Yield Losses from Second-generation European Corn Borers (Lepidoptera: Pyralidae) in Long-season Maize Hybrids Planted Early Compared with Short-season Hybrids Planted Late1

1986 ◽  
Vol 79 (1) ◽  
pp. 243-246 ◽  
Author(s):  
J. L. Jarvis ◽  
W. D. Guthrie ◽  
J. C. Robbins
Keyword(s):  
Second Generation ◽  
Yield Losses ◽  
Maize Hybrids ◽  
Corn Borers ◽  
Lepidoptera Pyralidae ◽  
Short Season

EFFECTS OF A NATURAL BIVOLTINE STRAIN OF THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS (LEPIDOPTERA: PYRALIDAE), ON GRAIN CORN YIELDS IN SOUTHWESTERN ONTARIO, 1973–77

1981 ◽  
Vol 113 (7) ◽  
pp. 585-591
Author(s):  
W. H. Foott ◽  
P. R. Timmins
Keyword(s):  
Moisture Content ◽  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
First Generation ◽  
Second Generation ◽  
Yield Losses ◽  
Corn Borer ◽  
Lepidoptera Pyralidae

AbstractA 5-year study of a bivoltine strain of the European corn borer, Ostrinia nubilalis (Hübner), showed that first-generation moths deposited more eggs on early-planted corn, whereas second-generation moths oviposited more frequently on late-planted corn. The second generation was much larger than the first generation and caused the greater reduction in yield, regardless of whether the yields were based on physiological losses or a combination of physiological losses and dropped ears. It was shown that delay of harvest beyond the time that moisture content of the corn was sufficiently low for machine harvesting could result in severe yield losses from broken stalks and dropped ears during autumn storms.

POSTMATING AGE ESTIMATES FOR FEMALE EUROPEAN CORN BORER MOTHS, OSTRINIA NUBILALIS (LEPIDOPTERA: PYRALIDAE), USING TIME-RELATED CHANGES IN SPERMATOPHORES

1979 ◽  
Vol 111 (12) ◽  
pp. 1325-1335 ◽  
Author(s):  
W. M. Elliott ◽  
V. A. Dirks
Keyword(s):  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Second Generation ◽  
Light Trap ◽  
Age Groups ◽  
Volume Depletion ◽  
Corn Borer ◽  
Corn Borers ◽  
Lepidoptera Pyralidae ◽  
Modal Values

AbstractThe spermatophores in mated female European corn borers, Ostrinia nubilalis (Hübner), were shown to lose volume (depletion), change colour, and retract their spiral stalks over a period of about 7 days in such a way that postmating age could be estimated from their appearance. Colour changes and stalk retraction occurred more slowly in females that laid fertile eggs than in those that did not, but depletion occurred at the same rate. The average postmating age was estimated as 5.2, 6.3, 3.9, and 2.6 days for small light trap catches of first generation females in 1974, 1975, 1976, and 1977 and 4.4, 3.9, and 3.2 days for larger catches of second generation females in 1974, 1975, and 1977. Catches did not show decreasing numbers in successive age groups but tended to show modal values at < 1 day and at 4–6 days with only 1% living > 7 days. Redistribution of the moths from the date of capture back to the date of mating tended to give a unimodal curve of numbers on time in the 1975 second generation but not in 1974 or 1977. The unimodal curve of redistributed moths in 1975 was significantly different from a normal distribution. The redistribution showed that 58% of the moths mated within the heat unit interval when the second generation was expected to emerge, whereas only 38% of the actual catches occurred in this interval. Redistribution also showed that mating probably occurred even on cold nights when few moths were trapped, and conversely that on some warm nights with large catches most of the moths had mated on earlier nights.

scholarly journals Gene Flow Among Three Races of European Corn Borers (Lepidoptera: Pyralidae) in New York State

1991 ◽  
Vol 20 (5) ◽  
pp. 1356-1362 ◽  
Author(s):  
Thomas J. Glover ◽  
Janet J. Knodel ◽  
Paul S. Robbins ◽  
Charles J. Eckenrode ◽  
Wendell L. Roelofs
Keyword(s):  
New York ◽  
Gene Flow ◽  
New York State ◽  
York State ◽  
Corn Borers ◽  
Lepidoptera Pyralidae

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.

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