scholarly journals Examining population structure of a bertha armyworm, Mamestra configurata (Lepidoptera: Noctuidae), outbreak in western North America: Implications for gene flow and dispersal

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0218993
Author(s):  
Martin A. Erlandson ◽  
Boyd A. Mori ◽  
Cathy Coutu ◽  
Jennifer Holowachuk ◽  
Owen O. Olfert ◽  
...  
1999 ◽  
Vol 131 (1) ◽  
pp. 11-28 ◽  
Author(s):  
James E. O’Hara

AbstractThe bertha armyworm, Mamestra configurata Walker, causes periodic but severe damage to canola crops in North America, particularly in the Canadian provinces of Alberta, Saskatchewan, and Manitoba. This paper provides information on the tachinid flies (Tachinidae: Diptera) recorded from bertha armyworm in North America. A key to adults is provided for separation of the genera, and each species known from bertha armyworm is characterized with respect to recognition, biology (including hosts), and distribution. The species included are Athrycia cinerea (Coquillett), Blondelia sp., Chetogena claripennis (Macquart) species complex, Chetogena tachinomoides (Townsend) (new record), Eurithia consobrina (Meigen), Exorista mella (Walker), Lespesia archippivora (Riley), Panzeria ampelus (Walker), Phryxe pecosensis (Townsend), Phryxe vulgaris (Fallén), Spallanzania hebes (Fallén) (new record), Winthemia rufopicta (Bigot), and Winthemia quadripustulata (Fabricius). Eurithia consobrina is a Palearctic species that has been introduced into Canada for control of M. configurata but is probably not established; it is included here in the event it is introduced again and establishment is achieved.


1988 ◽  
Vol 120 (5) ◽  
pp. 401-413 ◽  
Author(s):  
W. J. Turnock

AbstractPopulations of larvae of the bertha armyworm, Mamestra configurata Wlk., in four physiographic regions of Manitoba showed similar trends over time: a decline from the outbreak of 1971–1972 to very low densities in 1975–1977, an increase to a peak during the years 1979–1981, and a subsequent decline. During the period of peak larval populations, brief (1 or 2 years) outbreaks [at least some fields with > 20 larvae per square metre) occurred at five locations in two regions, the Swan River Plain and the Valley River Plain, but not in the Western Uplands or the Manitoba Lowlands. In the first two regions, larval densities rose rapidly (from < 1.6 to > 13.8/m2) in 1 year. Although the general trend of population density was similar, there were differences in density among and within regions, and in the timing, severity, and duration of peak populations. Two parasitoids (Banchus flavescens Cress., Athrycia cinerea (Coq.)) and two pathogens (a nuclear polyhedrosis virus (NPV) and fungi of the Entomophthorales) occurred regularly in larval populations. Of these, B. flavescens had the highest constancy among collections and may help to keep bertha armyworm populations at low densities. NPV was rarely found among larvae from low-density populations but appeared in all populations that reached outbreak levels. No single biotic agent could be associated with the population declines because of multiple parasitism and the difficulty in partitioning mortality when only a single sample could be taken. The rapid increase of bertha armyworm larvae from very low to outbreak levels in 1 year will prevent predictions of outbreaks from being based on larval densities in the preceding year.


1983 ◽  
Vol 115 (8) ◽  
pp. 1039-1042 ◽  
Author(s):  
B. M. Hegdekar

AbstractThe critical photoperiod for diapause induction in pupae of Mamestra configurata Walker in Manitoba was 16 h 06 min at Glenlea (49°38′ N), 16 h 20 min at Grandview (51°10′ N), and 16 h 42 min at Birch River (52°24′ N). The differences in cirtical photoperiods observed at Glenlea and Grandview were not significant. At least two different photoperiods exist, one in the Glenlea and Grandview areas and the other in the Birch River area. In the laboratory, the critical photoperiod was 13.5 h when larvae were exposed to a daily fluctuating temperature regime of 12 h at 25 °C and 12 h at 10 °C. Longer critical photoperiods found for the field populations may be related to the relatively low ambient temperatures to which the larvae were exposed in field cages.


2013 ◽  
Vol 45 (6) ◽  
pp. 799-813 ◽  
Author(s):  
Kyle M. FONTAINE ◽  
Elfie STOCKER-WÖRGÖTTER ◽  
Tom BOOTH ◽  
Michele D. PIERCEY-NORMORE

AbstractDermatocarpon luridum is a subaquatic lichen which is distributed within temperate climatic zones around the world. It colonizes rock substrata along the shoreline of lakes and rivers of watersheds that regularly experience water level fluctuations. The mycobiont produces perithecia with small, simple spores that are thought to be wind dispersed. The photobiont, Diplosphaera chodatii, occurs both free-living and lichenized but little is known about its distribution and dispersal. The goal of this study was to compare the population structure of the photobiont from lakes and rivers in central North America with those of Europe. Specimens were collected in Manitoba, Canada and Austria. Population structure of the algal symbiont was assessed using the internal transcribed spacer (ITS) of ribosomal DNA (rDNA) and actin gene sequences. Results showed that genetic diversity and gene flow was high within local populations, but gene flow was low between continental populations. Low levels of gene flow between the most distant populations support the isolation-by-distance theory. The photobiont on both continents is also reported to be the photobiont for other lichen species contributing to photobiont availability for D. luridum.


1986 ◽  
Vol 118 (12) ◽  
pp. 1221-1230 ◽  
Author(s):  
M.A. Howlader ◽  
G.H. Gerber

AbstractThe effects of age, egg development, and mating on calling behavior of the bertha armyworm, Mamestra configurata Walker, were studied at 20°C, 60% RH, and a 16-h L: 8-h D photoperiod. Most virgin females called and copulated for the first time during the second or third scotophase after emergence. The first copulation was 17.0 ± 0.2 h (mean±SE) long and was terminated within 1 h after lights off in the scotophase following the initiation of copulation. The ovaries contained the first chorionated eggs before the beginning of the second scotophase after emergence. The first egg laying occurred during the same scotophase in which the first copulation was terminated, i.e. scotophase three or four. Almost 75% of the eggs were laid by the end of the seventh scotophase after emergence. Mated females resumed calling after a refractory period of about 2 days. Once calling was resumed after copulation, most females laid eggs and called nightly, with egg laying occurring during the first 5–6 h and calling during the last 2–3 h of the scotophase. Mated females called for a shorter period during each scotophase than virgin females of the same age (1–3 h vs. 4–6 h). In virgin females, the diel periodicity of calling was advanced and the length of the daily calling period was increased with age until the seventh scotophase after emergence; thereafter, both remained relatively unchanged.


1972 ◽  
Vol 104 (11) ◽  
pp. 1745-1750 ◽  
Author(s):  
Y. W. Lee ◽  
R. J. Ford ◽  
H. McDonald ◽  
K. S. McKinlay ◽  
L. G. Putnam ◽  
...  

AbstractResidues of methomyl in rape plants and seed were determined after its application for bertha armyworm control. In one experiment application of 3 oz of methomyl per acre left 17 p.p.m. residue on the rape plants immediately after application. This level rapidly declined to 1.5, 1.0, 0.4, and 0.2 p.p.m. 1, 2, 5, and 9 days later, respectively, and no residue was detected (less than 0.02 p.p.m.) in seed harvested 22 days after application of the toxicant. Rape plant samples collected from several farms immediately after the application of 3 to 4 oz of methomyl per acre had 2.5 to 16 p.p.m. residues, indicating inefficient application of the insecticide in some cases. Analysis of rape seed samples collected from 36 farms showed little residue in three samples (0.02 to 0.03 p.p.m.) and none in 33, indicating that the use of methomyl for bertha armyworm control is not likely to contaminate rape seed with undesirable levels of residues.


1987 ◽  
Vol 119 (10) ◽  
pp. 931-940 ◽  
Author(s):  
J.D. Lafontaine ◽  
K. Mikkola ◽  
V.S. Kononenko

AbstractThe status of Anarta cordigera (Thunberg, 1788), formerly treated as a circumboreal holarctic species, is reassessed in the light of characters of the male vesica and female bursa copulatrix. Populations are arranged in four species: A. cordigera in Europe; A. carbonaria Christoph, 1893 in Siberia and the Far East; A. luteola Grote and Robinson, 1865 in North America; and A. macrostigma Lafontaine and Mikkola, new species, in western North America. Adults and genitalia are illustrated for the four species.


2004 ◽  
Vol 136 (6) ◽  
pp. 823-834
Author(s):  
J. Donald Lafontaine ◽  
James T. Troubridge

AbstractAlastriagen. nov. is described, and Callierges tropicalis Schaus is transferred to the genus. Alastria chicosp. nov. is described from western North America and Alastria machosp. nov. is described from Costa Rica. We provide illustrations of the adults and genitalia of all three species, as well as the male genitalia of two related genera, Nedra Clarke and Actinotia Hübner.


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