PARASITISM OF THE ARMY CUTWORM, EUXOA AUXILIARIS (GRT.) (LEPIDOPTERA: NOCTUIDAE), BY COPIDOSOMA BAKERI (HOWARD) (HYMENOPTERA: ENCYRTIDAE) AND EFFECT ON CROP DAMAGE

1993 ◽  
Vol 125 (2) ◽  
pp. 329-335 ◽  
Author(s):  
J.R. Byers ◽  
D.S. Yu ◽  
J.W. Jones
Keyword(s):  
Life Cycles ◽  
High Rate ◽  
Crop Damage ◽  
Successful Strategy ◽  
Single Location ◽  
Southern Alberta ◽  
Late Instar ◽  
Lepidoptera Noctuidae ◽  
Host Development

AbstractDuring an outbreak of army cutworm in southern Alberta in the spring of 1990, the overall incidence of parasitism by the polyembryonic parasitoid, Copidosoma bakeri (Howard), was 61% in samples from seven fields. The incidence of parasitism in samples of army cutworms collected on five dates from a single location, during the spring of 1991, increased from about 20% in the early samples to about 50% in the later samples. Cutworms parasitized by C. bakeri feed for a longer time than unparasitized ones; therefore estimates of the incidence of parasitism by C. bakeri, based on samples of late-instar cutworms, are misleadingly high. Parasitized cutworms also grow considerably larger than unparasitized ones and may have a supernumerary instar. Larger hosts support larger broods of C. bakeri and apparently a successful strategy of C. bakeri is to prolong host development so as to maximize an acquired resource. Because cutworms parasitized by C. bakeri feed more and longer than unparasitized cutworms, a high rate of parasitism can exacerbate crop damage and complicate control recommendations. The life cycles of army cutworm and C. bakeri are asynchronous and it is likely that high rates of parasitism are dependent on the presence of intermediary hosts.

Developmental and reproductive effects of clothianidin exposure in monarch butterflies (Lepidoptera: Nymphalidae)

2021 ◽  
pp. 1-16
Author(s):  
Alana A.E. Wilcox ◽  
Amy E.M. Newman ◽  
D. Ryan Norris
Keyword(s):  
Egg Size ◽  
Insect Pests ◽  
Danaus Plexippus ◽  
Crop Damage ◽  
High Dose ◽  
Monarch Butterflies ◽  
Insecticide Treatment ◽  
Late Instar ◽  
Length Width ◽  
The Impact

Abstract Neonicotinoid insecticides are used to reduce crop damage caused by insect pests, but sublethal levels could affect development and reproduction in nontarget insects, such as monarch butterflies (Danaus plexippus) (Lepidoptera: Nymphalidae). To investigate the impact of field-realistic concentrations of the neonicotinoid clothianidin on monarch butterflies, we grew swamp milkweed (Asclepias incarnata) (Apocynaceae) in either low (15 ng/g of soil) or high (25 ng/g of soil) levels of clothianidin, or in a control (0 ng/g), then raised monarchs on the milkweed. Morphological traits of monarch caterpillars were measured during development and, once they eclosed, were mated as adults to quantify egg size and mass and the number of eggs laid. Although the effects of the treatment had complex effects on caterpillar length, width and volume of late-instar caterpillars were negatively affected. Fifth-instar caterpillars from the high-dose insecticide treatment had lower mass than other groups. Adult monarch butterflies raised on treated milkweed were larger than controls, but clothianidin exposure did not affect the number of eggs laid or egg size. Although the magnitude of the effect depends on clothianidin concentration, our results suggest that exposure to clothianidin during early life can impact monarch caterpillar development but is unlikely to reduce female reproductive output.

VARIATION IN CATCHES WITH SEX ATTRACTANT OF THE CLOVER CUTWORM, SCOTOGRAMMA TRIFOLII, AND ARMY CUTWORM, EUXOA AUXILIARIS (LEPIDOPTERA: NOCTUIDAE), DUE TO TRAP LOCATION

1979 ◽  
Vol 111 (1) ◽  
pp. 11-14 ◽  
Author(s):  
G. E. Swailes ◽  
D. L. Struble
Keyword(s):  
Significant Influence ◽  
Sex Attractant ◽  
Ground Level ◽  
The South ◽  
South Side ◽  
Southern Alberta ◽  
Trap Location ◽  
Lepidoptera Noctuidae ◽  
Scotogramma Trifolii

AbstractSex attractant traps for males of the clover cutworm, Scotogramma trifolii (Rottenberg), on farms in southern Alberta caught more moths within crops or on fallow than those near or within the farmyards except for traps immediately on the south side of the yard For males of the army cutworm, Euxoa auxiliaris (Grote), two trap placements in open areas were more effective than locations within the farmyard, again with the exception of the traps on the south side of the yards. Traps 2 m high caught significantly fewer moths than those at 1 m or ground level and the crop in which the trap was placed had no significant influence on catch of either cutworm.

The incidence and distribution of the armyworms Mythimna convecta (walker) and Persectania spp. (Lepidoptera: Noctuidae) and their parasitoids in major agricultural districts of Victoria, south-eastern australia

1986 ◽  
Vol 76 (2) ◽  
pp. 199-210 ◽  
Author(s):  
G. McDonald ◽  
A. M. Smith
Keyword(s):  
Light Trapping ◽  
Light Trap ◽  
Field Studies ◽  
Abundant Species ◽  
Crop Damage ◽  
Eastern Australia ◽  
Two Generations ◽  
Regular Sampling ◽  
Trap Catches ◽  
Lepidoptera Noctuidae

AbstractField studies of Mythimna convecta (Walker), Persectania ewingii (Westwood) and P. dyscrita Common, and their associated parasitoids, were conducted in cereals and pastures in Victoria, Australia, in 1980–83. The study included a survey of the armyworm fauna in the major agricultural districts, detailed phenological studies within five oat crops, and ultraviolet-light trapping of adults. M. convecta was the most abundant species in cereals and was found more commonly in the warmer months of spring and summer in all districts. Larval development in oat crops during spring was preceded by little moth activity in light traps. P. ewingii was common in the southern districts and in the cooler months from May to September. It was the most prevalent armyworm species in pastures and rarely occurred in barley. P. dyscrita was the least abundant species and occurred mostly in the drier inland areas, particularly in the west. Light-trap catches of P. ewingii and P. dyscrita suggested there were two generations, one in spring and one in the autumn. Regular sampling in oat crops showed that M. convecta developed faster and was usually more abundant than P. ewingii during seed development and ripening, and hence had the potential to inflict more crop damage. Of the 17 species of parasitoids reared from field-collected larvae, the wasp Campoletis sp. was the most abundant. In 1980–82, average parasitism ranged from 13 to 16% but fell to 2% after the drought of 1982.

scholarly journals Fertigation of wheat and canola in southern Alberta

2019 ◽  
Vol 99 (4) ◽  
pp. 536-545 ◽  
Author(s):  
Elwin G. Smith ◽  
Danny G. Le Roy ◽  
Daniel Donkersgoed ◽  
Doon Pauly ◽  
Ross H. McKenzie ◽  
...  
Keyword(s):  
Flag Leaf ◽  
Triticum Aestivum L ◽  
High Rate ◽  
Growth Stages ◽  
Brassica Napus L ◽  
Net Returns ◽  
Southern Alberta ◽  
Plant Growth Stages ◽  
Oil Concentration ◽  
Effect On Yield

An irrigation study in southern Alberta compared spring-banded nitrogen (N) to spring-banded N plus fertigation at three plant growth stages for spring wheat (Triticum aestivum L.) and canola (Brassica napus L.). Yield and quality impacts were quantified when N fertigation was applied to (i) wheat at the early tillering, flag leaf, and anthesis stages and (ii) canola at the four-leaf rosette, bolting, and early flowering stages. For both crops, fertigation could replace some spring-banded N without an effect on yield. However, the results revealed that for canola grown with a large amount of N, applying it all in the spring often generated higher yields than if an equivalent amount of N was delivered at later stages by fertigation. Canola oil concentration declined marginally (about 1%) from no applied N to the high rate of applied N. The application of more than 60 kg N ha−1 and delayed application each increased wheat protein content. Comparing revenues to costs, fertigation did not improve profit margins for canola growers. When growers applied 90 or 120 kg N ha−1 in the spring, fertigation was financially counter-productive. In contrast, the main benefit to wheat growers from fertigation was higher grain protein, especially with N applied at later growth stages. When protein premiums increase during the growing season, fertigation would facilitate growers to obtain higher net returns than they would otherwise.

EFFECTS OF LARVAL AGE ON SUSCEPTIBILITY OF SPODOPTERA LITURA (LEPIDOPTERA: NOCTUIDAE) TO SPODOPTERA LITURA MULTIPLE NUCLEAR POLYHEDROSIS VIRUS

2000 ◽  
Vol 132 (3) ◽  
pp. 337-340 ◽  
Author(s):  
M.D. Monobrullah ◽  
Masao Nagata
Keyword(s):  
Spodoptera Litura ◽  
Nuclear Polyhedrosis Virus ◽  
Actual Mechanism ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Time Required ◽  
Lepidoptera Noctuidae ◽  
Host Development

Susceptibility of many insects to baculoviruses decreases with host development (Hochberg 1991), whereas the time required for infected hosts to die increases with larval age (Boucias et al. 1980; Bucher and Turnock 1983; Smits and Vlak 1988). The actual mechanism of this phenomenon, however, has not been established in many cases. The present study was undertaken to investigate the effect of larval age on the susceptibility of Spodoptera litura Fabricius to nuclear polyhedrosis virus (NPV) through oral and intrahaemocoelic routes of infection.

MODIFICATIONS IN THE CALLING BEHAVIOUR OF PSEUDALETIA VNIPUNCTA (LEPIDOPTERA: NOCTUIDAE), INDUCED BY TEMPERATURE CONDITIONS DURING PUPAL AND ADULT DEVELOPMENT

1983 ◽  
Vol 115 (8) ◽  
pp. 1015-1022 ◽  
Author(s):  
Jean J. Turgeon ◽  
Jeremy N. McNeil
Keyword(s):  
Adult Development ◽  
Field Experiments ◽  
Species Differences ◽  
Adult Life ◽  
Onset Time ◽  
Life Cycles ◽  
Field Observations ◽  
Pupal Development ◽  
Calling Behaviour ◽  
Lepidoptera Noctuidae

AbstractThe age at which Pseudaletia unipuncta females initiated calling varied with temperatures experienced during pupal and adult stages. Entrainment was induced by temperatures during pupal development if similar to or lower than temperatures during adult life. However, adult temperatures were of major importance if lower than those experienced during pupal development. These observations were generally supported by data from field experiments repeated at different periods of the summer. The possibility that entrainment occurs at a specific period of development is proposed to explain certain field observations.Changes in mean onset time of calling and the time spent calling also varied, although generally not in the same manner as reported for other species. Differences in the life cycles, particularly the site of pupation, are proposed to explain these discrepancies.

Being successful in the world of narrow opportunities: transmission patterns of the trematode Ichthyocotylurus pileatus

Parasitology ◽  
2009 ◽  
Vol 136 (11) ◽  
pp. 1375-1382 ◽  
Author(s):  
A. FALTÝNKOVÁ ◽  
A. KARVONEN ◽  
M. JYRKKÄ ◽  
E. T. VALTONEN
Keyword(s):  
Perca Fluviatilis ◽  
Life Cycles ◽  
High Rate ◽  
Complex Life Cycle ◽  
Temporal Window ◽  
Holistic Approaches ◽  
Transmission Mechanisms ◽  
Northern Latitudes ◽  
Key Characteristics ◽  
Cercarial Emergence

SUMMARYParasites with complex life cycles face 2 major challenges for transmission in northern latitudes. They have to cope with the general unpredictability associated with the series of transmission events required for completion of the cycle, and transmission has to be completed within a narrow temporal window because of strong seasonality. Despite this, some parasites show high transmission success, suggesting the operation of effective transmission mechanisms. We explored the transmission of Ichthyocotylurus pileatus (Trematoda) from its snail (Valvata macrostoma) to fish (Perca fluviatilis) hosts by examining some key characteristics in the dynamics of the cercarial emergence from snails. Transmission took place within a few weeks mainly in July, thus verifying the narrow temporal window for transmission. The output of the short-lived cercariae from the snails was low and variable in magnitude, but nevertheless resulted in a rapid and high rate of infection in newly hatched fish. The cercarial emergence showed a strong circadian rhythm with most of the cercariae emerging in early evening and night, which might represent the most likely mechanism underlying the high rate of transmission in this species. We emphasize the importance of holistic approaches combining aspects of multiple host species in studies on transmission of complex life-cycle parasites.

scholarly journals Potential of the Parasitoid Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) on the Control of Helicoverpa armigera (Hübner, 1805) (Lepidoptera: Noctuidae)

2020 ◽  
Vol 12 (7) ◽  
pp. 146
Author(s):  
Juliana Simonato ◽  
Harley N. de Oliveira ◽  
José F. J. Grigolli ◽  
Mirian M. Kubota Grigolli ◽  
Ivana F. da Silva
Keyword(s):  
Life Cycle ◽  
Sex Ratio ◽  
Helicoverpa Armigera ◽  
Insect Pest ◽  
Field Evaluation ◽  
High Rate ◽  
No Release ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae ◽  
Helicoverpa Armigera Hubner

Helicoverpa armigera (Hubner, 1805) (Lepidoptera: Noctuidae) is an insect pest that attacks several cultures and has been a cause of concern in Brazil. The objective of this study was to evaluate parasitism in pupae and caterpillars of H. armigera by Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae), in laboratory, as well as checking if T. howardi parasitoid has the ability to locate and infect H. armigera. In the laboratory, pupae of H. armigera and Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) were exposed to 15 T. howardi females for 24 hours. Third, fourth and fifth instars of H. armigera were exposed to three T. howardi females for 24 hours. In the field experiment, cages were installed. Ten caterpillars of the fifth instar of H. armigera were released in each cage and waited for the necessary period for them to soak in the soil. After this period, 150 T. howardi females were released in each of four cages and in one cage there was no release of parasitoids. In the laboratory, the percentage of parasitized and emergent pupae was 100% in both hosts. The life cycle of T. howardi in H. armigera pupae was 15 days, and for D. saccharalis it was 16 days. The progeny was significantly larger for the host H. armigera (689.00) compared to D. saccharalis (358.27). The sex ratio was 0.91 and 0.87 for H. armigera and D. saccharalis, respectively. The longevity of males (25.60 days) and females (26.95 days) in the treatment with H. armigera differed from the treatment with D. saccharalis, which was 21.70 days for males and 22.95 days for females. For the experiment with H. armigera caterpillars, it was found that only two caterpillars from the fifth instar were parasitized with emergence of parasitoids in the pupal phase, with a progeny of 81 individuals; egg-adult cycle was 19.5 days; sex ratio of 0.88; male longevity was 19.6 days and for females 20.3 days. Despite the high rate of parasitism of T. howardi in H. armigera pupae in the laboratory, the same did not occur for caterpillars. In the field evaluation, of the total of 50 caterpillars released in the cages, 34 pupae were collected. Of these, 31 pupae had emergence of the H. armigera moth. No parasitism by T. howardi was found in H. armigera pupae. Further studies should be conducted to evaluate T. howardi parasitism in H. armigera pupae under field conditions.

BIOSYSTEMATICS OF THE GENUS EUXOA (LEPIDOPTERA: NOCTUIDAE): V. REARING PROCEDURES, AND LIFE CYCLES OF 36 SPECIES

1976 ◽  
Vol 108 (12) ◽  
pp. 1345-1357 ◽  
Author(s):  
C. F. Hinks ◽  
J. R. Byers
Keyword(s):  
Life Histories ◽  
Artificial Diet ◽  
Antimicrobial Agents ◽  
Life Cycles ◽  
Seasonal Distribution ◽  
Rearing Method ◽  
Laboratory Conditions ◽  
Laboratory Colonies ◽  
Lepidoptera Noctuidae

AbstractA rearing method, based upon an artificial diet, has proved successful in establishing laboratory colonies of 36 species of the genus Euxoa. The diet is described, along with methods for controlling disease, particularly by the use of antimicrobial agents.Many of the 36 species of Euxoa have not been reared before and their habits and life histories are little known. The data derived from their development under laboratory conditions and which can be related to seasonal distribution are recorded. Particular emphasis is given to the overwintering stage and to the occurrence of an aestivating stage.

Sign in / Sign up

Export Citation Format

Share Document