PHENOLOGY OF THE EUROPEAN CORN BORER (OSTRINIA NUBILALIS) IN ALBERTA

1986 ◽  
Vol 118 (10) ◽  
pp. 943-956 ◽  
Author(s):  
Dennis A. Lee ◽  
John R. Spence

AbstractDifferences in phenology were observed between two populations of Ostrinia nubilalis (Hbn.) in Alberta. In the South Saskatchewan River valley, borers pupated and emerged 3–6 days earlier than on the plains. This was not simply a function of different microclimates because median pupation occurred at 331 degree-days (DD) for plains populations and at 490 DD for valley populations. First-generation flight extended from the last week in June until the 1st week in August. Flight peaks in 1983 occurred on 8 July in the valley and on 14 July on the plains. Flight was delayed in 1984 by cold nightly temperatures. In 1983 valley populations had a partial second generation, with a flight peak in late August. Mean pupal mass was significantly less for plains populations than valley populations. Transplant experiments demonstrated that these differences reflected mainly environmental influences. During spring 1984, mean larval mass in the two populations did not differ until early June, when both mean wet and dry mass of valley larvae increased significantly but those of plains larvae did not change. This variability of phenotypes contributes to the colonizing ability of the European corn borer.

1990 ◽  
Vol 122 (6) ◽  
pp. 1247-1258 ◽  
Author(s):  
Douglas H. Kelker ◽  
Dennis A. Lee ◽  
John R. Spence

AbstractA degree-day model was developed for Alberta populations of Ostrinia nubilalis Hübner. Starting with overwintered fifth-instar larvae, the model calculates the temporal distribution of first- and second-instar larvae which are the stages most vulnerable to chemical suppression. Predictions from three alternative models were compared against field data from southern Alberta. Use of a standard 10°C growth threshold to calculate physiological time scales allowed predictions as accurate as those obtained using either a pooled threshold (11.4°C) calculated specifically from Alberta populations, or a model using two thresholds (12.3°C for fifth-instar larvae to adult and 10.2°C for eggs to second-instar larvae) that incorporated significant differences in growth characteristics observed among life stages. We conclude that standard thresholds are sufficient for degree-day models for northern populations of O. nubilalis. The standard model (t0 = 10°C) predicts that moth emergence will peak at ca. 145 degree-days after median pupation, and that numbers of eggs, and first- and second-instar larvae should peak at 200, 310, and 450 degree-days, respectively. Model predictions can be used to time sampling effort in support of management decisions.


1963 ◽  
Vol 95 (12) ◽  
pp. 1285-1292 ◽  
Author(s):  
C. A. Barlow

AbstractA method of forecasting the size of first-generation or summer infestations of Ostrinia nubilalis in Kent County, Ontario, is described. A function is derived from partial regression analysis relating the estimated size of the expected summer infestation to (1) the number of females caught in a light-trap during the first or spring flight, and (2) average rainfall per day during the first flight. The function explains 94% of the observed variation in estimated size of first-generation infestations in this area between 1947 and 1961. A means of categorizing the estimated size of the predicted infestation based on the frequency distribution of previously estimated infestations is also described. Methods of sampling and estimating population size and the applicability of the predictive equation to other environments are discussed.


1981 ◽  
Vol 113 (7) ◽  
pp. 585-591
Author(s):  
W. H. Foott ◽  
P. R. Timmins

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.


Genetika ◽  
2020 ◽  
Vol 52 (1) ◽  
pp. 351-365
Author(s):  
Snezana Gosic-Dondo ◽  
Dragan Grcak ◽  
Milosav Grcak ◽  
Danijela Kondic ◽  
Djuradj Hajder ◽  
...  

The objective of the paper was to determine the effect of insecticides on the development of the European corn borer (Ostinia nubilalis Hbn) and the effect of damage in six maize hybrids of different maturity groups. The research involved the following hybrids: ZP 427, ZP 434, ZP 555, ZP 600, ZP 606 and ZP 666. In the field trial, insecticides were applied in two terms, during the flight of O. nubilalis first generation and during the flight of second O. nubilalis generation. We used Fobos EC insecticide and a combination of Match 050 EC + Nurelle D insecticides, whose active substances are different. The active substance in Fobos EC insecticide is bifenthrin 100 g l-1, in Match 050 EC lufenuron 50 g l-1 and, in Nurelle D insecticide, the active ingredient is a combination of chlorpyrifos 500 g l-1 and cypermethrin 50 g l-1. The damage inflicted on plants was assessed in July and September. Fobos insecticide had the best plant protection effect, after its use, the arithmetic mean of the total attack percentage of all hybrids was approximately 81.62% while in the control group, it was approximately 91.72%.


2009 ◽  
Vol 19 (1) ◽  
pp. 173-180 ◽  
Author(s):  
Steve M. Spangler ◽  
Dennis D. Calvin ◽  
Joe Russo ◽  
Jay Schlegel

Infestation of sweet corn (Zea mays) at harvest by european corn borer (Ostrinia nubilalis) was examined in 16 hybrid/harvest date combinations from 1994 through 1996 in central Pennsylvania. Two general periods of sweet corn ear infestation levels were observed. Infestations, expressed as proportion of ears infested, were 0.11 (11%) or lower in 10 of 11 plots harvested from 21 July to 23 Aug., whereas they were noticeably higher (30%–88%) in September and early October. Infestations expressed as larvae per ear showed the same temporal pattern. A nonlinear (sigmoidal) relationship was found between degree-days from 1 Jan. and proportion of ears infested. The higher infestations were caused by the second-generation larvae of the bivoltine ecotype. Based on these relationships, a risk-prediction system is proposed that anticipates, at planting, harvest infestation by using predicted harvest dates of sweet corn, european corn borer life stages, and infestation levels. Examples are presented for multiple plantings and hybrids for a specific site and a landscape (Pennsylvania). The risk prediction system we propose will allow growers to anticipate the risk of ear infestations at planting time, thus providing predictions that would help with management decisions.


2020 ◽  
Vol 18 ◽  
pp. 00012
Author(s):  
Inna Grushevaya

The European corn borer Ostrinia nubilalis (Hübner) is a dangerous corn pest – a convenient object for studying population dynamics and assessing various pest mortality factors. The mortality of European corn borer’s eggs by the natural parasite population Trichogramma evanescens (Westwood) was estimated in 2013–2018 in the Gulkevichsky district of the Krasnodar Territory. Two generations of the European corn borer are developing in the Krasnodar Territory. Often pest’s first generation of is not infected with the parasite. When monitoring the abundance of the second generation, even in years with a low abundance of the European corn borer, infected phytophage eggs are found in the crops of grain corn. Infection of eggs of the second-generation European corn borer in 2013-2018 ranged from 0.26 to 69.55 eggs / m2, with an average of 37.53 eggs / m2.


2000 ◽  
Vol 36 (No. 4) ◽  
pp. 147-149 ◽  
Author(s):  
Ľ. Cagáň ◽  
G. Sobota ◽  
B. Gabryš ◽  
C. Kania

From 1992 to 1996 the voltinism of the European com borer, Ostrinia nubilalis Hbn., was investigated in Poland. During the study, over 6000 larvae were collected in maize stalks in autumn. In 1994, pupal cases were observed in stalks. This indicated the development of second generation adults of the pest. Pupal cases were not found in other years of the study. The difference between 1994 and the other years was found when the degree-days accumulation at base 10°C was calculated for the periods between July 1 and July 19 (daylight 15 hrs 58 min), or July 29 (daylight 15 hrs 32 min). These values were highest in 1994 and reached 246.5°C, or 414.0°C respectively. The results indicate that degree-days accumulation during the whole year is not responsible for the development of the second generation. It appears that high temperatures in July (not only at the beginning, but also at the end) influenced the development of the second generation of 0. nubilalis in Poland. Average July daily temperatures in 1994 were extremely high (24.5°C). Such temperatures can allow a small partial development of the second generation of O. nubilalis at a relatively cold location like Wroclaw in Poland with a standard annual mean temperature of 8.3°C.


1963 ◽  
Vol 41 (6) ◽  
pp. 963-970 ◽  
Author(s):  
C. A. Barlow ◽  
H. B. Wressell ◽  
G. R. Driscoll

Partial regression analysis of the indicial size of first generation, or summer. infestations of Ostrinia nubilalis estimated from light-trap matches and surveys of cornfields in Kent County, Ontario, suggested that the size of infestations was largely determined by three factors: (1) the number of females in the first flight, (2) average rainfall per day during the first flight, and (3) average daily temperature during the first flight. The first factor was apparently most important, rainfall had less effect, and the influence of temperature was evidently negligible. Estimated size of first generation infestations increased by 3.7 individuals for every unit increase in the number of females trapped during the first flight, by 12.2 individuals for every 0.01 in. of rain which fell during the first flight, and by 1.3 individuals for every 1°-F increase in mean daily temperature during the first flight. The regression explained 94% of the variation in estimated size of summer infestations of the corn borer between 1947 and 1961. A hyperbolic relationship was implied between the number of females in the first flight and the number of progeny per female in first generation infestations.


1979 ◽  
Vol 111 (3) ◽  
pp. 233-236 ◽  
Author(s):  
D. G. R. McLeod ◽  
C. Ritchot ◽  
T. Nagai

AbstractThere are now two strains of the European corn borer, Ostrinia nubilalis (Hübner), in Quebec. The strain normally found produces one generation while the more recently introduced strain produces two generations per year. Both strains have been characterized and compared with corn borer strains from Ontario and New York State. The two attributes of the recently introduced strain that promote the development of a second generation are (1) early emergence in the spring with less intense diapause and (2) a lower critical photoperiod for diapause induction. The latter characteristic allows pupation of first generation larvae. Field and laboratory tests on the pheromone response of adult male moths demonstrated that the origin of this recent introduction was New York State.


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