Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-22T20:02:12.669Z Has data issue: false hasContentIssue false

Inter-relationships of the Parasites of the Frit-fly, Oscinella frit (L.), in eastern North America

Published online by Cambridge University Press:  10 July 2009

F. J. Simmonds
Affiliation:
Commonwealth Institute of Biological Control.

Extract

Studies are reported on the extent and importance of competition amongst larval and pupal parasites of Oscinella frit.

In Ontario, 30–40 per cent. of frit larvae are parasitised by Hexacola in July–August and superparasitism is thus likely. Subsequent attack by Polyscelis may occur, but probably unsuccessfully.

Competition between the larval parasites and the pupal ecto-parasites Callitula and Spalangia is generally slight, because the former species is not abundant and the latter tends to select only healthy hosts.

Experiments are described to test the inter-relations of the three pupal parasites by exposing puparia of Drosophila melanogaster to two species simultaneously and in sequence.

When Callitula and Spalangia are allowed to oviposit simultaneously, the former is more successful when hosts are relatively few, but otherwise the two species are equally successful. When Callitula parasitises puparia recently exposed to Spalangia, equal numbers of the two parasites emerge, but in the reverse experiment Callitula is superior. Callitula is able to parasitise successfully a proportion of puparia already containing Spalangia whatever the age of the latter; mature Spalangia thus attacked are mostly killed.

Similar comparisons of Callitula and Spalangia with the endoparasitic Loxotropa show that Loxotropa is inferior to both the others, but that all three show marked avoidance of multiple parasitism.

In general, there is little interference between the various species in the parasite complex associated with the frit-fly.

The parasite complex associated with the frit-fly appears to be one that is very well balanced, there being little interference between the various species involved. Moreover, when, for any reason, one species does not attain its accustomed degree of parasitism, this is offset by an increase in the numbers of one or more of the other species.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1953

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

Fiske, W. F. (1910). Superparasitism: an important factor in the natural control of insects.—J. econ. Ent., 3, pp. 8897.CrossRefGoogle Scholar
Howard, L. O. (1897). A study in insect parasitism: a consideration of the parasites of the White-marked Tussock Moth, with an account of their habits and interrelations, and with descriptions of new species.—Tech. Bull. U.S. Dep. Agric., no. 5, 57 pp.Google Scholar
Lloyd, D. C. (1938). A study of some factors governing the choice of hosts and distribution of progeny by the Chalcid Ooencyrtus kuvanae Howard.—Phil. Trans., (B) 229, pp. 275322.Google Scholar
Lloyd, D. C. (1940). Host selection by Hymenopterous parasites of the moth Plutella maculipennis Curtis.—Proc. roy. Soc., (B) 128, pp. 451484.Google Scholar
Lloyd, D. C. (1942). Further experiments on host selection by Hymenopterous parasites of the moth, Plutella maculipennis Curtis.—Rev. Canad. Biol., 1, pp. 633645.Google Scholar
Pemberton, C. E. & Willard, H. F. (1918). Interrelations of fruit-fly parasites in Hawaii.—J. agric. Res., 12, pp. 285295.Google Scholar
Salt, G. (1932). Superparasitism by Collyria calcitrator, Grav.—Bull. ent. Res., 23, pp. 211216.CrossRefGoogle Scholar
Salt, G. (1934). Experimental studies in insect parasitism. I–II.—Proc. roy. Soc., (B) 114, pp. 450476.Google Scholar
Salt, G. (1935). Experimental studies in insect parasitism. III.—Proc. roy. Soc., (B) 117, pp. 413435.Google Scholar
Salt, G. (1936). Experimental studies in insect parasitism. IV.—J. exp. Biol., 13, pp. 363375.CrossRefGoogle Scholar
Salt, G. (1937). Experimental studies in insect parasitism. V.—Proc. roy. Soc., (B) 122, pp. 5775.Google Scholar
Simmonds, F. J. (1943). The occurrence of superparasitism in Nemteritis canescens. Grav.—Rev. Canad. Biol., 2, pp. 1558.Google Scholar
Simmonds, F. J. (1952). Parasites of the frit-fly, Oscinella frit (L.), in eastern North America.—Bull. ent. Res., 43, pp. 503542.CrossRefGoogle Scholar
Smith, H. S. (1929). Multiple parasitism: its relation to the biological control of insect pests.—Bull. ent. Res., 20, pp. 141149.CrossRefGoogle Scholar
Thompson, W. R. (1923). A criticism of the “sequence” theory of parasitic control.—Ann. ent. Soc. Amer., 16, pp. 115128.CrossRefGoogle Scholar
Thompson, W. R. (1939). Biological control and the theories of the interactions of populations.–Parasitology, 31, pp. 299388.CrossRefGoogle Scholar
Ullyett, G. C. (1936). Host selection by Microplectron fuscipennis, Zett. (Chalcididae, Hymenoptera).—Proc. roy. Soc., (B) 120, pp. 253291.Google Scholar