Theeraphap Chareonviriyaphap

Kasetsart University | KU · Department of Entomology

Infectious diseases that cause illness and/or death in humans can be contracted from mosquito bites. A viable and alternate method of personal protection that can lower the danger of human exposure to mosquito-borne diseases is the use of plant-based repellents. Using a high-throughput screening system, the current work examined the toxicity, conta...

Mosquito surveillance is critical for actively tracking the location and monitoring population levels and the threat of mosquito-borne disease. Although light-emitting diodes (LEDs) light traps have grown in popularity, there is still a limited understanding of the application of light wavelengths for trapping nocturnally active wild mosquitoes in...

The Asia-Pacific region has had decades of progress in reducing malaria cases and deaths. The region is now accelerating its efforts towards malaria elimination by 2030 using a science-based approach by applying evidence-based best practices alongside existing tools. However, there are concerns of knowledge gaps and external factors challenging thi...

Increasing temperature can enhance the geographical spread and behavior of disease vector mosquitoes, exposing vulnerable populations to Aedes-borne viruses and infections. To address this risk, cost-effective and sustained intervention vector control tools are required, such as volatile pyrethroid spatial repellents. This study used a high-through...

BACKGROUND Controlling the spread of arboviral diseases remains a considerable challenge due to the rapid development of insecticide resistance in Aedes mosquitoes. This study evaluated the effects of boric acid‐containing toxic sugar bait (TSB) on field populations of resistant Aedes aegypti mosquitoes. In addition, this study examined the flight...

Background The Anopheles dirus complex plays a significant role as a malaria vector in the Greater Mekong Subregion (GMS), with varying degrees of vector competence among species. Accurate identification of sibling species in this complex is essential for understanding malaria transmission dynamics and deploying effective vector control measures. H...

The stable fly, Stomoxys calcitrans L. (Diptera: Muscidae), is a significant insect pest with global veterinary implications due to its capacity to both cause nuisance and transmit disease‐causing pathogens to livestock. This study aimed to determine the livestock bedding preferred for use as a development substrate by S. calcitrans larvae and fiel...

There is an increased awareness of the importance of data publication, data sharing, and open science to support research, monitoring and control of vector-borne disease (VBD). Here we describe the efforts of the Global Biodiversity Information Facility (GBIF) as well as the World Health Special Programme on Research and Training in Diseases of Pov...

The mosquito Aedes aegypti , known to transmit important arboviral diseases, including dengue, chikungunya, Zika and yellow fever. Given the importance of this disease vector, a number of control programs have been proposed involving the use of the sterile insect technique (SIT). However, the success of this technique hinges on having a good unders...

The growth and associated traits of Aedes aegypti (L.) mosquitoes may adapt and evolve in response to the costs associated with body size in relation to latitudinal variation. We analyzed the life-history traits and energy reserves of field-collected mosquitoes from Taiwan, Thailand, and Indonesia along a latitudinal range spanning from 23°N to 6°S...

WHO tube and CDC bottle bioassays are currently available for insecticide resistance monitoring and malaria transmission research. Multiple parameters including mosquito density, age, and nutritional status may affect the readout in these bioassays’ tests. This study aims to assess the effects of experimental factors on knockdown and mortality meas...

Volatile pyrethroids exert a range of both lethal and behavioral effects on mosquitoes through the passive release of insecticides into the atmosphere. We investigated the protective efficacy (PE) of transfluthrin-treated jute (TI-jute) and cotton (TI-cotton) fabrics, worn at the back of a protective black vest, against laboratory-reared pyrethroid...

The effectiveness of vector-control tools is often assessed by experiments as a reduction in mosquito landings using human landing catches (HLCs). However, HLCs alone only quantify a single characteristic and therefore do not provide information on the overall impacts of the intervention product. Using data from a recent semi-field study which used...

Simple Summary Over the past 20 years, there has been a worldwide resurgence in the nuisance biting insects known as bed bugs. The resurgence is due to the development of insecticide resistance, such that modern bed bugs are very hard to kill. This also means that control is expensive, and not everyone has the financial resources to pay for eradica...

Background The Anopheles dirus complex plays a significant role as malaria vectors in the Greater Mekong Subregion (GMS), with varying degrees of vector competence among species. Accurate identification of sibling species in this complex is essential for understanding malaria transmission dynamics and deployment of effective vector control measures...

Simple Summary The deployment of synergistic insecticide combinations is intended to reduce both the dose of the substances used and the danger of insect populations developing physiological resistance to these insecticides. In order to test this hypothesis, two compounds (β-caryophyllene oxide and vetiver oil), with proven mosquito-repellent prope...

Simple Summary Aedes aegypti (L.) is a major vector of dengue fever in tropical regions. To prevent their contact with human hosts, spatial repellents (SRs) like transfluthrin (TFT) and metofluthrin (MFT) have shown promise in delaying pesticide resistance and addressing gaps in outdoor transmission not covered by other interventions such as indoor...

Efficacies of essential oils (EOs) of Vetiveria zizanioides (L.) Nash. (Poales: Poaceae) (VZ EO), Cananga odorata (Lam) Hook. F. & Thomson (Magnoliales: Annonaceae) (CO EO), and crude extract (CE) of Andrographis paniculata (Burm.F.) Wall ex. Nees (Lamiales: Acanthaceae) (AP CE), against laboratory (lab) and field strains of Culex quinquefasciatus...

Mosquitoes play a crucial role as primary vectors for various infectious diseases in Thailand. Therefore, accurate distribution information is vital for effectively combating and better controlling mosquito-borne diseases. Here, we present a curated dataset of the mosquito distribution in Thailand comprising 12,278 records of at least 117 mosquito...

Background The mosquito landing rate measured by human landing catches (HLC) is the conventional endpoint used to evaluate the impact of vector control interventions on human-vector exposure. Non-exposure based alternatives to the HLC are desirable to minimize the risk of accidental mosquito bites. One such alternative is the human-baited double ne...

The effectiveness of vector-control tools is often assessed by experiments as a reduction in mosquito landings using human landing catches (HLCs). However, HLCs alone only quantify a single characteristic and therefore do not provide information on the overall impacts of the intervention product. Using data from a recent semi-field study which used...

We evaluated the behavioral responses of Aedes albopictus and Anopheles minimus to 3 isovaleric acid and lactic acid-based chemical lure blends and 2 individual alcohols, using Spatial Repellency Assay in a high-throughput screening system (HITSS). Five doses of 0.0002, 0.001, 0.0025, 0.005, and 0.01 g were tested per lure. A BG-lure was used as a...

Haemoproteus columbae is a common haemosporidian parasite of wild pigeons (Columba livia) reported worldwide. In Thailand, the wild pigeon population is increasing due to paddy field monoculture. However, there are limited reports on the presence of H. columbae in these pigeon populations. The aim of the study was to characterize H. columbae in wil...

Aedes aegypti and Ae. albopictus (Aedes) transmit highly pathogenic viruses such as dengue, chikungunya, yellow fever, and Zika which can cause life-threatening diseases in humans. They are the most important vectors of arboviruses in Thailand. Their vectorial capacity (VC) is highly complex mainly due to the interplay between biotic and abiotic fa...

Complementary approaches to tackle outdoor and early evening biting mosquitoes are urgently required. Transfluthrin (TFT) is a volatile pyrethroid capable of altering mosquito feeding behaviour. This study investigated the efficacy of TFT-treated jute (TFT-J) and cotton (TFT-C) fabrics on human landing activity, feeding and fecundity of Anopheles m...

Each binary mixture formulation of Vetiveria zizanioides (L.) Nash (VZ) with Andrographis paniculata (Burm.f.) Wall. ex Nees (AP) or Cananga odorata (Lam.) Hook.f. & Thomson (CO) and AP with CO at 1:1, 1:2, 1:3, and 1:4 ratios (v:v) was investigated for behavioral responses on laboratory and field strains of Aedes aegypti. Irritant and repellent ac...

The performances of the human-baited double net trap (HDNT) and the human-baited host decoy trap (HDT) methods were compared against the outdoor human landing catch (OHLC) method in Thailand and Vietnam. Two study sites were selected in each country: a rural village and a nearby forest setting. The three outdoor trap methods were rotated nightly be...

Background Whilst the human landing catch (HLC) technique is considered the ‘gold standard’ for estimating human-biting rates, it is labor-intensive and fraught with potential risk of exposure to infectious mosquito bites. This study evaluated the feasibility and performance of an alternative method, the human double net trap (HDNT) relative to HLC...

Mosquito repellents play a major role in reducing the risk of mosquito borne diseases by preventing mosquito bites. The present study evaluated the mosquito-repellent activity of β-caryophyllene oxide 1% (BCO), vetiver oil 2.5% (VO) and their binary mixtures [BCO+VO (1:1), BCO+VO (2:1), BCO+VO (1:2)] against four laboratory-colonized mosquito speci...

Background The entomological inoculation rate (EIR) is one of the key indices used to evaluate malaria transmission and vector control interventions. One of the components of the EIR is the sporozoite rate in Anopheles vectors. A systematic review and meta-analysis was performed to identify the prevalence of Plasmodium spp. in field-collected Anoph...

A mark-release-recapture study was conducted to refine the ''push-pull'' strategy for controlling the dengue, chikungunya, and Zika virus vector Aedes aegypti in a peridomestic environment by determining optimal locations and distances from human-occupied experimental huts for placement of the ''pull'' component (Biogents Sentinele [BGS] traps) to...

Background: An integrated approach to reduce densities of adult Aedes aegypti inside homes is currently being evaluated under experimentally controlled field conditions. The strategy combines a spatial repellent (SR) treatment (applied indoors) with the Biogents Sentinel ™ (BGS) mosquito trap positioned in the outdoor environment. In essence, when...

Numerous plant-based repellents are widely used for personal protection against host-seeking mosquitoes. Vitiveria zizanioides (L.) Nash essential oil and its constituents have demonstrated various mosquito repellent activities. In this study, three chemical actions of vetiver oil and five constituents (terpinen-4-ol, α-terpineol, valencene, vetive...

Well-designed surveillance systems are required to facilitate a control program for vector-borne diseases. Light traps have long been used to sample large numbers of insect species and are regarded as one of the standard choices for baseline insect surveys. The objective of this study was to evaluate the efficacy of six ultraviolet light-emitting d...

Climatic variation is a key driver of genetic differentiation and phenotypic traits evolution, and local adaptation to temperature is expected in widespread species. We investigated phenotypic and genomic changes in the native range of the Asian tiger mosquito, Aedes albopictus. We first refine the phylogeographic structure based on genome-wide reg...

The development of local plant extracts as a mosquito repellent is environmentally safe, inexpensive, and easily accessible for residents. In this study, three extracts from two local plants, Myristica fragrans Houtt. (flesh and mace) and Curcuma longa L. (rhizome) from southern Thailand, were investigated for their inherent repellent activity usin...

Additional vector control tools are needed to supplement current strategies to achieve malaria elimination and control of Aedes -borne diseases in many settings in Thailand and the Greater Mekong Sub-region. Within the next decade, the vector control community, Kasetsart University (KU), and the Ministry of Higher Education, Science, Research and I...

Efficacies of essential oils (EOs) of Vetiveria zizanioides (L.) Nash. (Poales: Poaceae) (VZ EO), Cananga odorata (Lam) Hook. F. & Thomson (Magnoliales: Annonaceae) (CO EO), and crude extract (CE) of Andrographis paniculata (Burm.F.) Wall ex. Nees (Lamiales: Acanthaceae) (AP CE), against laboratory (lab) and field strains of Culex quinquefasciatus...

The susceptibility to six pyrethroid insecticides (permethrin, deltamethrin, alpha-cypermethrin, cypermethrin, lambda-cyhalothrin and bifenthrin), each at the recommended concentration, was evaluated for the two stable fly species Stomoxys calcitrans (Linnaeus) and Stomoxys indicus Picard, through tarsal contact using a World Health Organization (W...

Background Entomological surveillance is an important means of assessing the efficacy of insect vector management programs and estimating disease transmission thresholds. Among baited traps, Biogents’ BG-Sentinel (BGS) trap baited with BG-Lure is considered to have the most similar outcome to, and be a possible replacement for, human-landing catche...

Volatile organic compounds from various plants have received popular interest as one of the vector control tools due to their eco-friendliness and insect-repellent activities. In this study, an excito-repellency assay system was used to examine the noncontact repellency, contact excitation, and knockdown (KD) effects of guava leaf (Psidium guajava...

The 2018 Asia Pacific Malaria Elimination Network’s Vector Control Working Group (APMEN VCWG) annual meeting took place 3–5 September 2018 in Bangkok, Thailand. It was designed to be a forum for entomology and public health specialists from APMEN country programmes (over 90 participants from 30 countries) to discuss current progress and challenges...

Light traps are a common method for attracting and collecting arthropods, including disease vectors such as mosquitoes. Various types of traps have been used to monitor mosquitoes in a forest in Western Thailand. In this study, four Light Emitting Diodes (LED) light sources (UV, blue, green, and red) and two fluorescent lights (white and UV) were u...

Information on factors influencing the behavioral responses of mosquitoes to repellents is lacking and poorly understood, especially in the Anopheles species, night-biting mosquitoes. Our goal was to investigate the impact of different time periods on circadian activity and behavioral responses of two malaria vectors, Anopheles minimus and An. diru...

Essential oil of Cananga odorata Hook. F. & Tomson is a source of insect repellent, but contact irritancy and noncontact repellency actions that stimulate insect’s avoidance behavior (escape away from chemical source after direct physical contact or without making physical contact, respectively) have not been investigated. Therefore, an excito-repe...

Mosquito surveillance is the cornerstone for determining abundance, species diversity, pathogen infection rates, and temporal and spatial distribution of different life stages in an area. Various methods are available for assessing adult mosquito populations, including mechanical trap devices using different forms of attractant cues (chemical and v...

Flesh flies are received greater attention due to their use as evidence in forensic investigations of decomposing human remains. Investigators will often use age of immature insects associated with such remains as the minimal postmortem interval (PMImin) given certain assumptions. Boettcherisca peregrina is a significant flesh fly species of forens...

BACKGROUND Exploiting indoor‐resting mosquitoes' innate behavioral responses to commonly used insecticide is crucial in vector control programs. Indoor residual spraying (IRS) and long‐lasting insecticidal nets (LLINs) treated with pyrethroids have become widely used for controlling dengue fever vectors. The present study tested the effects of pipe...

Duck Tembusu virus (DTMUV) is an emerging flavivirus that causes severe disease in avian hosts, while also affecting mammalian hosts; however, information on viral interaction with mosquito vectors for mammalian hosts is limited. Vector competence of Aedes (Ae.) aegypti and Aedes albopictus mosquitoes for DTMUV were investigated. Both Aedes mosquit...

Indoor residual spray with deltamethrin remains the most common tool for reducing malaria transmission in Thailand. Deltamethrin is commonly used to spray the entire inner surfaces of the walls to prevent mosquitoes from resting. This study compared the mosquito landing responses on humans inside three experimental huts treated with deltamethrin at...

Successful monitoring of physiological resistance of malaria vectors requires about 150 female mosquitoes for a single set of tests. In some situations, the sampling effort is insufficient due to the low number of field-caught mosquitoes. To address this challenge, we demonstrate the feasibility of using the forced oviposition method for producing...

Several types of olfactometers have been used to evaluate mosquito responses to agents that mimic natural volatiles that repel or attract. The Y-tube olfactometer has been widely used to study repellents and attractants, while the high-throughput screening system assay has only been used to study repellents. Whether the high-throughput screening sy...

Species of the Anopheles barbirostris complex (Myzorhynchus Series of the subgenus Anopheles) are potential vectors of malaria and filariasis parasites. Owing to the lack of reliable identification methods, the biting activity and host preference of the species within this complex have not been previous described. In this study, the trophic behavio...

Ultrasonic pest repellers are often promoted as a means of protecting people and pets from the bites of hematophagous arthropods, such as ticks. However, to date, there has been no published research on the effectiveness of these devices against the Australian paralysis tick, Ixodes holocyclus Neumann. The purpose of this study was to test the effe...

Natural volatile host cues play a critical role for mosquito orientation and locating a blood source for egg production. Similar olfactory activation responses have allowed the use and development of artificial chemical attractants to lure mosquitoes to trapping devices. Using a pre-formulated commercial product mixture of different attractant chem...

Background: Understanding and improving the durability of long-lasting insecticidal nets (LLINs) in the field are critical for planning future implementation strategies including behavioral change for care and maintenance. LLIN distribution at high coverage is considered to be one of the adjunctive transmission reduction strategies in Nepal's Mala...

The objective of this study was to investigate evidence of emerging anaplasmosis and bartonellosis in rodents from endemic areas of Nakhon Ratchasima, Thailand. Rodent trapping was undertaken in 13 sub‐districts of Muang District. The live‐capture traps were set up in three locations of selected scrub typhus patient houses for three consecutive nig...

Background Wolbachia, obligate intracellular bacteria, infect the majority of arthropods, including many mosquito species of medical importance. Some Wolbachia strains interfere with the development of Plasmodium parasites in female Anopheles, a major vector of malaria. The use of Wolbachia as a means to block malaria transmission is an emerging ve...

Exophilic vectors are an important contributor to residual malaria transmission. Wearable spatial repellents (SR) can potentially provide personal protection in early evening hours before people retire indoors. An SR prototype for passive delivery of transfluthrin (TFT) for protecting humans against nocturnal mosquitoes in Kanchanaburi, western Tha...

Background Members of the Anopheles hyrcanus group have been incriminated as important malaria vectors. This study aims to identify the species and explore the insecticide susceptibility profile within the Anopheles hyrcanus group in Ubon Ratchathani Province, northeastern Thailand where increasing numbers of malaria cases were reported in 2014. M...

Abstract The fall armyworm (FAW), Spodoptera frugiperda (Smith), is a major pest native to the Americas. A recent invasion of FAWs from Africa eastward to South Asia, the Indochina Peninsula, and mainland China has received much attention due to the considerable economic losses in agriculture. FAWs can rapidly colonise a new area, likely due to the...

Permethrin is a pyrethroid insecticide that has been widely used for the impregnation of fabrics to prevent the bites from arthropods such as mosquitoes and ticks. There are two types of permethrin impregnation: Do-It-Yourself (DIY) packs and pre-impregnated fabrics. Both forms have been on sale for many years in Australia, however to date, no data...

Control strategies exploiting the innate response of mosquitoes to chemicals are urgently required to complement existing traditional approaches. We therefore examined the behavioral responses of 16 field strains of Aedes aegypti (L.) from two countries, to deltamethrin and permethrin by using an excito-repellency (ER) test system. The result demon...