Physaloptera Rara Research Articles

Evaluation of parasitic infections with histological and molecular detection in Anoles from St. Kitts

Anoles are a widely distributed group of reptiles that are also increasing in popularity as a pet animal. These species have been described as paratenic and intermediate hosts for many parasites of veterinary and medical importance. However, while human and animals such as cats and dogs may often interact with anoles, little research has been conducted in terms of assessing the full potential of anoles to harbor parasites of public and veterinary health significance. The current study analyzed the parasites of anoles captured and dissected in St. Kitts, West Indies, to describe the parasitic population within these reptiles and evaluate the potential role of anoles as intermediate/paratenic hosts. From March until May of 2019, samples from 11 anoles were collected following humane euthanasia and evaluated grossly, histologically, and molecularly for the presence of parasites. Histologic evaluation revealed adult ascarids, oxyurids, and spirurids within the stomach, as well as intraluminal adult ascarids within the intestine, and encysted larval trematodes within the intestinal wall. Molecular analysis based on 18S rRNA and ITS2 DNA markers for nematodes and trematodes, respectively, identified Physaloptera sp. (99.4–99.8% identical with Physaloptera turgida, Physaloptera mirandai, Physaloptera retusa, Physaloptera rara) and Platynosomum illiciens (99.7% identical). Phylogenetic analysis of ITS 2 sequences of P. illiciens from this study cladded monophyletically with the same species from different geographic areas and hosts. Our study highlights the importance of understanding the role anoles play in the life cycles of less well-studied parasites, and the potential of these animals to act as intermediate or paratenic hosts.

Wildlife Baiting is Associated with an Increased Parasite Intensity in Raccoons (Procyon lotor) in Mississippi, USA

Gastrointestinal tracts were obtained from 120 raccoons (Procyon lotor) on properties in the state of Mississippi, US, with and without wildlife baiting to observe the effects of baiting on parasite prevalence and intensity. Raccoons from baited properties had higher prevalence of Gnathostoma procyonis and higher intensities of Physaloptera rara and Macracanthorhynchus ingens, which can cross species barriers.

Distributional records of helminths of the swift fox (Vulpes velox)from New Mexico

Four nematodes Physaloptera rara (11/31, 35.5%), Physaloptera (5/31, 16.0%), Toxascaris leonina (1/31, 3.2%), and Toxocara canis (17/31, 54.8%) and two cestodes Dipylidium caninum (11/31, 35.5%) and Mesocestoides variabilis (9/31, 29.0%) were recovered from 23 of 31 (74%) swift foxes, Vulpes velox, for the first time from New Mexico.

Helminth Parasites from the Kit Fox,Vulpes macrotis(Carnivora: Canidae), from New Mexico

Fifty-three kit foxes (Vulpes macrotis) were collected from 9 counties in New Mexico from 1996 to 1998 and examined for helminth parasites. Forty-seven (88.7%) were infected. The cestodes found included Dipylidium caninum in 15 (28.3%), Mesocestoides variabilis in 29 (54.7%), and Taenia multiceps in 1 (1.9%). The nematodes include Ancylostoma caninum in 2 (3.8%), Toxocara canis in 2 (3.8%), Toxocara cati in 1 (1.9%), Toxascaris leonina in 32 (60.4%), and Physaloptera rara in 31 (58.5%) foxes. This is the first report of these parasites in kit foxes from New Mexico. Taenia multiceps, Ancylostoma caninum, Toxocara canis, Toxocara cati, and P. rara are recorded for the first time in kit foxes.

Ultrastructural characterization of male and female Physaloptera rara (Spirurida: Physalopteridae): feline stomach worms

Physaloptera rara (Spirurida: Physalopteridae) has been found in dogs, coyotes, raccoons, wolves, foxes, cats, and bobcats in North America. The parasites' developmental cycles involve insects, including beetles, cockroaches, and crickets, as intermediate hosts. The nematodes firmly attach to the wall of the stomach and duodenum, where they feed on the mucosa and suck blood. Frequent movement of these nematodes results in erosions and ulcers in the gastrointestinal tract. The present study reports the morphological features of adult P. rara using scanning electron microscopy. Adult worms were removed from the stomach of an infected domestic cat. Male and female worms measured 25-29 and 27-41mm, respectively. The worms were stout and the cuticle was reflected over the lips to form a large cephalic collarette with fine transverse striations. The worms possessed two large, simple triangular lateral pseudolabia, each armed with one external tooth, three internal teeth, two submedian cephalic papillae, an amphid, and three porous-like circumscribed regions. The internal margins of the lips had a pair of cuticular folds. At the anterior end of both male and female worms, an excretory pore was located on the ventral side and a pair of lateral ciliated cervical papillae was seen. The vulva was anterior to the middle of the body of female worms. The tail ends of the female worms were stumpy, with two large phasmids near their extremities. The males' tails bore large lateral alae. Ventral ornamentation, in male worms, was composed of three different cuticular patterns; coblestone-like formations, longitudinal cuticular ridges, and rows of bead-like structures. The spicules were unequal and dissimilar; the right spicule had a thick end and the left spicule had a sharp tip. At the posterior end of the males, four pairs of stalked precloacal papillae, three pairs of postcloacal papillae, and two phasmids were present. Three and four sessile papillae were seen directly anterior and posterior to the cloaca, respectively. The middle papilla of the three sessile papillae, directly anterior to cloaca was different in shape and size.

Endoparasites of the Coyote (Canis latrans), a Recent Migrant to Insular Newfoundland

This study provides the first data on the helminth fauna of the coyote (Canis latrans) in insular Newfoundland. Sixty-nine coyotes were collected between 2001 and 2003 and examined for helminths. A total of 10 helminth species were recorded: the cestodes Taenia ovis krabbei (9%), Taenia hydatigena (4%), Taenia pisiformis (1%), and Mesocestoides spp. (5%); and the nematodes Toxocara canis (19%), Toxascaris leonina (1%), Crenosoma vulpis (19%), Physaloptera rara (6%), Uncinaria stenocephala (3%), and Angiostrongylus vasorum (1%). No significant differences (P< or =0.05) were detected between sexes. Mesocestoides spp., T. canis, and C. vulpis were more prevalent in juveniles than adults. Angiostrongylus vasorum is reported in coyotes for the second time in Newfoundland, Canada.

GASTROINTESTINAL HELMINTHS IN RACCOONS IN TEXAS

Raccoons (n=590) were collected from October 1999 to August 2003 from 35 counties across Texas, and gastrointestinal tracts were examined for helminth parasites. Prevalence was calculated and differences in mean abundance were examined among habitat ecoregions, age classes, and between sexes. Twenty different species of helminths (13 nematodes, two cestodes, two acanthocephalans, and three trematodes) were positively identified in the gastrointestinal tracts of 590 raccoons in Texas. Five of the 20 helminth species collected (Physaloptera rara, Placoconus lotoris, Molineus barbatus, Atriotaenia procyonis, and Macracanthorhynchus ingens) had a prevalence >20%. The total number of individuals of these five species (n=22,777) accounted for over 86% of the total number of individuals of all helminth species (n=26,426) collected. Subsequent analyses were based on these five helminths. Mean abundance differed among habitat ecoregions, age classes, and between sexes for all five parasites evaluated. This study is the most comprehensive statewide survey ever done of gastrointestinal helminths of raccoons across Texas. The five most prevalent helminths identified have all been reported in at least one previous survey, indicating that these parasites are not new to Texas and that raccoons are not naïve to the effects these parasites have on them. It may be helpful to wildlife rehabilitators, trappers, wildlife biologists, and other professionals to be aware of parasite abundance in raccoons from different areas of the state, as frequent human-raccoon interactions occur, and some of these parasites could be harmful to humans and domestic animals.

Parasitic Helminths and Arthropods of Coyotes (Canis latrans) from Florida, U.S.A

Twenty-six coyotes (Canis latrans) collected in Florida, U.S.A., were examined for parasites. Nine species of helminths (1 trematode, 1 cestode, 6 nematodes, and 1 acanthocephalan), 1 species of biting louse, and 2 species of ticks were identified. Dirofilaria immitis (43%), Ancylostoma caninum (33%), Physaloptera rara (29%), and Taenia pisiformis (24%) were the most prevalent helminths. Macracanthorhynchus ingens is reported from coyotes for the first time, and Spirocerca lupi is reported in coyotes from Florida for the first time. Ectoparasites collected included the biting louse Trichodectes canis and the ticks Amblyomma maculatum and Dermacentor variabilis. A coyote infected with 66 Di. immitis had evidence of chronic pulmonary arteritis and medial hypertrophy of pulmonary aterioles.

Helminths of the ocelot from southern Texas.

In the USA, the ocelot (Leopardus pardalis) is a highly endangered felid found only in a few remaining vestiges of native thornshrub brushland in the Lower Rio Grande Valley (LRGV) of extreme southern Texas. From 1987-1998, carcasses of 15 adult ocelots that died of vehicular accidents or natural causes were examined for helminths. All cats had 1-8 (mean = 3) helminth species. All were infected with 1-101 (mean +/- SE = 32 +/- 7) Toxascaris leonina. Other helminths from these ocelots were Alaria marcianae, Brachylaima sp., Mesocestoides lineatus, Taenia rileyi, Oncicola canis, Dirofilaria immitis, Physaloptera rara, Ancylostoma tubaeformae, Cylicospirura chevreuxi, Vogeloides felis, and Metathelazia californica. Additionally, two cats had scarring of the aorta with lesions typical of those caused by Spriocerca lupi, although larval nematodes were not seen. A clinal variation in size of nearly three orders of magnitude was noted in the diplostomatid trematodes in the small intestine of one adult male ocelot. Despite the differences in size, all specimens appeared morphologically identical and were regarded as A. marcianae. Helminth prevalences and abundances, including those of potentially pathogenic species like D. immitis, were low. Although a single heartworm infection may have contributed to the death of one ocelot, helminth infections in general seemed to be of no great consequence to this endangered ocelot population. The helminth fauna of ocelots in the LRGV is reflective of that from wild felids in general; all have been reported previously from the bobcat (Lynx rufus) and mountain lion (Puma concolor) elsewhere in Texas.

Effect of short-term coyote removal on populations of coyote helminths.

Coyote (Canis latrans) removal programs often are initiated despite the potential population regulatory mechanism of parasitism with increased coyote density. We investigated the effect of intensive, short-term coyote removal on population levels of helminths in juvenile and adult coyotes from western Texas. Coyotes were killed by aerial gunning every 3 mo for 2 yr on two 5,000 ha areas, which reduced the overall coyote density of these areas by about 50%. Two other 5,000 ha areas were used as comparison sites where a limited number of coyotes were killed each season. Densities on comparison sites remained stable throughout the study at a mean +/- 1 SE of 0.14 +/- 0.01 coyotes/km2. Twelve helminth species consisting of seven nematodes (Ancylostoma caninum, Physaloptera rara, Toxascaris leonina, Dirofilaria immitis, Spirocerca lupi, Oslerus osleri, and Capillaria aerophila), three cestodes (Taenia pisiformis, Taenia multiceps, and Mesocestoides sp.), one acanthocephalan (Oncicola canis), and one trematode (Alaria marcianae) were found in 252 coyotes. Of these, A. caninum, P. rara, T. multiceps, T. pisiformis, T. leonina, and S. lupi were common species. Rank-transformed values for the mean abundances of A. caninum and T. multiceps and A. caninum, T. multiceps, and S. lupi were reduced in juvenile and adult coyotes, respectively, from the removal sites compared to respective helminth abundances in similar age class coyotes from comparison sites. Because A. caninum has been suggested as a population regulator of coyotes, a coyote removal program that results in a reduced density of coyotes and at the same time causes a reduced abundance of A. caninum, may in fact negate the regulatory effect that A. caninum has on coyote populations.

Helminth Parasites of the Raccoon (Procyon lotor) from North-Central Arkansas

Twenty-three species of helminths (4 trematodes, 2 cestodes, 14 nematodes, and 3 acanthocephalans) were found in the gastrointestinal tract, lungs, pancreas, tongue, urinary bladder, and subcutaneous tissues of 30 live-trapped or hunter-shot raccoons from north-central Arkansas between November 1989 and April 1990. Helminths were not detected in the brain, diaphragm, gallbladder, heart, liver, reproductive system, or trachea. Each raccoon examined was infected with 3 or more of the following helminths: Brachylaima virginiana, Eurytrema procyonis, Fibricola cratera, Pharyngostomoides procyonis, Atriotaenia procyonis, Mesocestoides spp., Arthrocephalus lotoris, Capillaria aerophila, Capillaria plica, Capillaria procyonis, Capillaria putorii, Crenosoma goblei, Cruzia americana, Dirofilaria tenuis, Dracunculus insignis, Enterobius sp., Gnathostoma procyonis, Molineus barbatus, Physaloptera rara, Trichinella spiralis, Centrorhynchus wardae, Macracanthorhynchus ingens, and Oligacanthorhynchus tortuosa. All helminths collected with the exception of D. insignis constitute new geographic distribution records. Occurrences of C. aerophila, C. wardae, and O. tortuosa are new host records. One nymphal pentastome, Porocephalus crotali, was found in the liver of 1 raccoon, constituting a new host record.

Effects of milbemycin oxime on adult hookworms in dogs with naturally acquired infections

SUMMARY Previous work indicated that adult Ancylostoma caninum can be removed from experimentally infected dogs, using a formulation of milbemycin oxime at dosage of 0.5 mg/kg of body weight. To determine the efficacy of this treatment in dogs naturally infected with adult hookworms, 24 mixed-breed dogs with patent hookworm infections were purchased from an out-of-state vendor, and 6 male and 6 female dogs were assigned to either a control group or a group that would be treated. Dogs were treated 10 days after their arrival and were euthanatized 1 week after treatment. Beginning 3 days before treatment, fecal samples were collected daily from all dogs, and the number of Ancylostoma eggs per gram of dry weight of feces was determined from each sample. By 1 week after treatment, the mean number of eggs being passed by the treated dogs had dropped from 12,700 to 10 eggs/g of dried feces; there was no apparent change in fecal egg counts for dogs of the control group. At necropsy, the mean number of adult A caninum in dogs of the treated and control groups was 1.3 and 56, respectively; in these naturally infected dogs, efficacy of treatment was calculated to be 97.8%. The mean number of adult Trichuris vulpis recovered in dogs of the control and treated groups at necropsy was 24 and 0, respectively, which yielded treatment efficacy of 100%. Although Uncinaria stenocephala and Toxocara canis appeared also to be removed by use of this dosage, too few dogs were in the study to calculate meaningful efficacies. The milbemycin oxime formulation appeared to have no effect on the cestodes (Taenia pisiformis and Dipylidium caninum) and spirurids (Physaloptera rara) that were present in some dogs.

Proposed field evaluation of a rabies recombinant vaccine for raccoons (Procyon lotor): site selection, target species characteristics, and placebo baiting trials.

Prior to a limited field application of an orally-administered vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine for wildlife, background data were obtained for the proposed site on Parramore Island, Virginia (USA). Mammalian target and nontarget species, potentially at risk for exposure to vaccine were inventoried. Placebo baiting trials with a fishmeal polymer bait resulted in high bait disturbance (88 to 100%), primarily by raccoons (Procyon lotor), with infrequent visitation and no evidence of bait consumption by deer (Odocoileus virginianus), small mammals or avian species. Definitive bait acceptance rates by raccoons (indicative of bait ingestion) were difficult to accurately determine based exclusively on premolar and vibrissae samples collected antemortem from live-trapped raccoons for tetracycline and rhodamine B biomarker analyses, respectively. Bait acceptance rate was more accurately determined during a pilot baiting trial conducted on North Island, South Carolina, when mandibles (postmortem samples) were examined for tetracycline incorporation. Parasitologic findings in raccoons on Parramore Island included Hepatozoan procyonis, Phagicola angrense and Physaloptera rara and a variety of incidental microscopic lesions, and provided baseline pathological data for comparison subsequent to V-RG vaccine application. A population density estimate of one raccoon/2.7 ha was calculated using mark-recapture data for comparison after vaccine deployment. Limited reproductive data, including estimates of pregnancy rates by palpation, the number of live kits/litter live-trapped with previously pregnant raccoons or observed in the dens of radio-collared raccoons, was gathered to assess the effect of proposed oral vaccination with V-RG vaccine. Home ranges were assessed by radio-telemetry of 15 raccoons; all radio-collared raccoons currently reside on Parramore Island.(ABSTRACT TRUNCATED AT 250 WORDS)

Helminths of mountain lions (Felis concolor) from southwestern Texas, with a redescription of Cylicospirura subaequalis (Molin, 1860) Vevers, 1922

Nine nematode and two cestode species were recovered from the viscera of 53 mountain lions (Felis concolor) collected from four counties in southwestern Texas. The distribution patterns of the common (&gt; 20% prevalence) helminth species (Taenia omissa, Physaloptera praeputialis, Physaloptera rara, Cylicospirura subaequalis, Ancylostoma tubaeforme, Toxascaris leonina, Metathelazia californica, and Vogeloides felis) were overdispersed and did not change with host age or sex. Abundances of the common helminth species were examined relative to sex and age-groups of the lions. Significant differences were found for abundances of T. omissa, C. subaequalis, and T. leonina between host age-groups, and for T. omissa between host sexes. Only 2 of 29 species were shared among the helminth communities of mountain lions from Texas, Oregon, and Florida, indicating a basic disparity of species common to this host across its geographic range in North America. Taenia omissa is regarded as the single core species across this host's range in North America. New host records are reported for the occurrence of Taenia multiceps, P. rara, Gnathostoma procyonis, A. tubaeforme, and V. felis. Cylicospirura subaequalis is redescribed and compared with Cylicospirura felineus, a species commonly found in Felis lynx and Felis rufus. In addition to previously described bifid versus trifid teeth in C. subaequalis and C. felineus, respectively, differences were noted in the length of spicules in males and the location of the vulva in females.

Helminths of the Raccoon (Procyon lotor) in Western Kentucky

Seventy raccoons (Procyon lotor) from western Kentucky were examined for helminths from December 1985 through May 1986. Twenty-three species of helminths were collected including 10 species of Trematoda (Brachylaima virginiana, Euryhelmis squamula, Eurytrema procyonis, Fibricola cratera, Gyrosoma singulare, Maritreminoides nettae, Mesostephanus appendiculatoides, Metagonimoides oregonensis, Paragonimus kellicotti, Pharyngostomoides procyonis), 2 species of Cestoda (Atriotaenia procyonis, Mesocestoides variabilis), 10 species of Nematoda (Arthrocephalus lotoris, Baylisascaris procyonis, Capillaria putorii, C. plica, Crenosoma goblei, Dracunculus insignis, Gnathostoma procyonis, Molineus barbatus, Physaloptera rara, Trichinella spiralis), and 1 species of Acanthocephala (Macracanthorhynchus ingens). A mean of 6.4 (3-11) helminth species per host was recorded. Fibricola cratera, Atriotaenia procyonis, Mesocestoides variabilis, Arthrocephalus lotoris, Capillaria plica, Dracunculus insignis, Molineus barbatus, and Physaloptera rara were ubiquitous parasites of the raccoon, whereas specific nidi were observed for Eurytrema procyonis, Gyrosoma singulare, Paragonimus kellicotti, Baylisascaris procyonis, Trichinella spiralis, and Macracanthorhyncus ingens. With an overall prevalence of 10% or higher, 15 of the 23 helminth species were considered common parasites of the raccoon in western Kentucky. When the 10% prevalence rate was applied within geographical quadrants to correct for the presence of nidi it was found that 18 of the 23 helminth species were common and 5 were regarded as rare parasites of the raccoon. Two species of nematodes, T. spiralis and B. procyonis, displayed a markedly higher prevalence in male raccoons.

Helminth Parasites of the Coyote (Canis latrans) in Tennessee

From 1980 to 1984, 267 coyotes (Canis latrans) from Tennessee were examined for helminth parasites. Hearts were examined for the presence of Dirofilaria immitis, diaphragms for Trichinella spiralis, and digestive tracts for other helminths. Six species were found including 5 nematodes (D. immitis, Physaloptera rara, Trichuris vulpis, Ancylostoma caninum, and Toxascaris leonina) and 1 cestode (Taenia pisiformis). Univariate and multivariate statistical techniques were used to assess parasite prevalence and intensity. For prevalence data, a matrix of correlation among characters was computed, and the first 3 principal components were extracted from the original distance matrix. These accounted for 93.7% of the variation in the character set. Three-dimensional projections of localities showed spatial variability on each component. Significant relationships were found between principal component I and longitude, component II and latitude and mean January temperature, and component III and mean July precipitation and mean January actual evapotranspiration. For intensity data, no spatial variability was determined.

Helminth parasites of Canada lynx (Felis canadensis) from northern Ontario

Six helminths were common in lynx (Felis canadensis) throughout northern Ontario: Troglostrongylus wilsoni (Stough, 1953) Sarmiento &amp;Stough, 1956 in the lung (54% of 127 infected), Cylicospirura felineus (Chandler, 1925) Sandground, 1932 in the stomach (91% of 360), Toxascaris leonina (von Linstow, 1902) and Toxocara cati (Schrank, 1788) in the stomach and intestine(97% and 22% of 274, respectively), and Taenia laticollis Rudolphi, 1819, and Taenia rileyi Loewen, 1929 in the intestine (94% and 47% of 275, respectively). Only Toxascaris leonina is transmitted by both lynx and canids in northern Ontario. Lynx is the only definitive host of the other common parasites. Seven helminths usually found in canids occurred infrequently in lynx: Alaria marcianae (LaRue, 1917) Walton, 1949 and immature Taenia pisiformis (Bloch, 1780) Gmelin, 1790 in 4% of those examined; and Capillaria aerophila (Creplin, 1839) Travassos, 1915, Physaloptera rara Hall &amp;Wigdor, 1918, Ancylostoma caninum (Ercolani, 1859), Uncinaria stenocephalia (Railliet, 1884), and Taenia serialis (Gervais, 1847) Baillet, 1863 in one to three lynx each. Abundances of the common parasites varied only slightly among five forest regions, and did not differ between male and female lynx or among lynx older than kits. Cylicospirura felineus and Taenia rileyi were less abundant in kits, and Taenia laticollis and Toxocara cati tended to be more abundant in kits than in older lynx. Host condition and numbers of many of the common helminths tended to be positively correlated, but the inclusion of kits affected the result. The few helminth species established in lynx and their apparent uniform distribution in the host population may reflect the dominance of snowshoe hare in the diet.

Helminth Parasites of the Raccoon (Procyon lotor) from Tennessee and Kentucky

From December 1980 through November 1981, 145 raccoons (Procyon lotor) from Land Between The Lakes in Stewart County, Tennessee, and Lyon and Trigg counties, Kentucky, were examined for helminth parasites. Diaphragms were examined for Trichinella spiralis and gastrointestinal tracts for other helminth parasites. Ten species were found including 7 nematodes (T. spiralis, Physaloptera rara, Arthrocephalus lotoris, Molineus barbatus, Baylisascaris procyonis, Gnathostoma procyonis, Dracunculus insignis), 2 cestodes (Mesocestoides variabilis, Atriotaenia procyonis), and 1 acanthocephalan (Macracanthorhynchus ingens). Dracunculus insignis is reported from Tennessee and Kentucky raccoons for the first time. Of the parasites detected, only T. spiralis showed a statistically significant preference for one sex (male) over the other. It was also the only parasite found in greater prevalence in relation to age classes (highest in age classes III and IV). Arthrocephalus lotoris, M. barbatus, B. procyonis, M. ingens, and D. insignis all had seasonal trends in prevalence, and winter intensity of parasites was found to be most similar to that of spring, spring to summer, and summer to fall. The raccoon, Procyon lotor, is a medium-sized mammal that is widely distributed in North America (Hall, 1981). Due to its economic importance, it has been the subject of numerous biologic investigations (see Lotze and Anderson, 1979). Of the previous studies, many have been directed toward questions relating to raccoon parasites (e.g., Chandler, 1942; McNeil and Krogsdale, 1953; Babero and Shepperson, 1958; Jordan and Hayes, 1959; Harkema and Miller, 1964; Bafundo et al., 1980). However, with the exception of Bafundo et al. (1980), little attention has been given to raccoon parasites in Tennessee. Bafundo et al. (1980) investigated prevalence and intensity of helminth parasites in the digestive tract and examined interlocality variation in P. lotor using helminth parasites as characters. This work provided information relating to broad trends in variation of a selected group of endoparasites that were collected during a restricted time period (as is the case in most previous studies). They grouped raccoons occurring in large physiographic regions as single samples and primarily utilized P. lotor specimens taken during October through February (the hunting season). To date, few investigators (see Lotze and Anderson, 1979) have examined raccoon parasitism in a small geographic area over extended periods. Studies of this type appear critical in order to provide a complete understanding of the natural Received 12 December 1983; revised 26 February 1985; accepted 26 February 1985. history of P. lotor and raccoon (host)-parasite relationships. The purpose of the present investigation was to study the helminth parasites of P. lotor (in a small geographic area) as follows: (1) determine the prevalence; (2) compare prevalence between male and female raccoons; (3) examine prevalence in relation to age of the host; (4) observe seasonal trends in prevalence and intensity of parasite species; (5) examine interspecific associations of prevalence. MATERIALS AND METHODS The study area (Land Between The Lakes = LBL) was a 69,000 ha peninsula located between Kentucky Lake and Lake Barkley in Stewart County, Tennessee, and Lyon and Trigg counties, Kentucky. With cooperation of the Tennessee Valley Authority (TVA), 145 P. lotor were collected from December 1980 through November 1981. Counties from which raccoons were collected and sample sizes for male (given first) and female P. lotor are as follows: Tennessee, Stewart-23, 15; Kentucky, Lyon-11, 16; Trigg-35, 38. Specific locality information was not available for 3 additional males and 4 females. Specimens were taken during different seasons (those of the calendar year) in the following numbers (male sample size is given first): winter-8, 13; spring-20, 15; summer-27, 25; fall17, 18. Seasonal data were incomplete for 2 females. Most animals were collected by gun with the use of dogs or spotlight from a boat or truck. Animals were frozen and housed in TVA facilities and later transported to the Department of Biology, Memphis State University, where they were examined. Sixty-one specimens (those with available skeletal material) were aged as juvenile (class I, n = 12), subadult (class II, n = 8), adult (class III, n = 15), or old adult (class IV, n = 26) following Junge and Hoffmeister (1980). Sex of all specimens was recorded. In-

Population Dynamics across Selected Habitat Variables of the Helminth Community in Coyotes, Canis latrans, from South Texas

The effects of selected intrinsic variables operating on host subpopulations and of extrinsic variables across the collective host population on the distributions of 10 common helminth species from coyotes in south Texas were compared. The intrinsic variables of host sex and presence and severity of sarcoptic mange had little effect on the distributions of most helminth species. The combined influences of (1) seasonal changes across the collective host population and (2) host subpopulations delineated by age were responsible for the overdispersed distributions of Oncicola canis, Physaloptera rara, and Protospirura numidica. Overdispersion in Ancylostoma caninum, Alaria marcianae, and Spirocerca lupi populations resulted almost exclusively from the heterogeneity of factors contributing to their rates of establishment, survival, and reproduction as generated across host age subpopulations. Aggregated abundances of A. caninum and A. marcianae occurred in young hosts, but were cumulative in older animals infected with S. lupi. The hypothesis that heterogeneity within the host population, rather than across the collective host population, is the main factor generating overdispersion in natural populations was confirmed for only 3 of 10 helminth species (A. caninum, A. marcianae, and S. lupi). The effects of extrinsic factors operating across the collective host population appeared to be equal to, or in some instances of greater importance than, these forces operating over host subpopulations in determining the dispersion patterns of some helminth species (O. canis, P. rara, and P. numidica). The distributions of Taenia pisiformis, Mesocestoides lineatus, Oslerus osleri, and Toxascaris leonina were not affected, or only minimally influenced, by these intrinsic or extrinsic variables. The effects of these habitat variables on dispersion patterns are highly correlated with the life cycle and mode of transmission of the respective helminth species.

Helminth and arthropod parasites of black bear, Ursus americanus, in central Ontario.

One hundred and forty-eight black bears (Ursus americanus) from central Ontario, Canada, were examined for parasites between 1975and 1977. Nine species of helminths and two species of ectoparasites were recovered: Taenia krabbei Moniez, 1879 in 2 of 83 bears; Alaria americana Hall and Wigdor, 1918 in 1 of 83; Baylisascaris transfuga (Rudolphi 1819) in 20 of 83; Crenosoma spp. (C. petrowi Morozov, 1939, C. potos Buckley, 1930, and C. vulpis (Dujardin 1844)) in 21 of 64; Dirofilaria ursi Yamaguti, 1941 in 140 of 148; Physaloptera rara Hall and Wigdor, 1918 in 1 of 83; Trichinella sp. in 1 of 59; Oropsylla arctomys (Baker) on 1 of 5; and Trichodectes pinguis euarctidos Hopkins on 1 of 5 bears. The data are discussed in relation to previous records of parasites within central Ontario and previous reports of parasites of bears. Alaria americana is considered a new host record for North American ursids.