The life cycle of 5 generations of Leptotrombidium (L.) fletcheri infected with Rickettsia tsutsugamushi and reared under ambient temperatures in Malaysia was presented and compared with a colony reared at a constant 27 degrees C (Neal and Barnett, 1961). In general our colony had a longer generation time (average of 54 days from engorged larvae to adult compared with 37 days) and produced fewer eggs (average of 127.9 compared with 900.0) than the comparison colony. Possible factors causing these differences are discussed.
Der p 2 is a major dust mite allergen and >80% of mite allergic individuals have specific IgE to this allergen. Although it is well characterized in terms of allergenicity, there is still some ambiguity in terms of its biological function. Three-dimensional structural analysis of Der p 2 and its close homologues indicate the presence of a hydrophobic cavity which can potentially bind to lipid molecules. In this study, we aimed to identify the potential ligand of Der p 2. Using a liposome pulldown assay, we show that recombinant Der p 2 binds to liposomes prepared with exogenous cholesterol in a dose dependent fashion. Next, an ELISA based assay using immobilized lipids was used to study binding specificities of other lipid molecules. Cholesterol was the preferred ligand of Der p 2 among 11 different lipids tested. Two homologues of Der p 2, Der f 2 and Der f 22 also bound to cholesterol. Further, using liquid chromatography-mass spectrometry (LC-MS), we confirmed that cholesterol is the natural ligand of Der p 2. Three amino acid residues of Der p 2, V104, V106 and V110 are possible cholesterol binding sites, as alanine mutations of these residues showed a significant decrease in binding (p
Mite foci were fenced above and below ground to prevent the entry of host animals and to prevent the migration of mites within the soil. Weekly counts were made over a period of thirty weeks with larvae being collected at the beginning and end of the study, but not during the intervening period of hot, dry weather. Post-larval forms can survive for long periods and mite foci can remain productive without being visited by the host animals. Mite foci may be missed by normal survey methods during hot, dry weather.
Canine demodicosis is a common skin disorder with multiple risk factors, including age and breed predisposition. There is relatively limited information about the risk factors for canine demodicosis in large canine populations. This retrospective case-control study was conducted by searching the electronic records of dogs with skin lesions for the presence of Demodex mites in skin scrapings. Diagnosis of demodicosis was based on the presence of skin lesions and mites in skin scrapings. Multivariate analysis was conducted using logistic regression analysis to estimate the relative risk and odds ratio of variables hypothesized to influence the risk of canine demodicosis, such as age, sex, breed, season, and parasitic infection. The results of multivariate logistic regression analysis showed a positive correlation between the dogs' age and demodicosis. Dogs older than three years, as well as puppies, had a high risk of demodicosis (P0.05). Breeds with the greatest association (odds ratio) with demodicosis included the American Staffordshire Terrier (OR=0.9) and Moscow Watchdog (OR=0.2). The presence of intestinal parasites, such as Diphyllobothrium latum, was significantly associated with demodicosis.
A survey of ticks and other ectoparasites was carried out during a national biodiversity scientific expedition at Ulu Muda Forest Reserve, Kedah, Malaysia from 23-29 March 2003. A total of 161 animals comprising 20 species of birds, 16 species of bats, six species of non-volant small mammals and 12 species of reptiles were examined for ticks and other ectoparasites. From these animals, nine species in five genera of ticks, 10 species in two families of Mesostigmatid mites and five species of chiggers were collected. Three of the ectoparasitic species found, Dermacentor auratus, Ixodes granulatus and Leptotrombidium deliense are of known public health importance. This survey produced the first list of ticks and other ectoparasites in the forest reserve and the third study of ectoparasites in Kedah. Fourteen species of these ectoparasites are new locality records.
A new genus Trachyibana gen. nov. is described and illustrated on the basis of Trachyibana sarawakiensis sp. nov. from Malaysia. The new genus belongs to the family Trachyuropodidae, on the basis of its fringed internal malae, the T-shaped dorsal setae and the position of hypostomal setae h3 (lateral to h1-h2-h4). The new genus differs from the other trachyuropodid genera and species by its lemon-shaped idiosoma, the presence of deep opisthogastric ventral furrows, and the absence of strongly sclerotised dorsal structures.
Two new species of the family Eriophyidae (Acari: Eriophyoidea) from Mount Trusmadi, Malaysia, are described and illustrated. They are Neodicrothrix grandcaputus sp. nov. on Stachyurus himalaicus (Stachyuraceae) and Latitudo asiaticis sp. nov. on Psychotria asiatica (Rubiaceae). Both of the two new species are vagrant on the lower leaf surface. No damage to the host was observed. In addition to the description, a key to species of Neodicrothrix is provided.
The populations of scrub typhus vector chiggers were compared in two developing oil palm areas, one 5 years old and the other 7 years old at the inception of the study. Both areas were located within the same oil palm scheme in central Peninsular Malaysia. Leptotrombidium (L.) deliense, a principal vector of scrub typhus in Malaysia, was found in reduced numbers in the older oil palm habitat. This reduction is attributed to changes in the microhabitat, specifically the elimination of grasses between the oil palm trees due to canopy shading and to cultural practices.
Varroa jacobsoni was first described as a natural ectoparasitic mite of the Eastern honeybee (Apis cerana) throughout Asia. It later switched host to the Western honeybee (A. mellifera) and has now become a serious pest of that bee worldwide. The studies reported here on genotypic, phenotypic and reproductive variation among V. jacobsoni infesting A. cerana throughout Asia demonstrate that V. jacobsoni is a complex of at least two different species. In a new classification V. jacobsoni is here redefined as encompassing nine haplotypes (mites with distinct mtDNA CO-I gene sequences) that infest A. cerana in the Malaysia Indonesia region. Included is a Java haplotype, specimens of which were used to first describe V. jacobsoni at the beginning of this century. A new name, V. destructor n. sp., is given to six haplotypes that infest A. cerana on mainland Asia. Adult females of V. destructor are significantly larger and less spherical in shape than females of V. jacobsoni and they are also reproductively isolated from females of V. jacobsoni. The taxonomic positions of a further three unique haplotypes that infest A. cerana in the Philippines is uncertain and requires further study. Other studies reported here also show that only two of the 18 different haplotypes concealed within the complex of mites infesting A. cerana have become pests of A. mellifera worldwide. Both belong to V. destructor, and they are not V. jacobsoni. The most common is a Korea haplotype, so-called because it was also found parasitizing A. cerana in South Korea. It was identified on A. mellifera in Europe, the Middle East, Africa, Asia, and the Americas. Less common is a Japan/Thailand haplotype, so-called because it was also found parasitizing A. cerana in Japan and Thailand. It was identified on A. mellifera in Japan, Thailand and the Americas. Our results imply that the findings of past research on V. jacobsoni are applicable mostly to V. destructor. Our results will also influence quarantine protocols for bee mites, and may present new strategies for mite control.
Descriptions are presented of new species of water mites from two mountains in the Malaysian part of Borneo. A new subgenus of the genus Javalbia (Hygrobatidae), i.e. Megapes n. subgen., and 34 new species are described: Limnocharidae: Limnochares (Limnochares) spinosa n. sp.; Oxidae: Oxus (Oxus) fuscus n. sp.; Hydryphantidae: Protzia borneoensis n. sp.; Sperchontidae: Sperchon kinabaluensis n. sp., Sperchonopsis orientalis n. sp.; Hygrobatidae: Hygrobates (Hygrobates) acutipalpis n. sp., H. (Hygrobates) hamatoides n. sp., H. (Hygrobates) striatus n. sp., Atractides (Atractides) neospatiosus n. sp., A. (Atractides) sabahensis n. sp., A. (Atractides) crockerensis n. sp., A. (Atractides) curtisetus n. sp., A.(Tympanomegapus) borneoensis n. sp.; Frontipodopsidae: Frontipodopsis suturalis n. sp.; Aturidae: Javalbia (Javalbia) montana n. sp., J. (Javalbia) solitaria n. sp., J. (Javalbiopsis) borneoensis n. sp., J. (Javalbiopsis) kinabaluensis n. sp., J. (Javalbiopsis) magniseta n. sp., J. (Javalbiopsis) reticulata n. sp., J. (Megapes) uncinata n. sp., Albaxona mahuaensis n. sp., Axonopsis (Axonopsis) longigenitalis n. sp., A. (Axonopsis) rugosa n. sp., A. (Paraxonopsis) truncata n. sp., A. (Brachypodopsis) latipalpis n. sp., A. (Vicinaxonopsis) caeca n. sp., Erebaxonopsis kipungitensis n. sp., Ljania inconspicua n. sp., L. obliterata n. sp., Albia (Albiella) crocker n. sp., Aturus borneoensis n. sp.; Athienemanniidae: Africasia acuticoxalis n. sp.; Arrenuridae: Thoracophoracarus uniacetabulatus n. sp. A key is presented for the Javalbia species of Borneo. New records are given for 10 further species. In the course of revisional work, lectotypes are designated for the following species: Atractides cognatus (K. Viets) and A. propatulus (K. Viets).