Hostname: page-component-848d4c4894-wzw2p Total loading time: 0 Render date: 2024-06-08T11:57:37.660Z Has data issue: false hasContentIssue false
  • English
  • Français

ECONOMIC IMPORTANCE OF INSECTS ON REGROWTHS OF ESTABLISHED ALFALFA FIELDS IN ONTARIO

Published online by Cambridge University Press:  31 May 2012

S. M. Smith  and
C. R. Ellis
S. M. Smith
Affiliation:
Department of Environmental Biology, University of Guelph, Guelph, Ontario N1G 2W1
C. R. Ellis
Affiliation:
Department of Environmental Biology, University of Guelph, Guelph, Ontario N1G 2W1
Get access Rights & Permissions [Opens in a new window]

Abstract

Damage caused by Empoasca fabae (Harris) and Philaenus spumarius (L.), caged on second and third alfalfa harvests, was additive. Numbers of E. fabae were linearly correlated negatively with plant height, leaf area, and percentage protein, and positively with percentage chlorosis. Perceptible stunting and yellowing occurred with mean infestations per stem of 0.09 E. fabae and 0.6 P. spumarius nymphs. P. spumarius adults reduced plant height only at infestations of 0.3/stem, while 0.6 nymph/stem also reduced dry weight. E. fabae reduced protein at 0.11/stem and dry weight and leaf area at higher populations of 0.17/stem. None of these parameters was affected on subsequent regrowths. Lygus lineolaris (P. de B.) could not be maintained on pre-bloom alfalfa and was not considered a pest. Adelphocoris lineolatus (Goeze) reduced protein at levels of 0.01 bug/stem and dry weight at 0.06 bug/stem but results were confounded by high mortality. Field populations of all these species were reduced by the second cutting but redeveloped on the regrowth. Although applications of dimethoate (200 g AI/ha) and dimethoate (200 g AI/ha) plus endosulphan (280 g AI/ha) were effective in reducing populations of E. fabae, Acyrthosiphon pisum (Harris), A. lineolatus, and Hypera postica (Gyllenhal), insecticides were cost-effective on only one field. This field had 1.9 E. fabae/sweep and a 3% loss in protein resulted. Plant height, density, dry weight, protein content, and overwintering survival were not significantly affected at harvest in other fields. With the exception of E. fabae, the sum of the maximum field populations, each expressed as a fraction of its threshold, did not reach 50% of an economic threshold.

Résumé

Les dommages dus à Empoasca fabae (Harris), et Philaenus spumarius (L.) maintenus en cage sur de la luzerne de deuxième et de troisième coupe, étaient additifs. Les nombres de E. fabae étaient linéairement corrélés (1) avec la hauteur des plants, la surface foliaire et le pourcentage de protéine, de façon négative, et (2) avec le pourcentage de chlorose, de façon positive. Du fannage visible et du jaunissement se sont manifestés à une densité larvaire moyenne par tige de 0.09 pour E. fabae ou de 0.6 pour P. spumarius. Les adultes de P. spumarius n'ont réduit la hauteur des plants qu'à un niveau d'infestation de 0.3/tige, alors que 0.6 larve/tige ont également réduit le poids sec. E. fabae a réduit les protéines à une densité de 0.11/tige, et le poids sec ainsi que la surface foliaire à une densité de 0.17/tige. Aucun de ces paramètres ne fut affecté lors des repousses subséquentes. Lygus lineolaris (P. de B.) n'a pu être maintenue sur la luzerne pré-floraison et n'a pas été considérée comme nuisible. Adelphocoris lineolatus (Goeze), a réduit les protéines à la densité de 0.01 individus/tige et le poids sec à 0.06/tige, cependant les résultats étaient affectés par la mortalité élevée. Les populations de terrain de ces espèces ont diminué à la deuxième coupe mais ont remonté avec la repousse. Quoique des applications de dimethoate (200 g IA/ha), ou de dimethoate (200 g IA/ha) avec endosulphan (280 g IA/ha) se sont avérées efficaces pour réduire les populations de E. fabae, Acyrthosiphon pisum (Harris), A. lineolatus, et Hypera postica (Gyllenhal), les insecticides ont été rentables dans un champ seulement. Ce champ avait 1.9 E. fabae/coup de filet, causant 3% de perte en protéine. La hauteur des plants, la densité, le poids sec, la teneur en protéine et la survie hivernale n'ont pas été affectés significativement à la récolte dans les autres champs. A l'exception de E. fabae, la somme des maxima des populations de terrain, chacune exprimée en rapport avec son seuil, n'a pas atteint 50% du seuil économique.

Type
Articles
Information
The Canadian Entomologist , Volume 115 , Issue 7 , July 1983 , pp. 859 - 868
Copyright
Copyright © Entomological Society of Canada 1983

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

Anonymous. 1978. Pest management strategies for leafhoppers, spittlebugs, and aphids on alfalfa. Cooperative Regional Project Outline. 28 pp.Google Scholar
Blair, G. E. 1975. The potato leafhopper on alfalfa. Ohio State University Cooperative Extension Service, Field and Forage Insect Series 1. 2 pp.Google Scholar
Burkhart, C. C. 1959. What methods do you use in estimations of the extent of losses caused by forage crop insects? Proc. N. Cent. ent. Soc. Am. 14: 75–76.Google Scholar
Curtis, C. E. and McCoy, C. E.. 1964. Some host-plant preferences shown by Lygus lineolaris (Hemiptera: Miridae) in the laboratory. Ann. ent. Soc. Am. 57: 511–513.CrossRefGoogle Scholar
Davey, K. G. and Manson, G. F.. 1958. Chemical control of insects attacking alfalfa in southwestern Ontario. Can. J. Pl. Sci. 38: 34–38.CrossRefGoogle Scholar
Dondale, C. D. 1972. Effects of carbofuran on arthropod populations and crop yield in hayfields. Can. Ent. 104: 1433–1437.CrossRefGoogle Scholar
Hower, A. A. Jr., 1979. Relationship of potato leafhopper density to alfalfa quality. Proc. 14th Northeastern Reg. Alfalfa Insects Conf., Newark, N.J. Oct. 5–9.Google Scholar
Kindler, S. D., Kehr, W. R., Ogeen, R. L., and Schalf, J. M.. 1973. Effect of potato leafhopper injury on yield and quality of resistant and susceptible alfalfa clones. J. econ. Ent. 66: 1298–1302.CrossRefGoogle Scholar
Newton, R. C., Hill, R. R. Jr., and Elgin, J. H. Jr., 1970. Differential injury to alfalfa by male and female potato leafhoppers. J. econ. Ent. 63: 1077–1079.CrossRefGoogle Scholar
Ogundala, M. and Pedigo, L. P.. 1974. Economic injury levels of potato leafhopper on soybeans in Iowa. J. econ. Ent. 67: 29–32.Google Scholar
O'Neal, L. H. and Peterson, A. G.. 1971. A population study of Lygus lineolaris on alfalfa grown for forage and an evaluation of its damage. Proc. N. cent. Brch ent. Soc. Am. 25: 84–85.Google Scholar
Parman, V. R. and Wilson, M. C.. 1982. Alfalfa crop responses to feeding by the meadow spittlebug (Homoptera: Cercopidae). J. econ. Ent. 75: 481–486.CrossRefGoogle Scholar
Simonet, D. E. 1978. Population studies on the potato leafhopper Empoasca fabae (Harris), on alfalfa, Medicago sativa L. Ph.D. Thesis, VPI and SCI, Blacksburg, VA.103 pp.Google Scholar
Stern, V. M. 1973. Economic thresholds. A. Rev. Ent. 18: 259–290.CrossRefGoogle Scholar
Wheeler, A. G. 1974. Studies on the arthropod fauna of alfalfa. VI. Plant bugs (Miridae). Can. Ent. 106: 1267–1275.CrossRefGoogle Scholar
Wilson, M. C. 1973. Damage from alfalfa weevil infestations. Proc. N. cent. Brch ent. Soc. Am. 28: 28–31.Google Scholar
Wilson, M. C., Stewart, J. K., and Vail, H. D.. 1979. Full seasonal impact of the alfalfa weevil, meadow spittlebug, and potato leafhopper in an alfalfa field. J. econ. Ent. 72: 830–834.CrossRefGoogle Scholar