Agricultural and Forest Entomology (2008) 10, 347-354

Micaela Buteler, David K. Weaver and Perry R. Miller (2008)
Wheat stem sawfly-infested plants benefit from parasitism of the herbivorous larvae
Agricultural and Forest Entomology 10 (4), 347-354
Abstract: 1 Parasitoids Bracon cephi (Gahan) and Bracon lissogaster Muesebeck and their herbivorous host the wheat stem sawfly Cephus cinctus Norton, a pest of wheat Triticum aestivum, were investigated for yield in T. aestivum grown in the field.
2 Wheat stem sawfly-infested stems had a higher yield potential than uninfested stems. However, final reproductive output was not significantly different between ears on infested stems that supported complete larval development compared with ears on uninfested stems.
3 Stems containing parasitized larvae and stems containing larvae that died before completing their development had a higher mean number of seeds and seed weight, when accounting for number of fertile spikelets of each ear, than either infested with live larvae and uninfested stems.
4 The results obtained suggest that larval feeding prevented infested stems from attaining their yield potential, and that the negative impact of the pest on wheat yield was reduced when late instar sawfly larvae were parasitized. Even though some feeding occurs before parasitism, this early damage has a comparatively low impact on yield.
5 This is the first study to show a yield benefit and enhanced plant fitness due to the wheat stem sawfly parasitoids B. cephi and B. lissogaster. This results from the maintenance of increased seed number and seed weight in the higher yielding stems that are preferentially infested by this pest.
(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): David K. Weaver

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
damage/losses/economics
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.
	Cephus cinctus
Bracon cephi (parasitoid)	Cephus cinctus	Wheat (Triticum)
Bracon lissogaster (parasitoid)	Cephus cinctus	Wheat (Triticum)