Constitutive Heterochromatin Differentiation and Evolutionary Divergence of Karyotype in Oriental Anopheles (Cellia)

Analysis of the mitotic karyotype of two clusters of closely related species of oriental Anopheles, the A . balabacensis and A. maculatus complexes, has revealed interspecific differences in the amount and distribution of constitutive heterochromatin, particularly in sex chromosomes. Such a qualitative diagnosis of heterochromatin is useful in identification of these sibling species. The cytological evidence indicates a significant role of heterochromatin in chromosomal evolution of anopheline mosquitoes. The novel heterochromatin differentiation in sex chromosomes suggests an evolutionary role in the process of species divergence. Furthermore, extensive intraspecific variations of sex chromosome heterochromatin have been observed in natural populations of A . dirus A and B, while chromosomal rearrangement is very rare , if not absent. The gross heterochromatin variation may be correlated with variability in vectorial capacity, which may reflect its functional significance in coevolutionary processes

Evidence to Support Karyotypic Variation of the Mosquito, Anopheles peditaeniatus in Thailand

Eight isoline colonies of Anopheles peditaeniatus Leicester (Diptera: Culicidae) were established from wild-caught females collected from buffalo-baited traps at 8 localities in Thailand. They showed 2 types of X (X2, X3) and 4 types of Y (Y2, Y3, Y4, Y5) chromosomes based on the number and amount of major block(s) of heterochromatin present in the heterochromatic arm, and were tentatively designated as Forms B (X2, X3, Y2), C (X3, Y3), D (X3, Y4) and E (X2, X3, Y5). Form B was found in Nan, Ratchaburi, and Chumphon provinces; Form C was obtained in Chon Buri province; Form D was recovered in Kamphaeng Phet province; and Form E was acquired in Chiang Mai, Udon Thani, and Ubon Ratchathani provinces. Crossing studies among the 8 isoline colonies, which were representative of 4 karyotypic forms of An. peditaeniatus, revealed genetic compatibility in providing viable progenies and synaptic salivary gland polytene chromosomes through F2-generations, thus suggesting the conspecific nature of these karyotypic forms. These results were supported by the very low intraspecific sequence variations (0.0 – 1.1%) of the nucleotide sequences in ribosomal DNA (ITS2) and mitochondrial DNA (COI and COII) of the 4 forms

Parasites of larval black flies (Diptera: Simuliidae) in Thailand

Parasites of larval black flies are reported for the first time from Thailand, including mermithid nematodes(Mermithidae), microsporidian fungi (Zygomycota), and the fungus Coelomycidium simulii Debaisieux (Blastocladiomycetes).The following nine species of black flies were infected with one or more parasites: Simulium asakoae, S. chamlongi,S. chiangmaiense, S. fenestratum, S. feuerborni, S. nakhonense, S. nodosum, S. quinquestriatum, and S. tani. The prevalenceof patent infections per host species per season was 0.1–7.1% for mermithids, 0.1–6.0% for microsporidia, and 0.1–3.0% forC. simulii

MORPHOMETRIC STUDY FOR IDENTIFICATION OF THE BACTROCERA DORSALIS COMPLEX (DIPTERA : TEPHRITIDAE) USING WING IMAGE ANALYSIS

The Bactrocera dorsalis complex (Diptera: Tephritidae) used in this study included B. dorsalis, B. arecae, B. propinqua, B. pyrifoliae, B. verbascifoliae, and three new species complexes are species E, species K and species P. Bactrocera tau was used as an out-group. A total of 424 adults, which emerged from pupae collected from natural populations in Thailand, were prepared for wing measurements. Morphometric analysis was performed on measurements of wing vein characters. Wing images were captured in digital format and taken through digital  image processing to calculate the Euclidean distance between wing vein junctions. Discriminant and cluster analyses were used for dichotomy of classification processes. All 424 wing specimens were classified to species in terms of the percentage of "grouped" cases which yielded about 89.6% accurate identification compared with the formal description of these species. After clustering, the percentage of "grouped"cases yielded 100.0%, 98.9%, 98.1%, 95.2% and 84.6% accurate identification between the B. dorsalis complex and B. tau; B. arecae and Species E; B. dorsalis and B. verbascifoliae; B. propinqua and B. pyrifoliae; and species K and species P, respectively. This method of numerical taxonomy may be useful for practical identification of other groups of agricultural pests. Key words: Bactrocera dorsalis complex/wing image processing/morphometric/discriminant and cluster analyses

Market Potential Estimation for Tourism in Emerging Markets

The objective of this paper was to develop a useful framework for estimating demand for tourism in emerging markets. Tourism has become one of the most crucial sectors in a large number of emerging countries. Moreover, the tourism industry in such markets is forecasted to keep increasing in the next decade. Hence, understanding and accurately forecast demand in the industry is essential in order to manage this sector effectively. Using stepwise regression analysis, we found a number of im-portant variables in estimating demand for tourism in emerging markets. Our regression model can benefit travel agencies and policy makers dealing with the tourism industryEl objetivo de este trabajo fue desarrollar un marco útil para la estimación de la demanda para el turismo en los mercados emergentes. El turismo se ha convertido en uno de los sectores más cruciales en un gran número de países emergentes. Por otra parte, la industria del turismo en estos mercados se prevé que seguirán aumentando en la próxima década. Por lo tanto, comprender y predecir con exactitud la demanda en la industria es esencial para gestionar este sector de manera eficaz. Mediante un análisis de regresión por pasos, nos encontramos con una serie de variables im-portante en la estimación de la demanda turística en los mercados emergentes. Nuestro modelo de regresión se pueden beneficiar las agencias de viajes y los responsables de las políticas relacionadas con la industria del turism

Morphometric Study for Identification of the Bactrocera Dorsalis Complex (Diptera : Tephritidae) Using Wing Image Analysis

The Bactrocera dorsalis complex (Diptera: Tephritidae) used in this study included B. dorsalis, B. arecae, B. propinqua, B. pyrifoliae, B. verbascifoliae, and three new species complexes are species E, species K and species P. Bactrocera tau was used as an out-group. A total of 424 adults, which emerged from pupae collected from natural populations in Thailand, were prepared for wing measurements. Morphometric analysis was performed on measurements of wing vein characters. Wing images were captured in digital format and taken through digital image processing to calculate the Euclidean distance between wing vein junctions. Discriminant and cluster analyses were used for dichotomy of classification processes. All 424 wing specimens were classified to species in terms of the percentage of "grouped" cases which yielded about 89.6% accurate identification compared with the formal description of these species. After clustering, the percentage of "grouped"cases yielded 100.0%, 98.9%, 98.1%, 95.2% and 84.6% accurate identification between the B. dorsalis complex and B. tau; B. arecae and Species E; B. dorsalis and B. verbascifoliae; B. propinqua and B. pyrifoliae; and species K and species P, respectively. This method of numerical taxonomy may be useful for practical identification of other groups of agricultural pests

Physical and Linkage Maps for Drosophila serrata, a Model Species for Studies of Clinal Adaptation and Sexual Selection

Drosophila serrata is a member of the montium group, which contains more than 98 species and until recently was considered a subgroup within the melanogaster group. This Drosophila species is an emerging model system for evolutionary quantitative genetics and has been used in studies of species borders, clinal variation and sexual selection. Despite the importance of D. serrata as a model for evolutionary research, our poor understanding of its genome remains a significant limitation. Here, we provide a first-generation gene-based linkage map and a physical map for this species. Consistent with previous studies of other drosophilids we observed strong conservation of genes within chromosome arms homologous with D. melanogaster but major differences in within-arm synteny. These resources will be a useful complement to ongoing genome sequencing efforts and QTL mapping studies in this species

Use of Malaria Rapid Diagnostic Test to Identify Plasmodium knowlesi Infection

Reports of human infection with Plasmodium knowlesi, a monkey malaria, suggest that it and other nonhuman malaria species may be an emerging health problem. We report the use of a rapid test to supplement microscopic analysis in distinguishing the 5 malaria species that infect humans

Evolution and diversity of the courtship repertoire in the Drosophila montium species group (Diptera: Drosophilidae)

SYW is funded by the National Scientific Foundation of China (31372187). MGR is funded by the NERC, UK (grants NE/E015255/1 and NE/J020818/1).Changes in elements of courtship behaviour can influence sexual isolation between species. Large‐scale analyses of changes, including loss and gain of courtship elements, across a relatively complete phylogenetic group are rare but needed to understand the significance of such changes, for example whether the gain and loss of courtship elements are essentially arbitrary or equally reversible. In most species of Drosophila, courtship, including singing, mainly occurs before mounting as pre‐mounting courtship. The Drosophila montium species group is unusual because loss of pre‐mounting courtship and gain of post‐mounting one has been detected in this group. Here we provide an extensive analysis on the courtship repertoire and songs of 42 species in this group. Synchronously captured video and audio recordings were analysed to describe courtship patterns and male courtship songs and changes were analysed in a phylogenetic context. Ancestral state reconstruction suggests that a gain of post‐mounting courtship singing at the ancestor of this species group has been accompanied with a concurrent decrease in the incidence of pre‐mounting courtship singing and has led to subsequent further decrease and eventually complete loss of pre‐mounting courtship song in several lineages. Alongside this evolutionary trend towards post‐mounting courtship, sine song and a special type of “high pulse repetition song” have become more widely used for courtship during species diversification in the montium group. It is likely that the elaboration of post‐mounting courtship behaviours is associated with changes in the relative importance of pre‐ and post‐mounting components of mating systems, such as sperm competition or cryptic female choice.PostprintPeer reviewe

The insecticide resistance status of malaria vectors in the Mekong region

<p>Abstract</p> <p>Background</p> <p>Knowledge on insecticide resistance in target species is a basic requirement to guide insecticide use in malaria control programmes. Malaria transmission in the Mekong region is mainly concentrated in forested areas along the country borders, so that decisions on insecticide use should ideally be made at regional level. Consequently, cross-country monitoring of insecticide resistance is indispensable to acquire comparable baseline data on insecticide resistance.</p> <p>Methods</p> <p>A network for the monitoring of insecticide resistance, MALVECASIA, was set up in the Mekong region in order to assess the insecticide resistance status of the major malaria vectors in Cambodia, Laos, Thailand, and Vietnam. From 2003 till 2005, bioassays were performed on adult mosquitoes using the standard WHO susceptibility test with diagnostic concentrations of permethrin 0.75% and DDT 4%. Additional tests were done with pyrethroid insecticides applied by the different national malaria control programmes.</p> <p>Results</p> <p><it>Anopheles dirus s.s</it>., the main vector in forested malaria foci, was susceptible to permethrin. However, in central Vietnam, it showed possible resistance to type II pyrethroids. In the Mekong delta, <it>Anopheles epiroticus </it>was highly resistant to all pyrethroid insecticides tested. It was susceptible to DDT, except near Ho Chi Minh City where it showed possible DDT resistance. In Vietnam, pyrethroid susceptible and tolerant <it>Anopheles minimus s.l</it>. populations were found, whereas <it>An. minimus s.l</it>. from Cambodia, Laos and Thailand were susceptible. Only two <it>An. minimus s.l</it>. populations showed DDT tolerance. <it>Anopheles vagus </it>was found resistant to DDT and to several pyrethroids in Vietnam and Cambodia.</p> <p>Conclusion</p> <p>This is the first large scale, cross-country survey of insecticide resistance in <it>Anopheles </it>species in the Mekong Region. A unique baseline data on insecticide resistance for the Mekong region is now available, which enables the follow-up of trends in susceptibility status in the region and which will serve as the basis for further resistance management. Large differences in insecticide resistance status were observed among species and countries. In Vietnam, insecticide resistance was mainly observed in low or transmission-free areas, hence an immediate change of malaria vector control strategy is not required. Though, resistance management is important because the risk of migration of mosquitoes carrying resistance genes from non-endemic to endemic areas. Moreover, trends in resistance status should be carefully monitored and the impact of existing vector control tools on resistant populations should be assessed.</p