Comparison between anopheline mosquitoes (Diptera: Culicidae) caught using different methods in a malaria endemic area of Papua New Guinea

The mosquito sampling efficiency of CDC (Centers for Disease Control) miniature light traps hung adjacent to mosquito nets, was compared with that of both indoor and outdoor human-bait collections in ten villages in the Wosera area of Papua New Guinea. The most frequently collected anopheline in the matched indoor and light trap samples was Anopheles koliensis Owen, followed by A. punctulatus D?nitz, A. karwari (James), A. farauti Laveran (sensu lato), A. longirostris Brug and A. bancroftii Giles. All species were much less frequent in the light traps than in landing catches. The hypothesis that the numbers of mosquitoes in light traps are proportional to human landing catches was examined using regression models that allowed for sampling error in both entomological measurements. Light traps under-sampled A. punctulatus and A. farauti s.l. at high densities. The models indicated that the ratio of light trap to landing catch females of A. koliensis and A. karwari increased with increasing mosquito density. Light trap catches of A. longirostris were proportional to indoor landing rates but when outdoor landing rates were high this species was under-sampled by light traps. Numbers of A. bancroftii in light traps were found to be proportional to those in outdoor landing catches, but were negatively related to those attempting to bite indoors. Circumsporozoite positivity rates for both Plasmodium falciparum Welch and P. vivax (Grassi & Feletti) in A. punctulatus and A. farauti s.l. were significantly higher in light trap collections than in either indoor or outdoor landing catches, suggesting that light traps may selectively sample older mosquitoes of these species.     

The Anopheles punctulatus group of mosquitoes in the Solomon Islands and Vanuatu surveyed by allozyme electrophoresis

Abstract. Four species within the Anopheles punctulatus group of mosquitoes (Diptera: Culicidae) were identified by allozyme analysis of samples collected from thirty-three localities in Guadalcanal, Makira, Malaita, Temotu and Western Provinces in the Solomon Islands and six localities on Efate, Espiritu Santo, Maewo and Malekula Islands in Vanuatu. Three of these species are members of the An. farauti complex. A key is given to identify five species of the An. punctulatus group known to occur in the Solomon Islands using their isoenzyme characteristics.
An. farauti No. 1 was widespread in coastal areas of the Solomon Islands and was the only species detected in Vanuatu, including Efate Island (where Faureville is the type locality of An. farauti Laveran sensu stricto). An. farauti No. 2 and An. punctulatus were common in the Solomon Islands in more inland areas. An. farauti No. 7, reported here for the first time, was found as larvae in freshwater at six localities on north Guadalcanal. Three other members of the An. punctulatus group which have been reported previously from the Solomon Islands: An. koliensis, An. renellensis and an electrophoretic variant of An. farauti sensu lato, were not found in our samples.
Previously recognized vectors of malaria and bancroftian filariasis in the Solomon Islands are An. farauti No. 1 (i.e. An. farauti s.s. ), An. koliensis and An. punctulatus s. s. Adult females of An. farauti No. 2 and An. farauti No. 7 were not attracted to human bait in areas where their larvae occurred, indicating that these two species are not anthropophilic and therefore unlikely to transmit human pathogens.     

A phylogenetic study of the Anopheles punctulatus group of malaria vectors comparing rDNA sequence alignments derived from the mitochondrial and nuclear small ribosomal subunits

A phylogenetic study of the members of the Anopheles punctulatus group was performed using structural and similarity-based DNA sequence alignments of the small ribosomal subunit (SSU) from both the nuclear and the mitochondrial genomes. The mitochondrial SSU gene (12S, approximately 650 bp) proved to be highly restricted by its secondary structure and displayed little informative sequence variation. Consequently, it was considered unsuitable for a phylogenetic study of these closely related mosquito species. A structural alignment of the nuclear ribosomal DNA SSU (18S, approximately 2000 bp) proved to be more informative than similarity-based alignments. Analyses showed the A. punctulatus group to be monophyletic with two major clades; a Farauti clade containing members displaying an all-black-scaled proboscis (A. farauti 1-3 and 5-7) and the Punctulatus clade containing members displaying extensive white scaling on the apical half of the proboscis (A. farauti 4, A. punctulatus, and An. sp. near punctulatus). Anopheles koliensis was positioned basal to the Farauti clade.     

The Anopheles punctulatus complex: DNA probes for identifying the Australian species using isotopic, chromogenic, and chemiluminescence detection systems

Isotopic and enzyme-labeled species-specific DNA probes were made for the three known members of the Anopheles punctulatus complex of mosquitoes in Australia (Anopheles farauti Nos. 1, 2, and 3). Species-specific probes were selected by screening total genomic libraries made from the DNA of individual species with 32P-labeled DNA of homologous and heterologous mosquito species. The 32P-labeled probes for A. farauti Nos. 1 and 2 can detect less than 0.2 ng of DNA while the 32P-labeled probe for A. farauti No. 3 has a sensitivity of 1.25 ng of DNA. Probes were then enzyme labeled for chromogenic and chemiluminescence detection and compared to isotopic detection using 32P-labeled probes. Sequences of the probe repeat regions are presented. Species identifications can be made from dot blots or squashes of freshly killed mosquitoes or mosquitoes stored frozen, dried, and held at room temperature or fixed in isopropanol or ethanol with isotopic, chromogenic, or chemiluminescence detection systems. The use of nonisotopic detection systems will enable laboratories with minimal facilities to identify important regional vectors.     

Helminth communities of pademelons, Thylogale stigmatica and T. thetis from eastern Australia and Papua New Guinea

Gastrointestinal helminths were collected from pademelons of the genus Thylogale (Marsupialia: Macropodidae) in eastern Australia and Papua New Guinea. Examined were 12 Thylogale stigmatica stigmatica and 13 T. s. wilcoxi, the latter subdivided into eight specimens from the northern limit of their distribution and five from southern areas, all from eastern Queensland, Australia, one T. s. oriomo from Papua New Guinea and ten T. thetis from southeastern Queensland and northern New South Wales, Australia. Six species of cestodes and 40 species of nematodes were found. The helminth community of T. s. stigmatica was similar to that found in northern specimens of T. s. wilcoxi, while differences from the helminth community present in southern T. s. wilcoxi could be accounted for by parasites acquired from sympatric T. thetis. Thylogale thetis harboured a community of helminths distinct from but related to that in T. stigmatica. The evidence suggests that all subspecies of T. stigmatica examined share a common helminth community, but that in areas of sympatry, T. stigmatica and T. thetis share some of their parasites.     

Contributions to the Cladocera fauna from Papua New Guinea

Twenty-eight taxa of the Cladocera are identified in collections from Papua New Guinea, 17 being new records for New Guinea, bringing the total number of Cladocera taxa reported for this region to 39. Most of the taxa are circumtropical. One species (Sarsilatona papuana) is endemic to Papua New Guinea and northern Australia. The species list includes two species that are normally listed as Holarctic:Alonella nana andAlona rustica. Widespread genera such asDaphnia, Pleuroxus, Disparalona, Acroperus were strikingly absent from the Papua New Guinean material.     

Responses of mosquitoes of the Anopheles farauti complex to 1-octen-3-ol and light in combination with carbon dioxide in northern Queensland, Australia

Abstract. In northern Queensland, Australia, three experiments were conducted to determine the response of mosquitoes of the Anopheles farauti complex to CDC traps baited with four attractant combinations: octenol + C0₂ and light; octenol and light; CO, and light; or C0₂ and octenol without light. A CDC-modified updraft light-trap was also trialled, but did not significantly enhance collections of An.farauti sensu lato. The combination of light, octenol and C0₂ caught significantly more An.farauti s.l. (both An.farauti No. 1 and No. 2 sibling species) when compared to C0₂ and light alone. Only small numbers of the An.farauti complex were captured when CDC traps were baited with octenol alone, i.e. no light or C0₂.     

Differential ecology of Anopheles punctulatus and three members of the Anopheles farauti complex of mosquitoes on Guadalcanal, Solomon Islands, identified by PCR-RFLP analysis

From a series of larval collections made across northern Guadalcanal during the dry season, October–November 1997, four members of the Anopheles punctulatus group of mosquitoes (Diptera: Culicidae) were identified using PCR‐RFLP analysis. Anopheline larvae were found in 54/57 (95%) of the sites sampled, comprising An. farauti Laveran sensu stricto (32 sites), An. farauti species no. 2 (39 sites), An. farauti no. 7 (36 sites) and An. punctulatus Dönitz (10 sites). Anopheles punctulatus occurred only on the coastal plain, where it was associated with the more transient sites. Anopheles farauti sensu lato was more widespread throughout the survey region, with similar proportions of all three sibling species in both transient and permanent sites. Two members of the An. farauti complex, An. farauti s.s. and species no. 2, were found in brackish water. All breeding sites of An. punctulatus were cohabited by An. farauti s.l., sometimes by all three sibling species. Anopheles farauti s.s. was the only species collected on human bait, with a much higher biting rate early in the evening (57 bites/human/hour at 18.30–20.00 hours) than later (0.8 bites/human/hour at 21.00–24.00 hours).     

Aphis clerodendri Matsumura (Hemiptera: Aphididae), attendant ants (Hymenoptera: Formicidae) and associates on Clerodendrum (Verbenaceae) in Australia

Abstract Aphis clerodendri Matsumura is newly recorded from Australia and is known from the Northern Territory, on islands in Torres Strait, and in rainforest in northern Queensland and New South Wales. It induces the formation of leaf pseudogalls on native species of Clerodendrum and is commonly attended by ants, which penetrate and may polydomously nest in the galls. Previously known only from eastern Asia, A. clerodendri can now be classified as native to Australia and Australasian in natural distribution. The species is also newly recorded from Papua New Guinea and Vietnam.     

The synonymy and distribution of the crenaticeps-group of Atractomorpha Saussure, 1862 (Orthoptera, Acridoidea, Pyrgomorphidae)

The general distribution of Atractomorpha australis Rehn, A. similis Bolívar and A. crenaticeps (Blanchard) in Australia and the South Pacific is discussed. Detailed synonymies and lists of known localities are given for each species, together with a distribution map. A. australis is confined to cooler, moister regions of Australia from eastern Victoria to south-western Queensland; A. similis is more tropical, occurring in the southern Moluccas, Timor, southern New Guinea and associated islands to northern and eastern Australia, but it extends, in suitable localities, as far south as central New South Wales, and, in inland areas, even to north-western Victoria and south-eastern South Australia; A. crenaticeps , formerly thought to embrace both the above species, is restricted to the northern Moluccas, western and other parts of New Guinea north of and including the central mountain chains and associated islands to the north and west, and to the Bismarck Archipelago and the Solomon Islands.     

An extended survey of the genetic polymorphism at the human coagulation factor XIII: a subunit structural locus

The distribution of the three previously reported alleles, with normal products at the factor XIII A subunit structural locus, FXIIIA*1, FXIIIA*2 and FXIIIA*4 has been studied in populations from the region extending from the Indonesian archipelago through Papua New Guinea, Australia and New Zealand to the Pacific Islands of Micronesia, Melanesia and Polynesia. In addition a population from the Caspian Littoral of Iran and a population of South American Indians were studied. The FXIIIA*1 and FXIIIA*2 alleles were polymorphic in all populations studied. The distribution of the FXIIIA*4 allele suggests that it may be a Melanesian marker.     

Population genetics of Anopheles koliensis through Papua New Guinea: New cryptic species and landscape topography effects on genetic connectivity

New Guinea is a topographically and biogeographically complex region that supports unique endemic fauna. Studies describing the population connectivity of species through this region are scarce. We present a population and landscape genetic study on the endemic malaria‐transmitting mosquito, Anopheles koliensis (Owen). Using mitochondrial and nuclear sequence data, as well as microsatellites, we show the evidence of geographically discrete population structure within Papua New Guinea (PNG). We also confirm the existence of three rDNA ITS2 genotypes within this mosquito and assess reproductive isolation between individuals carrying different genotypes. Microsatellites reveal the clearest population structure and show four clear population units. Microsatellite markers also reveal probable reproductive isolation between sympatric populations in northern PNG with different ITS2 genotypes, suggesting that these populations may represent distinct cryptic species. Excluding individuals belonging to the newly identified putative cryptic species (ITS2 genotype 3), we modeled the genetic differences between A. koliensis populations through PNG as a function of terrain and find that dispersal is most likely along routes with low topographic relief. Overall, these results show that A. koliensis is made up of geographically and genetically discrete populations in Papua New Guinea with landscape topography being important in restricting dispersal.     

Population structure, mitochondrial polyphyly and the repeated loss of human biting ability in anopheline mosquitoes from the southwest Pacific

Australia and New Guinea contain high levels of endemism and biodiversity, yet there have been few evaluations of population‐level genetic diversity in fauna occurring throughout the Australo‐Papuan region. Using extensive geographical sampling, we examined and compared the phylogenetic relationships, phylogeography and population structure of Anopheles farauti, An. hinesorum and An. irenicus throughout their ranges in the southwest Pacific using mitochondrial (mtDNA COI) and nuclear (ribosomal protein S9 and ribosomal DNA ITS2) loci. Phylogenetic analyses suggest that the ability to utilize humans as hosts has been lost repeatedly, coincident with independent colonizations of the Solomon Islands. As some of the species under investigation transmit malaria in the region, this is a medically important finding. Maximum likelihood and Bayesian phylogenetic analyses of nuclear loci also showed that the three species are monophyletic. However, putative introgression of An. hinesorum mtDNA onto a nuclear background of An. farauti was evident in populations from Queensland, Torres Strait and southern New Guinea. Haplotype networks and pairwise F_ST values show that there is significant genetic structure within New Guinea and Australia in both An. farauti and An. hinesorum, consistent with a long‐term history of low gene flow among populations.     

Genetic diversity in two sibling species of the <Emphasis Type="Italic">Anopheles punctulatus</Emphasis> group of mosquitoes on Guadalcanal in the Solomon Islands

Background  

The mosquito Anopheles irenicus, a member of the Anopheles punctulatus group, is geographically restricted to Guadalcanal in the Solomon Islands. It shows remarkable morphological similarities to one of its sibling species, An. farauti sensu stricto (An. farauti s.s.), but is dissimilar in host and habitat preferences. To infer the genetic variations between these two species, we have analyzed mitochondrial cytochrome oxidase subunit II (COII) and nuclear ribosomal internal transcribed spacer 2 (ITS2) sequences from Guadalcanal and from one of its nearest neighbours, Malaita, in the Solomon Islands.     

The effect of permethrin-impregnated bednets on a population of Anopheles farauti in coastal Papua New Guinea

The effect of introducing bednets impregnated with 0.4 g/m2 permethrin on local populations of the malaria vector mosquitoes Anopheles farauti Laveran and An. koliensis Owen was monitored in a coastal village of Papua New Guinea. Whole-night landing collections were undertaken for 25 consecutive nights before and 21 nights after the introduction of the nets. Capture-recapture experiments and resting collections were also performed before and after the introduction of the nets. Following the introduction of treated nets, the biting population of An. farauti, the predominant vector, dropped from an average of 689 to 483 per man-night and the oviposition cycle became irregular, although survival rates (determined by time series analysis of the landing catches and log regression of recapture rates) were not significantly affected. The densities of An. farauti resting in and around houses and the human blood index of the engorged females also decreased significantly after introduction of the treated bednets. The population of An. koliensis dropped prior to the introduction of the nets. However, the number of nulliparous females in the landing catches remained more or less constant which implies that, in this species, survival rates were affected by the nets but that recruitment to the population was not.     

Multilocus population genetic analysis of the Southwest Pacific malaria vector Anopheles punctulatus

The population structure and history of the cryptic malaria vector species, Anopheles punctulatus (Doenitz), was investigated throughout Papua New Guinea and the Solomon Islands with the aim of detailing genetic subdivisions and the potential for movement through this biogeographically complex region. We obtained larval collections from over 80 sites and utilised a diverse array of molecular markers that evolve through different processes. Individuals were initially identified to species and genotyped using the ribosomal DNA second internal transcribed spacer. DNA sequencing of a single copy nuclear ribosomal protein S9 and the mitochondrial cytochrome oxidase I loci were then investigated and 12 nuclear microsatellite markers were developed and analysed. Our data revealed three genetically distinct populations – one in Papua New Guinea, the second on Buka Island (Bougainville Province, Papua New Guinea), and the third on Guadalcanal Island (Solomon Islands). Genetic differentiation within Papua New Guinea was much lower than that found in studies of other closely related species in the region. The data does suggest that A. punctulatus has undergone a population bottleneck followed by a recent population and range expansion in Papua New Guinea. Humans and regional economic growth may be facilitating this population expansion, as A. punctulatus is able to rapidly occupy human modified landscapes and traverse unsealed roads. We therefore anticipate extensive movement of this species through New Guinea – particularly into the highlands, with a potential increase in malaria frequency in a warming climate – as well as relatively unrestricted gene flow of advantageous alleles that may confound vector control efforts.     

Connectivity and the development of population genetic structure in Indo‐West Pacific coral reef communities

Aim To identify connectivity patterns among coral reefs of the Indo‐West Pacific. Projecting connectivity forward in time provides a framework for studying long‐term source–sink dynamics in the region, and makes it possible to evaluate the manner in which migration shapes population genetic structure at regional scales. This information is essential for addressing critical gaps in knowledge for conservation planning efforts in one of the most biologically diverse regions on earth. Location Coral reefs of the Indo‐West Pacific, ranging from 15° S to 30° N and 95° E to 140° E. Methods Individual‐based biophysical dispersal models were used in conjunction with matrix projection to identify the expected patterns of exchange between coral reefs over time. Results Present‐day oceanographic conditions lead to the transport of larvae from the South China Sea into the Coral Triangle region via the Sulu Sea, and from northern Papua New Guinea and the Solomon Islands via Halmahera. The directionality of the system leads to the expected accumulation of organisms from outlying areas into the Coral Triangle region over time, particularly in the vicinity of the Maluku Islands and eastern Sulawesi. Coral reefs in Papua New Guinea, the Sulu Archipelago and areas within the Philippines are expected to be areas of high diversity as well. Main conclusions Biophysical dispersal models, used in conjunction with matrix projection, provide an effective means of simulating connectivity structure across the Indo‐West Pacific and thereby evaluating the directionality of genetic diversity. Migration appears to have a significant influence on population genetic structure in the region. Based on present‐day ocean currents, coral reefs in the South China Sea, northern Papua New Guinea and the Solomon Islands are contributing to high levels of diversity in the Coral Triangle.     

The Leiognathus splendens complex (Perciformes: Leiognathidae) with the description of a new species, Leiognathus kupanensis Kimura and Peristiwady

Taxonomic analysis of a group of morphologically similar ponyfishes (Perciformes: Leiognathidae) establishes the Leiognathus splendens complex comprising four valid species: L. jonesi James, 1971, widely distributed in the Indo-West Pacific, from Mauritius to Papua New Guinea, north to Hainan I. (China), and south to Brisbane, Australia; L. kupanensis sp. nov., currently known only from Kupang, Timor, Indonesia; L. rapsoni Munro, 1964, currently known only from India, Indonesia, and Papua New Guinea, and L. splendens Cuvier, 1829, widely distributed in the eastern Indian and western Pacific oceans, from India to Papua New Guinea, and from southern Japan to northern Australia. The L. splendens complex can be defined by the following combination of characters: body depth 42–60% of standard length; mouth protruding downward; slender, minute teeth uniserially on jaws; lower margin of orbit above the horizontal through the gape when mouth closed; breast almost completely scaled; lateral line complete, and a dark blotch on top of spinous dorsal fin. Diagnostic characters of the members are as follows: L. jonesi—anterior dorsolateral body surface with a semicircular naked area on nape, and a paler dark blotch on spinous dorsal fin; L. kupanensis—anterior dorsolateral body surface widely naked; L. rapsoni—cheek scaled; L. splendens—anterior dorsolateral body surface completely scaled and a jet black blotch on spinous dorsal fin.