RELATION BETWEEN POD DAMAGE CAUSED BY LARVAE OF BERTHA ARMYWORM, MAMESTRA CONFIGURATA WALKER (LEPIDOPTERA: NOCTUIDAE), AND YIELD LOSS, SHELLING, AND SEED QUALITY IN CANOLA

1987 ◽  
Vol 119 (4) ◽  
pp. 365-369 ◽  
Author(s):  
G.K. Bracken
Keyword(s):  
Yield Loss ◽  
Seed Quality ◽  
Control Measures ◽  
Feeding Duration ◽  
Plot Yield ◽  
Control Decision ◽  
Field Plots ◽  
Lepidoptera Noctuidae ◽  
Army Worm ◽  
Bertha Armyworm

AbstractCanola plants in 0.84-m2 field plots were exposed to 120 bertha army worm larvae per square metre, beginning at mid 5th instar, for increasing durations. Yield loss increased with feeding duration throughout the feeding period whereas the proportion of pods damaged increased rapidly at first then leveled at 45%. Pod damage was negatively correlated with plot yield but the regression was not statistically significant. More seed shelled from plants with damaged pods than from plants with no pod damage under field conditions simulating drying in the swath. Seed from damaged pods had greater proportions of green and broken seeds causing lower seed grade and these defects were evident in seed from plots with 21% or more damaged pods. Although control measures for bertha armyworm should not be undertaken before pod damage is observed, a control decision should be made before 20% of the pods are damaged.

EVIDENCE FOR CIS-11-HEXADECEN-1-OL ACETATE AS A MAJOR COMPONENT OF THE SEX PHEROMONE OF THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

1975 ◽  
Vol 107 (4) ◽  
pp. 361-366 ◽  
Author(s):  
M. D. Chisholm ◽  
W. F. Steck ◽  
A. P. Arthur ◽  
E. W. Underhill
Keyword(s):  
Sex Pheromone ◽  
Biological Response ◽  
Retention Data ◽  
Synthetic Materials ◽  
Lepidoptera Noctuidae ◽  
Army Worm ◽  
Antennal Responses ◽  
Laboratory Bioassays ◽  
Bertha Armyworm ◽  
Insect Sex

AbstractA potent sex pheromone produced by female bertha army worm moths was isolated. A 16 carbon, unsaturated, alkenol acetate was indicated from chemical degradative and GLC retention data. The location and configuration of the double bond was determined from the antennal responses (EAG) of male moths to a series of cis and trans mono-unsaturated alken-1-ol acetates; cis-11-hexadecen-1-ol acetate elicited the greatest EAG response. GLC retention times of the purified insect sex pheromone corresponded exactly with those of authentic cis-11-hexadecen-1-ol acetate on several analytical columns. Maximum biological response in laboratory bioassays of synthetic materials was obtained from a mixture of approximately 85% cis- and 15% trans-11-hexadecen-1-ol acetates.

SEX PHEROMONE TRAPS IN POPULATION MONITORING OF ADULTS OF THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

1979 ◽  
Vol 111 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Warren Steck ◽  
E. W. Underhill ◽  
M. D. Chisholm ◽  
C. C. Peters ◽  
H. G. Philip ◽  
...  
Keyword(s):  
Sex Pheromone ◽  
Population Monitoring ◽  
Pheromone Traps ◽  
Light Traps ◽  
Mamestra Configurata ◽  
Sex Pheromone Traps ◽  
Lepidoptera Noctuidae ◽  
Army Worm ◽  
Bertha Armyworm ◽  
Prairie Provinces

AbstractTraps baited with the sex pheromone of the bertha army worm moth, Mamestra configurata (Walker), were operated at 36 sites across the prairie provinces in 1976 and 1977. They captured ca. 15 times as many bertha moths as did light traps and were considered to constitute a useful method for detection of adults of this species.

MEASURING THE COST-BENEFIT OF CONTROL MEASURES FOR BERTHA ARMYWORM (LEPIDOPTERA: NOCTUIDAE) INFESTATIONS IN RAPESEED

1984 ◽  
Vol 116 (4) ◽  
pp. 591-595 ◽  
Author(s):  
G. K. Bracken ◽  
G. E. Bucher
Keyword(s):  
Yield Loss ◽  
Larval Density ◽  
Cost Benefit ◽  
Economic Loss ◽  
Control Measures ◽  
Field Cage ◽  
A Value ◽  
Percentage Yield ◽  
Break Even Point ◽  
Bertha Armyworm

AbstractYield saved by insecticidal applications against the bertha armyworm, Mamestra configurata Walker, in commercial fields was measured by comparing yield in protected (unsprayed) plots of 74.4 m2 and in adjacent sprayed areas. Coefficients of variation of yield from sample units 2, 1, and 0.5 m2 ranged from 0.12 to 0.51; statistical precision was increased by taking twenty-five 0.5 m2 sample units per plot. Analysis of pod damage from selected plants predicted percentage yield loss equal to that determined by area sampling.The results showed that yield saved by control in commercial situations did not exceed 0.325 g/larva, a value that was determined in previous work by field cage trials. Using 1981 costs for spraying and rapeseed prices and a yield loss of 0.325 g/larva, the break-even point for cost-benefit occurs when larval density is 23/m2, a value double the currently recommended density of 10 to 12/m2. Many rapeseed growers therefore are controlling the bertha armyworm at net economic loss, a situation verified by an analysis of 42 separate control decisions made by growers in 1981.

HOSTS OF BANCHUS FLAVESCENS (HYMENOPTERA: ICHNEUMONIDAE) AND ATHRYCIA CINEREA (DIPTERA: TACHINIDAE) IN MANITOBA

1979 ◽  
Vol 111 (6) ◽  
pp. 747-748 ◽  
Author(s):  
H.G. Wylie ◽  
G.L. Ayre
Keyword(s):  
Mamestra Configurata ◽  
Lepidoptera Noctuidae ◽  
Athrycia Cinerea ◽  
Army Worm ◽  
Bertha Armyworm

Banchus flavescens Cress. and Athrycia cinerea (Coq.) were reared each year (1972–1975) from larvae of bertha army worm, Mamestra configurata Walk. (Lepidoptera: Noctuidae), collected during an outbreak of this species on rapeseed in Manitoba. Neither parasite was reared from other Lepidoptera collected at that time from rapeseed; two separate attempts to propagate the parasites on native Lepidoptera other than M. configurata were unsuccessful (Wylie and Bucher 1977; Ewen and Arthur 1976). Since 1975 M. configurata has been rare in Manitoba. In 1976 both B. flavescens and A. cinerea were reared from bertha armyworm larvae from temporary artificial populations on rapeseed at Glenlea, south of Winnipeg. The presence of the two parasites in this locality, where M. configurata was not found during the outbreak, suggested that both B. flavescens and A. cinerea parasitize other lepidopterous species in Manitoba, especially when bertha armyworms are not present.

Effects of Harvesting Date on Yield Loss Percentage of Mechanical Harvest and Seed Quality in Rapeseed

2014 ◽  
Vol 40 (4) ◽  
pp. 650
Author(s):  
Qing-Song ZUO ◽  
Hai-Dong HUANG ◽  
Shi CAO ◽  
Shi-Fen YANG ◽  
Qing-Xi LIAO ◽  
...  
Keyword(s):  
Yield Loss ◽  
Seed Quality

scholarly journals Influence of Flower Thrips on Fusarium Hardlock Severity

Plant Disease ◽  
2007 ◽  
Vol 91 (11) ◽  
pp. 1423-1429 ◽  
Author(s):  
D. J. Mailhot ◽  
J. J. Marois ◽  
D. L. Wright
Keyword(s):  
Gossypium Hirsutum ◽  
Untreated Control ◽  
Yield Loss ◽  
Fusarium Verticillioides ◽  
Field Conditions ◽  
Control Group ◽  
Flower Thrips ◽  
The Impact ◽  
Field Plots

Cotton (Gossypium hirsutum) fiber is sometimes affected by hardlock, which is characterized by a failure of the fiber to expand outward from the boll at maturity. Because affected fiber is inaccessible to mechanical harvesters, yield loss can be considerable. Hardlock has been linked to infection by Fusarium verticillioides. The involvement of flower thrips (Frankliniella spp.), which are commonly found in cotton flowers, was explored. At 1100 h, approximately 10% of cotton flowers contained thrips that were carrying F. verticillioides. The effect of thrips and/or Fusarium in flowers and bolls was explored under greenhouse conditions. Exposing flowers to Fusarium and thrips resulted in bolls with the most severe symptoms. Exposure to either Fusarium or thrips alone resulted in more hardlock than was noted in the control group. The impact of thrips was also evaluated under field conditions. Field plots were treated with insecticides, a fungicide, both, or left untreated. Insecticides reduced thrips numbers and reduced hardlock severity. The fungicide had no impact on thrips numbers and was less effective at reducing hardlock. Combining insecticide and fungicide applications was no more effective than using insecticides alone, although it more frequently increased yield. The untreated control plots generally had the most severe hardlock and lowest yields. Reducing hardlock severity resulted in higher yields, although not consistently. These studies suggest that thrips increase the severity of hardlock, and reducing their numbers may diminish hardlock severity.

DENSITY, PARASITISM, AND DISEASE INCIDENCE OF LARVAE OF THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA WALKER (LEPIDOPTERA: NOCTUIDAE), IN MANITOBA, 1973–1986’

1988 ◽  
Vol 120 (5) ◽  
pp. 401-413 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
Disease Incidence ◽  
Population Declines ◽  
Mamestra Configurata ◽  
Trends Over Time ◽  
Nuclear Polyhedrosis ◽  
Physiographic Regions ◽  
River Plain ◽  
Swan River ◽  
Lepidoptera Noctuidae ◽  
Bertha Armyworm

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.

EFFECT OF LATITUDE ON THE CRITICAL PHOTOPERIOD FOR DIAPAUSE INDUCTION IN THE BERTHA ARMYWORM, MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

1983 ◽  
Vol 115 (8) ◽  
pp. 1039-1042 ◽  
Author(s):  
B. M. Hegdekar
Keyword(s):  
Temperature Regime ◽  
Diapause Induction ◽  
The Other ◽  
Fluctuating Temperature ◽  
Mamestra Configurata ◽  
Ambient Temperatures ◽  
Critical Photoperiod ◽  
Lepidoptera Noctuidae ◽  
H 20 ◽  
Bertha Armyworm

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.

Arthropod Invasions Versus Soybean Production in Brazil: A Review

2020 ◽  
Vol 113 (4) ◽  
pp. 1591-1608 ◽  
Author(s):  
Henrique Pozebon ◽  
Rafael P Marques ◽  
Guilherme Padilha ◽  
Matthew O´Neal ◽  
Ivair Valmorbida ◽  
...  
Keyword(s):  
Control Measures ◽  
Soybean Production ◽  
Arthropod Species ◽  
Management Measures ◽  
Soybean Pest ◽  
Development Data ◽  
Health And Economic Development ◽  
Aphis Glycines Matsumura ◽  
Tetranychus Urticae Koch ◽  
Lepidoptera Noctuidae

Abstract Soybean production in Brazil has been markedly affected by invasions of non-native arthropod species that feed on the crop, severely impacting biodiversity, food security, health, and economic development. Data on soybean production losses and increase in insecticide usage over the last two decades have not been explored in association with past invasion events, and the dynamics underlying the recent blitz of invasive species into Brazil remain largely unclear. We provide a review of arthropod invasions in the Brazilian soybean agroecosystem since 1990, indicating that the introductions of Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae), Tetranychus urticae (Koch) (Acari: Tetranychidae), and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) are likely correlated with periods of increase in insecticide usage for soybean production. Using these three cases as examples, we review factors that could lead to increased likelihood of future invasions by particular pests, outlining four possible criteria to evaluate potential invasiveness of non-native arthropods: likelihood of entry, likelihood of establishment, biological features of the species, and availability of control measures. Spodoptera litura (F.) (Lepidoptera: Noctuidae) and Aphis glycines (Matsumura) (Hemiptera: Sternorrhynca) are examples of highly damaging soybean pests, related to one or more of these factors, that could be introduced into Brazil over the next years and which could lead to problematic scenarios. Melanagromyza sojae (Zehnter) (Diptera: Agromyzidae) also meets these criteria and has successfully invaded and colonized Brazilian soybean fields in recent years. Our review identifies current issues within soybean pest management in Brazil and highlights the need to adopt management measures to offset future costs and minimize lost revenue.

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