Search USGSSearch

SEARCH · Search USGS

Results for “Journal of Entomological Science”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

2 recordsLinked to original sources

Parasitization of meadow voles, Microtus pennsylvanicus (ORD), by American dog ticks, Dermacentor variabilis (Say), and adult tick movement during high host density

The numbers of host-seeking adult American dog ticks, Dermacentor variabilis (Say), in a sweet gum field in Maryland reflected changes in the population density of a host species, the meadow vole, Microtus pennsylvanicus (Ord), which within 1.5 yr fell from an estimated 157 to 8 voles on a 0.8 ha grid. During high vole density, there was no significant difference ( P > 0.05) in tick burdens between sexes on an annual basis. Juvenile and subadult voles (< 33 g) harbored significantly fewer D. variabilis larvae and nymphs than did mature voles (> 33 g) on an annual basis. However, during periods of both peak host-seeking activity by D. variabilis larvae and nymphs and high host density nearly all the voles examined were infested. There was no evidence of a relationship between weight of adult voles and likelihood of parasitization by D. variabilis during months of moderate tick host-seeking activity. Of 163 adult D. variabilis recaptured ≥ one week after marking, 86 (52.7%) had moved > 3.8 m, 59 (36.2%) > 5.3 m.

Journal of Entomological Science

Thermoregulation in larval aggregations of carrion-feeding blow flies (Diptera: Calliphoridae)

The growth and development of carrion-feeding calliphorid (Diptera Calliphoridae) larvae, or maggots, is of great interest to forensic sciences, especially for estimation of a postmortem interval (PMI). The development rate of calliphorid larvae is influenced by the temperature of their immediate environment. Heat generation in larval feeding aggregations (=maggot masses) is a well-known phenomenon, but it has not been quantitatively described. Calculated development rates that do not include internally generated temperatures will result in overestimation of PMI. Over a period of 2.5 yr, 80 pig, Sus scrofa L., carcasses were placed out at study sites in north central Florida and northwestern Indiana. Once larval aggregations started to form, multiple internal and external temperatures, and weather observations were taken daily or every few days between 1400 and 1800 hours until pupation of the larvae. Volume of each aggregation was determined by measuring surface area and average depth. Live and preserved samples of larvae were taken for species identification. The four most common species collected were Lucilia coeruleiviridis (=Phaenicia) (Macquart) (77%), Cochliomyia macellaria (F.) (8.3%), Chrysomya rufifaces (Macquart) (7.7%), and Phormia regina (Meigen) (5.5%). Statistical analyses showed that 1) volume of a larval mass had a strong influence on its temperature, 2) internal temperatures of masses on the ground were influenced by soil temperature and mass volume, 3) internal temperatures of masses smaller than 20 cm3 were influenced by ambient air temperature and mass volume, and 4) masses larger than 20 cm3 on the carcass had strongly regulated internal temperatures determined only by the volume of the mass, with larger volumes associated with higher temperatures. Nonsignificant factors included presence of rain or clouds, shape of the aggregation, weight of the carcass, species composition of the aggregation, time since death, or season.

Journal of Medical Entomology