Variations in attack behaviours between Glossina palpalis gambiensis and G. tachinoides in a gallery forest suggest host specificity

Tsetse flies Glossina palpalis gambiensis and G. tachinoides are among the major vectors of sleeping sickness (Human African Trypanosomiasis‐HAT) and nagana (African Animal Trypanosomiasis – AAT) in West Africa. Both riparian species occur sympatrically in gallery forests of south west Burkina Faso, but little is known of their interspecies relationships although different authors think there may be some competition between them. The aim of this study was to check if sympatric species have different strategies when approaching a host. A man placed in a sticky cube (1 m × 1 m × 1 m) and a sticky black‐blue‐black target (1 m × 1 m) were used to capture tsetse along the Comoe river banks in a Latin Square design. The number and the height at which tsetse were caught by each capture method were recorded according to species and sex. Glossina p. gambiensis was more attracted to human bait than to the target, but both species were captured at a significantly higher height on the target compared with the human bait (P < 0.05). No significant difference in heights was found between G. tachinoides and G. p. gambiensis captured on targets (33 and 35 cm, respectively, P > 0.05). However, catches on human bait showed a significant difference in height between G. tachinoides and G. p. gambiensis (22.5 and 30.6 cm, respectively, P < 0.001). This study showed that these sympatric species had different attack behaviours to humans, which is not the case with the target. The implications of these findings are discussed.     

A survey of the ixodid ticks parasitising cattle in the Eastern Province of Zambia

The results of tick surveys carried out in the Eastern province of Zambia between December 1982 and February 1996 were principally in agreement with the findings of earlier surveys conducted during the period 1965–72. Boophilus decoloratus has almost been replaced by Boophilus microplus . Hyalomma truncatum was found in small numbers throughout the province and Hyalomma marginatum rufipes was only rarely encountered in collections made from cattle. Rhipicephalus evertsi evertsi was largely confined to the southern part of the plateau and the valleys of the Zambezi tributaries. The main difference between the present survey and the previous one concerns the status of Rhipicephalus appendiculatus . This species is currently expanding its range in a westward direction, whereas it was virtually absent from the southern part of the province during the period 1965–72. The majority of specimens collected are morphologically intermediate between R. appendiculatus and the closely allied Rhipicephalus zambeziensis . The available evidence indicates that R. zambeziensis ( sensu stricto ) is absent from the province. The phenology of R. appendiculatus is aberrant in the province: at lower altitudes a second generation of adult ticks is recorded on the hosts at the start of the dry season.     

High-Resolution Polyacrylamide Gradient Gel Electrophoresis (PGGE) of Isoenzymes from Five Naegleria Species

ABSTRACT. High-resolution polyacrylamide gradient gel electrophoresis (PGGE) was used to separate isoenzymes of 12 Naegleria strains: one N. australiensis , two N. lovaniensis , one N. jadini , two N. gruberi isolated from environmental samples, and six N. fowleri strains isolated from patients with primary amoebic meningoencephalitis. Of the eight enzymes studied, seven showed zymograms with interspecific variation that identified all the species tested. Although the six N. fowleri strains were biochemically the most homogeneous, they showed intraspecific isoenzyme variation that allowed them to be grouped into four zymodemes. The PGGE technique, which separates isoenzymes by their molecular shape, is both sensitive and economical. It offers an addition or an attractive alternative to isoelectric focusing which has commonly been used to aid species identification of Naegleria by separating isoenzymes by their isoelectric point.     

Ontogenetic Change of the PSI- and PSII-Distribution in the Thylakoid System of Euglena gracilis

The thylakoid membranes of isolated Euglena chloroplasts wereseparated into two fractions by aqueous two-phase-partitioning(mixture of dextran 500 and poly(ethylene glycol) 4000) followingpress disruption. These two fractions differ in many respectsduring most of the cell cycle of this alga in comparison withthe thylakoid characteristics of higher plants or green algae.The amount of thylakoid membranes with separation characteristicscomparable with inside-out-vesicles of higher plant chloroplastschanges depending on the cell cycle stage of Euglena gracilis.Photosystems II and I are not restricted to one fraction. Boththylakoid membrane fractions evolve oxygen photosynthetically.When chloroplast differentiation in Euglena gracilis is complete(i.e. at the end of the light-time) the composition and thephotosynthetic efficiency of the two thylakoid fractions aregenerally equal. Photosystem I-related LHCI is present in bothfractions. Photosystem II-related CP29, however, was only detectedin unfractionated thylakoid membranes. The implications forthylakoid organization in Euglena chloroplasts are discussed. Key words: Euglena gracilis, photosystem I, photosystem II, stacking, thylakoids     

Breeding behaviour, home range and habitat selection in Rock Firefinches Lagonosticta sanguinodorsalis in the wet and dry season in central Nigeria

Knowledge of a species’ movement behaviour and habitat choice is a prerequisite for assessing its ecological requirements to plan successful conservation strategies. Little is known about these factors in the Rock Firefinch, a recently described species which is probably endemic to the Jos Plateau in central Nigeria. We investigated home range size, habitat use and breeding behaviour of the Rock Firefinch in Amurum forest reserve in central Nigeria during the wet (August–October) and the dry season (November–December) using radiotracking. Birds showed high site fidelity. They mainly moved alone or in pairs but did not have exclusive home ranges. Home range size tended to be larger during the dry season due to long movements to water sources. Birds generally preferred inselberg habitat and avoided farmland. During the dry season they additionally utilized gallery forests where water was readily available, and as a result of having to cross scrub savannah to get to water, scrub savannah was also more heavily used during the dry season. Birds bred between the late rainy (September–October) and the early dry season (November). Nest‐sites were associated with rocky boulders. Both sexes contributed to incubation. Daily egg survival rate calculated using the Mayfield method was 0.89 (0.83–0.95 95% confidence interval); no nests failed during the chick stage, but sample size was only four nests. Of all 14 nests found, 50% were depredated and only 29% of breeding attempts succeeded in producing Rock Firefinch chicks. A second breeding attempt was recorded when the first one failed. Chick production just about compensated adult mortality (measured in a separate study at the site) such that the population is probably stable at present. However, given the large uncertainty in our underlying assumptions, more data are needed to confirm this. We suggest that the presence of inselberg habitat in close proximity to water sources is the essential and limiting resource for this species.