Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-23T22:10:01.125Z Has data issue: false hasContentIssue false

AN APPRAISAL OF METHODS OF SAMPLING APPLE TREES AND RESULTS OF SOME TESTS USING A SAMPLING UNIT COMMON TO INSECT PREDATORS AND THEIR PREY1

Published online by Cambridge University Press:  31 May 2012

F. T. Lord
Affiliation:
Researoh Station, Canada Department of Agriculture, Kentville, Nova Scotia

Abstract

Current methods of sampling predator and prey populations on apple trees use two different indexes to measure the comparative abundance of each. Techniques are sought that relate the proportions of one to the other in the sampling universe (the orchard) in a quantitative manner. The most important criterion is that the sampling unit be one common to both predator and prey species and encompass representative portions of the habitat of each. The whole tree meets this criterion but it is too cumbersome to sample in toto. The large limb was, therefore, appraised for feasibility as a basic sampling unit common to many species. All clusters were counted and the predators and prey expressed as numbers per 100 clusters. The whole limb was examined for insect predators but only a representative portion of it was used in estimating mite populations. The test prey species was the European red mite, Panonychus ulmi (Koch), and the predators a small number of active insect species, mostly Diaphnocoris pellucida (Uhler) and Anthocoris musculus (Say). It was found that the numbers of mites on randomly chosen clusters from a limb were representative of the total population of mites on a limb but the associated variation was high. Samples of relatively uniform (standard) clusters of good vigour overestimated the mite population. Some other causes of variation were also examined and are discussed. A 2-year orchard test showed it was feasible to estimate the abundance of both mites and predators on a common basis and thus obtain a measure of the ratio of mites to predators in the sampling universe.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1968

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

Collyer, Elsie. 1951. A method for the estimation of insect populations on fruit trees. Rep. E. Malling Res. Stn for 1950. pp. 148151.Google Scholar
Lord, F. T. 1965. Sampling predator populations on apple trees in Nova Scotia. Can. Ent. 97: 287298.CrossRefGoogle Scholar
McMurtrie, J. A., and Johnson, H. G.. 1966. An ecological study of the spider mite Oligonychus punicae (Hirst) and its natural enemies. Hilgardia 37: 363402.CrossRefGoogle Scholar
Morris, R. F. 1955. The development of sampling techniques for forest insect defoliators, with particular reference to the spruce budworm. Can. J. Zool. 33: 225294.CrossRefGoogle Scholar
Muir, R. C. 1958. On the application of the capture-recapture method to an orchard papulation of Blepharidopterus angulatus (Fall.) (Heteroptera: hbidae) and its prey, Panonychus ulmi (Koch) (Acarina: Tetranychidae). J. appl. Ecol. 2: 4357.CrossRefGoogle Scholar
Muir, R. C. 1960. A note on the knock-down method for estimating numbers of insect predators on fruit trees. Ann. Rep. E. Malling Res. Stn for 1959. pp. 109111.Google Scholar
Muir, R. C. 1965. The effect of sprays on the, fauna of apple trees. II. Some aspects of the interaction between populations of Blepharidopterus angulatus (Fall.) (Heteroptera: Miridae) and its prey, Panonychus ulmi (Koch) (Acarina: Tetranychidae). J. appl. Ecol. 2: 4357.CrossRefGoogle Scholar
Putman, W. L., and Herne, D. H. C.. 1966. The role of predators and orher biotic agents in regulating the population density of phytophagous mites in Ontario peach orchards. Can, Ent. 98: 808820.CrossRefGoogle Scholar