Large sticky traps for capturing house flies and stable flies in dairy calf greenhouse facilities.

Large sticky traps were evaluated for stable fly, Stomoxys calcitrans (L.), and house fly, Musca domestica L., (Diptera: Muscidae) capture under field conditions in 5 dairy calf greenhouse facilities in New York. The farm with the highest stable fly capture had the highest house fly capture, and the farm with the lowest stable fly capture had the lowest house fly capture, suggesting that fly management practices greatly influenced trap captures. In general, stable fly populations, as reflected by increased trap capture, generally rose during the summer. Numbers of flies counted on calves did not increase, however, suggesting that the traps greatly reduced the potential stable fly pressure on the calves as the fly population increased. Estimated number of stable flies and house flies captured during this 10-wk study exceeded 142,000 and 900,000, respectively. Producers were generally pleased with the trap performance and most felt that these traps reduced flies in their calf greenhouses to acceptable levels.

Seasonal variation in Carcinops pumilio (Coleoptera: Histeridae) dispersal and potential for suppression of dispersal behavior.

Seasonal dispersal of Carcinops pumilio (Erichson) was evaluated using two trapping methods-a black-light pitfall trap and a mesh-bottomed trap placed on poultry manure. The black-light trap collected larger numbers than the mesh-bottomed trap from March through June. The mesh-bottomed trap gathered larger numbers of beetles from June through August and numbers were less variable throughout the year. Often, when very low numbers of beetles were recovered from manure cores, large numbers of beetles could be collected with the black-light trap suggesting that beetle density may not be an important factor in dispersal behavior. The greatest dispersal in the dispersal arenas (approximately 90%) occurred using beetles collected by both trap types in June 2000. Beginning in March and ending in August, a cyclic rise and then fall pattern in both laboratory dispersal and beetle collections was observed. Trap collection patterns were similar in both years of the study. In January and March, we were unable to prevent dispersal behavior of beetles captured in black-light traps. However, in May, after beetles had been in a dispersal phase for several months, we were able to suppress dispersal. In contrast, dispersal behavior among beetles captured with the mesh-bottomed trap did not change following the photoperiod-altered exposure.

Impact of exposure length and pupal source on Muscidifurax raptorellus and Nasonia vitripennis (Hymenoptera: Pteromalidae) parasitism in a New York poultry facility.

Commercially obtained Nasonia vitripennis Walker and Muscidifurax raptorellus Kogan & Legner were released weekly for 12 wk into a high-rise, caged-layer poultry house. After the release period, parasitoids were sampled using sentinel house fly (Musca domestica L.) pupae that were either laboratory-reared or field-collected as larvae and exposed for 2, 4, 7, and 14 d. Parasitoid-induced mortality was observed in 31% of laboratory colony pupae and in 26% of field-collected pupae, whereas successful parasitism rates of 48 and 51% were observed from these pupal sources, respectively. Parasitism was primarily by M. raptorellus (88%), and Muscidifurax raptor Girault & Sanders (11%), while N. vitripennis accounted for <1%. Percent female progeny ranged from 43%, in M. raptorellus to 76% in N. vitripennis. Parasitoid emergence from 2-d exposed sentinel pupae was the lowest of all treatments. Parasitoid emergence from 7-d exposed sentinel pupae was the highest of all treatments. We found no differences between pupal source, suggesting that when sampling for M. raptor, M. raptorellus, and N. vitripennis, in poultry facilities, pupal source is not a confounding factor.

Monitoring insecticide resistance in house flies (Diptera: Muscidae) from New York dairies.

House flies were collected from dairies across New York state and the levels of resistance to seven insecticides were measured using standard laboratory assays with three to five diagnostic concentrations. The highest levels of resistance were found for tetrachlorvinphos, permethrin and cyfluthrin. Although levels of resistance to methomyl were somewhat lower, they were among the highest ever reported for field-collected house flies. Resistance to pyrethrins was limited primarily to the lowest diagnostic concentration. House flies were susceptible to fipronil at all dairies, suggesting that this material would be highly effective for fly control. The levels of resistance were similar at all the dairies, irrespective of their insecticide use, suggesting substantial movement of flies between facilities. Relative to resistance levels found at New York dairies in 1987, resistance levels had increased for permethrin, were unchanged for tetrachlorvinphos and had decreased for dimethoate. To identify a single diagnostic concentration that could be used in the laboratory assays to assess accurately resistance levels in future studies, we carried out a 'simulated' field bioassay using formulated materials. A diagnostic concentration for each insecticide is proposed on the basis of a comparison of our bioassays.

Efficacy of chlorfenapyr (AC 303630) experimental pour-on and CyLence formulations against naturally acquired louse infestations on cattle in New York.

The four chlorfenapyr formulations examined provided 100% control of both the nymphal and adult stages of naturally acquired Bovicola bovis (L.) on cattle up to 35 days after application. Treatment with 6mg chlorfenapyr per kg BW in a 0.12ml per kg BW formulation was as effective as treatment with CyLence (cyfluthrin) in controlling naturally acquired Solenopotes capillatus (Enderlein) on cattle for 35 days. Percent reduction was never greater than 90% with any chlorfenapyr application against Linognathus vituli (L.). However, percent reduction was greater than 90% with CyLence from day 21 through 35. No adverse effects were noted on cattle from any of the chlorfenapyr dosages used.

Parasitism rates of Muscidifurax raptorellus and Nasonia vitripennis (Hymenoptera: Pteromalidae) after individual and paired releases in New York poultry facilities.

Commercially reared parasitoids were released into three high-rise, caged-layer poultry houses; one house received only N. vitripennis Walker, the second house received only M. raptorellus Kogan & Legner, and the third house received an equal ratio of both species. Overall, house fly parasitism by M. raptorellus was never higher than 7% in any house. Most parasitism in the M. raptorellus release house was attributed to N. vitripennis. Parasitism of house fly pupae by M. raptorellus did not significantly increase during or after the 6-wk release period in the house that received both parasitoids. However, a depression in total parasitism was not detected when releases of the two species were made in this house.

Larval production from field-collected Carcinops pumilio (Coleoptera: Histeridae) following three starvation periods.

Carcinops pumilio (Erichson) were collected from high-rise, caged-layer poultry facilities using two trapping methods, a blacklight pitfall trap and a mesh-bottomed trap placed on poultry manure. Starvation for 14 d significantly reduced larval production during the first 3-d oviposition period regardless of trapping method. Beetles collected with blacklight traps and subsequently starved for 14 d had higher larval production in the third through fifth oviposition periods than those fed daily, indicating that lack of nutrition was a limiting factor in C. pumilio larval production. No differences were observed in larval production, after the first oviposition period, between the 14-d starved and daily fed groups collected with the mesh-bottom trap. In all blacklight-captured treatments, larval production was lowest during the first oviposition period with the largest differences found among the three starved treatments. Larval production in the 14-d starved treatment increased significantly during the later oviposition periods in mesh-bottom trap studies. Within the fed treatment, larval production was consistently greater among beetles collected with the mesh-bottom trap than among beetles collected with blacklight traps.

Prey- and density-mediated dispersal in Carcinops pumilio (Coleoptera: Histeridae), a predator of house fly (Diptera: Muscidae) eggs and larvae.

Carcinops pumilio (Erichson) were collected using two trapping methods: a black light pitfall trap and a mesh-bottomed trap placed on poultry manure. C. pumilio collected with black lights and subsequently starved had a significantly higher dispersal rate during days 1-3 than fully fed groups. When densities of < 500 Caloglyphus berlesei (Michael) (Acarina: Acaridae) per 50 C. pumilio were provided, mite availability had a significant effect on dispersal of beetles captured with both black light traps and the mesh-bottomed trap during the day 1-3 period. Our results indicate that the availability of acceptable food sources can delay and possibly prevent dispersal by C. pumilio. Black light-captured beetles appeared to be in a state of dispersal when captured. A subset of dispersing beetles was present in groups captured with the mesh-bottomed trap.

Susceptibility of house flies (Diptera: Muscidae) and five pupal parasitoids (Hymenoptera: Pteromalidae) to abamectin and seven commercial insecticides.

Assays of five commercial insecticides applied as residual sprays at label rates to plywood indicated the most toxic insecticide overall for pteromalid parasitoids of house flies, Musca domestica L., was Atroban (permethrin), followed by Ciodrin (crotoxyphos), Rabon (tetrachlorvinphos), Ectrin (fenvalerate), and Cygon (dimethoate). Insecticide-susceptible house flies were susceptible to all five insecticides (mortality, 62-100%). Flies that were recently colonized from populations on dairy farms in New York were susceptible only to Rabon. Urolepis rufipes (Ashmead) was the most susceptible parasitoid species overall to these insecticides, followed by Muscidifurax raptor Girault & Sanders, Nasonia vitripennis Walker, Pachycrepoideus vindemmiae (Rondani), and Spalangia cameroni Perkins. Compared with susceptible flies, newly colonized flies showed moderate resistance to avermectin B1a (abamectin). Abamectin was more toxic to all of the parasitoids except N. vitripennis and S. cameroni than to newly colonized house flies when exposed for 90 min to plywood boards treated with 0.001-0.1% abamectin. Space sprays with Vapona (dichlorvos) killed all of the parasitoids and susceptible flies and 64% of the newly colonized flies when insects were placed directly in the path of the spray; mortality was substantially lower among flies and parasitoids protected under 5 cm of wheat straw. Space sprays with Pyrenone (pyrethrins) killed greater than 86% of all insects exposed to the spray path except for the newly colonized flies (1% mortality); mortality of insects protected under straw was low (less than 12%) except for S. cameroni (76%). Because responses of the five parasitoids to the different insecticides varied considerably, general conclusions about parasitoid susceptibility to active ingredients, insecticide class, or method of application were not possible.

Comparative toxicity of seven insecticides to immature stages of Musca domestica (Diptera: Muscidae) and two of its important biological control agents, Muscidifurax raptor and Spalangia cameroni (Hymenoptera: Pteromalidae).

The toxicity of seven insecticides was evaluated against unparasitized Musca domestica L. pupae and pupae parasitized by Muscidifurax raptor Girault & Sanders or Spalangia cameroni Perkins, two important biological control agents. Only pyrethrins + piperonyl butoxide (Pyrenone) was less toxic to M. raptor compared with house flies. Conversely, all of the insecticides except crotoxyphos were less toxic to S. cameroni compared with house flies. A plateau in the tetrachlorvinphos bioassay line for S. cameroni suggested that this colony had approximately 45% resistant individuals. The selectivity observed between immature stages of house flies and M. raptor or S. cameroni is different from that reported against adult stages of these same species, suggesting that selectivity of an insecticide varies considerably between different life stages.

Susceptibility of insecticide-susceptible and wild house flies (Diptera: Muscidae) to abamectin on whitewashed and unpainted wood.

Unpainted plywood panels treated with 0.1% abamectin (avermectin B1) provided greater than 90% control of house flies, Musca domestica L., susceptible to insecticides for 4 wk and greater than 70% control for 7 wk compared with 46-92% control observed with permethrin at the same time and rate of application. Efficacy of abamectin on whitewashed panels was similar to that observed on unpainted panels, whereas permethrin was ineffective on whitewashed panels at all rates tested (range, 0.001-0.1%) at all intervals after treatment. Bioassays of newly colonized house flies resistant to permethrin indicated that wild populations may be cross-resistant to abamectin.

Cattle lice (Anoplura, Mallophaga) in New York: seasonal population changes, effects of housing type on infestations of calves, and sampling efficiency.

A year-long survey was made of commercial dairy herds in New York for cattle lice (Anoplura and Mallophaga). All herds were infested with lice. The cattle bitting louse, Bovicola bovis (L.), accounted for about 90% of the observed infestations; infestations of mature animals were most common during the winter months, especially March (26% infested); and infestation rates of calves were high (30-45%) from January through June. Cows that were housed in stanchion barns were about twice as likely to be infested (24.7%) as were those in free stalls (11.1%). Calves housed in individual outdoor hutches had substantially lower infestation rates (4.5%) than calves maintained inside barns in collective stalls and pens (46.0%).

Costs of existing and recommended manure management practices for house fly and stable fly (Diptera: Muscidae) control on dairy farms.

Costs of fly control practices were estimated for 26 New York and Maryland dairy farms. Objectives were to characterize existing practices, compare them with the cost of more frequent and complete manure removal to reduce fly breeding, and to compare costs of manure removal and insecticide application. Information was collected in scouting visits and personal interviews of farm operators. Equipment, labor, and bedding costs were included for manure removal. Insecticide application costs included chemicals and labor for application. A typical farm with a stanchion barn had manure removal costs of $0.348 per cow per day. Recommended changes would increase costs by $0.016-0.033 per cow per day. Insecticide costs averaged $0.021 per cow per day. It may be possible to eliminate many of the insecticide applications on the farms by using the recommended 7-d manure removal practice. Even if insecticides are not eliminated entirely, increased manure removal costs would be offset by some reduction in insecticide cost. This also would have the additional benefit of greatly slowing the development of insecticide resistance by the flies.

Influence of habitat and temperature on dispersal behaviour of two pteromalid parasitoids of houseflies during an inundative release at a dairy barn.

1. About 11,000 each of Muscidifurax raptor Girault and Saunders and Urolepis rufipes (Ashmead) were released weekly for 7 weeks at a commercial dairy farm in central New York state, U.S.A. Dispersal behaviour was monitored by parasitism rates of house fly, Musca domestica L., pupae placed in sentinel bags. 2. M. raptor, which was released inside the barn, parasitized fly pupae both inside and outside, and it achieved highest rates of parasitism in indoor straw calf-bedding and in outdoor manure and silage. 3. U. rufipes, which was released outside the barn, did not attack pupae inside the barn, and its highest rates of parasitism occurred in outdoor manure and silage. 4. M. raptor appeared to be more effective than U. rufipes in parasitizing pupae located at sites where natural fly-breeding occurred. 5. Interspecific competition did not appear to explain these distribution patterns. 6. There was no significant trend in parasitism by M. raptor as a function of distance from the release station. Furthermore, high rates of parasitism near open doorways and at an outdoor site 30 m away suggests that M. raptor dispersed throughout the barn and its immediate surroundings. 7. Air temperature was positively correlated to flight activity, but not to parasitization activity in natural fly-breeding substrates.

Evaluation of fly-electrocuting black light devices in caged-layer poultry facilities.

Insect-electrocuting black light devices were evaluated for their effectiveness in killing flies in caged-layer poultry facilities. Concurrently, the effect of the addition of the attractant muscalure (Z-9-tricosene) to these devices on their fly-killing efficiency was evaluated. An average of over 29,000 flies were killed per device per week in Facility 1 and 7,000 flies per device per week in Facility 2 over the 8-wk evaluation period. The addition of muscalure (25 to 200 mg/device) increased the number of flies killed by the devices by as much as 76% but only one of the increases was statistically significant. Both the house fly, Musca domestica, and the garbage fly, Ophyra spp. were apparently attracted to muscalure, as the number of both fly species killed was consistently higher in devices containing the attractant than in devices without the attractant.