The Role of Disease and Desiccation in the Population Dynamics of the Gypsy Moth Porthetria dispar (L.) (Lepidoptera: Lymantriidae)

1963 ◽  
Vol 95 (4) ◽  
pp. 426-434 ◽  
Author(s):  
Robert W. Campbell
Keyword(s):  
New York ◽  
Population Dynamics ◽  
Gypsy Moth ◽  
Disease Incidence ◽  
Egg Mass ◽  
Population Reduction ◽  
Porthetria Dispar ◽  
Insect Density ◽  
The Town

AbstractThe population dynamics of the gypsy moth, Porthetria dispar (L.), are being studied on 10 sites in the Town of Glenville, New York. This paper discusses the role of disease and a condition here termed “desiccation” in the dynamics of these populations during a 4-year period, 1958-1961 inclusive.The term “desiccation” refers to dead pre-pupae that appeared shriveled, and were stiff to the touch, and which had a solid mass of food in their gut. The incidence of desiccation among pre-pupae was closely related to the number of eggs per egg mass produced at the end of the generation (a measure of relative insect density).Disease incidence among larval gypsy moth populations was directly related to insect density. Disease incidence was also related to site conditions, with higher mortality occurring in wet sites.When larval populations reached high densities, they always declined from the dense level within a few generations. These declines ranged from a sudden drastic reduction to a much more gradual decline. The former was preceded by virtual food exhaustion, while the latter was not usually preceded by exhaustion of the food supply.Disease and desiccation were primary factors in producing the sudden type of population reduction noted above. Pathogens may also play an important part in the more gradual type of decline, but this point remains to be clarified.

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.

Some Ichneumonid-Sarcophagid Interactions in the Gypsy Moth Porthetria dispar (L.) (Lepidoptera: Lymantriidae)

1963 ◽  
Vol 95 (4) ◽  
pp. 337-345 ◽  
Author(s):  
Robert W. Campbell
Keyword(s):  
New York ◽  
Gypsy Moth ◽  
Host Population ◽  
Porthetria Dispar ◽  
The Town

AbstractFour ichneumonid species, Itoplectis conquisitor (Say), Pimpla pedalis Cress., Theronia atalantae (Poda), and Theronia hilaris (Say), were seen attacking the gypsy moth, Porthetria dispar (L.), in the Town of Glenville, Schenectady County, New York. These species stung and killed many more host pupae than they successfully parasitized (success here being measured by the development of an ichneumonid offspring within the host). The ratio between the total number of hosts stung by ichneumonids and the number of ichneumonid offspring emerging was different for each of the three primary ichneumonids studied, ranging from 4 to 1 for T. atalantae to more than 200 to 1 for I. conquisitor.The sarcophagids associated with the gypsy moth, although apparently parasitic, are largely scavengers. Their attacks almost always follow those of ichneumonids. Since the sting by an ichneumonid kills the host but is not always discernible, the number of pupae containing sarcophagid larvae has been used to, indicate the true effects of ichneumonids on the host population.

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.

RELATIONSHIPS BETWEEN DIFFERENT SAMPLING PROCEDURES FOR THE GYPSY MOTH, PORTHETRIA DISPAR (LEPIDOPTERA: LYMANTRIIDAE) AND ITS NATURAL ENEMIES

1974 ◽  
Vol 106 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Ronald M. Weseloh
Keyword(s):  
Gypsy Moth ◽  
Natural Enemies ◽  
Sampling Methods ◽  
Egg Mass ◽  
Regression Analyses ◽  
Field Sampling ◽  
Tree Defoliation ◽  
Porthetria Dispar ◽  
Sampling Procedures ◽  
Adult Abundance

AbstractA variety of field sampling procedures were used to estimate population levels of the gypsy moth, Porthetria dispar (L.) (Lepidoptera: Lymantriidae), and the following natural enemies: Apanteles melanoscelus (Ratzeburg) (Hymenoptera: Braconidae), Blepharipa scutellata (Robineau-Desvoidy) (Diptera: Tachinidae), and Calosoma sycophanta (L.) (Coleoptera: Carabidae). Regression analyses indicated, among other things, that gypsy moth egg mass counts were not good indicators of tree defoliation, but that defoliation and number of gypsy moth larvae on branch terminals were correlated. Estimates of adult abundance of A. melanoscelus and B. scutellata were negatively correlated with estimates of numbers of immature parasitoids. Numbers of gypsy moth larvae parasitized by A. melanoscelus were positively correlated with numbers of A. melanoscelus cocoons sampled. Numbers of adult C. sycophanta were not correlated with larval numbers of this insect. It was concluded from these results that the procedures used to estimate numbers of natural enemy adults were not entirely adequate, but may be useful for supplementing other sampling methods.

scholarly journals Hard Times as Bodie: the allegorical functionality in E.L. Doctorow’s Welcome to Hard Times (1960)

Literator ◽  
2007 ◽  
Vol 28 (2) ◽  
pp. 49-74
Author(s):  
P. Van der Merwe
Keyword(s):  
New York ◽  
Theoretical Analysis ◽  
Historical Events ◽  
Starting Point ◽  
Hard Times ◽  
The Town ◽  
Basic Level

“Welcome to Hard Times” (1960), E.L. Doctorow’s first novel, differs from the rest of his oeuvre because it is not set in a metropolitan context like New York. References to historical events that contain an apparent “mixture” of “factual” and fictional elements that are typical of Doctorow’s oeuvre are less prominent than in his other fiction, though definitely not absent. An analysis of the pioneer setting, the town Hard Times, reveals that other settings (including metropolitan ones like New York) are not merely representations of specific contexts, but portrayals with allegorical elements. Criticism of Doctorow’s fiction does not sufficiently point out the rationale of Doctorow’s fiction in relation to his first novel: it is not just the basic level that contains the true topicality but also the underlying causal and thematic relationships. This article sets out to explore “Welcome to Hard Times” as a case in point. The objective of this article is therefore also to show that an analysis of this novel provides a valuable basis for understanding the allegorical character of his fiction. Angus Fletcher’s theoretical analysis, “Allegory: the theory of a symbolic mode” (1964), serves as a useful starting point for the analysis of the allegorical value of space and the town Hard Times as a microcosmic or symbolic society, as well as the “daemonic agents” in the town and the role of causality.

38. Max Brodel (1870-1941): His artistic influence on surgical learning at John Hopkins Medical School

2007 ◽  
Vol 30 (4) ◽  
pp. 47
Author(s):  
P. Pace-Asciak ◽  
T. Gelfand
Keyword(s):  
New York ◽  
Neck Surgery ◽  
The United States ◽  
Spoken Word ◽  
Medical Illustration ◽  
3 Dimensional ◽  
Teaching Anatomy ◽  
Computer Based ◽  
Pathological Disease

Medical students depend on illustration to learn anatomical facts and details that may be too subtle for the written or spoken word. For surgical disciplines, learners rely on tools such as language, 2-dimensional illustrations, and 3-dimensional models to pass on important concepts. Although a photograph can convey factual information, illustration can highlight and educate the pertinent details for understanding surgical procedures, neurovascular structures, and the pathological disease processes. In order to understand the current role of medical illustration in education, one needs to look to the past to see how art has helped solve communication dilemmas when learning medicine. This paper focuses on Max Brodel (1870-1941), a German-trained artist who eventually immigrated to the United States to pursue his career as a medical illustrator. Shortly after his arrival in Baltimore, Brodel made significant contributions to medical illustration in Gynecology at John Hopkins University, and eventually in other fields of medicine such as Urology and Otolaryngology. Brodel is recognized as one of America’s most distinguished medical illustrators for creating innovative artistic techniques and founding the profession of medical illustration. Today, animated computer based art is synergistically used with medical illustration to educate students about anatomy. Some of the changes that have occurred with the advancement of computer technology will be highlighted and compared to a century ago, when illustrations were used for teaching anatomy due to the scarcity of cadavers. Schultheiss D, Udo J. Max Brodel (1870-1941) and Howard A.Kelly (1858-1943) – Urogynecology and the birth of modern medical illustration. European Journal of Obstetrics & gynecology and Reproductive Biology 1999; 86:113-115. Crosby C. Max Brodel: the man who put art into medicine. New York: Springer-Verlag, 1991. Papel ID. Max Brodel’s contributions to otolaryngology – Head and Neck surgery. The American Journal of Otology 1986; 7(6):460-469.

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