Wheat stem sawfly infested plants benefit from parasitism of the herbivorous larvae. Agricultural and Forest Entomology. 10: 347–354.

BUTELER, M.; D. K. WEAVER; P. R. MILLER

Agricultural and Forest Entomology

The Royal Entomological Society

Lugar: Londres; Año: 2008 vol. 10 p. 347 - 354

Abstract 1 Parasitoids Bracon cephi (Gahan) and Bracon lissogaster Muesebeck and theirherbivorous host the wheat stem sawfly Cephus cinctus Norton, a pest of wheatTriticum aestivum , were investigated for yield in T. aestivum grown in the field.2 Wheat stem sawfly-infested stems had a higher yield potential than uninfestedstems. However, final reproductive output was not significantly different betweenears on infested stems that supported complete larval development comparedwith ears on uninfested stems.3 Stems containing parasitized larvae and stems containing larvae that died beforecompleting their development had a higher mean number of seeds and seedweight, when accounting for number of fertile spikelets of each ear, than eitherinfested with live larvae and uninfested stems.4 The results obtained suggest that larval feeding prevented infested stems from attainingtheir yield potential, and that the negative impact of the pest on wheatyield was reduced when late instar sawfly larvae were parasitized. Even thoughsome feeding occurs before parasitism, this early damage has a comparativelylow impact on yield.5 This is the first study to show a yield benefit and enhanced plant fitness due tothe wheat stem sawfly parasitoids B. cephi and B. lissogaster . This results fromthe maintenance of increased seed number and seed weight in the higher yieldingstems that are preferentially infested by this pest.