MORTALITY FACTORS AFFECTING EGGS OF THE FOREST TENT CATERPILLAR, MALACOSOMA DISSTRIA (LEPIDOPTERA: LASIOCAMPIDAE)

1972 ◽  
Vol 104 (5) ◽  
pp. 705-710 ◽  
Author(s):  
J. A. Witter ◽  
H. M. Kulman
Keyword(s):  
Larval Mortality ◽  
Malacosoma Disstria ◽  
Egg Mass ◽  
Forest Tent Caterpillar ◽  
Mortality Factors ◽  
Egg Masses ◽  
Factors Affecting ◽  
Egg Mortality ◽  
Significant Difference ◽  
Tent Caterpillar

AbstractParasitism, infertility, and death of fully developed first-stage larvae in eggs (pharate larvae) were the egg mortality factors encountered during a 1967–69 study on the bionomics of the forest tent caterpillar, Malacosoma disstria Hübner, in northern Minnesota. There was no significant difference in the average yearly per cent parasitization and infertility per egg mass; these ranged from 7 to 10% and 1 to 3%, respectively. There was a year to year difference in pharate larval mortality. It ranged from 39% in 1968 to only 9 and 3% for 1967 and 969. Studies showed that egg masses had a tendency to be either nearly complete y hatched or unhatched only in 1968. The variation in pharate larval mortally in these studies suggests qualitative differences in the population. The pharate larval mortality has the potential of influencing population trends of the forest tent caterpillar.

SEQUENTIAL EGG-BAND SAMPLING AND PROBABILITY METHODS OF PREDICTING DEFOLIATION BY MALACOSOMA DISSTRIA (LASIOCAMPIDAE: LEPIDOPTERA)

1971 ◽  
Vol 103 (10) ◽  
pp. 1371-1379 ◽  
Author(s):  
R. F. Shepherd ◽  
C. E. Brown
Keyword(s):  
Mass Density ◽  
Local Area ◽  
Malacosoma Disstria ◽  
Egg Mass ◽  
Probability Method ◽  
Forest Tent Caterpillar ◽  
Sampling System ◽  
Probability Methods ◽  
Tent Caterpillar

AbstractA sequential egg-band sampling system for predicting defoliation of aspen by the forest tent caterpillar (Malacosoma disstria Hbn.) is described and its accuracy assessed. A probability method of predicting defoliation from the stage of the outbreak in each local area is also established. A third method, which promises to be the most accurate and consistent, is proposed. In this last system, egg-mass density is established and related to defoliation levels which are adjusted depending upon age of outbreak.

NUMERICAL ANALYSIS OF A FOREST TENT CATERPILLAR (LEPIDOPTERA: LASIOCAMPIDAE) OUTBREAK IN NORTHERN MINNESOTA

1975 ◽  
Vol 107 (8) ◽  
pp. 837-854 ◽  
Author(s):  
J. A. Witter ◽  
W. J. Mattson ◽  
H. M. Kulman
Keyword(s):  
Tree Mortality ◽  
Population Change ◽  
Larval Mortality ◽  
Weather Conditions ◽  
Forest Tent Caterpillar ◽  
Mortality Factors ◽  
Components Of Variance ◽  
Tree Defoliation ◽  
Disease Dispersal ◽  
Tent Caterpillar

AbstractAn outbreak of the forest tent caterpillar began in northern Minnesota in 1964 and ended abruptly in 1972. During 1968–71 when egg densities ranged from 1 to 9 million per acre, caterpillars caused virtually complete tree defoliation in all study plots. As a result, tree stem densities and basal areas were reduced per plot by 41 and 27%, respectively. Tree mortality was more severe on plots having higher water tables. Graphical and components of variance analyses both showed that: (1) variations in annual egg densities were due mostly to variations in survival during the egg to 30-day larval stage (SI) and secondly to variations in survival during the 30-day larval to adult stage (S2), (2) S2 tended to change in the opposite direction from S1, (3) the net result was a tendency to produce a constant amount of eggs per unit area. Variations in S1 were due primarily to pharate larval mortality and mortality of larvae 2–3 weeks after hatch while variations in S2 were due mainly to unmeasured mortality factors such as starvation, disease, dispersal, etc. Survival during the egg stage (SE) and fecundity (F) varied significantly by years, but not by plots and both were apparently related to weather conditions. Plots of two simultaneous equations were presented to demonstrate the nature of population change in relation to the densities of eggs and 30-day larvae per acre.

EFFECTS OF COLD TEMPERATURES ON HATCHING OF THE FOREST TENT CATERPILLAR, MALACOSOMA DISSTRIA (LEPIDOPTERA: LASIOCAMPIDAE)

1973 ◽  
Vol 105 (8) ◽  
pp. 1145-1149 ◽  
Author(s):  
B. W. Wetzel ◽  
H. M. Kulman ◽  
J. A. Witter
Keyword(s):  
Malacosoma Disstria ◽  
Forest Tent Caterpillar ◽  
Minimal Effect ◽  
Cyclic Pattern ◽  
Cold Temperatures ◽  
Egg Masses ◽  
Embryo Mortality ◽  
Length Of Treatment ◽  
Laboratory Exposure ◽  
Tent Caterpillar

AbstractEgg masses of the forest tent caterpillar, Malacosoma disstria Hübner, were collected from new and old infestation areas of northern Minnesota before development started in the spring. Mortality of embryos was recorded after laboratory exposure to −10°, −15°, −20°, −25°, and −30° C for 12, 24, and 72 hours at 1, 2, 3, and 4 days before anticipated hatch. Length of treatment and temperatures of −10° and −15°C had minimal effect on survival. Mortality of embryos varied with days before hatch in an erratic cyclic pattern with temperatures and years. Temperature treatments of −20°, −25°, and −30 °C caused about 50%, 66%, and 100% embryo mortality. Mortality in new infestation areas was consistently higher than in older areas for all treatments.

Prevalence and biology of Furia gastropachae (Zygomycetes: Entomophthorales) in populations of forest tent caterpillar (Lepidoptera: Lasiocampidae)

2003 ◽  
Vol 135 (3) ◽  
pp. 359-378 ◽  
Author(s):  
Melanie J. Filotas ◽  
Ann E. Hajek ◽  
Richard A. Humber
Keyword(s):  
New York ◽  
United States Of America ◽  
Pieris Rapae ◽  
Viral Infections ◽  
Danaus Plexippus ◽  
Malacosoma Disstria ◽  
Forest Tent Caterpillar ◽  
Resting Spore ◽  
Tent Caterpillar ◽  
Marked Tendency

AbstractFuria gastropachaecomb. nov. (= Furia crustosa MacLeod et Tyrrell) has long been associated with declines in populations of the forest tent caterpillar, Malacosoma disstria Hübner; however, its prevalence and impact on host populations have never been documented. We clarify the nomenclature for this species, which has previously been called F. crustosa, and describe the morphology of F. gastropachae isolates from Maryland and New York. Epizootics of F. gastropachae were studied in M. disstria populations in New York and Maryland, United States of America. Prevalence (mean ± SE) of F. gastropachae in late fifth instar larvae in New York was 25.6 ± 7.8% compared with 22.2 ± 11.3% infection by virus and 23.3 ± 8.4% parasitism. In Maryland, F. gastropachae was not found in early instars and its incidence in fourth and fifth instars was 14.5 ± 7.3 and 21.6 ± 17.6%, respectively. Dipteran parasitoids were also important natural enemies with 38.3 ± 3.0 and 17.9 ± 1.4% parasitism in fourth and fifth instars, respectively. Virus was found in fewer than 5% of larvae collected. Furia gastropachae showed a marked tendency toward resting spore production in infected larvae, with 100% of larvae collected in New York and >80% of larvae collected in Maryland producing resting spores, either alone or in combination with conidia. The appearance of cadavers of larvae dying from fungal and viral infections was similar. Of 13 species of Lepidoptera exposed to F. gastropachae conidia in host-range bioassays, only 3.3% of Danaus plexippus (L.) (Lepidoptera: Danaidae), 5.6% of Pieris rapae (L.) (Lepidoptera: Pieridae), and 3.7% of Manduca sexta (L.) (Lepidoptera: Sphingidae) were successfully infected by this fungus.

The Light Reactions of Larvae of the Tent Caterpillars, Malacosoma disstria Hbn., M. americanum (Fab.), and M. pluviale (Dyar). (Lepidoptera: Lasiocampidae)

1953 ◽  
Vol 85 (8) ◽  
pp. 297-310 ◽  
Author(s):  
C. R. Sullivan ◽  
W. G. Wellington
Keyword(s):  
Physical Environment ◽  
Malacosoma Disstria ◽  
General Interest ◽  
Deciduous Trees ◽  
Physical Factors ◽  
Forest Tent Caterpillar ◽  
Field Observations ◽  
Larval Behaviour ◽  
Tent Caterpillars ◽  
Tent Caterpillar

The forest tent caterpillar, Malacosoma disstria Hbn., and the eastern and western tent caterpillars, M. americanum (Fab.) and M. pluviale (Dyar), are common pests of several species of deciduous trees in Canada. All are colonial during the larval stage, but M. disstria differs from the others in one respect: it does not construct a communal tent. This difference in habit merits special consideration in any comparative study of larval behaviour, particularly in one concerned with the effects of physical factors upon the insects, since a tent modifies the effects of the physical environment considerably. Recently, a series of such studies was carried out, and one part of the work consisted of laboratory and field observations on the light reactions of larvae. The results obtained have raised a number of new questions which unfortunately cannot be answered now, hecause two of the species have been difficult to obtain in quantity since 1950. Nevertheless, the findings are presented here without additional delay, since they are of general interest, and other workers may wish to use them.

Identification and behavioral assays of the trail pheromone of the forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae)

1993 ◽  
Vol 71 (8) ◽  
pp. 1511-1515 ◽  
Author(s):  
T. D. Fitzgerald ◽  
F. X. Webster
Keyword(s):  
Trail Pheromone ◽  
Malacosoma Disstria ◽  
Forest Tent Caterpillar ◽  
Laboratory Studies ◽  
Malacosoma Americanum ◽  
Eastern Tent Caterpillar ◽  
Highly Sensitive ◽  
True Threshold ◽  
Behavioral Assays ◽  
Tent Caterpillar

Behavioral assays show that the steroid 5β-cholestan-3-one, isolated from the abdomen of the larva of the forest tent caterpillar (Malacosoma disstria), constitutes the chemical basis of trail following in this insect. Caterpillars follow artificial trails prepared from solvent dilutions of the compound at rates as low as 10−11 g∙mm−11 of trail, though the true threshold sensitivity is likely to be one or two orders of magnitude lower than this. Fourth-instar caterpillars store an average of 58 ng of the pheromone. Field and laboratory studies indicate that the compound is fully competitive with their authentic trails. The caterpillars are highly sensitive to differences in the concentration of the pheromone, preferring stronger trails to weaker trails. The caterpillars also respond to 5β-cholestane-3,24-dione, a chemical not found in M. disstria but known to be a component of the trail pheromone of the eastern tent caterpillar, Malacosoma americanum.

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

1988 ◽  
Vol 120 (10) ◽  
pp. 841-853 ◽  
Author(s):  
Dennis A. Lee
Keyword(s):  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Larval Mortality ◽  
Reproductive Potential ◽  
Moisture Stress ◽  
Mortality Factors ◽  
Corn Borer ◽  
Factors Affecting ◽  
Rainy Weather ◽  
Early Instar

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.

CO2 and O3 effects on host plant preferences of the forest tent caterpillar (Malacosoma disstria)

2005 ◽  
Vol 11 (4) ◽  
pp. 588-599 ◽  
Author(s):  
Jep Agrell ◽  
Brian Kopper ◽  
Evan P. McDonald ◽  
Richard L. Lindroth
Keyword(s):  
Host Plant ◽  
Malacosoma Disstria ◽  
Forest Tent Caterpillar ◽  
Tent Caterpillar

INFECTION AND MORTALITY OF SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA, AND FOREST TENT CATERPILLAR, MALACOSOMA DISSTRIA, CAUSED BY NUCLEAR AND CYTOPLASMIC POLYHEDROSIS VIRUSES

1969 ◽  
Vol 101 (12) ◽  
pp. 1269-1285 ◽  
Author(s):  
F. T. Bird
Keyword(s):  
Larval Development ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Malacosoma Disstria ◽  
Forest Tent Caterpillar ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Tent Caterpillar

AbstractCytoplasmic polyhedrosis viruses are, in general, more infectious to spruce budworm, Choristoneura fumiferana (Clemens), and forest tent caterpillar, Malacosoma disstria (Hübner), than the nuclear polyhedrosis viruses which affect these insects. The cytoplasmic polyhedrosis viruses interfere with and retard development of the nuclear polyhedrosis viruses.Larvae of both insects, as they grow older, develop resistance to both viruses. Resistance develops more rapidly and to a greater degree against the nuclear polyhedrosis than against the cytoplasmic polyhedrosis viruses.The nuclear polyhedrosis viruses are more lethal than the cytoplasmic polyhedrosis viruses, and all larvae infected with the nuclear polyhedrosis viruses die except those infected so late in larval development that they are able to pupate. Most young larvae infected with the cytoplasmic polyhedrosis virus die or are seriously affected, but infection has progressively less effect as the larvae mature.

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