Ecological Entomology (2012) 37, 269-282

Christopher D. Harvey and Christine T. Griffin (2012)
Host activity and wasp experience affect parasitoid wasp foraging behaviour and oviposition on nematode-infected larvae of the forestry pest Hylobius abietis
Ecological Entomology 37 (4), 269-282
Abstract: 1. Entomopathogenic nematodes (EPN) are currently being used as introduced biological control agents against the larvae of the native European forestry pest Hylobius abietis L. which develop under the bark of stumps and roots of newly dead conifer trees.
2. The potential for resource competition between gregarious ectoparasitoid Bracon hylobii Ratz and EPN by recording oviposition and related behaviours of B. hylobii females on EPN-infected H. abietis larvae was investigated. Wasps did not parasitise EPN-infected host larvae that were dead when presented, but naÏve and experienced wasps parasitised live EPN-infected hosts. NaÏve wasps parasitised live EPN-infected hosts significantly less frequently than healthy hosts only when the infected larvae were close to death (i.e. died during 24-h trial). Parasitism by experienced wasps was unaffected by host infection.
3. Wasp probing and oviposition were positively associated with the amount of host movement. Preventing H. abietis larvae from chewing on bark significantly reduced parasitism by naÏve, but not experienced wasps.
4. The number of eggs per clutch was not affected by bark chewing or EPN-infection of H. abietis larvae.
5. Naive and experienced B. hylobii parasitised two abnormal hosts (larvae of coleopteran Rhagium bifasciatum Fabricius and lepidopteran Galleria mellonella L.), both of which moved and chewed on bark during trials.
6. It was concluded that B. hylobii can use vibrational cues generated by host movement and feeding to locate hosts at short range and accepts unsuitable (EPN-infected or abnormal) hosts as long as these create such cues. The implications for competition between B. hylobii and EPN and possible ways of minimising it when applying EPN are discussed.
(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): Christine T. Griffin

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Hylobius abietis
Bracon hylobii (parasitoid)	Hylobius abietis