determined. The superparasitization behavior was observed in the laboratory. Results indicated that female wasps could produce male offspring in nymphs that had been parasitized five days previously. Wasp offspring were 40.54 and 59.42 % male when exposed nymphs were parasitized 5 and 5.5 days previously, respectively. Superparasitism significantly prolonged the duration of development of female offspring, which increased from 11.5 days for one parasitization to 15.8 days for three parasitizations. Exposure interval also affected superparasitism: when the interval was increased from 0 to 96 h, superparasitism decreased from 70.0 to 23.8 %. With increasing parasitization, the time wasps spent on internal probing plus oviposition increased from 147.4 s for the first parasitization of nymphs to 285.4 s for the third parasitization, whereas there was no significant difference in the time wasps spent on external inspection of nymphs that had been parasitized one, two, or three times. When the ratio of wasps to nymphs was increased from 1:10 to 5:10, superparasitism increased from 0.4 to 46.4 %.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Yuan-Xi Li

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
rearing/culturing/mass production

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Bemisia tabaci biotype MEAM1
Encarsia sophia (parasitoid)	Bemisia tabaci biotype MEAM1