Distribution of Ecnomus McLachlan, 1864 (Trichoptera, Ecnomidae) from the Lower Mekong River with a description of Ecnomusstungtrengensis new species.

Background: Trichoptera were surveyed from four different physiographic regions of the Lower Mekong River, including the Northern Highlands, the Khorat Plateau, the Tonle Sap Basin and the Mekong Delta in Myanmar, Laos, Thailand, Cambodia and Vietnam. New information: Twenty-three species of the genus Ecnomus, including a new species, were identified and mapped. Ecnomusmammus Malicky & Chantaramongkol, 1993 is a common species which is found from Tonle Sab Basin and Mekong Delta. Ecnomusalkmene Malicky & Chantaramongkol, 1997, E.volovicus Malicky & Chantaramongkol, 1993 and Ecnomusquordaio Malicky, 1993 are the common species in the area of the Northern Highlands and the Khorat Plateau. Ecnomusplotin Malicky & Laudee 2010 is found in the Mekong Delta. Ecnomustriangularis Sun, 1997 is a new species record for Southeast Asia. In addition, E.stungtrengensis sp. n. is described and illustrated. The male genitalia of E.stungtrengensis sp. n. are clearly different from those of other species in the genus Ecnomus by the shape of superior appendages which are slender and bent downwards distally in lateral view.

Three new species of caddisflies (Trichoptera, Hydroptilidae, Polycentropodidae, Leptoceridae) from Khon Phapheng Waterfall, the Mekong River, Laos.

The Mekong River is a hotspot area for freshwater biodiversity, but caddisfly diversity is largely understudied. Three new species of caddisflies from three different families are described and illustrated from Khon Phapheng Waterfall, the Mekong River, Laos; Orthotrichiachoengthongi Malicky & Laudee, sp. nov. (Hydroptilidae), Pseudoneureclipsiskhonphaphengensis Malicky & Thamsenanupap, sp. nov. (Polycentropodidae), and Setodeskarrilai Malicky & Laudee, sp. nov. Orthotrichiachoengthongi Malicky & Laudee, sp. nov. can be differentiated from the most similar OrthotrichiatritonMalicky 2008 by the specific shape of segment X which is long and tubular, pointed apically and curved inward then immediately upward in dorsal view. Pseudoneureclipsiskhonphaphengensis Malicky & Thamsenanupap, sp. nov. differs from the similar P.kaineus Malicky & Bunlue in Malicky et al. 2004 by the shape of the inferior appendages that are usually broad, almost circular in lateral view. Setodeskarrilai Malicky & Laudee, sp. nov. is mainly different to S.omphale Malicky & Changthong in Malicky et al. 2004 by the distal part of segment X which has a brush-like process.

New species of caddisflies (Trichoptera, Ecnomidae, Polycentropodidae, Psychomyiidae) from Mekong tributaries, Laos.

Four new species of caddisflies are added to the fauna of Mekong River, Laos. Described and illustrated are Ecnomus petchanaae sp. nov. and E. boonsawaengae sp. nov. (Ecnomidae), Polyplectropus proukaewi sp. nov. (Polycentropodidae), and Psychomyia srichanai sp. nov. (Psychomyiidae) from tributaries of the Mekong River, Laos. Ecnomus petchanaae sp. nov. can be distinguished by the characters of the superior appendages, which are slender and club-shaped in lateral view. In E. boonsawaengae sp. nov., the inferior appendages are tubular with a concave incision subapically and truncated apex. Polyplectropus proukaewi sp. nov. has the distal process of the dorsal branch of the inferior appendage close to the base of the inferior appendages and the length of the process is half of inferior appendages. Psychomyia srichanai sp. nov. can be distinguished by the structure of the dorsal branches of the harpagones and apical sclerite. The outer branches of the harpago in the latter species are bifurcated and bent 90° degrees outward, and the inner dorsal branches of harpago are curved outward. The apical sclerite is indiscernible.

Mosquito (Diptera: Culicidae) repellency field tests of essential oils from plants traditionally used in Laos.

Essential oils of Hyptis suaveolens (Lamiaceae), Croton roxburghii (Euphorbiaceae), and Litsea cubeba (Lauraceae) were tested in the field near Vientiane city, Lao PDR, on humans for repellent activity against mosquitoes. Landing mosquitoes were collected and later identified. The most abundant mosquitoes captured belonged to the genera Armigeres, Culex, and Aedes. All the plant oils tested at concentrations of 1.7 microg/cm(2), 3.3 microg/cm(2), and 6.3 microg/cm(2) were significantly more mosquito repellent than the negative control. Croton oil was significantly repellent against mosquitoes of the three genera at the highest (6.3 microg/cm(2)) concentration tested. Litsea oil was significantly repellent against Armigeres at all (1.7 microg/cm(2), 3.3 microg/cm(2), and 6.3 microg/cm(2)) concentrations tested. Hyptis oil was significantly repellent against Armigeres at 3.3 microg/cm(2) and 6.3 microg/cm(2) and against Culex at 1.7 microg/cm(2) and 6.3 microg/cm(2). The oils were analyzed for chemical content of volatiles, mainly terpenes. Main constituents were beta-pinene, sabinene, and 1,8-cineol from oils of the green parts of H. suaveolens; alpha-pinene, beta-pinene, and alpha-phellandrene from fresh bark of C. roxburghii; and alpha-pinene, beta-phellandrene, sabinene, and 1,8-cineol from fresh fruits of L. cubeba.

A fly in the ointment: evaluation of traditional use of plants to repel and kill blowfly larvae in fermented fish.

INTRODUCTION: In rural areas in Laos, fly larvae infestations are common in fermenting fish. Blowflies (Chrysomya megacephala, Diptera: Calliphoridae) are attracted to oviposit (and/or larviposit) onto fermenting fish which results in infestations with fly larvae. Knowledge of traditional use of plants to repel larvae during the production of fermented fish is common and widespread in Lao PDR. RESEARCH QUESTIONS: How effective are the most salient species in repelling, and killing fly larvae in fermenting fish? MATERIAL AND METHODS: The three plant species most frequently reported to repel fly larvae during an ethnobotanical survey throughout Lao PDR were tested for repellence and larvicidal activity of fly larvae infesting fermented fish. The lethality and repellence of Tadehagi triquetrum (L.) H. Ohashi (Fabaceae), Uraria crinita (L.) Desv. ex DC. (Fabaceae) and Bambusa multiplex (Lour.) Raeusch. ex Schult. & Schult. f. (Poaceae) were tested in an experimental design using fermenting fish in Vientiane, Lao PDR. RESULTS: The repellent effect of fresh material of T. triquetrum and U. crinita, and the larvicidal effect of fresh B. multiplex, is significantly more effective than that of dried material of the same species, and the total effect (repellence and larvicidal effect combined) for each of the three species was significantly more effective for fresh than for dry material. Fresh material of T. triquetrum, U. crinita, or B. multiplex added on top of the fermenting fish repelled 50%, 54%, 37%, and killed 22%, 28%, and 40% of fly larvae. The total effect was not significantly different per species at 72%, 82%, and 77%, respectively. DISCUSSION AND CONCLUSIONS: The three most salient species are effective in repelling and killing fly larvae in the production of fermented fish, and may be essential to augment food safety during traditional fermentation in open jars.

Keeping leeches at bay: field evaluation of plant-derived extracts against terrestrial blood-sucking leeches (Haemadipsidae) in Lao PDR.

Terrestrial blood-sucking leeches (Haemadipsidae) are common in the damp forests of the subtropical and tropical Indo-Pacific region. Members of the genus Haemadipsa are abundant in Laos and adjacent countries of Southeast Asia, and discomfort to people and livestock. Plant-derived repellents against arthropods and leeches are common in Lao PDR, and have been used by Lao ethnic groups for generations. Numerous studies have been conducted on the efficacy of traditional plant-derived repellents against mosquitoes but only a few on repellents against terrestrial blood-sucking leeches. Field experiments were conducted to evaluate the leech repellent activities of aqueous extracts of three traditionally used plant species, Sapindus rarak DC., Catunaregam spathulifolia Tirv. and Vernonia elaeagnifolia DC. Stockings impregnated with aqueous extracts exhibited moderate to high leech repellent activity, C. spathulifolia (62.6%), V. elaeagnifolia (63.0%), and S. rarak (82.6%). The corresponding repellencies of deltamethrin and DEET were 73.1% and 88.4%, respectively. An aqueous extract of S. rarak applied on cloth at a concentration of 1.9 mg/cm(2) is an effective and practical prevention method significantly reducing the number of blood-feeding leeches recorded on stockings worn by humans. This plant species is common in Southeast Asia and can be obtained at limited or no cost.

Botanical repellents and pesticides traditionally used against hematophagous invertebrates in Lao People's Democratic Republic: a comparative study of plants used in 66 villages.

Hematophagous parasites such as leeches, ticks, mites, lice, bedbugs, mosquitoes, and myiasis-producing fly larvae are common health problems in Lao People's Democratic Republic. Several arthropod-borne infections, e.g., malaria, dengue fever, and Japanese encephalitis, are endemic there. Effective vector control methods including the use of pesticides, insecticide-treated bed nets, and synthetic and plant-based repellents are important means of control against such invertebrates and the pathogens they may transmit or directly cause. In this study, we documented traditional knowledge on plants that are used to repel or kill hematophagous arthropods, including mosquitoes, bedbugs, human lice, mites and ticks, fly larvae, and blood-sucking leeches. Structured interviews were carried out in 66 villages comprising 17 ethnic groups, covering a range of cultures, throughout Lao People's Democratic Republic. A total of 92 plant species was recorded as traditional repellents (including plants for pesticidal usages) in 123 different plant-ectoparasite combinations. The number and species of plants, and animal taxa repelled (or killed) per plant species differed per region, village, and ethnic group. Traditional use was confirmed in the scientific literature for 74 of these plant species, and for an additional 13 species using literature on closely related species. The use of botanical repellents and pesticides from many plant species is common and widespread in the Lao countryside. In the future, the identification of the active components in certain plants to develop more optimal, inexpensive repellents, insecticides, acaricides, or antileech compounds as alternatives to synthetic repellents/pesticides against blood-feeding insects, ticks, mites, and leeches is warranted.