PREDATION BY CALOSOMA SYCOPHANTA L. (COLEOPTERA: CARABIDAE): EVIDENCE FOR A LARGE IMPACT ON GYPSY MOTH, LYMANTRIA DISPAR L. (LEPIDOPTERA: LYMANTRIIDAE), PUPAE

1985 ◽  
Vol 117 (9) ◽  
pp. 1117-1126 ◽  
Author(s):  
Ronald M. Weseloh
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Ground Level ◽  
Mortality Factor ◽  
Substantial Impact ◽  
Entire Study ◽  
Dispersal Potential ◽  
Capture Recapture ◽  
The Impact ◽  
Entire Study Area

AbstractThe impact of predation by Calosoma sycophanta L. on an increasing prey population was assessed by recapturing marked adult beetles, periodically observing tagged gypsy moth pupae, and examining gypsy moth pupal remains in different microhabitats. Adult beetles dispersed in random directions but many tended to remain near the trap at which they were originally caught, suggesting a low dispersal potential. About 75% of the adult beetles present in the plot on one day were still present the next day. Capture–recapture estimates suggested that there were at most about 250 male beetles and half as many females/ha in the plot. Calosoma larvae destroyed 70% of tagged gypsy moth pupae under burlap bands on tree trunks near ground level, which was much more than any other mortality factor. Although this percentage was the same when mortality was assessed by looking at pupal remains within 5 m of the ground on tree trunks, pupae higher in trees and on leaves were not attacked as frequently. On average, about 40% of the pupae present in the entire study area were destroyed by Calosoma larvae. Each female beetle in the site would have had to produce about 30 progeny to have this effect. These data suggest that a relatively low number of adult beetles can have a substantial impact on gypsy moth populations.

scholarly journals Summer Diet of the Peregrine Falcon in Faunistically Rich and Poor Zones of Arizona Analyzed with Capture-Recapture Modeling

The Condor ◽  
2004 ◽  
Vol 106 (4) ◽  
pp. 873-886 ◽  
Author(s):  
David H. Ellis ◽  
Catherine H. Ellis ◽  
Beth Ann Sabo ◽  
Amadeo M. Rea ◽  
James Dawson ◽  
...  
Keyword(s):  
Peregrine Falcon ◽  
Falco Peregrinus ◽  
Entire Study ◽  
Northern Arizona ◽  
Prey Mass ◽  
Capture Recapture ◽  
Dietary Component ◽  
Prey Remains ◽  
Central Arizona ◽  
Entire Study Area

AbstractWe collected prey remains from 25 Peregrine Falcon (Falco peregrinus) territories across Arizona from 1977 to 1988 yielding 58 eyrie-years of data. Along with 793 individual birds (107 species and six additional genera), we found seven mammals and nine insects. In addition, two nestling peregrines were consumed. We found a larger dependence upon White-throated Swifts (Aeronautes saxatalis) and birds on migration in northern Arizona, while in southeastern and central Arizona average prey mass was greater and columbiforms formed the largest dietary component. In northern, central, and southeastern Arizona, 74, 66, and 56 avian prey taxa, respectively, were recorded. We used capture-recapture modeling to estimate totals of 111 ± 9.5, 113 ± 10.5, and 86 ± 7.9 (SE) avian taxa taken in these same three areas. These values are counterintuitive inasmuch as the southeast has the richest avifauna. For the entire study area, 156 ± 9.3 avian taxa were estimated to be taken by peregrines.Dieta Estival de Falco peregrinus en Arizona Comparando Zonas Ricas y Pobres en Avifauna Mediante un Modelo de Captura-RecapturaResumen. Desde 1977 a 1988 colectamos restos de presas en 58 nidos de Falco peregrinus a través de Arizona. Conjuntamente con 793 aves individuales (107 especies y seis géneros adicionales), encontramos siete mamíferos y nueve insectos. Además, fueron consumidos dos pichones de Falco peregrinus. En la zona norte encontramos una mayor dependencia sobre Aeronautes saxatalis y aves en migración, mientras que en las zonas sureste y central la masa promedio de presa fue más grande y los columbiformes constituyeron el componente principal de la dieta de Falco peregrinus. En las zonas norte, central y sureste se registraron 74, 66 y 56 taxa de aves presa, respectivamente. Para estimar el número total de taxa capturados por Falco peregrinus usamos un modelo de captura-recaptura. Los valores calculados fueron 111 ± 9.5, 113 ± 10.5 y 86 ± 7.9 (EE) taxa para las zonas norte, central y sureste, respectivamente. Estos valores no reflejan los que esperábamos, ya que la zona sureste tuvo una avifauna más rica. Se estimó que 156 ± 9.3 taxa fueron capturados por Falco peregrinus en la totalidad del área de estudio.

SUPERPARASITISM OF GYPSY MOTH, LYMANTRIA DISPAR (L.) (LEPIDOPTERA: LYMANTRIIDAE), LARVAE BY PARASETIGENA SILVESTRIS (ROBINEAU-DESVOIDY) (DBPTERA: TACHINIAE)

1992 ◽  
Vol 124 (3) ◽  
pp. 425-436 ◽  
Author(s):  
Juli R. Gould ◽  
Joseph S. Elkinton ◽  
Thomas M. ODell
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Fourth Instar ◽  
Laboratory Studies ◽  
Single Host ◽  
Negative Effect ◽  
Host Mortality ◽  
The Impact

AbstractIn the field, superparasitism of Lymantria dispar (L.) by Parasetigena silvestris (Robineau-Desvoidy) was not the result of random oviposition, but, because parasitoid eggs were aggregated, certain hosts were more likely to be parasitized than average. Parasitoid eggs were more aggregated when gypsy moth larvae were collected from under burlap bands than when larvae were collected elsewhere in the same 9-ha plot, resulting in lowered mortality due to parasitism. This finding suggests that collecting larvae from burlap bands may not provide accurate estimates of the impact of P. silvestris on populations of L. dispar. In laboratory studies, deposition of more than one egg on a single host significantly increased parasitoid emergence and host mortality. However, increasing superparasitism had a negative effect on both the probability that an individual parasitoid would survive to emerge from a host and the size of the puparium produced by the parasitoid. The probability of parasitoid survival was higher when fifth- rather than fourth-instar gypsy moth larvae were attacked, but puparia produced by parasitoids emerging from fifth-instar larvae were smaller.

scholarly journals Integrated statistical modelling of spatial landslide probability

2015 ◽  
Vol 3 (9) ◽  
pp. 5677-5715 ◽  
Author(s):  
M. Mergili ◽  
H.-J. Chu
Keyword(s):  
Regional Scale ◽  
Model Performance ◽  
Statistical Modelling ◽  
Cumulative Probability ◽  
Entire Study ◽  
Release Probability ◽  
Southern Taiwan ◽  
The Impact ◽  
Landslide Distribution ◽  
Entire Study Area

Abstract. Statistical methods are commonly employed to estimate spatial probabilities of landslide release at the catchment or regional scale. Travel distances and impact areas are often computed by means of conceptual mass point models. The present work introduces a fully automated procedure extending and combining both concepts to compute an integrated spatial landslide probability: (i) the landslide inventory is subset into release and deposition zones. (ii) We employ a simple statistical approach to estimate the pixel-based landslide release probability. (iii) We use the cumulative probability density function of the angle of reach of the observed landslide pixels to assign an impact probability to each pixel. (iv) We introduce the zonal probability i.e. the spatial probability that at least one landslide pixel occurs within a zone of defined size. We quantify this relationship by a set of empirical curves. (v) The integrated spatial landslide probability is defined as the maximum of the release probability and the product of the impact probability and the zonal release probability relevant for each pixel. We demonstrate the approach with a 637 km2 study area in southern Taiwan, using an inventory of 1399 landslides triggered by the typhoon Morakot in 2009. We observe that (i) the average integrated spatial landslide probability over the entire study area corresponds reasonably well to the fraction of the observed landside area; (ii) the model performs moderately well in predicting the observed spatial landslide distribution; (iii) the size of the release zone (or any other zone of spatial aggregation) influences the integrated spatial landslide probability to a much higher degree than the pixel-based release probability; (iv) removing the largest landslides from the analysis leads to an enhanced model performance.

NATURAL MORTALITY OF THE GYPSY MOTH ALONG A GRADIENT OF INFESTATION

1999 ◽  
Vol 131 (4) ◽  
pp. 507-519 ◽  
Author(s):  
V.G. Nealis ◽  
P.M. Roden ◽  
D.A. Ortiz
Keyword(s):  
Snow Cover ◽  
Relative Abundance ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Rank Order ◽  
Ground Level ◽  
Common Species ◽  
Natural Mortality ◽  
Single Source ◽  
Entomophaga Maimaiga

AbstractNatural mortality of gypsy moth [Lymantria dispar (L.) (Lepidoptera: Lymantriidae)] eggs, larvae, and pupae was examined at several locations along a gradient of infestation in Ontario, Canada. Most mortality of eggs was the result of exposure to winter weather. This mortality was mitigated in egg masses located near ground level where they benefited from snow cover. At least six species of parasitoids were found attacking gypsy moth larvae and pupae. The most common species were present in the same rank order of abundance at all sites. Identified pathogens were also present in most sites but their relative abundance varied greatly. The mycopathogen Entomophaga maimaiga Humber, Shimazu & Soper (Zygomycetes: Entomophthorales) was found at all sites and usually was responsible for the highest levels of observed, single-source mortality at the site.

Studies on the impact of two Nosema isolates from Bulgaria on the gypsy moth (Lymantria dispar L.)

2004 ◽  
Vol 87 (2-3) ◽  
pp. 105-113 ◽  
Author(s):  
Dörte Goertz ◽  
Daniela Pilarska ◽  
Manana Kereselidze ◽  
Leellen F. Solter ◽  
Andreas Linde
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
The Impact

The Impact of Internal Work Environment on the Retention of Healthcare Providers at Turaif General Hospital

2019 ◽  
Vol 10 (12) ◽  
pp. 1183-1199
Author(s):  
Mohammed Alrouili ◽  
Keyword(s):  
Work Environment ◽  
General Hospital ◽  
Professional Growth ◽  
Healthcare Providers ◽  
Entire Study ◽  
Internal Work ◽  
Research Findings ◽  
Study Population ◽  
The Right ◽  
The Impact

This study attempted to identify the impact of internal work environment on the retention of healthcare providers at Turaif General Hospital in the Kingdom of Saudi Arabia. In particular, the study aimed to identify the dimensions of work circumstances, compensation, and relationship with colleagues, professional growth, and the level of healthcare providers’ retention. In order to achieve the study goals, the researcher used the descriptive analytical approach. The researcher used the questionnaire as the study tool. The study population comprised all the healthcare providers at Turaif General Hospital. Questionnaires were distributed to the entire study sample that consisted of 220 individuals. The number of questionnaires valid for study was 183 questionnaires. The research findings were as follows: the participants’ estimate of the work circumstances dimension was high (3.64), the participants’ estimate of the compensation dimension was moderate (3.32), the participants’ estimate of the relationship with colleagues dimension was high (3.62), the participants’ estimate of the professional growth dimension was weak (2.39), and the participants’ estimate of healthcare providers’ retention level was intermediate (2.75). Accordingly, the researcher’s major recommendations are: the need to create the right atmosphere for personnel in hospitals, the interest of the hospital to provide the appropriate conditions for the staff in terms of the physical and moral aspects for building the work adjustment in the staff, and conducting training courses and educational lectures for personnel in hospitals on how to cope with the work pressures.

The Digital Divide and K-12 Student Computer Use

10.28945/2926 ◽  
2005 ◽  
Author(s):  
James N. Morgan ◽  
Craig A. VanLengen
Keyword(s):  
Digital Divide ◽  
Computer Use ◽  
Census Data ◽  
Internet Access ◽  
Demographic Characteristics ◽  
The Internet ◽  
Substantial Impact ◽  
Limited Basis ◽  
K 12 ◽  
The Impact

The divide between those who have computer and Internet access and those who do not appears to be narrowing, however overall statistics may be misleading. Measures of computer availability in schools often include cases where computers are only available for administration or are available only on a very limited basis (Gootman, 2004). Access to a computer and the Internet outside of school helps to reinforce student learning and emphasize the importance of using technology. Recent U.S. statistics indicate that ethnic background and other demographic characteristics still have substantial impact on the availability and use of computers by students outside of the classroom. This paper examines recent census data to determine the impact of the household on student computer use outside of the classroom. Encouragingly, the findings of this study suggest that use of a computer at school substantially increases the chance that a student will use a computer outside of class. Additionally, this study suggests that computer use outside of the classroom is positively and significantly impacted by being in a household with adults who either use a computer at work or work in an industry where computers are extensively used.

Sign in / Sign up

Export Citation Format

Share Document