Reservoir competence of Carcinops pumilio for Salmonella enteritidis (Eubacteriales: Enterobacteriaceae).

The histerid beetle Carcinops pumilio (Erichson) occurs naturally in poultry house manure and is an important predator of house fly eggs and larvae. Because efforts to commercially produce C. pumilio have been unsuccessful, one fly control strategy under consideration is the direct transport of adult C. pumilio between poultry houses to facilitate their establishment. However, we demonstrate that C. pumilio is a competent reservoir of Salmonella enteritidis (Gaertner). Adult C. pumilio exposed to S. enteritidis-inoculated house fly eggs harbored the bacterium externally and internally for up to 4 and 13 d, respectively, and feces were culture-positive for S. enteritidis for at least 14 d. This suggests that C. pumilio can be a reservoir of S. enteritidis; therefore its movement between poultry facilities should be carefully considered.

Spatio-temporal dynamics of resident and immigrating populations of Carcinops pumilio (Coleoptera: Histeridae) in high-rise poultry facilities.

The histerid beetle Carcinops pumilio (Erichson) is an important natural predator of the house fly, Musca domestica L., in accumulated poultry house manure. We examined the spatio-temporal dynamics of establishing adult C. pumilio in high-rise poultry facilities using conventional and geostatistical approaches. The growth curves of resident and immigrating populations followed logistic and exponential equations, respectively, and their rates of establishment were statistically the same. Frequency distributions for both populations were strongly positively skewed, and approximately 53% of sampling intervals were significantly modeled by the negative binomial. Taylor's power law indicated both populations to be aggregated, and gave excellent least squares regression fits to both populations. Correlograms, a geostatistical tool, suggested little local spatial structure (e.g., 2nd order effects) for either population. The resident population was 'randomly' aggregated: beetles were clustered around randomly distributed aggregations of house fly immatures. The immigrating population exhibited significant spatial trends (e.g., 1st order effects) consistently seen at all sampling intervals. C. pumilio spatial structure was represented primarily by this spatial trend; thus, immigration of C. pumilio may have been either a singular event in time, or initiating at 1 or multiple times from a singular location.

Flotation method for extracting insects from poultry manure samples.

We examined the efficacy of a sucrose-based flotation method for extracting 3 prevalent insect species from poultry house manure: 3rd-instar Musca domestica L. (Diptera: Muscidae), Carcinops pumilio (Erichson) (Coleoptera: Histeridae) adults, and Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) adults. A 0.6 M sucrose solution in distilled water altered the specific gravity to 1.2 and caused the 3 species to float to the water surface for easy separation. An analysis of variance (ANOVA) showed significant effects of the solution volume to sample mass ratio on recovery rates (F = 35.96, P < 0.0001), but no differences in species-specific recovery rates (F = 0.97, P = 0.3824). Among samples agitated in a ratio of at least 3.2 ml solution per gram of sample mass, we observed neither significant ratio effects (F = 1.37, P = 0.2442) nor significant differences in species-specific recovery rates (F = 2.05, P = 0.1353); overall, we recovered 97.49 +/- 0.20% of all individuals of the 3 species. Our analyses demonstrated that sucrose-based flotation was a statistically valid method of collecting these species from poultry manure samples.

Flight behavior of Musca domestica and Stomoxys calcitrans (Diptera: Muscidae) in a Kansas dairy barn.

Aerial density, flight thresholds, and periodicity were estimated for the house fly, Musca domestica L., and the stable fly, Stomoxys calcitrans (L.), from data collected by suction traps located in a dairy barn in Kansas between 1 July and 31 October 1970. M. domestica catches increased from July to August, declining to near zero by the end of October. S. calcitrans catches peaked in July and September with a major decline in August. Both species exhibited a diel periodicity in flight with maximal activity during the early afternoon. Secondary peaks were detected in the late afternoon or early evening. M. domestica activity peaked about two hours after S. calcitrans. Male and female S. calcitrans flight activity patterns were slightly different, but peaked at the same time. Both species flew at temperatures between 20 and 38 degrees C. At temperatures over 33 degrees C, stable fly activity decreased rapidly. No upper threshold for flight by M. domestica was detected. The median temperature-flight thresholds of male and female S. calcitrans were significantly different, with females flying at lower temperatures than males. The threshold for M. domestica flight was lower than for S. calcitrans. The shape of the temperature-flight relationship indicated that the flight threshold was determined by heat accumulation.

A feed additive to control flies in poultry manure.

To determine methoprene's effect on fly emergence from poultry manure, 18,000 8-wk.-old caged pullets were fed continuously 10 gm. of methoprene per ton of feed 42 days. Hatch mates (13,500) in an adjacent, similarly constructed and equipped house were fed untrated feed. Data on fly emergence were recorded twice a week after counting average numbers of flies in fly traps, in buckets of manure, and on fly strips and spot cards. Differences between average counts in the treated and control groups were significant by each of the four data-gathering methods. The methoprene reduced fly emergence by 77.0% in manure buckets, 65.5% in fly traps, but increased fly emergence 19.2% on fly strips, and 92.2% on spot cards. We attribute the increases in fly counts by the latter two counting methods in the treated house to migration of flies from adjacent untreated houses.