The seasonal temporal and spatial distribution and emergence of overwintering and summer cohorts of host-seeking American dog tick, Dermacentor variabilis (Say) (Acari: Ixodidae), adults were examined for 5 years in the Bluegrass region of Kentucky. Weekly drag cloth sampling was conducted from early March until late September 1992-1995 and early March until the end of May 1996. Overwintering adult cohorts became active in early to mid-April followed by bimodal host-seeking activity each year, with the duration and intensity of the first activity period being related to the previous year's summer cohort activity. The first activity peak extended from mid-April through late May and the second activity peak occurred in July. All host-seeking activity ceased by early August, except in 1995, when activity ended on 22 August. Laboratory survival of adults, collected weekly during 1993-1996, was used to estimate the emergence of summer adult cohorts. Summer adult cohorts became active in late May or early June and overlapped with overwintering adult host-seeking activity. The termination of host-seeking activity in overwintering adults could not be determined using the methods employed in this study and is most likely to have continued for the entire season. Host-seeking adults displayed contagious distribution patterns along trails bordering ecotone habitats, as determined by fitting a negative binomial frequency distribution to weekly sampling data. These patterns did not vary from year to year. In addition, the location of D. variabilis activity did not change from year to year, which suggests that microhabitats within apparently homogeneous environments enhance adult survival and lead to 'hot spots' of tick activity despite the ability of vertebrate hosts to disperse D. variabilis populations more widely. These data better define our understanding of D. variabilis adult seasonal and spatial host-seeking activity, estimate for the first time the intensity of summer cohort host-seeking activity, and relate summer cohort activity with spring activity the following year.

A baited jug-trap for sampling house fly populations is described. We found trapping of house flies to be most effective at the roof peak in a narrow caged-layer poultry house and ca. 1 m above the manure in a high-rise poultry house, using the jug-trap baited with Super Golden Malrin@, containing 0.025% 2-(1-methylethoxy) phenol methylcarbamate, 0.04% 2,2-dichlorovinyl dimethyl phosphate, and 0.025% (Z)-9-tricosene. Yellow painted jug-traps caught more house flies than red, green, blue, black, or white. The period of greatest fly catches in the trap was between 1200 and 1700 EST. Traps baited with the slowrelease synthetic house fly attractant (88% fishmeal, 5% trimethylamine hydrochloride, 5% ammonium sulfate, 1% indole, and 1% linoleic acid) caught fewer flies than traps baited with Improved Golden Malrin@, containing 1.0% methomyl (S-methyl N-[methylcarbamoyl] oxy) thioacetimidate and 0.025% (Z)-9-tricosene, or Super Golden Malrin, and caught more flies than traps baited with Golden Malrin@, containing 0.093% 2,2-dichlorovinyl dimethyl phosphate and 0.25% O,O-dimethyl O-(2,4,5-trichlorophenyl) phosphorothioate, when tested in a narrow caged-layer poultry house. Indole was found to be the most attractive chemical in the synthetic formulation and ammonium sulfate decreased the attractiveness of the formulation. We advocate the use of a white, translucent jug-trap baited with 25 g of Improved Golden Malrin and hung at the level of the upper cages as a simple, practical method for monitoring house fly populations in caged-layer houses.

No abstract

Slow release formulations of 375, 750, and 1,125 mg (AI) in 50-g boluses and a subcutaneous injectable formulation (0.2 mg AI/kg body wt) of moxidectin (CL301423) were tested for the control of the little blue cattle louse, Solenoptes capillatus (Enderlein), and the cattle biting louse, Bovicola bovis (L). S. capillatus populations were reduced 4 wk after treatment and complete control was observed 6 wk after treatment in groups treated with boluses, B. bovis were first observed at 3 wk and continued to increase throughout the 14-wk test period. These were experimental boluses and future boluses may perform differently. Subcutaneous injections of moxidectin gave complete control of S. capillatus for a 27-d test period. Feces from animals treated with boluses were tested with face fly larvae, Musca autumnalis De Geer, to demonstrate fecal activity of moxidectin. Larval mortality in these groups ranged from 90 to 30% from 2 d to 10 wk after treatment.

The population density of host-searching nymphal and adult lone star ticks, Amblyomma americanum (L.) (Acari: Ixodidae), was determined at the Robinson tract of the Kansas Ecological Reserves and a private farm 5 km north-west of the Robinson tract using standard drag cloth methods. Nymphs, males and females were counted and collected weekly from shaded habitats and adjacent sunlit habitats from mid-May through late July, 2003. Of the 1598 nymphs and 549 males collected by drag sampling, 74.0% and 72.1%, respectively, were collected from shaded sections of the habitats, whereas 77.3% of 472 females were found in sunlit sections. A. americanum collected during each sampling period were maintained unfed at >95% relative humidity and a 14 : 10 h photoperiod, and survival was recorded weekly until all ticks had died. Survival of nymphs, males and females did not differ between ticks collected in the shade vs. those collected in the sun. Nymphs survived significantly longer than adults, whereas male and female survival did not differ from each other. These results suggest that host-searching A. americanum populations may partition their environment to increase the chances of coming into contact with a potential vertebrate host.