Journal of Economic Entomology (2012) 105, 1524-1531

Bishwo P. Mainali, S. Kim and U. T. Lim (2012)
Interactive influence of temperature and relative humidity on egg parasitoids of Riptortus pedestris (Hemiptera: Alydidae)
Journal of Economic Entomology 105 (5), 1524-1531
Abstract: Previous studies reported that of the two egg parasitoids of Riptortus pedestris (F.) (Hemiptera: Alydidae) found in Korea, Gryon japonicum (Ashmead) (Hymenoptera: Scelionidae) appears in soybean fields much earlier than Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae). To explain this phenomenon,we evaluated the interactive influence of temperature and relative humidity (RH) on the biological attributes of these parasitoids, including adult parasitoid longevity and survival. Temperature had significant effects on all the biological attributes examined for both parasitoids, while RH only affected rates of parasitism and adult emergence. Interaction between temperature and species, but not RH and species was found to affect significantly on parasitism. G. japonicum showed higher relative increment in parasitism than O. nezarae at temperatures higher than 25°C. No significant differences in progeny sex ratio were detected for either species at any temperature x humidity combination. RH had no effect on the developmental time of O. nezarae but on the developmental time of G. japonicum, which was longer at low RH. Although the biological attributes of adult parasitoids of both species showed a wide range of adaptability, but it did not explain the patterns of occurrence of these species in the field. However, G. japonicum showed greater longevity than O. nezarae at all combinations of temperature and RH and this may partially explain the seasonal pattern of occurrence of adult parasitoids in the field previously observed.
(The abstract has been supplied by the author or ISPI and is excluded from the Creative Commons licence.)
Link to article at publishers website
Database assignments for author(s): Bishwo Prasad Mainali, Un Taek Lim

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Riptortus pedestris	Soybean (Glycine max)
Hadronotus japonicus (parasitoid)	Riptortus pedestris	Soybean (Glycine max)
Ooencyrtus nezarae (parasitoid)	Riptortus pedestris	Soybean (Glycine max)