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ECONOMIC THRESHOLD FOR PLANT BUGS, LYGUS SPP. (HETEROPTERA: MIRIDAE), IN CANOLA1

Published online by Cambridge University Press:  31 May 2012

I.L. Wise  and
R.J. Lamb
I.L. Wise
Affiliation:
Cereal Research Centre, Agriculture and Agri-Food Canada, 195 Dafoe Road, Winnipeg, Manitoba, Canada, R3T 2M9.
R.J. Lamb
Affiliation:
Cereal Research Centre, Agriculture and Agri-Food Canada, 195 Dafoe Road, Winnipeg, Manitoba, Canada, R3T 2M9.
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Abstract

Plant bugs in the genus Lygus infest canola (Brassica napus L. and Brassica rapa L.) when the crop is producing buds, flowers, and pods. Field studies in cages and open plots show that plant bugs can reduce yield by 20% or more, but have little effect on seed size. A single application of a foliar insecticide when the crop has finished flowering and is beginning to produce pods will prevent most or all of the yield loss. The yield loss of canola that can be prevented by control is 0.007 t/ha per plant bug per 10 sweeps sampled at the end of flowering or the beginning of pod formation. The yield loss that can be prevented by a later application drops to 0.005 t/ha. When precipitation is greater than 100 mm from the onset of bud formation to the end of flowering, the crop may partially compensate for plant bug damage. The economic threshold for control of plant bugs in canola at the end of flowering or at the beginning of pod formation is 15 plant bugs per 10 sweeps, based on crop prices and control costs from 1989 to 1992. If plant bugs are present but control is not warranted when most flowering is complete, plant bug densities should be assessed again 5–7 days later as pods develop, but at this stage the threshold is 20 plant bugs per 10 sweeps. The use of economic thresholds for chemical control of plant bugs will maximize seed yield and minimize unnecessary or ineffectively timed insecticide applications.

Résumé

Les punaises des plantes du genre Lygus infestent les cultures de colza (Brassica napus L. et B. rapa L.) quand les plants produisent des bourgeons, des fleurs et des gousses. Les études en nature dans des cages et dans des champs à découvert ont démontré que les punaises peuvent réduire la récolte de 20% ou plus, mais ont peu d’effet sur la taille des graines. Une seule application d’un insecticide foliaire après la floraison et à l’apparition des gousses peut prévenir les pertes, entièrement ou presque. La perte de récolte qui peut être enrayée par une lutte efficace est de 0,007 t/ha par punaise par 10 coups de filet à la fin de la floraison ou à l’apparition des premières gousses. La perte de récolte qui peut être enrayée par une application plus tardive n’est plus que de 0,005 t/ha. Lorsque les précipitations dépassent 100 mm entre le bourgeonnement et la fin de la floraison, l’importance de la récolte peut compenser partiellement les dommages dûs aux punaises. Le seuil économique qui détermine la pertinence de la lutte contre les punaises dans le colza à la fin de la floraison ou au début de la formation des gousses est de 15 punaises par 10 coups de filet; ce chiffre est basé sur les coûts reliés à la récolte et à la lutte de 1989 à 1992. Si les punaises sont présentes, mais qu’il n’y a pas lieu de les contrôler au moment où la floraison est presque terminée, les densités des punaises devraient être réévaluées 5–7 jours plus tard, pendant le développement des gousses, mais à ce stade le seuil est de 20 punaises par 10 coups de filet. La détermination de seuils économiques dans la lutte chimique contre les punaises des plantes peut maximiser la production et minimiser le nombre d’applications d’insecticide superflues ou mal synchronisées.

[Traduit par la Rédaction]

Type
Articles
Information
The Canadian Entomologist , Volume 130 , Issue 6 , December 1998 , pp. 825 - 836
Copyright
Copyright © Entomological Society of Canada 1998

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References

Butts, R.A., and Lamb, R.J.. 1990. Injury to oilseed rape caused by mirid bugs (Lygus) (Heteroptera: Miridae) and its effect on seed production. Annals of Applied Biology 117: 253–266.CrossRefGoogle Scholar
Butts, R.A., and Lamb, R.J.. 1991 a. Seasonal abundance of three Lygus species (Heteroptera: Miridae) in oilseed rape and alfalfa in Alberta. Journal of Economic Entomology 84: 450–456.CrossRefGoogle Scholar
Butts, R.A., and Lamb, R.J.. 1991 b. Pest status of Lygus bugs (Heteroptera: Miridae) in oilseed Brassica crops. Journal of Economic Entomology 84: 1591–1596.CrossRefGoogle Scholar
Canada Grains Council. 1993. Statistical handbook. Canada Grains Council, Winnipeg, Manitoba.Google Scholar
Gerber, G.H., and Wise, I.L.. 1995. The phenology and number of generations of Lygus lineolaris and L. borealis (Heteroptera: Miridae) in southern Manitoba. The Canadian Entomologist 127: 543–559.CrossRefGoogle Scholar
Harper, F.R., and Berkenkamp, B.. 1975. Revised growth-stage key for Brassica campestris and B. napus. Canadian Journal of Plant Science 55: 657–658.CrossRefGoogle Scholar
Headley, J.C. 1973. Defining the economic threshold. pp. 154–162in Shepard, M. (Ed.), Insect pest management readings. MSS Information, New York.Google Scholar
Kelton, L.A. 1975. The lygus bugs (genus Lygus Hahn) of North America (Heteroptera: Miridae). Memoirs of the Entomological Society of Canada 95.Google Scholar
Lamb, R.J. 1989. Entomology of oilseed Brassica crops. Annual Review of Entomology 34: 211–229.CrossRefGoogle Scholar
Lamb, R.J., and Turnock, W.J.. 1982. Economics of insecticidal control of flea beetles (Coleoptera: Chrysomelidae) attacking rape in Canada. The Canadian Entomologist 114: 827–840.CrossRefGoogle Scholar
Leferink, J.H.M., and Gerber, G.H.. 1997. Development of adult and nymphal populations of Lygus lineolaris (Palisot de Beauvois), L. elisus Van Duzee, and L. borealis (Kelton) (Heteroptera: Miridae) in relation to seeding date and stage of plant development on canola (Brassicaceae) in southern Manitoba. The Canadian Entomologist 129: 777–787.Google Scholar
Nilsson, C. 1987. Yield losses in summer rape caused by pollen beetles (Meligethes spp.). Swedish Journal of Agricultural Research 17: 105–111.Google Scholar
Ogulana, M.O., and Pedigo, L.P.. 1974. Economic injury levels of the potato leafhopper on soybeans in Iowa. Journal of Economic Entomology 67: 29–31.CrossRefGoogle Scholar
SAS Institute Inc. 1990. SAS/STAT user's guide, version 6 edition. SAS Institute Inc., Cary, NC.Google Scholar
Schwartz, M.D., and Foottit, R.G.. 1992. Plant bugs on the prairies: biology, systematics and distribution. Agriculture Canada Research Branch Technical Bulletin 1992–4F.Google Scholar
Sekhon, B.S., and Bakhetia, D.R.C.. 1991. Determination of economic injury level for mustard aphid, Lipaphis erysimi (Kaltenbach), on Brassica napus. pp. 1677–1682in Proceedings of the 8th Groupe Consultatif International de Recherche sur la Colza (GCIRC) International Rapeseed Congress, Vol. 6.Google Scholar
Stone, J.D., and Pedigo, L.P.. 1972. Development and economic injury level of the green cloverworm on soybean in Iowa. Journal of Economic Entomology 65: 197–201.CrossRefGoogle Scholar
Tatchell, G.M. 1983. Compensation in spring-grown oil-seed rape (Brassica napus L.) plants in response to injury to their flower buds and pods. Journal of Agricultural Science (Cambridge) 101: 565–573.CrossRefGoogle Scholar
Tayo, T.O., and Morgan, D.G.. 1979. Factors influencing flower and pod development in oil-seed rape (Brassica napus L.). Journal of Agricultural Science (Cambridge) 92: 363–373.CrossRefGoogle Scholar
Timlick, B.H., Turnock, W.J., and Wise, I.. 1993. Distribution and abundance of Lygus spp. (Heteroptera: Miridae) on alfalfa and canola in Manitoba. The Canadian Entomologist 125: 1033–1041.CrossRefGoogle Scholar
Turnock, W.J., Gerber, G.H., Timlick, B.H., and Lamb, R.J.. 1995. Losses of canola seeds from feeding by Lygus species (Heteroptera: Miridae) in Manitoba. Canadian Journal of Plant Science 75: 731–736.CrossRefGoogle Scholar
Williams, I.H., and Free, J.B.. 1979. Compensation of oil-seed rape (Brassica napus L.) plants after damage to their buds and pods. Journal of Agricultural Science (Cambridge) 92: 53–59.CrossRefGoogle Scholar
Wise, I.L. 1988. Efficacy of foliar treatments in canola for plant bug control. Pesticide Research Report, Agriculture Canada Publication 5258.Google Scholar
Wise, I.L., and Lamb, R.J.. 1998. Sampling plant bugs, Lygus spp. (Heteroptera: Miridae), in canola to make control decisions. The Canadian Entomologist 130: 837–851.CrossRefGoogle Scholar