Seasons and water container types affecting Culex spp. in southern Thailand

Abstract

Usually, Culex mosquitoes are responsible for spreading several human diseases such as malaria, Japanese encephalitis, yellow fever, filariasis, and Zika. Lymphatic filariasis and Zika cases are increasing in Thailand with more prevalent in southern Thailand. In this study, our aim is to examine how seasons and water container types affect Culex spp. larvae numbers in Lansaka district, Nakhon Si Thammarat province, southern Thailand. This study was conducted in five sub-districts (Lansaka, Khaokaew, Thadi, Kamlon, and Khunthale) in Lansaka district. In each subdistrict, 120 houses were randomly selected to study the breeding sites of Culex mosquito in dry (March-May, 2018) and wet (October-December, 2018) seasons. Mosquito larvae were collected from indoor, outdoor, natural, artificial, darkcoloured, light-coloured, with lid, and without lid containers. It was observed that in all sub-districts, Culex larvae numbers were higher in dry season compared to wet season. In both seasons, outdoor, without lid, dark-coloured, and artificial containers contained more Culex larvae than inside, with lid, light-coloured, and natural containers, respectively. This study shows that seasons and water container types affect Culex mosquito larvae. Since the larvae numbers are higher in dry season, as well as in outdoor, without lid, dark-coloured, and artificial containers, people should reduce the usage of these containers, especially in the dry season, to prevent Culex borne diseases.

Prevalence and Diversity of Blood Parasites (Plasmodium, Leucocytozoon and Trypanosoma) in Backyard Chickens (Gallus gallus domesticus) Raised in Southern Thailand

“…The study area was located in the central region of southern Thailand that is close to the coastal area, with water bodies that may support mosquitoes and other blood-sucking insects' development. The examples of insect vector found in Southern Thailand were Culex mosquitoes [50], * AK = area of kinetoplast, AN = area of nucleus, AT = area of trypomastigote, BW = width of body through center of nucleus, FF = free flagellum, KN = center of nucleus to kinetoplast, NA = center of nucleus to anterior end, PA = total length without free flagellum, PK = posterior end to kinetoplast, PN = center of nucleus to posterior end.…”

“…The study area was located in the central region of southern Thailand that is close to the coastal area, with water bodies that may support mosquitoes and other blood-sucking insects' development. The examples of insect vector found in Southern Thailand were Culex mosquitoes [50], Culicoides biting midges [51] and Simuliidae [52]. Additionally, the high prevalence and diversity of these parasites might be related to anthropogenic disturbance and activities in this area [53] or landscape characteristics in this area [54].…”

A Maximum Entropy Model of the Distribution of Dengue Serotype in Mexico

“…Our study supports other findings [38] that also strongly suggest distinct ecological preferences by DENV larvae based on their serotypes. This may suggest Aedes larvae sensitivity to water temperature, turbidness, and other conditions affecting larvae survival in pools, as such partly explaining DENV serotype-specific preferences in relation to habitats [39][40][41][42].…”

Chemical Ecology and Management of Dengue Vectors

“…The most decisive cues in oviposition site selection have been difficult to decipher. Physiochemical factors (e.g., container type, color, size, shape, and volume; fill method; temperature; pH; lid type; exposure to sun) have been described in relation to container larval productivity (29,123,139,142). Sources of olfactory cues released from these sites include plant infusions, conspecific and heterospecific larvae, and microorganisms (82), although how these sources interact to define specific site choice is less well understood.…”