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

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

Nowa Konstytucja Państwa Litewskiego

Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201

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

Susceptibility of Anopheles campestris-like and Anopheles barbirostris species complexes to Plasmodium falciparum and Plasmodium vivax in Thailand

Nine colonies of five sibling species members of Anopheles barbirostris complexes were experimentally infected with Plasmodium falciparum and Plasmodium vivax. They were then dissected eight and 14 days after feeding for oocyst and sporozoite rates, respectively, and compared with Anopheles cracens. The results revealed that Anopheles campestris-like Forms E (Chiang Mai) and F (Udon Thani) as well as An. barbirostris species A3 and A4 were non-potential vectors for P. falciparum because 0% oocyst rates were obtained, in comparison to the 86.67-100% oocyst rates recovered from An. cracens. Likewise, An. campestris-like Forms E (Sa Kaeo) and F (Ayuttaya), as well as An. barbirostris species A4, were non-potential vectors for P. vivax because 0% sporozoite rates were obtained, in comparison to the 85.71-92.31% sporozoite rates recovered from An. cracens. An. barbirostris species A1, A2 and A3 were low potential vectors for P. vivax because 9.09%, 6.67% and 11.76% sporozoite rates were obtained, respectively, in comparison to the 85.71-92.31% sporozoite rates recovered from An. cracens. An. campestris-like Forms B and E (Chiang Mai) were high-potential vectors for P. vivax because 66.67% and 64.29% sporozoite rates were obtained, respectively, in comparison to 90% sporozoite rates recovered from An. cracens

Simulium tani Takaoka and Davies 1995

&lt;i&gt;Simulium tani&lt;/i&gt; Takaoka and Davies, 1995 (complex) &lt;p&gt; The members of the &lt;i&gt;S. tani&lt;/i&gt; complex can be distinguished from other species of the &lt;i&gt;S. tuberosum&lt;/i&gt; group by the roundish margins of the postgenal cleft (Fig. 3 F, G) and ventral tubercles of the larva, short terminal spines (Fig. 8) of the pupa, absence of a pair of clustered hairs on sternite VII in the female, and a narrow median sclerite in the male (Fig. 9 D). Structural variation within each of the nine cytoforms is typically as great as it is among cytoforms (Table 1), with one exception. The pupa of cytoform H has a lower density of cephalic microtubercles (Fig 5 B) and a longer ventralmost gill stalk (Fig. 7 F) than do other cytoforms in the complex. Variation in meristic characters among cytoforms, such as the number of primary rays in the labral fan, probably is related to habitat (Zhang &amp; Malmqvist 1997). Some of the cytoforms of the &lt;i&gt;S. tani&lt;/i&gt; complex might prove to be valid species. Cytoform B or D, because of geographical location, probably represents true &lt;i&gt;S. tani&lt;/i&gt;, which was described from Malaya.&lt;/p&gt;Published as part of &lt;i&gt;Tangkawanit, Ubon, Kuvangkadilok, Chaliow, Baimai, Visut &amp; Adler, Peter H., 2009, Morphotaxonomy of the Simulium (Simulium) tuberosum species group (Diptera: Simuliidae) in Thailand, pp. 31-46 in Zootaxa 2048&lt;/i&gt; on page 38, DOI: &lt;a href="http://zenodo.org/record/186496"&gt;10.5281/zenodo.186496&lt;/a&gt

Simulium

&lt;i&gt;Simulium&lt;/i&gt; unknown species 2 &lt;p&gt; This taxon was recognized cytologically based on 8 larvae from Champa Thong waterfall in Phayao Province (Tangkawanit &lt;i&gt;et al.&lt;/i&gt; 2009). The larvae are morphologically similar to those of &lt;i&gt;S. yuphae&lt;/i&gt;, but lack head spots and infuscation on the frontoclypeal apotome. The larva of &lt;i&gt;S.&lt;/i&gt; unknown species 2 is described below, but we defer formal description and naming of this species until pupae and adults are available.&lt;/p&gt; &lt;p&gt;Body grayish black to grayish brown. Head capsule yellowish to light brown; head spots faint (Fig. 2 I); ventral surface of head capsule whitish yellow except area along margins of postgenal cleft dark brown; faint negative transverse spot on each side of postgenal cleft (Fig. 3 J). Antenna longer than stem of labral fan; length ratios of articles (proximal to distal) 1.00: 1.05: 0.76. Labral fan with 36&ndash;38 primary rays. Hypostoma with median tooth and each lateral tooth longer than others; 5 or 6 hypostomal bristles per side. Postgenal cleft deep, triangular, pointed anteriorly (Fig. 3 J). Abdominal cuticle nearly bare; both sides of anal sclerite moderately covered with simple colorless setae. Anal sclerite X shaped with broadened anterior arms 0.8&ndash;0.9 times as long as posterior arms. Abdominal segment IX lacking ventral tubercles. Posterior circlet with 70&ndash;80 rows of hooklets and up to 14 hooklets per row.&lt;/p&gt;Published as part of &lt;i&gt;Tangkawanit, Ubon, Kuvangkadilok, Chaliow, Baimai, Visut &amp; Adler, Peter H., 2009, Morphotaxonomy of the Simulium (Simulium) tuberosum species group (Diptera: Simuliidae) in Thailand, pp. 31-46 in Zootaxa 2048&lt;/i&gt; on pages 40-41, DOI: &lt;a href="http://zenodo.org/record/186496"&gt;10.5281/zenodo.186496&lt;/a&gt