FURTHER OBSERVATIONS ON THE CHANGES TAKING PLACE IN THE CORN BORER POPULATION IN WESTERN ONTARIO

1947 ◽  
Vol 79 (5) ◽  
pp. 81-83 ◽  
Author(s):  
Geo. Wishart
Keyword(s):  
European Corn Borer ◽  
Corn Borer ◽  
Important Relationship ◽  
Two Generations ◽  
History Of ◽  
Consistent Increase ◽  
Pyrausta Nubilalis ◽  
Seasonal History

The seasonal history of an insect has an important relationship to the success or failure of any efforts to usr parasites in its control. In the work on parasites of thr European corn borer, Pyrausta nubilalis Hubn., over a period of years, the writer has had an opportunity to observe the changes which have taken place in the seasonal history of this insect in Western Ontario. It was shown by the writer (Wislwt, 1942, 1944) that there was a gradual and rather consistent increase in the proportion of the population which had two generations instead of one. The present paper presents further data pertinent to this subject.

Some Factors Influencing the Occurrence and Size of the Midsummer Flight of the European Corn Borer, Ostrinia nubilalis (Hbn.) (Lepidoptera: Pyralidae), in Southwestern Ontario

1959 ◽  
Vol 91 (12) ◽  
pp. 798-806 ◽  
Author(s):  
J. A. Mutchmor
Keyword(s):  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Economic Value ◽  
Light Trap ◽  
The United States ◽  
Corn Borer ◽  
Collection Data ◽  
History Of ◽  
Lepidoptera Pyralidae ◽  
Seasonal History

In southwestern Ontario the European corn borer, Ostrinia nubilalis (Hbn.), produces two flights annually. The first flight, beginning in June, consists of moths from larvae that have overwintered. The midsummer, or second, flight begins late in July or early in August, and its moths are the progeny of the first flight. Until about 20 years ago the borer produced only one annual flight and was thought to be univoltine. The change in the seasonal history of the borer in Ontario was described by Wressell (1953) and Miller (1956). The literature describing similar changes in parts of the United States has been reviewed by Lees (1955) and Everett et al. (1958). Wressell (1953) summarized light trap collection data of moth flights in the Chatham, Ontario, area for the years 1932 to 1951. The summary includes the percentage of the moths that were from the midsummer flight, and it is evident that the size of this flight varies greatly from year to year. Aside from its intrinsic interest, it would be of some economic value to know what governs the size of the midsummer flight. This is a report of studies undertaken to examine the case, and to relate the findings to the larger problem of why the borer now produces a second flight where formerly it produced only one.

Scambus pterophori (Ashm.) (Hymenoptera: Ichneumonidae), a New Parasite of the European Corn Borer, Pyrausta nubilalis (Hbn.) (Lepidoptera: Pyralidae), in Canada

1959 ◽  
Vol 91 (2) ◽  
pp. 128-128
Author(s):  
Marcel Hudon
Keyword(s):  
European Corn Borer ◽  
Second Generation ◽  
Petri Dish ◽  
First Record ◽  
Corn Borer ◽  
Lepidoptera Pyralidae ◽  
Pyrausta Nubilalis ◽  
Experimental Plots

In late August, 1957, a parasitized second-generation pupa of Pyrausta nubilalis (Hbn.) was observed in silks of an immature corn ear in the experimental plots at St. Jean. The pupa was incubated at 75°F. in a petri dish, and two weeks later an ichneumonid parasite emerged and was identified by Mr. G. S. Walley, Entomology Division, Ottawa, as Scambus pterophori (Ashm.). Asecond generation of P. nubilalis is very unusual in the St. Jean area. This is apparently the first record of this ichneumonid as a parasite of P. nubilalis in Canada.

On a new Species of Ephialtes (Hym., Ichneumonidae) parasitising the Codling Moth

1942 ◽  
Vol 33 (3) ◽  
pp. 171-174 ◽  
Author(s):  
J. F. Perkins
Keyword(s):  
New Species ◽  
European Corn Borer ◽  
Cydia Pomonella ◽  
British Museum ◽  
Codling Moth ◽  
Species Group ◽  
Type Specimens ◽  
Corn Borer ◽  
Pyrausta Nubilalis ◽  
A New Species

In 1939 I dealt with two species of Ephialtes which parasitise the codling moth, Cydia pomonella, L., namely E. caudatus, Ratz., and E. crassiseta, Thoms., and showed how they differed from E. punctulatus, Ratz. (=extensor, Tasch.) with which species they had formerly been confused. During 1940, F. J. Simmonds, of the Imperial Institute of Entomology, sent to the British Museum a series of a species of Ephialtes bred from this same host in the south of France. This is a new species, and it was previously known to me only from a single female which had been bought by D. S. Wilkinson from O. Schmiedeknecht, who had incorrectly named it Pimpla roborator, F. In fact, this new species does not belong to the same species group as Ephialtes (Exeristes) roborator, F., Grav. (=Pimpla roborator, F., Schmied.), which is a well-known parasite of the European Corn Borer (Pyrausta nubilalis, Hb.) and also parasitises many other hosts.As there has been considerable confusion in the synonymy and interpretation of E. roborator, F., it seems advisable to give notes on the relevant type specimens seen by me. It has been impossible to find the type of Ichneumon roborator, F. Gravenhorst's interpretation of this very variable species has therefore been taken. The description given by Schmiedeknecht in his Opuscula Ichneumonologica is adequate for the recognition of the female ; the male is very distinct, having a tubercle in the middle of the clypeus, a character unknown in any other described European species. Pimpla cicatricosa, Ratz., which is given by Schmiedeknecht as a synonym of P. roborator, F., is a distinct species.

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