A METHOD OF DETECTING OVIPOSITION IN EUROPEAN CORN BORER MOTHS, OSTRINIA NUBILALIS (LEPIDOPTERA: PYRALIDAE), AND ITS RELATION TO SUBSEQUENT LARVAL DAMAGE TO PEPPERS

Abstract

The formation of a yellow band inside the stalk of each ovariole was a good indicator that a female European corn borer had laid eggs. The absence of these bands was less reliable as an indicator that no eggs had been laid, probably due to the time taken for the bands to form. The numbers of moths accumulating in a light trap over a week at Harrow, Ontario, and the numbers of females estimated to have laid eggs correlated significantly with the numbers of larvae developing in nearby green pepper plots 3, 4, and 5 weeks later during second generation flights. This enabled linear equations for forecasting pepper damage to be developed, in which the dissection data was more useful than the total moth catch alone.

Ostrinia nubilalis (Hb.) (Lep., Pyralidae) on sweet corn: relationship between adults caught in multibaited traps and ear damages

“…Stockel (1984) found a positive correlation between the number of males caught in pheromone sticky traps and the number of larvae in stems of maize for low ECB populations, but the correlation was negative when the population levels of ECB were higher. Elliott (1978) found a significant correlation on sweet pepper in Canada between the weekly catches of ECB adults in light traps and the number of larvae/fruit and percentage of damage; this correlation was calculated for both sexes, for total number of females caught and for mated females, mated females not ovipositing and ovipositing, mated females. Again for this crop, but when grown in a greenhouse, Maini & Burgio (1993) demonstrated a significant positive correlation between the average number of females caught with phenylacetaldehyde and the percentage of damaged fruits; the average number of males or males plus females were not significantly related to larval attack of the fruits.…”

Morphological differences of the reproductive system could be used to predict the optimum Grapholita molesta (Busck) control period

“…Ovarian development is divided into different development levels according to internal structure, such as the maturity level and color of eggs and the consumption of fat 13 , 16 . The anatomical morphology and development levels of ovaries can predict the emergence period, moth quantity, and population trend of the investigated Lepidopteran pest 17 , and they could help to determine the optimum period for pest control 13 , 16 . Ovarian development is widely used to make predictions about important Lepidopteran pests, such as Heliothis zes 14 , Pseudaletia ( Mythimna ) separate 18 , Ostrinia nubilalis 17 , 19 , Cnaphalocrocis medinalis 20 , 21 , and Spodoptera exigua 22 .…”

“…The anatomical morphology and development levels of ovaries can predict the emergence period, moth quantity, and population trend of the investigated Lepidopteran pest 17 , and they could help to determine the optimum period for pest control 13 , 16 . Ovarian development is widely used to make predictions about important Lepidopteran pests, such as Heliothis zes 14 , Pseudaletia ( Mythimna ) separate 18 , Ostrinia nubilalis 17 , 19 , Cnaphalocrocis medinalis 20 , 21 , and Spodoptera exigua 22 . These works indicate that analyzing reproductive developmental morphology is an efficient way of predicting the occurrence status of moths.…”

THE AGE OF FEMALE EUROPEAN CORN BORER MOTHS, OSTRINIA NUBILALIS (LEPIDOPTERA: PYRALIDAE), IN THE FIELD AND TESTS OF ITS USE IN FORECASTING DAMAGE TO GREEN PEPPERS

“…The moths caught by the light trap have received most attention at Harrow in research on forecasts of corn borer populations and damage because of the ease of getting the information and because they represent the active dispersal phase. Catches include both sexes and females between emergence and mating and between the 1 and 4 matings and the end of egg laying (Elliott 1977;Elliott et al 1978). Hopefully light trap catches would be indicative of the moths leaving emergence sites and flying to new hosts which may be growing at sites where there are no hosts of the previous generations and therefore no source of moths.…”