Stable Fly Pupae Research Articles

LABORATORY STUDIES ON THE LIFE CYCLE AND PREY RELATIONSHIPS OF PACHYLISTER CAFFER ERICHSON (COLEOPTERA: HISTERIDAE)

The biology and behavior of Pachylister caffer Erichson were studied to determine the developmental history of this cattle manure-attracted, predaceous beetle and to evaluate its potential for controlling the horn fly, Haematobia irritans (L.). Females deposit eggs singly 0.5–3.0 cm deep in soil beneath cattle manure. Embryonic incubation averaged 3.9 days, larval development (two instars) 37.3 days, and pupal development 16.4 days. Development from oviposition to adult averaged 57.6 days. Prey consumption of horn fly; stable fly, Stomoxys calcitrans (L.), and house fly, Musca domestica L., pupae by P. caffer larvae was compared. Although the total weight of all prey species consumed was similar, the number of prey consumed and the development time of beetle larvae varied with prey species. Horn fly pupae accounted for 65.6% of the prey consumed, whereas stable fly and house fly pupae accounted for 26.9% and 7.5%, respectively.

Parasites that attack stable fly and house fly (Diptera: Muscidae) puparia during the winter on dairies in northwestern Florida.

Throughout the winter and early spring months, stable fly, Stomoxys calcitrans (L.), and house fly, Musca domestica L., puparia were collected from silage, hay, and manure from six dairies in northwestern Florida and evaluated for parasitism. Of the puparia producing flies or parasites, 23% of the stable flies and 46% of the house flies were parasitized. The predominant parasite observed attacking muscoid flies (76% for stable flies and 58% for house flies) was Spalangia cameroni Perkins. Muscidifurax sp. was recovered from 11 and 36% of the stable fly and house fly pupae, respectively. Other parasite species encountered were Spalangia endius Walker and S. nigroaenea Curtis. Significantly more parasitized fly pupae were collected from silage than from hay residues or manure. Winter and early spring parasite populations in northwestern Florida appear to be present as long as viable fly pupae are available to support the developing parasites.

Host Preference and Seasonal Distribution of Pteromalid Parasites (Hymenoptera: pteromalidae) of Stable Flies and House Flies (Diptera: Muscidae) Associated with Confined Livestock in Eastern Nebraska1

A total of 528 samples totaling 37,639 house fly and 11,447 stable fly pupae were collected from 34 confined bovine feedlots and dairies in eastern Nebraska and examined for pteromalid parasites. Parasitism averaged 14.2% for house flies and 7.9% for stable flies. Levels of parasitism were consistent from feedlot to feedlot but were higher on the dairies. Seven parasite species were identified: Muscidifurax spp. made up 56%, Spalangia cameroni 11%, S. nigroaenea 31%, S. nigra 1%, and others 1% of the 5,881 parasites attacking house flies; Muscidifurax spp. made up 25%, S. cameroni 26%, S. nigroaenea 44%, S. nigra 4%, and others 1% of the 979 parasites attacking stable flies. Muscidifurax spp. were recovered significantly ( P = 0.01) more often from house flies, and S. nigra were recovered significantly ( P = 0.01) more often from stable flies. Parasite activity was initially observed during the first week in June and increased to a mean of 20.9% during October. The activity and the species of parasites attacking fly pupae were influenced by the habitat in which the hosts were found

Characterization and seasonal distribution of breeding sites of stable flies and house flies (Diptera: Muscidae) on eastern Nebraska feedlots and dairies.

Sixteen different classes of breeding sites for the stable fly, Stomoxys calcitrans (L.), and the house fly, Musca domestica L., were identified through weekly searches, from late May to early October, on four small feedlots, one large feedlot, and one dairy, and single searches of an additional 25 feedlots and three dairies. A total of 526 samples of ca. 100 fly pupae per sample showed fencelines, drainage ditches, and haylage to account for 26.2, 18.4 and 12.9%, respectively, of the total stable fly pupae sampled on small feedlots. Swine manure and haylage were the most frequent and consistent producers of house flies on the small feedlots, accounting for 19.9, and 18.8%, respectively, of the total population sampled. Spilled feed was a consistent breeding site on the large feedlot and accounted for 53.0 and 16.0% of the sampled stable flies and house flies, respectively; stored manure on dairies accounted for 31.7 and 25.3% of the total stable flies and house flies sampled, respectively.

Purification and characterization of chitinase from the stable fly, Stomoxys calcitrans

Chitinase that appears as a single band by electrophoresis was purified from stable fly pupae. The chitinase has no cation requirements for activity, and a broad pH optimum around 5. The molecular weight of the chitinase, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is 48,000, and the isoelectric point is 4.85. Kinetic properties were determined using acetylated chitosan. The K m is 33 m m and V is 1.21 μmol/min/mg protein. The insect growth regulator diflubenzuron had no effect on chitinase activity.

Inhibition of DNA synthesis by diflubenzuron in pupae of the stable fly Stomoxys calcitrans (L.)

Biochemical assays of stable fly pupae treated with diflubenzuron at the white prepupal stage and then injected with either [ 3H]thymidine or [ 14C]thymidine showed no differences in uptake of the thymidine at 0–4, 0–24, 20–21, or 22–24 hr after injection of the radiolabeled thymidine. However, at 32–36 hr the diflubenzuron pupae incorporated only 10–11% of the amount of labeled thymidine incorporated by the untreated pupae. Autoradiographs taken from diflubenzuron-treated pupae at 22–24 and 32–36 hr after injection of the labeled thymidine showed that a reduction in DNA synthesis had occurred in cells originating from the imaginal epidermal histoblasts. The reduction in DNA synthesis at 22–24 hr was not detectable by the biochemical assay since the number of proliferating epidermal cells was too small a proportion of the total number of cells undergoing histogenesis at this time period. Thus, the insect growth regulator, diflubenzuron, appears to be cell specific in this species of fly in that the reduction in DNA synthesis is observed only in cells originating from the imaginal epidermal histoblasts. However, it is not known at this time whether this effect is primary or secondary.

Interrelationship between Two Species of Muscoid Flies and the Pupal Parasite Spalangia Endius (Hymenoptera: Pteromalidae)

When Spalangia endius was exposed to pupal house flies. Musca domestica, at host-parasite ratios of 0.5:1 through 25:1, the percentage of parasitism decreased and the number of parasitized pupae increased as the ratio of pupae to parasites increased. There were significant differences in the number of pupae parasitized per adult wasp, and the number of progeny produced per adult wasp associated with the ratio of host to parasite. There was a significant difference in the number of pupae parasitized per adult wasp associated with age of pupae at ratios above 1:5. i.e., more for 1- and 2-day-old than 3-day-old pupae. When S. endius was offered a choice of pupae of the house fly or the stable fly, Stomoxys calcitrans, the percentage of parasitism was similar to that obtained when house fly pupae or stable fly pupae were exposed to the wasps.