Feline cuterebrosis caused by a lagomorph-infesting Cuterebra spp. larva

Native species of rodents and lagomorphs in the Americas are the typical hosts of Cuterebra spp. larvae. Although these bot flies are relatively host specific, they occasionally parasitize other native and introduced mammals (including domestic animals and humans), an affliction termed cuterebrosis. Cuterebra spp. larvae generally cause benign, subcutaneous lesions (warbles), but when infesting domestic cats, they can invade the eyes, respiratory tract, and cerebral tissues, causing severe, and in some cases fatal, injury. Despite more than 2 dozen published reports of feline cuterebrosis, the type (rodent- or lagomorph-infesting) or species parasitizing domestic cats has rarely been determined. Here, I identify a larva removed from a kitten in southern Wisconsin as belonging to a lagomorph-infesting Cuterebra species, most likely C. abdominalis, based especially on features of the cuticular platelets covering its exterior, and its geographic location. This seems to be only the third substantiated report of feline cuterebrosis in more than 50 yr in which a larva has been identified beyond "Cuterebra spp." In each case, lagomorph-infesting species were involved, suggesting that domestic cats may not be susceptible to rodent-infesting Cuterebra species. However, because these studies are limited in number and geographic area, additional research is required to establish the spectrum of Cuterebra species involved in feline cuterebrosis.     

Biology of Cuterebra lepusculi Townsend (Diptera: Cuterebridae) in cottontail rabbits in Idaho

Cuterebra lepusculi Townsend parasitize cottontail rabbits (Sylvilagus nuttallii) in southern Idaho. Peak parasitism was 69% in mid-September. Mean development time in the host was 27 days. The species is univoltine in Idaho. Partially developed larvae were transferred from freshly killed to living hosts and the resulting larvae matured normally. Developing pupae were cooled or warmed to retard or speed development and synchronize adult emergence.     

Molecular identification of two species of myiasis-causing Cuterebra by multiplex PCR and RFLP

The myiasis-causing flies Cuterebra grisea (Coquillet) and Cuterebra fontinella (Clark) (Diptera: Oestridae) are normally parasites of mice, predominantly of the genus Peromyscus. The morphological similarities of these species and the existence of intermediate morphotypes bearing characters of both species make the identification of adults problematic; furthermore the identification of larvae is apparently not possible. This study presents two molecular approaches to discriminate between these species using specific band patterns: (i) species-specific primers designed in the cytochrome oxidase II (COII) region used in multiplex polymerase chain reaction (PCR) and (ii) restriction fragment length polymorphism (RFLP) on amplified segments of cytochrome oxidase I (COI) gene. Both methods were tested on Cuterebra larvae and on adult museum specimens. The two techniques showed a clear difference between C. grisea and C. fontinella, although species-specific primers were more successful than RFLP for degraded DNA. No intraspecific variation in RFLP and species-specific amplifications were detected for the two species of Cuterebra. The results exhibit discrepancies between molecular and morphological identification, suggesting that some of the adults were misidentified.     

A robotic molecular method for in situ detection of marine invertebrate larvae

Knowledge of the temporal and spatial abundance of invertebrate larvae is critical to understanding the dispersal capabilities and recruitment potential of marine and aquatic organisms. Traditional microscopic analyses are time-consuming and difficult given the diversity of larval species and a frequent lack of discriminating morphological characteristics. Here, we describe a sensitive rRNA targeted sandwich hybridization assay (SHA) that uses oligonucleotide probes to detect and enumerate the larvae of invasive green crabs (Carcinus maenas), native blue mussels (Mytilus), native barnacles (Balanus) and polychaetes (Osedax and Ophelia) that occur in the Monterey Bay National Marine Sanctuary, California. Laboratory-based assays demonstrate specificity, high sensitivity, and a quantitative response to cultured samples from three of the target organisms. Oligonucleotide probes were then printed in arrays on nitrocellulose membranes and deployed in our robotic Environmental Sample Processor (ESP) to detect larvae in situ and autonomously. We demonstrate that the SHA-detection method and ESP robot can be used for near real-time, in situ detection of larval species in the marine environment.     

Types of parasitism by larvae of water mites (Acari: Hydrachnellae)

The larvae of Hydrachnellae can be divided into three types, based on the habits of the parasitic (larval) stage in the life cycle. (1) The larvae do not leave the water. Parasitizing aquatic insects, they are permanently submerged and wet. Only some species of the family Hydrachnidae belong to this type. (2) The larvae leave the water. The parasitic phase occurs either on insects living on the water surface, or in the air stores of aquatic insects. In both cases the larvae are not in direct contact with water during the parasitic phase. The Limnocharidae, Eylaidae and some species of the Hydrachnidae belong to this type. (3) The larvae parasitize insects which live in the air and which can leave the direct proximity to water; therefore it may be difficult for the mite larva to return to water. Except for the Hydrachnidae, Limnocharidae and Eylaidae, all families of the Hydrachnellae belong to this type.     

Description and relationships of Chaetopterus pugaporcinus, an unusual pelagic polychaete (Annelida, Chaetopteridae)

An extraordinary new species, Chaetopterus pugaporcinus, is described from eight specimens collected from deep mesopelagic waters off Monterey Bay, California, by remotely operated vehicles. All specimens exhibit a consistent combination of both adult and larval characteristics, leaving in question the maturity of the specimens. All specimens lack ciliated larval bands and the stout, modified chaetae (cutting spines) typically found in segment A4 of chaetopterids. If the specimens described here are larvae, they are remarkable for their size, which ranged from 10 to 21 mm total length, nearly twice the length of the largest polychaete larvae previously reported and 5 to 10 times larger than known chaetopterid larvae. Then too, their lack of segment addition prior to settlement would be atypical. If adult, they are particularly unusual in their habitat choice and body form. Morphology of the uncini and comparison to larval morphology indicated a close relationship to either Chaetopterus or Mesochaetopterus. However, the lack of cutting spines and typical adult morphology made it impossible to determine to what genus this species should be allied. Thus, we carried out the first molecular phylogenetic analysis of the Chaetopteridae in order to appropriately place and name the new species. Three partial genes were sequenced for 21 annelid species. The sequencing also provides the first molecular evidence that Chaetopterus variopedatus sensu Hartman (1959) is not a single cosmopolitan species. The question of C. pugaporcinus being a delayed larva or a genuine holopelagic chaetopterid is discussed.     

The nonfeeding auricularia of Holothuria mexicana (Echinodermata,Holothuroidea)

Among echinoderms, nonfeeding larvae usually are simplified in body shape, have uniform ciliation, and have lost the larval gut. A few species have nonfeeding larvae that express some remnant features of feeding larvae like ciliated bands and larval skeleton or larval arms, but typically their larval mouth never opens and their gut does not function. Still other species have retained the feeding larval form, a functional gut, and can feed, but they do not require food to metamorphose. The present note describes the development of a tropical holothurian, Holothuria mexicana, which hatches as a gastrula that is already generating coelomic structures. A translucent auricularia forms with a mouth that opens but becomes reduced soon thereafter. In form and ciliation this auricularia resembles a feeding larva, but it does not respond to food. A doliolaria forms on day 4 and the pentactula on day 6 post‐fertilization. Further study of this larva and that of its closely related congener, Holothuria floridana, is warranted.     

Trichinella murrelli in scavenging mammals from south-central Wisconsin, USA

Tissues and serum from 59 raccoons (Procyon lotor), 42 coyotes (Canis latrans), and seven Striped Skunks (Mephitis mephitis) collected in Dane and Iowa Counties, Wisconsin, USA, between October 2005 and March 2006 were microscopically and serologically examined for the presence of Trichinella spp. Encapsulated larvae were found on compression slides prepared from tongue tissues from a few animals. Complete tissue digestion of tongues revealed that 19% of the raccoons, 26% of the coyotes, and none of the seven skunks tested were infected with Trichinella spp. Cats were subsequently experimentally infected by feeding them the raccoon tissues containing muscle larvae, and muscle larvae isolated from the collected tongues were experimentally transmitted to mice. Multiplex polymerase chain reaction analysis of the isolated muscle larvae demonstrated two distinct bands migrating at 127 base pairs (bp) and 316 bp in all samples, which together are diagnostic for Trichinella murrelli; the isolates were assigned Istituto Superiore di Sanita (ISS) codes ISS1656 through ISS1667, and ISS1708 through ISS1710 by the International Trichinella Reference Centre. These findings extend the geographic range of T. murrelli into Wisconsin, USA.     

Hyalomma (Hyalommina) arabica: nymphal and larval identity and spiny mouse hosts in Saudi Arabia (Acarina: Ixodoidea: Ixodidae)

Nymphal and larval Hyalomma (Hyalommina) arabica Pegram, Hoogstraal, and Wassef, 1982, described herein, closely resemble those of Hyalomma (Hyalommina) rhipicephaloides Neumann, differing chiefly in body size (both stages), nymphal basis capituli and scutal proportional dimensions, and distinctness of larval coxal spurs. Females of these species are also structurally similar but males differ in major critical characters. Nymphs and larvae of both species parasitize the spiny mouse (Acomys spp.), but immatures of the third African- Arabian species of this subgenus, Hyalomma (Hyalommina) punt Hoogstraal, Kaiser, and Pedersen, are unknown. Hyalomma (Hyalommina) arabica occurs in valleys and hills of western Saudi Arabia and western Yemen; H. (H.) rhipicephaloides in the Red Sea and Dead Sea areas; and H. (H.) punt in northeastern Somalia and eastern Ethiopia. The ibex (Capra ibex nubiana Cuvier) is probably the original host of adult H. (H.) arabica and H. (H.) rhipicephaloides; the related domestic goat is an important host of adults of the 3 species, which also parasitize domestic sheep. Gazelles are recorded hosts of adults of H. (H.) rhipicephaloides and H. (H.) punt and the latter is also recorded from goats, sheep, camels and cattle.     

Vulnerability of bot fly (Cuterebra) infected Peromyscus maniculatus to shorttail weasel predation in the laboratory

In the laboratory, Peromyscus bearing a single Cuterebra larva are no more vulnerable to weasel predation than are uninfected control mice, and may be taken less often under certain conditions. Mice bearing two or more larvae appear to be more vulnerable than either controls or singly infected mice. Their increased vulnerability probably results from their failure to use arboreal pathways. Decreased activity may be responsible for the relative advantage of singly infected mice. Previous reports of higher survivorship among mice with a single bot parasite than among uninfected mice, and of lower survivorship among multiply infected mice, may result in part from differential predation rates.     

How Phenological Variation Affects Species Spreading Speeds

In this paper, we develop a phenologically explicit reaction–diffusion model to analyze the spatial spread of a univoltine insect species. Our model assumes four explicit life stages: adult, two larval, and pupa, with a fourth, implicit, egg stage modeled as a time delay between oviposition and emergence as a larva. As such, our model is broadly applicable to holometabolous insects. To account for phenology (seasonal biological timing), we introduce four time-dependent phenological functions describing adult emergence, oviposition and larval conversion, respectively. Emergence is defined as the per-capita probability of an adult emerging from the pupal stage at a particular time. Oviposition is defined as the per-capita rate of adult egg deposition at a particular time. Two functions deal with the larva stage 1 to larva stage 2, and larva stage 2 to pupa conversion as per-capita rate of conversion at a particular time. This very general formulation allows us to accommodate a wide variety of alternative insect phenologies and lifestyles. We provide the moment-generating function for the general linearized system in terms of phenological functions and model parameters. We prove that the spreading speed of the linearized system is the same as that for nonlinear system. We then find explicit solutions for the spreading speed of the insect population for the limiting cases where (1) emergence and oviposition are impulsive (i.e., take place over an extremely narrow time window), larval conversion occurs at a constant rate, and larvae are immobile, (2) emergence and oviposition are impulsive (i.e., take place over an extremely narrow time window), larval conversion occurs at a constant rate starting at a delayed time from egg hatch, and larvae are immobile, and (3) emergence, oviposition, and larval conversion are impulsive. To consider other biological scenarios, including cases with emergence and oviposition windows of finite width as well as mobile larvae, we use numerical simulations. Our results provide a framework for understanding how phenology can interact with spatial spread to facilitate (or hinder) species expansion. This is an important area of research within the context of global change, which brings both new invasive species and range shifts for native species, all the while causing perturbations to species phenology that may impact the abilities of native and invasive populations to spread.     

Fatal Baylisascaris larva migrans in a colony of Japanese macaques kept by a safari-style zoo in Japan

A colony of Japanese macaques (Macaca fuscata fuscata) kept by a safari-style zoo in Japan experienced 9 sporadic cases of fatal neurological diseases, such as epilepsy and posterior paralysis, during the 12 yr from 1989 to 2001. This macaque colony consisted of approximately 30 animals, on average, during this period, and the macaques shared their living space with II American black bears (Ursus americanus) harboring zoonotic roundworms (Baylisascaris transfuga). Close to this enclosure, a cote for 2-3 raccoons (Procyon lotor) was placed, and raw sewage from this cote ran into a shallow drain in the area for macaques and bears. However, fecal examinations in recent years did not detect the infection of raccoons with zoonotic roundworms (Baylisascaris procyonis). Postmortem histological examination of the latest 2 ill macaques detected multifocal malacia in the brain; 2 ascarid larvae of 60 microm maximum width were encapsulated in the cerebrum and lungs of 1 of the animals. To determine the causative ascarid species of the fatal larva migrans, we analyzed 2 additional encapsulated Baylisascaris larvae collected from formalin-fixed lungs by morphological and molecular approaches. This sporadic outbreak is the second record of Baylisascaris larva migrans in animals in Japan.     

Innate Predator Recognition and the Problem of Introduced Trout

Innate predator recognition typically only occurs when there is an evolutionary history between predator and prey. Predator introductions thus can pose a substantial threat to native fauna that rely heavily on inherent identification of predators. In permanent aquatic habitats prey often encounter a variety of predatory and non-predatory fish species, and the ability to distinguish between the two is essential to avoid wasted time and energy spent in unnecessary antipredatory efforts. Here, we present a study evaluating the ability of lab-reared larvae of an endangered fully aquatic salamander (hellbenders: Cryptobranchus alleganiensis ) to recognize chemical cues from native and introduced fish predators. We recorded responses of hellbender larvae to chemical stimuli from native and non-native predatory fishes, a non-predatory fish and a blank control. Eastern hellbender larvae ( C. a. alleganiensis ) significantly reduced activity in response to chemical stimuli from native predators ( Micropterus salmoides , Micropterus dolomieu , Ambloplites rupestris , Sander vitreus , and Cottus carolinae ), but responses to non-native rainbow ( Oncorhynchus mykiss ) and brown ( Salmo trutta ) trout were not significantly different from responses to the non-predatory control (redhorse sucker, Moxostoma spp.). Responses of larval Ozark hellbenders ( C. a. bishopi ) to brown trout were similar to that of the native fishes and different from the blank control, but responses to rainbow trout did not differ from the blank control. The generally weak responses of larval hellbenders to chemical cues from introduced predatory trout could lead to increased predation in the wild, which may have exacerbated the decline of hellbender populations.     

Adult female and neonate larval plant preferences of the generalist herbivore, Epiphyas postvittana

The polyphagous leafroller moth, Epiphyas postvittana, is a pest of many fruit crops in New Zealand. Since the larva is highly mobile, host selection in this insect may involve both the adult female and the larva. In order to test the relative importance of the adult female and the neonate larva in the selection of host plants, the ovipositional preferences of females, and the preferences or acceptances of neonate larvae towards 26 plant species, consisting of 15 plants considered hosts and 11 not considered hosts, were investigated. In the ovipositional tests, the mean preferences of females for hosts and non-hosts were very similar. In contrast, larvae showed a significantly greater mean preference or acceptance towards hosts than to non-hosts, in both choice and no-choice bioassays, respectively. There were highly significant correlations between the preferences and acceptances of larvae for plants in the choice and no-choice tests. In the no-choice tests, there was a highly significant correlation between the acceptances of neonate larvae towards plants after one and three days (i.e., acceptances changed little over time). Moreover, in these no-choice tests, there was a significant negative correlation between larval acceptance at 1 day and larval mortality after 3 days; that is, the less acceptable a given plant at 1 day, the more likely larvae would fail to establish, feed, and survive on it by three days. Female and larval preferences towards the various plants were also negatively correlated. Together, these data suggest that the selection of a plant for the neonate larva to feed on is largely governed by the preferences of the larva, rather than by the preferences of the female. However, selection of a plant for oviposition by the female, may be important in host selection for reasons unrelated to larval preferences, for example, by encouraging dispersal, perhaps to other plant species, of the neonate larvae and thereby decreasing intersibling competition.     

Discovery of the Quedius antipodum Sharp larva from New Zealand: phylogenetic test of larval morphology for Staphylinini at the intratribal level (Coleoptera: Staphylinidae)

Quedius antipodum Sharp is an endemic species from New Zealand. Here we describe its larva, the first of the species‐rich group of the south temperate ‘Quedius’ spp. This finding throws light on the controversy between the conventional systematics of Quedius Stephens and newer phylogenetic analyses, both of which are based on non‐larval characters only. We compare the larva of Q. antipodum with those of the north temperate Quedius (Quediina), where it was traditionally placed, and with the known larvae of Amblyopinina, a group where Q. antipodum was placed by recent phylogenetic studies. Sister‐group relationships of Q. antipodum within the tribe Staphylinini are explored based on larvae by means of parsimony analysis: 77 morphological characters scored for 20 species from 17 genera. Consistent with the adult morphology and DNA sequences, larvae‐based cladistic analysis confirms that Q. antipodum should not be placed in the north temperate genus Quedius. However, larval analysis alone remains dubious with respect to finding the exact sister relationships of that species.     

First outbreak of Baylisascaris procyonis larva migrans in rabbits in Japan

A syndrome of progressive neurological signs was noticed in rabbits (Oryctolagus cuniculus) kept in a small wildlife park in mid-July 2000. Three out of 12 common raccoons (Procyon lotor) kept in this park were infected with Baylisascaris procyonis, and the larvae were found from affected rabbits. This outbreak is the first proven B. procyonis larva migrans in Japan, and the potential risk of serious zoonosis by this ascarid species should be considered by pet owners, veterinarians, physicians and public health authorities in this country as in North America where raccoons are endemic.