Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-24T14:59:57.696Z Has data issue: false hasContentIssue false
  • English
  • Français

Unexpectedly high levels of parasitism of wheat stem sawfly larvae in postcutting diapause chambers

Published online by Cambridge University Press:  07 September 2012

Tatyana A. Rand ,
Debra K. Waters  and
Thomas G. Shanower
Tatyana A. Rand*
Affiliation:
United States Department of Agriculture, Agricultural Research Service, Northern Plains Agricultural Research Laboratory, Sidney, MT 59270, United States of America
Debra K. Waters
Affiliation:
United States Department of Agriculture, Agricultural Research Service, Northern Plains Agricultural Research Laboratory, Sidney, MT 59270, United States of America
Thomas G. Shanower
Affiliation:
United States Department of Agriculture, Agricultural Research Service, Center for Grain and Animal Health Research, Manhattan, KS 66502, United States of America
*
1Corresponding author (e-mail: [email protected]).
Get access Rights & Permissions [Opens in a new window]

Abstract

We examined rates of late-season parasitism of larvae of the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), by native species of Bracon F. (Hymenoptera: Braconidae) over 8 years in Montana and North Dakota, United States of America. We found that rates of parasitism of larvae in diapause chambers reached a maximum of 46%, exceeding the previously reported maximum of 2.5% in 75% of sites and years examined. In contrast to previous work, our results demonstrate that C. cinctus larvae are suitable hosts for braconid parasitoids, even after the formation of diapause chambers, and suggest that parasitism rates may be underestimated if stems are sampled prior to harvest.

Résumé

Nous examinons les taux de parasitisme en fin de saison chez les larves du cèphe du blé, Cephus cinctus Norton (Hymnenoptera: Cephidae), par les espèces indigènes de Bracon F. (Hymenoptera: Braconidae) sur une période de 8 ans dans le Montana et le Dakota du Nord, États-Unis. Les taux de parasitisme des larves en diapause dans leur logette atteignent un maximum de 46 %, ce qui dépasse le maximum de 2,5 % enregistré antérieurement dans 75 % des sites et années examinés. Contrairement aux travaux précédents, nos résultats démontrent que les larves de C. cinctus sont des hôtes appropriés pour les parasitoïdes braconidés, même après la formation des logettes de diapause; il se peut que les taux de parasitisme aient été sous-estimés par le prélèvement des tiges avant la période des récoltes.

[Traduit par la Rédaction]

Type
Research Article
Information
The Canadian Entomologist , Volume 143 , Issue 5 , September 2011 , pp. 455 - 459
Copyright
Copyright © Entomological Society of Canada 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Cárcamo, H.A. Herle, C. Beres, S.B.L. McLean, H. McGinn, S. 2011. Solid-stemmed wheat does not affect overwintering mortality of Cephus cinctus. Journal of Insect Science. In press.CrossRefGoogle Scholar
Day, W.H. 1994. Estimating mortality caused by parasites and diseases of insects — comparisons of the dissection and rearing methods. Environmental Entomology, 23: 543–550.CrossRefGoogle Scholar
Holmes, N.D. Nelson, W.A. Peterson, L.K. Farstad, C.W. 1963. Causes of variations in effectiveness of Bracon cephi (Gahan) (Hymenoptera: Braconidae) as a parasite of the wheat stem sawfly. The Canadian Entomologist, 95: 113–126.CrossRefGoogle Scholar
Meers, S.B. 2005. Impact of harvest operation on parasitism of the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae). M.S. thesis, Montana State University, Bozeman, Montana.Google Scholar
Morrill, W.L. 1997. The wheat stem sawfly, Cephus cinctus, Norton (Hymenoptera:Cephidae), and associated parasitoids in the northern Great Plains of North America. Trends in Entomology, 1: 171–174.Google Scholar
Morrill, W.L. Kushnak, G.D. 1999. Planting date influences on the wheat stem sawfly (Hymenoptera: Cephidae) in spring wheat. Journal of Agricultural and Urban Entomology, 16: 123–128.Google Scholar
Morrill, W.L. Kushnak, G.D. Bruckner, P.L. Gabor, J.W. 1994. Wheat stem sawfly (Hymenoptera, Cephidae) damage, rates of parasitism, and overwinter survival in resistant wheat lines. Journal of Economic Entomology, 87: 1373–1376.CrossRefGoogle Scholar
Nelson, W.A. Farstad, C.W. 1953. Biology of Bracon cephi (Gahan) (Hymenoptera: Braconidae), an important native parasite of the wheat stem sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae), in Western Canada. The Canadian Entomologist, 85: 101–107.CrossRefGoogle Scholar
Runyon, J.B. Hurley, R.L. Morrill, W.L. Weaver, D.K. 2001. Distinguishing adults of Bracon cephi and Bracon lissogaster (Hymenoptera: Braconidae), parasitoids of the wheat stem sawfly (Hymenoptera: Cephidae). The Canadian Entomologist, 133: 215–217.CrossRefGoogle Scholar
Runyon, J.B. Morrill, W.L. Weaver, D.K. Miller, P.R. 2002. Parasitism of the wheat stem sawfly (Hymenoptera: Cephidae) by Bracon cephi and B. lissogaster (Hymenoptera: Braconidae) in wheat fields bordering tilled and untilled fallow in Montana. Journal of Economic Entomology, 95: 1130–1134.CrossRefGoogle Scholar
SAS Institute Inc 1989–2011. JMP version 8.0.1 [computer program]. SAS Institute Inc., Cary, North Carolina.Google Scholar
Shanower, T.G. Waters, D.K. 2006. A survey of five stem-feeding insect pests of wheat in the northern Great Plains. Journal of Entomological Science, 41: 40–48.CrossRefGoogle Scholar
Somsen, H.W. Luginbill, P. 1956. Bracon lissogaster Mues.: a parasite of the wheat stem sawfly. United States Department of Agriculture Technical Bulletin No. 1153.Google Scholar
Weaver, D.K. Sing, S.E. Runyon, J.B. Morrill, W.L. 2004. Potential impact of cultural practices on wheat stem sawfly (Hymenoptera: Cephidae) and associated parasitoids. Journal of Agricultural and Urban Entomology, 21: 271–287 .Google Scholar