A great variety of parasites and parasitoids exploit ant societies. Among them are the Mesostigmata mites, a particularly common and diverse group of ant-associated arthropods. While parasitism is ubiquitous in Mesostigmata, parasitoidism has only been described in the genus Macrodinychus. Yet information about the basic biology of most Macrodinychus species is lacking. Out of 24 formally described species, information about basic life-history traits is only available for three species. Here we formally describe two new Macrodinychus species, i.e. Macrodinychus hilpertae and Macrodinychus derbyensis. In both species, immature stages developed as ecto-parasitoids on ant pupae of the South-East Asian army ant Leptogenys distinguenda. By piercing the developing ant with their chelicera, the mites apparently suck ant hemolymph, ultimately killing host individuals. We compare infection rates among all studied Macrodinychus species and discuss possible host countermeasures against parasitoidism. The cryptic lifestyle of living inside ant nests has certainly hampered the scientific discovery of Macrodinychus mites and we expect that many more macrodinychid species await scientific discovery and description.
This paper reveals the hotspots of new mite discovery through of a survey of type localities of new Trombidiformes species described in two journals (Systematic & Applied Acarology and Zootaxa) during the last three years (2013-2015). Taxonomically, the 491 new species of the Trombidiformes are highly unevenly distributed among 55 families with top 10 families accounting for over 66% of the total. The Eriophyidae is the top-ranked family. Geographically, these 491 new species are from 55 countries around the world and their distribution among the countries is highly uneven. The majority of these new species (69%) are from the top 10 countries and six of the top ten countries are also megadiversity countries. The top three countries are all from Asia (Iran, China and Malaysia) and they together accounted for over one third of all new species of the Trombidiformes described in the two journals during 2013-2015.
Effects of sublethal exposure to abamectin on the biological performance of Neoseiulus longispinosus (Evans) were studied under ambient laboratory conditions of 28 +/- 2 degrees C and 80 +/- 15% RH with 24 h light. The red form of the twospotted spider mite, Tetranychus urticae Koch, complex (Acari: Tetranychidae), was offered as prey. The LC50 obtained from the contact bioassay at 48 h after treatment was 0.015 ppm (AI). A big change in kill for a given variation in dosage for the regression slope probably indicated that abamectin was unlikely selective. Sublethal exposure to abamectin caused a reduction in survival with the female reaching 50% mortality by the sixth day and the male 4 d later. The mean preoviposition period was extended by almost 1 d, whereas the mean oviposition period was shortened by almost 5 d causing a reduction in the mean fecundity female-1 to almost half that of the untreated females. The net reproductive rate (Ro), the intrinsic rate of increase (rm), and the finite rate of increase (lambda) of the treated females were markedly inferior. Treated males were seriously affected; the mean life span was almost half that of the untreated.
Birds are easily infested with ectoparasites due to their fitness, foraging behaviour, nesting cavities, micro- and macro-habitats. However, the status of ectoparasite infestation on birds in Sarawak is widely unknown. Rice field provides food resources to a variety of birds. This study was conducted to determine the species composition of ectoparasites from birds in a rice field at Kuap Village, Samarahan, Sarawak. A total of 69 birds consists of five species were caught from the rice field and the most common bird species found was the Chestnut Munia (Lonchura atricapilla). From these, 55 were found infested with ectoparasites with the infestation prevalence of 79.71%. A total of 2,513 ectoparasites from eight species were recovered from this study which comprised of six species of mites, one species of soft tick, and one species from the class Insecta. The most dominant ectoparasite species was mite namely, Nanopterodectes sp. with a total of 1,626 individuals. This baseline data on the ectoparasite composition and infestation of birds is important as some of the ectoparasites have the potential in transmitting zoonotic diseases to the farmers working at the rice fields in this region.
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.
Allergy to house dust mites (HDM) is an important cause of asthma and rhinitis in Malaysia. This study was carried out to evaluate the dust mite fauna in the Klang Valley. Dust samples were collected from 20 houses from March 1994 to February 1995. Thirty-three dust samples from mattresses were examined monthly for the occurrence of HDM. A total of 22 species in 9 families of HDM was identified. The most common and densely populated species was Blomia tropicalis with an average density of 8,934 mites/g of dust. Dermatophagoides pteronyssinus was the next in abundance, followed by Malayoglyphus intermedius. All houses surveyed were found to be infested with HDM and every house had at least 6 species of HDM. B. tropicalis and D. pteronyssinus were found in all mattresses. HDM in the Klang Valley were found to be highly prevalent and present in high densities. In this study, counts of D. pteronyssinus was found to exceed the proposed exposure threshold of 500 mites/g dust, for triggering acute asthma. Although counts of B. tropicalis exceeded D. pteronyssinus, no conclusion could be made because there is currently no exposure threshold for triggering acute asthma, for this species. Monthly distribution of B. tropicalis and D. pteronyssinus showed 2 peaks and 4 peaks, respectively. The major peak for D. pteronysinus was in January 1995 whereas for B. tropicalis, the major peak was more variable and occurred between November 1994 to January 1995. Both the species showed minor peak in April 1994.
Neoseiulus fallacis (Garman) is a predatory mite that is common in apple orchards and distributed throughout North America. However, N. fallacis may be susceptible to pesticides used for the management of crop pests. This study aimed to evaluate the temporal effects of commonly used insecticides on N. fallacis survival. Neoseiulus fallacis adults were exposed to field-aged residues, and mortality and lethal time were measured over 96 h of exposure. Carbaryl caused high mortality to N. fallacis and the shortest lethal time values (LT50), followed by spinetoram, with moderate lethal time values. Esfenvalerate, acetamiprid, chlorantraniliprole, and novaluron showed little to no lethality to N. fallacis following exposure to dry field-aged residues. The results of this study provide important field-relevant knowledge that is often void from laboratory-based studies, which can aid integrated pest management (IPM) decision-makers in apple production systems.
Scrub typhus is a widespread and at times serious infection in Asia. If results from central Malaysia can be applied, it appears to be economically important. Diagnosis is often difficult and treatment prone to fail if short courses of antibiotics are used. Prophylaxis is the key area of research with the development of a vaccine being the ultimate goal.
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.
Acari community structure and function associated with delayed pig carrion decomposition has not been examined. In this study, 18 swine carcasses were studied in central Texas, USA, during two consecutive summers (2013 and 2014). Samples of ca. 400 g soil were collected from beneath, aside, and 5 m away from each pig carcass over 180 days. Mites from soil samples were extracted using Berlese funnels and identified to order and family levels and classified according to ecological function. In total 1565 and 1740 mites were identified from the 2013 and 2014 soil samples, respectively. Significant differences were determined for mite community structure at order and family levels temporally on carrion (e.g., day 0 × day 14) regardless of treatments and between soil regions where mites were collected (e.g., soil beneath vs. soil 5 m away from carrion). However, no significant differences were found in mite community structure at the order level between pig carrion with and without delayed Diptera colonization (i.e., treatments). Analysis at the family level determined a significant difference across treatments for both summers. Ecological function of mites did not change significantly following the delayed decomposition of pig carcasses. However, detritivores and fungivores were significant indicator groups during the pig carrion decomposition process. Furthermore, 13 phoretic mite species associated with eight forensically important beetle species were documented. Data from this study indicated that the rate of nutrient flow into the soil impacted associated arthropod communities; however, detecting such shifts depends on the taxonomic resolution being applied.
The specific serum IgE levels to 20 allergens were determined by enzyme immunoassay in 90 Malaysian patients with allergic rhinitis. Ninety-two percent of patients had elevated IgE to at least 1 of the allergens. The housedust mites D. pteronyssinus and D. farinae were the major allergens, elevated IgE to either allergen being present in 86% of the patients. Prick skin tests were carried out in some of the patients, housedust mites, cat fur, dog hair and shrimp were the allergens used. Close correspondence was found between IgE and prick skin tests to the mites.
An indirect enzyme linked immunosorbent assay (ELISA) was developed for the diagnosis of allergy to a house dust mite, Dermatophagoides farinae. The efficacy of the ELISA was then evaluated against a prick test using a commercial allergen. Eighty five suspected allergic rhinitis patients from the Otorhinolaryngology Department, Kuala Lumpur General Hospital, were tested with the ELISA and prick test. Prick test and ELISA results were positive in 84.7% and 80.0% of the patients respectively. The ELISA was found to have 87.5% sensitivity, 61.5% specificity, 92.6% positive predictive value, 47.1% negative predictive value, 7.4% false positive and 52.9% false negative. There was total agreement between the prick test and ELISA for prick test grades of 3+ and 4+. It is concluded that the ELISA is a useful assay for detection of individuals who are highly sensitive to D. farinae.
The gamasine genus Berlesia Canestrini, 1884, is revived and further diagnosed, based on descriptions of adult females, males and nymphs of three new species (B. hospitabilis sp. nov., B. multisetosa sp. nov., B. vorontsovi sp. nov.) ectoparasitic on raspy crickets of three genera of Gryllacrididae (Ensifera) from Australia and the Philippines. A tight sister relationship of Berlesia with the monobasic genus Katydiseius Fain Lukoschus, 1983, known only from a pseudophylline katydid in Malaysia, is proposed. The subfamily Katydiseiinae Fain Lukoschus, 1983 (previously included in the family Otopheidomenidae in the superfamily Phytoseioidea) is redefined to include only those two genera, and moved to the dermanyssoid family Laelapidae, while its previously other monobasic genus, Eickwortius Zhang, 1995, is retained tentatively in the family Otopheidomenidae. Among other taxa relevant to Katydiseiinae reviewed here, Berlesia cultrigera Berlese, 1910a is transferred to the genus Orthopteroseius Mo, 1996, at present Otopheidomenidae, as Orthopteroseius cultrigerum (Berlese) comb. nov., and Berlesia nuda Berlese, 1910b is transferred to the genus Prasadiseius Wainstein, 1972, at present Otopheidomenidae, as Prasadiseius nudum (Berlese) comb. nov. A key to the two genera and five species recognized as belonging in Katydiseiinae is presented. Notable morphological traits of Berlesia, including only deutonymphs equipped with well-developed claws and males with dimorphically more elongated salivary stylets, are discussed. The one known life cycle of a species of Berlesia, B. hospitabilis sp. nov., includes protonymphipary, followed by a fully functioning deutonymph, and male copulation with pharate females-traits, rarely or not known among gamasine mite associates of invertebrates. The possible significance of elongate spermatodactyls and male reduced feeding are explored.