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Biomedical subjects

J J Petersen

Publications and source records attributed to J J Petersen.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of field propagation of Muscidifurax zaraptor (Hymenoptera: Pteromalidae) for control of flies associated with confined beef cattle.

The parasitic wasp Muscidifurax zaraptor Kogan & Legner was mass-reared in the field to control house flies, Musca domestica L., on two Nebraska beef cattle confinements. About 50,000 freeze-killed house fly pupae were exposed to a single release of M. zaraptor in the field. Placement of six additional cohorts of 50,000 freeze-killed pupae at the release sites at 2-wk intervals resulted in a mean parasite emergence of 56.4% over the study period. Mean fly mortality of 37.3 and 25.9% occurred in sentinel pupae placed around the perimeter of two release sites, compared with 3.9% for two control sites. We demonstrated a negative correlation between host reduction in sentinel cohorts and distances the cohorts were placed from parasite release sites. However, data indicated that other environmental factors also influenced the success of M. zaraptor in locating sentinel hosts. Correlation between mortality in sentinel pupae and numbers of parasites released was not evident. Temperatures above approximately 28 degrees C appeared to reduce the effectiveness of M. zaraptor.

Animals↗
PubMed1991

Infectivity of Serratia marcescens (Eubacteriales: Enterobacteriaceae) in Stomoxys calcitrans (Diptera: Muscidae).

Serratia marcescens Bizio, a facultative pathogen of insects, was isolated from stable flies, Stomoxys calcitrans (L.), collected from Nebraska beef cattle feedlots and dairies. Infection rates in laboratory-reared stable flies infected by topical exposures to the bacterium were 57 and 64% in two experiments. Per os exposures to sucrose and water solutions, and bovine blood inoculated with S. marcescens, produced mortality rates of about 45 and 10%, respectively.

Animals↗
PubMed1990

Effects of host age, host density and parent age on reproduction of the filth fly parasite Urolepis rufipes (Hymenoptera: Pteromalidae).

Urolepis rufipes Ashmead, a pteromalid wasp, was recently discovered parasitizing house fly and stable fly pupae in eastern Nebraska dairies. Studies have been conducted on the biology of this parasite to evaluate its potential as a biological control agent of stable flies (Stomoxys calcitrans (L.] and house flies (Musca domestica L.). House fly pupae were suitable as hosts for U.rufipes at all ages; however, significantly higher parasitism occurred on host pupae aged 96-120 h. Parasite-induced mortality (host mortality without progeny production) was higher than for other pteromalid parasites of filth flies under similar conditions. Parasitism increased with parasite--host ratio at 20 degrees C; however, the opposite was noted at 30 degrees C for parasite--host ratios ranging from 5:50 to 50:50. Fly eclosion decreased as parasite--host ratio increased at 20 degrees C, and no host eclosion occurred at the highest parasite--host ratios (20:50 and 50:50) at 30 degrees C. Females produced an average of 18.6 female and 7.6 male progeny. 88% of the progeny were produced during the first 6 days post parental eclosion. The short life span, low progeny emergence rate and high per cent host eclosion, in comparison with other parasite species, suggests that the Nebraska strain of U.rufipes may not an effective biological control agent of house flies.

Age Factors↗
PubMed1988

Early season dispersal of Muscidifurax zaraptor (Hymenoptera: Pteromalidae) utilizing freeze-killed housefly pupae as hosts.

The pteromalid wasp, Muscidifurax zaraptor Kogan and Legner, was released at three locations at a dairy in May before housefly and stable fly breeding had begun. Freeze-killed housefly pupae were placed adjacent to the emerging parasites at biweekly intervals for a 6-week period. Hosts placed out weeks 0 and 2 were heavily parasitized. Decreased parasitism in hosts placed out at week 4 suggested that many of the M. zaraptor had dispersed or died. High parasitism of hosts placed in the field at week 6 was the result of second generation parasites emerging from pupae placed out at week 0. Parasitism of freeze-killed housefly pupae placed 6 m and in the four cardinal directions from the release points was similar but lower than for hosts placed adjacent to the emerging parasites. The study demonstrated that emerging M. zaraptor readily utilized nearby freeze-killed housefly pupae but the availability of these hosts did not deter the parasites from searching for additional hosts.

Animals↗
PubMed1978

Release of Romanomermis culicivorax for the control of Anopheles albimanus in El Salvador I. Mass production of the nematode.

The mosquito parasite, Romanomermis culicivorax, was mass produced for the treatment of 144,000 m2 of Anopheles albimanus breeding area in El Salvador. The production of the necessary inoculum required the exposure of 1.6 X 10(6) first-instar Culex p. quinque-fasciatus larvae to 137 X 10(6) preparasites (1:14 ratio) each week for 6 weeks. The method employed produced an average 13.7 g (ca. 2,200/g) of postparasitic nematodes per rearing tray (20,000 mosquitoes), a total of 6,392 g (14.1 lb) for the 6-week period, and 425 cultures.

Anopheles↗
PubMed1978

Release of Romanomermis culicivorax for the control of Anopheles albimanus in El Salvador II. Application of the nematode.

The mosquito breeding area of Lake Apastepeque, El Salvador, was treated 11 times over a 7-week period with Romanomermis culicivorax to control Anopheles albimanus and An. p. pseudopunctipennis. Parasitism averaged 58% but varied greatly from treatment to treatment and from site to site. However, three applications made during evening hours to avoid wind and wave action on the lake produced an average 86% parasitism. No significant differences in susceptibility to R. culicivorax were found between instars or between species. Also, no correlation was found between nematode dosage rates and levels of parasitism. Though the parasitism averaged about 60% of the desired level, Anopheles populations dropped from more than 10 per dip at the beginning of the release program to 0.6 per dip at the end of the release period (a 94% reduction). This is the first successful attempt to control mosquitoes on a large scale by using a parasite or pathogen.

Anopheles↗