EFFECTS OF DENSITY ON THE PROPORTION OF MALE AND FEMALE PUPAE IN GYPSY-MOTH POPULATIONS

1985 ◽  
Vol 117 (5) ◽  
pp. 535-539 ◽  
Author(s):  
Yves Mauffette ◽  
Luc Jobin
Keyword(s):  
Population Dynamics ◽  
Linear Regression ◽  
Sex Ratio ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Larval Density ◽  
Dynamic State ◽  
Regression Analyses ◽  
Important Indicator ◽  
Male And Female

AbstractThe numbers of larvae and pupae of the gypsy moth, Lymantria dispar L., were monitored in southwestern Quebec from June through August 1980 at 13 sites. In 10 sites, the proportion of male pupae was significantly different from an expected proportion of 0.5. Linear-regression analyses of the proportion of male pupae on larval density showed a significant increase in the number of male pupae with increasing larval density. Changes in the sex ratio could be an important indicator of the dynamic state of a population, and should be considered in modeling the population dynamics of gypsy moth.

Gypsy moth Lymantria dispar L. in the southern Urals: Patterns in population dynamics and modeling

2016 ◽  
Vol 6 (1) ◽  
pp. 57-69 ◽  
Author(s):  
V. G. Soukhovolsky ◽  
V. I. Ponomarev ◽  
G. I. Sokolov ◽  
O. V. Tarasova ◽  
P. A. Krasnoperova
Keyword(s):  
Population Dynamics ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Southern Urals ◽  
The Southern Urals

Effects of Spined Soldier Bug (Hemiptera Pentatomidae) Augmentation and Sticky Barrier Bands on Gypsy Moth (Lepidoptera: Lymantriidae) Density in Oak Canopies2

1994 ◽  
Vol 29 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Kevin W. Thorpe ◽  
Ralph E. Webb ◽  
Jeffrey R. Aldrich ◽  
Kathy M. Tatman
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Larval Density ◽  
Podisus Maculiventris ◽  
Egg Masses ◽  
Oak Trees ◽  
Gypsy Moths ◽  
Spined Soldier Bug ◽  
Augmentative Releases

The effects of sticky barrier bands, augmentative releases of the spined soldier bug, Podisus maculiventris (Say), and the deployment of P. maculiventris pheromone on gypsy moth, Lymantria dispar (L.), larval density in the canopy of oak trees were tested. Sticky barrier bands used alone reduced larval gypsy moth density by ≈35%. The release of 5,810 P. maculiventris nymphs per tree or the deployment of P. maculiventris pheromone to trees on which sticky barrier bands had been applied had no additional effect on gypsy moth larval density. None of the treatments affected the number of gypsy moth egg masses produced. Significantly more P. maculiventris adults were observed on trees with the pheromone, but higher numbers of nymphs were not subsequently observed on these trees. Counts of gypsy moths beneath burlap bands prior to gypsy moth pupation were about four times higher on unbanded than on banded trees, but counts of pupae beneath burlap bands did not differ between treatments.

Some Factors that Distort the Sex Ratio of the Gypsy Moth Porthetria dispar (L.) (Lepidoptera: Lymantriidae)

1963 ◽  
Vol 95 (5) ◽  
pp. 465-474 ◽  
Author(s):  
Robert W. Campbell
Keyword(s):  
New York ◽  
Sex Ratio ◽  
Gypsy Moth ◽  
Larval Density ◽  
Mortality Factor ◽  
Differential Mortality ◽  
Porthetria Dispar ◽  
Population Consequences ◽  
Adult Sex Ratio ◽  
The Town

AbstractDuring a study on the population dynamics of the gypsy moth, Porthetria dispar (L.), conducted in the Town of Glenville, New York, some factors were found to affect the sexes differentially. The importance of this differential mortality is indicated by the fact that 78 per cent of the variation in the logarithm of an index of population trend (the ratio of population density from year to year) was associated with the logarithm of adult sex ratio.Disease and desiccation during instars IV-VI and among pre-pupae were strongly selective against the female insects. This differential mortality caused a change in the pupal sex ratio from about 70 per cent females where no disease occurred to less than 25 per cent female pupae following an epizoötic. Ichneumonids, on the other hand, usually killed more male pupae than females, except when host size was reduced by excessive larval density and competition. The net result from this series of factors that distort the sex ratio has been to produce adult sex ratios varying from more than 80 per cent female moths to only 2 per cent females.In this host species, as in most other animals, it seems that the population consequences of a mortality factor that kills the host sexes in different proportions should be evaluated in terms of the more critical (female) sex destroyed.

Population dynamics and geographical distribution of the gypsy moth, Lymantria dispar, in Japan

2019 ◽  
Vol 434 ◽  
pp. 154-164 ◽  
Author(s):  
Maki N. Inoue ◽  
Yukari Suzuki-Ohno ◽  
Yuri Haga ◽  
Hiroshi Aarai ◽  
Tomoya Sano ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Geographical Distribution ◽  
Gypsy Moth ◽  
Lymantria Dispar

scholarly journals Occurrence of gypsy moth (Lymantria dispar L.) in the Slovak Republic and its outbreaks during 1945–2020

2021 ◽  
Vol 67 (2) ◽  
pp. 55-71
Author(s):  
Milan Zúbrik ◽  
Andrej Kunca ◽  
Ján Kulfan ◽  
Slavomír Rell ◽  
Christo Nikolov ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Slovak Republic ◽  
Tree Plantations ◽  
Moth Population ◽  
The Past ◽  
Entomophaga Maimaiga ◽  
History Of

Abstract The gypsy moth is one of the most serious pests in forests and fruit tree plantations over prevailing parts of the Northern Hemisphere. This work is based on a literature review, and presents history of gypsy moth Lymantria dispar L., observed in Slovak forests within the period 1945–2020. The life cycle, hosts, natural enemies, population dynamics of pests, impact of outbreaks on forests and different management methods used in the past are discussed. Since 1945, there were nine gypsy moth outbreaks in Slovakia. Between 1945 and 2020, a total of 155,034 ha of deciduous forests were touched with varying intensity, representing an average annual damage of 2,040 ha. The strongest outbreak culminated in 2004. Totally 51,479 ha were attacked in the period of 2000–2008. We have found outbreak periods that repeat with frequency of 7.8 ±2.2 years and the average outbreak phase lasts 3.1 ±1.1 years. The period between two subsequent outbreaks seems to be more or less constant and duration of the outbreak phase seems to be gradually shortened during the study period. Several factors influencing the gypsy moth population dynamics in Slovakia are discussed. The role of biological control by using entomopathogenic fungus Entomophaga maimaiga is described.

scholarly journals Sex ratio distortion and severe inbreeding depression in the gypsy moth Lymantria dispar L. in Hokkaido, Japan

Heredity ◽  
1999 ◽  
Vol 83 (3) ◽  
pp. 290-297 ◽  
Author(s):  
Yasutomo Higashiura ◽  
Michio Ishihara ◽  
Paul W Schaefer
Keyword(s):  
Sex Ratio ◽  
Inbreeding Depression ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Ratio Distortion ◽  
Sex Ratio Distortion
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