Variation Between Samples of Immature Stages, and of Mortalities from Some Factors, of the European Corn Borer, <i>Ostrinia nubilalis</i> (Hübner) (Lepidoptera: Pyralidae), on Sweet Corn in Quebec

Self Cite

In May, 1958, studies on the distribution of fruit, and of fruit damages from all sources; were initiated in permanent apple orchard plots at Rougemont, Que. The object was to develop sound sampling techniques to determine, within error limits, damages to the fruit resulting from the feeding activities of orchard insect pests, and from mechanical causes, during the period apple set in early June to harvest in mid September. This is a report on variation in samples of apples, and of damages to the fruit from all sources, for the years 1958 and 1959, and on sampling recommendations.

Section: Suggested Sampling Plansupporting

confidence: 84%

Variation Between Samples of Fruit, and of Fruit Damages Mainly from Insect Pests, on Apple in Quebec

LeRoux¹

1961

Self Cite

“…Reviews by Brindley and Dicke (1963) and Brindley et al (1975) concluded that although natural enemies can reduce corn borer populations significantly in some locations or years, they cannot be depended upon over 5 years at any given site, and their effect is frequently minimal. A comprehensive 7-year life-table study in Quebec (Leroux et al 1963;Hudon and Leroux 1961) attributed greatest mortality to migration of moths and dispersal of larvae out of test plots.…”

Section: October 1988mentioning

confidence: 99%

FACTORS AFFECTING MORTALITY OF THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS (HÜBNER), IN ALBERTA

Lee

1988

A combination of laboratory and field trials, from 1983 to 1985, were used to determine mortality factors affecting all life stages of Alberta populations of the European corn borer, Ostrinia nubilalis (Hübner), feeding on corn. The resulting life table demonstrated that greatest mortality occurred during the first and second larval instars (62.2%), when mature larvae are in diapause (69.5%), and from moth migration and loss in reproductive potential (70.3%). Stages where mortality was slight included the egg stage (11.7%), non-diapausing third- to fifth-instar larvae (2%), and pupae (10.4%).Laboratory trials showed that greater egg mortality occurred at relative humidities (RH) of 35 and 55% than at a RH of 75%. In the field, egg parasitism was nil, predation of early-instar larvae (5.2%) and diapausing larvae (6%) was low, and parasitoids were scarce (emerging from ca. 2% of pupae). Sustained periods of hot, dry weather with high moisture stress were related to mortality of both eggs and early-instar larvae. Death of early-instar larvae also was related to periods of rainy weather with low evaporation. The 64% non-diapause larval mortality was much lower than that reported elsewhere. The dramatic increase in the corn borer since its recent introduction to Alberta may be due to a lack of natural enemies, and because only non-resistant corn hybrids are grown.

“…Observations made on the relationship existing between the number of samples needed for a given precision and population densities of the species studied by LeRoux and Reimer (1959), LeRoux (1961), and Hudon and LeRoux (1961) are applic2ble here since populations of A. argyrospilus are generally of the negative binomial type distribution.…”

Section: Sampling Considerationsmentioning

confidence: 99%

A Sampling Technique for Population and Mortality Factors of the Fruit-Tree Leaf Roller, Archips argyrospilus (Wlk.) (Lepidoptera: Tortricidae), on Apple in Quebec

Paradis¹,

LeRoux²

1962

Self Cite

Sampling techniques for population^ and mortality factors of cl~e fruit-tree leaf roller, Archips argyrospilus (Wlk.), on apple in Quebec, were developed at Rougemont from 1958 to 1960 with the object of obtaining reliable statistics for life tables on this species. Biometric teclltliques have not previously been applied for ecological studies of A. argyrospilzts, most workers having been primarily concerned with life history, chemical control, and general observations on natural control factors (Gill