BioControl (2002) 47, 499-511

Zu-Hua Shi, Shu-Sheng Liu and Yuan-Xi Li (2002)
Cotesia plutellae parasitizing Plutella xylostella: Host-age dependent parasitism and its effect on host development and food consumption
BioControl 47 (5), 499-511
Abstract: The braconid Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) is a major solitary, larval endoparasitoid of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). Parasitism of larvae of different host instars and four developmental ages of the 4th instar of the pest was examined. The effects of host instar at initial parasitization on the development, survival, size and fecundity of the parasitoid were determined in the laboratory at 25 °C. The effects of parasitism on host development and food consumption were investigated at 28 °C. Cotesia plutellae could parasitize larvae of all four instars of P. xylostella, but preferred 2nd and 3rd instars. In a choice test, the relative parasitism indices for 2nd, 3rd and 4th instars were 0.37, 0.39 and 0.24, respectively. Parasitism decreased sharply with increasing host age in the 4th instar and approached zero in host larvae that had gone beyond 37% of 4th stadium. The development time and the final adult size of the parasitoid varied with the host instar at initial parasitization. Parasitoids with initial parasitism in the 4th instar hosts had the shortest development time, followed by those in the 3rd instar, and then by those in the 2nd instar. Parasitoids starting parasitism in 2nd instar hosts were smaller in body size than those starting in the 3rd or 4th instar. However, resultant females starting parasitism in 3rd instar hosts had the highest fecundity. Parasitized larvae exhibited longer development time and increased food consumption compared with unparasitized ones. This study presents the first record that a solitary parasitoid regulates host behavior leading to an increase in food consumption by the host.
(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): Shu-Sheng Liu, Yuan-Xi Li, Zu-Hua Shi

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plutella xylostella
Cotesia vestalis (parasitoid)	Plutella xylostella