Major Mortality Factors in the Population Dynamics of the Eye-spotted Bud Moth, the Pistol Casebearer, the Fruit-tree Leaf Roller, and the European Corn Borer in Quebec

1963 ◽  
Vol 95 (S32) ◽  
pp. 67-82 ◽  
Author(s):  
E. J. LeRoux ◽  
R. O. Paradis ◽  
M. Hudon
1962 ◽  
Vol 94 (6) ◽  
pp. 561-573 ◽  
Author(s):  
R. O. Paradis ◽  
E. J. LeRoux

Sampling techniques for population and mortality factors of the 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 techniques have not previously been applied for ecological studies of A. argyrospilus, most workers having been primarily concerned with life history, chemical control, and general observations on natural control factors (Gill, 1913; Caesar, 1916 and 1917; Petch, 1916 and 1942; Herrick, 1917; Muesebeck, 1921; Regan, 1923; Viereck, 1924, Venables, 1924 and 1937; Harman, 1928; Hall, 1930 and 1934; Knull, 1932; Chapman et al., 1941; Greenwood, 1943).


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.


1988 ◽  
Vol 120 (10) ◽  
pp. 841-853 ◽  
Author(s):  
Dennis A. Lee

AbstractA 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.


1915 ◽  
Vol 47 (6) ◽  
pp. 185-187
Author(s):  
GLENN W. HERRICK ◽  
R. W. LEIBY
Keyword(s):  

2020 ◽  
Vol 21 ◽  
pp. 00040
Author(s):  
Inna Grushevaya ◽  
Anastasia Ignatieva ◽  
Yuri Tokarev

Microsporidia are obligate intracellular parasites that affect the population density of many insect pests. In particular, infection with Nosema pyrausta is one of the major mortality factors for the European corn borer Ostrinia nubilalis, the Asian corn borer Ostrinia furnacalis and the adzuki bean borer Ostrinia scapulalis. The purpose of the work is to compare the susceptibility to N. pyrausta and pathogenesis of three species of moths of the genus Ostrinia. Studies conducted over 2 years have shown that in all three species of host insects under laboratory conditions, both during oral infection and transovarian transmission of infection (in the daughter generations of experimentally infected insects), only diplokaryotic spores formed corresponding to the main morphotype of the genus Nosema. Mean lethal time increased with instar of larvae used for infection but didn’t differ between the three species. The rates of transovarial transmission of N. pyrausta were also similar. Thus, all the insect species examined may equally participate in the parasite persistence in nature and serve as model laboratory hosts for parasitological research and mass propagation of the microsporidium.


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