Six new species of Myrsidea Waterston, 1915 (Phthiraptera: Menoponidae) from New World jays of the genus Cyanocorax Boie (Passeriformes: Corvidae), with notes on the chorionic structure of eggs.

The only species of previously named Myrsidea Waterston, 1915 from Neotropical jays of the genus Cyanocorax Boie (Passeriformes: Corvidae), Myrsidea fallax Kéler, 1938 (type-host Cyanocorax cyanomelas Vieillot), is redescribed and six new species of lice in the genus Myrsidea are described: Myrsidea pseudofallax n. sp. [type-host C. c. chrysops (Vieillot)]; M. moriona n. sp. [type-host C. m. morio (Wagler)]; Myrsidea daleclaytoni n. sp. [type-host C. v. violaceus Du Bus de Gisignies]; Myrsidea lindolphoi n. sp. [type-host C. caeruleus (Vieillot)]; Myrsidea melanocyanei n. sp. [type-host C. melanocyaneus chavezi (Miller & Griscom)]; and Myrsidea cristatelli n. sp. [type-host C. cristatellus (Temminck)]. A key to the identification of both sexes of these seven species is provided. Immature stages of M. daleclaytoni n. sp. (all instars) and M. cristatelli n. sp. (nymph III) are described. External chorionic architecture of the eggs is described and illustrated for six Myrsidea spp. from corvine birds: M. picae (Linnaeus, 1758) ex Pica p. pica L.; M. cornicis (DeGeer, 1778) ex Corvus c. corone L.; M. isostoma (Nitzsch in Giebel, 1866) ex Co. f. frugilegus L.; M. interrupta (Osborn, 1896) ex Co. brachyrhynchus Brehm; M. fallax ex Cy. cyanomelas; and M. moriona n. sp. ex Cy. m. morio. This is the first review of the data on Myrsidea spp. infesting Neotropical Corvidae.

Scanning electron microscopy of Antarctophthirus microchir (Phthiraptera: Anoplura: Echinophthiriidae): studying morphological adaptations to aquatic life.

The members of the Family Echinophthiriidae (Phthiraptera: Anoplura) are unique among insects because they infest hosts with an amphibious lifestyle. During their evolution they developed morphological traits that are reflected in unique features. The SEM is a helpful tool to analyze them. Knowing in detail the external structure of these lice is the first step to understand the whole process that derived from the co-adaptation of lice and pinnipeds to the marine environment. For the first time, we studied the external structure of all stages of an echinophthiriid louse. The results are discussed in the light of their evolutionary, functional, and ecological implications.

Redescription of Gyropus parvus (Ewing, 1924) (Insecta: Phthiraptera: Amblycera: Gyropidae) from tucos-tucos (Rodentia: Ctenomyidae: Ctenomys ) in Patagonia, Argentina.

A detailed redescription of Gyropus parvus (Insecta: Phthiraptera: Amblycera: Gyropidae) is given based on specimens collected from the type host, Ctenomys colburni Allen 1903 , and the type locality, Estancia Huanuluán, Provincia de Rio Negro, Argentina. We expand and provide new chaetotaxy. New scanning electron microscopy images showing microstructural details of adults and eggs of G. parvus obtained from topotype specimens are included. Sexual dimorphism was mainly shown by differences in body size and abdominal chaetotaxy, with females being 17.5% larger than males and with more setae in each cluster. Significant differences between males and females were also observed in sternal plate measurements. Features described here show homogeneity within type host population. This information contributes to our knowledge of intra- and inter-specific variability for parasite populations. Our investigation constitutes the first collection of G. parvus from the type host and locality since it was described.

Demographic correlates of sexual size dimorphism and male genital size in the lice Philopterus coarctatus.

Sexual selection is an influential agent of evolution, often shaping the sex ratio, sexual size dimorphism (SSD), and genital size in animals. To explore its effects in ectoparasites, we quantified SSD and male genital size in relation to intensity and sex ratio across subpopulations of Philopterus coarctatus, a philopterid louse of the great grey shrike. SSD was calculated separately for the width and length of the head and abdomen. Presuming that sexual selection affects the evolution of avian lice, we would expect that infestation intensities should covary with sex ratio, relative male size, and relative male genital size, either positively or negatively depending upon presumptions. Contrary to former studies, there was a weak negative relationship between infestation intensity and sex ratio. The relative width of male abdomens exhibited a highly significant negative interaction with the intensity of infestations. In contrast, sex ratio did not predict any of the dimorphism measures. Similarly, male genital size did not covary with the intensity of infestations or sex ratios. These findings may indicate that intensity covaries positively with levels of inbreeding in this species, suggesting that more-inbred subpopulations, wasting less energy for sexual rivalry, can multiply more intensively. Thus, small subpopulations have more frequent males which also possess larger abdomens. Alternatively, however, the same pattern may also arise due to male-biased starvation in overcrowded habitats; thus, males are rarer and have smaller abdomens in larger infrapopulations.

The presence of quill mites (Gabucinia bicaudata) and lice (Struthiolipeurus struthionis) in ostrich wing feathers.

Quill mites (Gabucinia bicaudata) and lice (Struthiolipeurus struthionis) may infest ostrich feathers, resulting in skin damage, pruritus and excessive feather preening and loss. Four different feather types (prime white, femina extra wide, femina class 1, and femina short; n = 10) were collected. The quill mites and lice were removed with fine forceps, studied using a photographic optical microscope and counted microscopically at x 100 magnification following collection by sedimentation. They were placed in separate Petri dishes containing lactophenol solution and examined (x40 magnification). Anatomical features are described. The density of quill mites in all feather types of both wings was higher than that of the lice. There was no significant difference between the counts of both arthropods on the left wing and the right wing, respectively, except for the femina class 1 quill mites (P = 0.01). The femina extra wide feathers were a preferred habitat in both wings. Large standard deviations (quill mites left wing: 73 +/- 8; quill mites right wing: 69 +/- 7) suggested variations in the degree of migration between feather shafts or as a response to escape preening. It is recommended that ostriches be treated with an oral preparation of Ivermectin administered per os at a dosage rate of 0.2 mg/kg at 30-day intervals for quill mites, and with a 1-5 % Malathion dust at 14-day intervals for lice.

Ecomorphology of parasite attachment: experiments with feather lice.

The host specificity of some parasites can be reinforced by morphological specialization for attachment to mobile hosts. For example, ectoparasites with adaptations for attaching to hosts of a particular size might not be able to remain attached to larger or smaller hosts. This hypothesis is suggested by the positive correlation documented between the body sizes of many parasites and their hosts. We adopted an ecomorphological approach to test the attachment hypothesis. We tested the ability of host-specific feather lice (Phthiraptera: Ischnocera) to attach to 6 novel species of pigeons and doves that vary in size by nearly 2 orders of magnitude. Surprisingly, Rock Pigeon lice (Columbicola columbae) remained attached equally well to all 6 novel host species. We tested the relative importance of 3 factors that could facilitate louse attachment: whole-body insertion, tarsal claw use, and mandible use. Insertion, per se, was not necessary for attachment. However, insertion on coarse feathers of large hosts allowed lice to access feather barbules with their mandibles. Mandible use was a key component of attachment regardless of feather size. Attachment constraints do not appear to reinforce host specificity in this system.

Use of scanning electron microscopy to confirm the identity of lice infesting communally grazed goat herds.

Lice have been described on goats in commercial farming systems in South Africa but not from flocks on communal grazing. During a longitudinal survey on the causes of goat kid mortality, conducted in Jericho district, North West Province, lice were collected from communally grazed indigenous goats. These lice were prepared for and viewed by scanning electron microscopy, and micro-morphological taxonomic details are described. Three species of lice were found in the study area and identified as Bovicola caprae, Bovicola limbatus and Linognathus africanus. Sucking and biting lice were found in ten of the 12 herds of goats examined. Lice were found on both mature goats and kids. Bovicola caprae and L. africanus were the most common biting and sucking lice respectively in all herds examined. Scanning electron microscopy revealed additional features which aided in the identification of the louse species. Photomicrographs were more accurate aids to identification than the line drawings in the literature and facilitated identification using dissecting microscope.

Light and scanning electron microscopical study on Antarctophthirus ogmorhini lice from the Antarctic seal Leptonychotes weddellii.

Adult lice (Antarctophthirus ogmorhini) from the Weddell seal Leptonychotes weddellii were investigated by means of light and scanning electron microscopy. We established that this species is characterized by several morphological peculiarities which enable it to survive the low temperatures of the Antarctic sea and the body depression which occurs during the deep (450 m) and long diving periods of the seals. The main peculiarities are: (1) the cuticle of the ventral and lateral surfaces is much thinner than that of the dorsal surface, (2) the body has numerous stiff spines which are covered by a thick layer of the seal's sebum that closely surrounds the body of the louse, (3) the whole body is covered by a close layer of leaf-like scales which are apparently able to trap air bubbles and thus to provide a small zone of air close to the surface of the cuticle.

A new species of sucking louse (Insecta, Anoplura) parasitic on Auliscomys (Mammalia, Rodentia) in Argentina.

Hoplopleura auliscomydis n. sp. is described based on specimens collected from Auliscomys micropus (Waterhouse 1837), from Colln Curá, Neuquén Province, Argentina. Descriptions are provided for the holotype male, female, first nymphal instar, external architecture of eggs (by scanning electron microscopy), and sites of oviposition, providing differences from its close relative Hoplopleura neotomydis Castro, González, and Cicchino, 1995. The geographical ranges of these 2 species are restricted to the Neuquén Province in Argentina. A key to the 9 species of the Hoplopleura travassosi species-group recorded in Argentina is also given.

Identification of Microthoracius mazzai (Phthiraptera: Anoplura) as an economically important parasite of alpacas.

The hematophagous sucking louse Microthoracius mazzai Werneck, 1932, is redescribed and identified as a parasite of alpacas, Lama pacos L. Specimens were collected on animals 10-14 mo old, located on a large community farm at 4,600 m above sea level in the Peruvian Andes. In total, 26 scanning electron microscope (SEM) figures are included that highlight salient and differential characteristics, especially the unique elongated spindle-shaped head, which is almost as long as its abdomen. Alpacas, 1 of the 4 species of South American camelids, are important for their production of high-quality wool in the Andes Mountain range countries, especially Peru and Bolivia; to a lesser degree Chile; and more recently Argentina, where breeding and disease control programs are receiving increased technical support. Information is given on the prevalence of lice infestations in the flock, clinical signs, and economic losses. We report the efficacy of moxidectin (SC, 200 mcg/kg, b.w.) in a repeated treatment program of 7-10 d, which is currently used for mange control in these ruminants.

Histopathological effects of Bacillus thuringiensis on the alimentary canal of the sheep louse, Bovicola ovis.

Sequential observations were made of the ultrastructural effects of Bacillus thuringiensis (Bt) subsp. kurstaki strain WB3S16 on midgut epithelial cells of the sheep biting louse, Bovicola ovis, after the lice were fed, ad libitum, a powdered preparation of Bt spores, delta-endotoxin crystals, and lysed cellular components. Light microscope observations revealed cytopathological changes to the midgut epithelial cells 4 h postfeeding. Transmission electron micrographs showed that the microvilli of the midgut epithelial cells became disrupted 4-8 h postfeeding, after which the cells became vacuolated and swollen, and the cell organelles lost definition and disappeared. Paralysis and death of B. ovis occurred between 8 and 12 h postfeeding, coincident with midgut cells lysis and release of cellular contents into the midgut lumen. The histopathological effects reported here are similar to those reported in lepidopteran and coleopteran larvae affected by the delta-endotoxin crystal proteins. The constituent fractions of the Bt preparation were tested for toxicity to B. ovis using a feeding bioassay. Native delta-endotoxin crystals were not toxic to B. ovis and remained intact in the midgut of the insect. There was no evidence that the native Bt crystal was involved in the cytopathology and death of the lice. However, in vitro solubilized delta-endotoxin crystal proteins were significantly toxic to B. ovis. In addition, a louse active toxin was associated with the Bt membranes and culture supernatant.

Pediculus capitis bajo el microscopio electrónico / Pediculus capitis under the electron microscope

Este trabajo es un aporte para el conocimiento de la morfofisiología de Pediculus capitis, agente causal de la pediculosis, con imágenes a microscopía electrónica (AU)

Pediculus capitis bajo el microscopio electrónico / Pediculus capitis under the electron microscope

Este trabajo es un aporte para el conocimiento de la morfofisiología de Pediculus capitis, agente causal de la pediculosis, con imágenes a microscopía electrónica

Yellow marking and pteridine contents in the integument of albino Armadillidium vulgare.

The albino mutant strain in the woodlice, Armadillidium vulgare, was investigated with respect to the yellow patterns on the dorsal integument. Pigment cells were observed with electron microscope in order to determine the cell types of yellow markings. Quantitative analyses of pteridines in the albino were carried out by HPLC. The result indicated that the albino integument contain sepiapterin, biopterin, pterin, isoxanthopterin as in the wild type and the red mutant strain. The total amount of the four pteridines in the albino was about half as much as that in the red phenotype for both males and females, respectively. Males and females showed almost the same totals and ratios of the four pteridines in the albino and red phenotypes. Therefore, pteridine contents in both phenotypes of A. vulgare may not be related to the activity of androgenic gland hormone. Yellow chromatophores of the albino and red phenotypes were morphologically identical, emitting a yellow fluorescence. These cells contained numerous electron-lucent pigment organelles which were similar to pteridine granules of the wild type.

[Ultrastructural surface properties in Columbicola columbae s. str. (Esthiopteridae, Mallophaga-Ischnocera) from domestic pigeons]. / Osobliwosci ultrastruktur powierzchniowych u Columbicola columbae s. str. (Esthiopteridae, Mallophaga-Ischnocera) z golebia domowego.

All post-embryonal stages of Columbicola columbae columbae (L.), the common parasite of pigeon, were investigated with regard to morphology, particularly surface ultrastructures. Many qualitative characters differing C. columbae s. str. from the investigated up to now species of Mallophaga were found in SEM. They are among others double lateral protuberances of head (clavus and clavulus) as well as parallel sculpture of pore organs on the last two segments of antennae. The structures showed at the photograms were interpreted with regard to their functions.

The morphology of Laemobothrion (Laemobothrion) maximum (Phthiraptera: Laemobothriidae).

Adult specimens of Laemobothrion (L.) maximum (Scopoli, 1763), a buzzard louse species, were studied using scanning electron microscopy and paying special attention to sensitive structures, mainly those located on the head, mouthparts, abdomen and legs. Data on shape and size of palpl and antennal sensilla, as well as post-spiracular ones, were obtained. Some modifications of the mouthparts were observed.

Heterodoxus spiniger (Boopiidae, Mallophaga) from Canis familiaris from India in the light and scanning electron microscopes.

Knowledge of morphometric characteristics of Heterodoxus spiniger was widened on the basis of material collected from dog (Canis familiaris) from India. Study, mostly by scanning electron microscope, concerned the males, females and nymphs of H. spiniger. The functional role of some elements, particularly observed surface ultrastructures, has been pointed out. The differences between postembrional stages were determined as well as literature data on H. spiniger were critically analysed.

[Phthirus pubis as the cause of tubo-ovarian conglomerate tumor]. / Phthirus pubis als Ursache eines tuboovarialen Konglomerattumors.

A case of an inflammatory tubo-ovarian tumour is presented. Histology and entomology identified the infectious agent as Phthirus pubis.