Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-09T09:47:19.840Z Has data issue: false hasContentIssue false
  • English
  • Français

An Important Parasite of the Greenhouse White-fly (Trialeurodes vaporariorum, Westwood)

Published online by Cambridge University Press:  10 July 2009

Edward R. Speyer
Edward R. Speyer
Affiliation:
Experimental and Research Station, Cheshunt, Herts.
Get access Rights & Permissions [Opens in a new window]

Extract

1.—Encarsia formosa, Gahan, is a Chalcid wasp that parasitises the white-fly, Trialeurodes vaporariorum, Westw., a single female ovipositing in 50 or more young pupae of the host. The larvae of the parasite, on hatching from the egg, destroys the white-fly pupa, the skin of which becomes black in colour, thus distinguishing the parasitised pupa from the normal white scales and pupa of the white-fly.

2.—The parasite is parthenogenetic, males, probably impotent, only appearing when temperatures are low.

3.—The life-history of the parasite occupies at least 28 days, and adults may remain in the scales for some time before cutting their way out by a circular hole in the roof of the scale. The adult is capable of travelling over large areas in glasshouses.

4.—Low temperatures militate seriously against the increase of the parasite, which is probably a tropical insect and has possibly been imported into this country from India.

5.—Fumigation with hydrocyanic acid gas, as practised commercially for the control of white-fly, does not affect the parasites.

6.—The parasite is best distributed by detaching the black pupae of white-fly from the foliage, though 20 per cent, may be injured in this way. An almost complete emergence is obtained by cutting branches from plants and pinning them to the plants in houses where distribution is desired, but this involves risk of infecting the houses with various pests and diseases.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 17 , Issue 3 , March 1927 , pp. 301 - 308
Copyright
Copyright © Cambridge University Press 1927

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

1.Gahan, A. B.Some new Parasitic Hymenoptera with Notes on several described Forms.—Proc. U.S. Nat. Mus. lxv, art. 4, no. 2517, pp. 1–23. Washington, U.S.A., 1924.CrossRefGoogle Scholar
2.Gardeners', Chronicle. Answers to Correspondents. White-fly Parasite. 7th 08 1926, p. 120.Google Scholar
3.Garman, H. & Jewett, H. H. The White-flies of Hot-houses.—Kentucky Agric. Exp. St. Bull. 241, pp. 76–111. Lexington, Kentucky, U.S.A., 04 1922.Google Scholar
4.Green, E. E.Note on the Immunity of Chalcid Parasites to Hydrocyanic Acid Gas.—Ann. App. Biol., iv, 09 1917, p. 90.CrossRefGoogle Scholar
5.Horne, A. S.The occurrence of Fungi on Aleurodes vaporariorum in Great Britain.—Ann. App. Biol., ii, 05 1915, pp. 109–111.CrossRefGoogle Scholar
6.Lefroy, H. M. “ Gardeners' Chronicle,” lviii, 4th 09 1915, p. 154.Google Scholar
7.Lloyd, Ll.The Control of the Greenhouse White-fly.—Ann. App. Biol., ix, 04 1922, pp. 1–32.CrossRefGoogle Scholar
8.McDaniel, E. I. Greenhouse Insects.—Michigan Agric. Coll. Exp. St., Special Bull. 134. East Lancing, Michigan, U.S.A., 06 1924.Google Scholar