Phylogeny of "Philoceanus complex" seabird lice (Phthiraptera: Ischnocera) inferred from mitochondrial DNA sequences

The Philoceanus complex is a large assemblage of lice that parasitise procellariiform seabirds (petrels, albatrosses, and their relatives). We obtained mitochondrial 12S rRNA and cytochrome oxidase I DNA sequences from 39 species from diverse hosts and localities. Resolution of deeper relationships between genera was limited, however there is evidence for two major clades, one hosted by albatrosses, the other by petrels. Based on our results, the genera hosted by albatrosses are excellent candidates for detailed analysis of cospeciation. Our results also suggest that a previous estimate of a 5-fold difference in the relative rate of sequence evolution in lice and their avian hosts is an artefact of limited taxonomic sampling.     

The water-vapour uptake system of the phthiraptera

The occurrence of active water-vapour uptake was examined in 16 Phthirapteran species representing the two groups of biting lice or Mallophaga (Amblycera and Ischnocera) and the sucking lice or Anoplura. Water-vapour uptake could not be demonstrated in the Anoplura and although it is frequently encountered in the biting lice, some members of both the Ischnocera and Amblycera lack the faculty. Uptake performance in the absorbing species of biting lice is exceptionally efficient showing higher rates and lower thresholds than other absorbing arthropods. The critical equilibrium humidities were found to range between 43 and 52% r.h., 43% being the lowest value so far reported. The uptake rates, expressed as a percentage of total body water mass, by far surpass those of all other arthropods investigated. The Phthirapteran uptake pattern closely resembles that of the Psocoptera, showing abrupt initiation and termination of the uptake process, limitation of continuous absorption to relatively short periods of time and constancy of the absorption rate over the entire period of continuous uptake. Studies on the uptake site and mechanism in Phthiraptera revealed an oral-uptake system which is congruous with that of the Psocoptera. The structural components of the uptake device, like a pair of oval lingual sclerites, representing the site of water-vapour condensation and a cibarial sucking pump which is connected by a paired or branching selerotized tubule to the lingual selerites and is responsible for the transfer of the condensed water to the gut, are unique acquisitions of the Psocodea.In those members of the biting lice which have lost the faculty of water-vapour uptake the structural components of the uptake system are modified or reduced.     

Egg shells of mallophagans and anoplurans (Insecta: Phthiraptera): morphogenesis of specialized regions and the relation to F-actin cytoskeleton of follicular cells

The egg shells of investigated phthirapterans consist of three basic elements: an anterior operculum, a main egg shell and a posterior hydropyle. In some species these elements show further regional specializations: bristles and projections that facilitate attachment to feathers of the host, micropyles and aeropylar openings. All of the egg shell specializations are formed by distinct subpopulations of follicular cells. Staining with rhodamine-conjugated phalloidin has revealed that these subpopulations significantly differ in the distribution of microfilaments (F-actin). In this respect four morphological categories of the follicular cells have been distinguished: (1) cells devoid of processes and microvilli, with basal arrays of microfilaments, responsible for the secretion of a flat chorion; (2) cells devoid of processes and microvilli, separated by intercellular spaces, with basal arrays of microfilaments, responsible for the secretion of attachment structures; (3) cells equipped with actin-containing processes, responsible for the formation of micropyles or aeropyles, and (4) cells equipped with bundles of microvilli, responsible for the formation of hydropyles.     

Lice of farm animals in Libya

Abstract. This first report on the lice of farm animals in Libya lists a total of fifteen species, as follows: Haematopinus quadripertusus and Linognathus vituli from cattle, Bovicola ovis, Linognathus pedalis, L.afrlcanus and L.ovillus from sheep, L.stenopsis, L.africanus and Bovicola caprae from goats. Poultry harboured Lipeurus caponis, L.heterographus, Menacanthus stramineus, Menopon gallinae, Goniocotes gallinae, Goniodes gigas and G.dissimilis.     

Zoogeography and host associations of the Heterodoxus octoseriatus group and H. ampullatus (Phthiraptera: Boopiidae) from rock-wallabies (Marsupialia: Petrogale)

Species of the Heterodoxus octoseriatus group infest five species, comprising eight chromosome races, of Petrogale in Queensland and northern New South Wales, Australia. The precise host and geographic ranges of the 11 species of the H. octoseriatus group were determined. Individual hosts and host populations were infested by single species of lice only. The geographic ranges of lice were discrete. In some cases the geographic ranges of louse species and their hosts were approximately congruent. In others they were completely incongruent and it was unclear which species originally infested which hosts or even which was the most recent colonizer. In at least one case, expansion of the geographic range of one species of louse apparently led to fragmentation of the range of another and subsequently, to allopatric speciation.     

Resistance to insect growth regulator insecticides in populations of sheep lice as assessed by a moulting disruption assay

Abstract.  Low-volume, backline applications with the benzoylphenyl urea insecticides triflumuron and diflubenzuron represent in excess of 70% of treatments for the control of sheep lice, Bovicola ovis (Schrank) (Phthiraptera: Trichodectidae), in Australia. Reports of reduced effectiveness from 2003 and subsequent controlled treatment trials suggested the emergence of resistance to these compounds in B. ovis populations. A laboratory assay based on the measurement of moulting success in nymphs was developed and used to assess susceptibility to diflubenzuron and triflumuron in louse populations collected from sheep where a control failure had occurred. These tests confirmed the development of resistance to triflumuron and diflubenzuron in at least two instances, with estimated resistance ratios of 67–94X at LC₅₀.     

First records of <Emphasis Type="Italic">Trichodectes canis</Emphasis> (Insecta: Phthiraptera: Trichodectidae) from Darwin’s fox, <Emphasis Type="Italic">Pseudalopex fulvipes</Emphasis> (Mammalia: Carnivora: Canidae)

The presence of the dog biting louse, Trichodectes canis (De Geer, 1778; Ischnocera: Trichodectidae), is reported for the first time in the critically endangered Pseudalopex fulvipes (Martin, 1837) in Chiloé Island, south Chile.