Seasonal abundance and biting behaviour of Anopheles punctulatus and An.koliensis in Malaita Province, Solomon Islands, and a trial of permethrin impregnated bednets against malaria transmission

Seasonal abundance of the malaria vectors Anopheles punctulatus Donitz and An.koliensis Owen in Bilimanu, an isolated inland village with forty-two houses in Malaita Province of the Solomon Islands, was monitored over 28 months by means of all-night landing/biting catches at one site during June 1985 to September 1987. Totals of 1250 An.punctulatus and 141 An.koliensis were collected, the latter being the largest number of this species ever caught at any locality in the Solomons. Bednets impregnated with permethrin 0.5 g/m² were introduced in December 1986 to be used at night by all 190 villagers for protection against malaria vectors. Bioassay tests with An.punctulatus blood-fed females exposed under nets for lOmin resulted in 100% mortality up to 50 weeks post-impregnation. For An.punctulatus, the main vector species, the mean catch (indoors + outdoors) per man hour was 2.9 (range 0.7–13.2) before a cyclone on 19 May 1986, and, 0.66 (0.2-2.7) after the cyclone. The vector survival rates were usually high before the cyclone, but erratically lower thereafter for An.punctulatus. An.koliensis disappeared after the cyclone. Both An.punctulatus and An.koliensis consistently showed higher rates of biting man indoors than outdoors and their diel biting cycle showed a peak around midnight. Outdoors, the parous proportion of An.punctulatus was twice the nulliparous, and nearly so indoors. Following intervention with permethrin-treated bednets, the mean catch of An.punctulatus fell to 0.35 per man-hour (monthly range 0–1.5). The Plasmodium falciparum malaria infection rate reduced from 10% pre-intervention to zero in September 1987, 9 months after intervention, and then rose again. With re-impregnation of bednets in November 1987, the P.falciparum infection rate was again reduced by March 1988. No effect of treated bednets was observed on the prevalence of P.vivax malaria.     

The Solomon Islands Project: an introduction

The twin themes of the Solomon Islands Biomedical Project remain 1) the remarkable genetic heterogeneity of the groups in the Solomons; and 2) the differential responses to these groups to rapid modernization/acculturation over the past two decades of this long term study. This introduction summarizes the historical and ethnic relationships of the survey groups, their established genetic distances and their rankings with regard to acculturation at the times of their first survey, and changes occurring up to 1985-86. Relevant features of diet, life style, and epidemiology are described.     

Genetic variation in Bougainville and Solomon Islands populations

This paper reports the findings of genetic variation in eight populations of the Solomon Islands. Blood specimens collected from 345 Aita, 191 Nasioi and 416 Nagovisi of Bougainville, 379 Lau, 453 Baegu and 385 Kwaio of Malaita, and 504 Ontong Java, and 328 Ulawa subjects were tested for A-B-O, M-N-S-s, Rh, Hp, Tf, secretor, and red-cell acid phosphatase systems. Considerable differences were found among the eight populations with respect to all polymorphic systems studied. It was not possible to distinguish Austronesian groups from non-Austronesian groups on the basis of gene frequencies.     

A cautionary tale on ancient migration detection: mitochondrial DNA variation in Santa Cruz Islands,Solomon Islands

Over the past decade, the origin of the first Malayo-Polynesian settlers of the island Pacific has become a contentious issue in molecular anthropology as well as in archaeology and historical linguistics. Whether the descendants of the ancestral Malayo-Polynesian speakers moved rapidly through Indonesia and Island Melanesia in a few hundred years, or whether they were the product of considerable intermingling within the more westerly part of the latter region, it is widely accepted that they were the first humans to colonize the distant Pacific islands beyond the central Solomon Islands approximately 3,000 years ago. The Santa Cruz Islands in the Eastern Solomons would have most likely been the first in Remote Oceania to be colonized by them. Archaeologically, the first Oceanic Austronesian settlement of this region appears to have been overlain by various later influences from groups farther west in a complex manner. Molecular anthropologists have tended to equate the spread of various Austronesian-speaking groups with a particular mitochondrial variant (a 9-base-pair [bp] deletion with specific D-loop variants). We have shown before that this is an oversimplified picture, and assumed that the Santa Cruz situation, with its series of intrusions, would be informative as to the power of mitochondrial DNA haplotype interpretations. In the Santa Cruz Islands, the 9-bp deletion is associated with a small number of very closely related hypervariable D-loop haplotypes resulting in a star-shaped Bandelt median network, suggesting a recent population expansion. This network is similar to Polynesian median networks. In a pairwise mismatch comparison, the Santa Cruz haplotypes have a bimodal distribution, with the first cluster being composed almost entirely of the 9-bp-deleted haplotypes-again attesting to their recent origins. Conversely, the nondeleted haplogroups bear signatures of more ancient origins within the general region. Therefore, while the profiles of the two sets of haplotypes indicate very distinctive origins in different populations with divergent expansion histories, the sequence of their introduction into the Santa Cruz Islands clearly does not follow simply.     

Use ofDerris as a Fish Poison in Guadalcanal,Solomon Islands

The use of an ichthyotoxic legume in the genus Denis (Fabaceae) in Guadalcanal is reported. Contrasted with other traditional methods of fishing, fish poisoning with plants is a safe activity that results in small but consistent yields. Ethnotaxonomic terms for ichthyotoxic legumes and fruits in Melanesia and Polynesia are compared and discussed.     

Desmoscolecids (Nematode) from New Georgia,Solomon Islands

Two new desmoscolecid species are described: Desmoscolex koloensis sp. nov. and D. parakoloensis sp. nov. Additional information is given on Desmoscolex (Desmolorenzenia) montana, D. sieverti and D. fennicus. The genus Desmolorenzenia is considered a subgenus of Desmoscolex. Pareudesmoscolex lacustris represents a juvenile state of Desmocolex dussarti. Some reflections are made on terrestrial and freshwater desmoscolecids.     

The Role of Barrier Islands in Subsistence of the Inhabitants of Roviana Lagoon,Solomon Islands

This multidisciplinary study examines the strategy adopted by villagers in the Roviana Lagoon, South New Georgia, Solomon Islands, to cope with changing socioeconomic and demographic conditions. The study addresses land use, shifting cycles, land tenure, soil nutrients, subsistence production, vegetation, land cover change, and carrying capacity. The results suggested that even if a society had been integrated into the market economy and introduced cash cropping, they used a small island, which was fertile, mainly for traditional shifting cultivation under customary management. However, they used a large area of the main island for cultivation of potentially risky perennial cash crops for private income. This case suggests that a local society is able to develop a harmonized way of rural development, community welfare, and environmental preservation.     

Becoming Sinless: Converting to Islam in the Christian Solomon Islands

ABSTRACT   Islam is beginning to have a significant presence in the predominantly Christian nation of Solomon Islands. A few well-educated Islanders were drawn to Islam's elegant monotheism and promise of unity in the 1980s and early 1990s, but numbers have grown significantly in the years following a violent civil conflict (1998–2003). Many of these new Muslim converts, especially those from the island of Malaita, seem preoccupied with the problem of sin and blame Christianity for destroying customary rules, especially those enforcing gender segregation. Echoing long-standing Malaitan critiques of Christian freedom, they say that Christians rely too heavily on God's grace and their own ability to resist temptation. Unlike Christianity and similar to the traditional religion of the islands, Islam provides clear moral rules for living. Seeking an escape from a cycle of sin and redemption, these ex-evangelical Christians now see in Islam the possibility of becoming sinless.     

Custom Umbrellas (Poro) fromPandanus in Solomon Islands

The leaves ofPandanus dubius andP. solomonensis serve as a primary protective cover from the tropical sun and torrential rain in the Solomon Islands. A study of the process of manufacture and the present use was undertaken in 2 distinct geographical and linguistic areas of Guadalcanal to determine what features have enabled this traditional craft to survive relatively unaffected by over 100 yr of European contact. The traditional method of preparation and manufacture is described for the ethnobotanical record.     

Dicyrtotnina and Ptenothrix (Insecta:Collembola) of the Solomon Islands

This paper deals primarily with the collembolan species of the subfamily Dicyrtominae collected during the Royal Society Expedition to the Solomon Islands of 1965 by P. N. Lawrence, supplemented by material from these islands collected by Dr and Mrs P. J. M. Greenslade, all of which is in the British Museum (Natural History). Additional supporting material described here has been derived from the Noona Dan Expedition of the Zoological Museum, Copenhagen and from the Bernice P. Bishop Museum, Hawaii. I should like to express my thanks to the individuals and Museum sconcerned.     

Bridging near and remote Oceania: mtDNA and NRY variation in the Solomon Islands

Although genetic studies have contributed greatly to our understanding of the colonization of Near and Remote Oceania, important gaps still exist. One such gap is the Solomon Islands, which extend between Bougainville and Vanuatu, thereby bridging Near and Remote Oceania, and include both Austronesian-speaking and Papuan-speaking groups. Here, we describe patterns of mitochondrial DNA (mtDNA) and nonrecombining Y chromosome (NRY) variation in over 700 individuals from 18 populations in the Solomons, including 11 Austronesian-speaking groups, 3 Papuan-speaking groups, and 4 Polynesian Outliers (descended via back migration from Polynesia). We find evidence for ancient (pre-Lapita) colonization of the Solomons in old NRY paragroups as well as from M2-M353, which probably arose in the Solomons ～9,200 years ago and is the most frequent NRY haplogroup there. There are no consistent genetic differences between Austronesian-speaking and Papuan-speaking groups, suggesting extensive genetic contact between them. Santa Cruz, which is located in Remote Oceania, shows unusually low frequencies of mtDNA and NRY haplogroups of recent Asian ancestry. This is in apparent contradiction with expectations based on archaeological and linguistic evidence for an early (～3,200 years ago), direct colonization of Santa Cruz by Lapita people from the Bismarck Archipelago, via a migration that "leapfrogged" over the rest of the Solomons. Polynesian Outliers show dramatic island-specific founder events involving various NRY haplogroups. We also find that NRY, but not mtDNA, genetic distance is correlated with the geographic distance between Solomons groups and that historically attested spheres of cultural interaction are associated with the recent genetic structure of Solomons groups, as revealed by mtDNA HV1 sequence and Y-STR haplotype diversity. Our results fill an important lacuna in human genetic studies of Oceania and aid in understanding the colonization and genetic history of this region.