Rapid insecticide resistance bioassays for three major urban insects in Taiwan.

Background: Taiwan's warm and humid climate and dense population provide a suitable environment for the breeding of pests. The three major urban insects in Taiwan are house flies, cockroaches, and mosquitoes. In cases where a disease outbreak or high pest density necessitates chemical control, selecting the most effective insecticide is crucial.

Effectiveness and acceptance of total release insecticidal aerosol cans as a control measure in reducing dengue vectors.

The effectiveness of regular application of insecticidal fogging in reducing dengue is questionable, since delays occur between peak time of outbreak and insecticide administrations. Moreover, many residents do not accept indoor application because of concern about insecticide contamination of household items. The study described in this article was designed to evaluate the effectiveness and acceptance of insecticidal aerosol cans to reduce dengue vectors inside and outside of homes.

Immunologic characterization and allergenicity of recombinant Tyr p 3 allergen from the storage mite Tyrophagus putrescentiae.

Background: The involvement of the storage mite Tyrophagus putrescentiae in allergies has been increasingly reported in many countries. Molecular analysis has shown that group 3 mite allergens are homologous to trypsin. Similar allergens have not been identified in T.

A novel amino acid substitution in a voltage-gated sodium channel is associated with knockdown resistance to permethrin in Aedes aegypti.

To identify pertinent mutations associated with knockdown resistance to permethrin, the entire coding sequence of the voltage-gated sodium channel gene Aa-para was sequenced and analyzed from a Per-R strain with 190-fold resistance to permethrin and two susceptible strains of Aedes aegypti. The longest transcript, a 6441bp open reading frame, encodes 2147 amino acid residues with an estimated molecular mass of 241kDa. A total of 33 exons were found in the Aa-para gene over 293kb of genomic DNA.

Differential survival of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) larvae exposed to low temperatures in Taiwan.

Aedes aegypti (L.) and Aedes albopictus (Skuse) differ in their distribution in Taiwan. The former species is distributed in the south of Taiwan, whereas the latter is found throughout the island.

Seaport as a source of hantavirus: a study on isolated isles.

Since small mammals from seaports have relative higher seroprevalences of hantavirus, this seroepidemiologic study was conducted on the isles in Kinmen and Lienchiang Counties along the coast of southern mainland China to determine whether seaport may play the role as a source of hantavirus. Among six species of small mammals trapped in Kinmen County, only male Mus musculus (6.7%) and Rattus losea (5.

Impact of a short-term community-based cleanliness campaign on the sources of dengue vectors: an entomological and human behavior study.

In June 2002, a considerable number of cases of dengue fever/dengue hemorrhage fever were reported in South Taiwan. To effectively reduce the sources of dengue vectors, the government conducted a weeklong community-based cleanliness campaign. The study reported here was designed to evaluate the effectiveness of the campaign.

The differences of dengue vectors and human behavior between families with and without members having dengue fever/dengue hemorrhagic fever.

Dengue vectors, human knowledge and behavior have been reported to play an important role in the transmission of dengue. This study was designed to understand the differences of dengue vectors and the behavior between families with (target group) and without (control group) members having dengue fever/dengue hemorrhagic fever. Population density of dengue vectors were determined by ovitrap index.

Insecticide resistance in German cockroaches (Blattella germanica) from hospitals and households in Taiwan.

Since a high percentage of cockroach infestation has been determined in hospitals in Kaohsiung, South Taiwan, insecticide resistances may have developed in the cockroach populations. To determine the resistances in cohorts of German cockroach (Blattella germanica) from hospitals and households to organophosphates, carbamates and pyrethroids, cockroaches were trapped from 30 hospitals and 30 households in this area. Bioassays by topical application were then carried out on the first generation bred in the laboratory.

Genetic relationships among populations of Aedes aegypti in Taiwan by using phenotypic and random amplified DNA-polymerase chain reaction markers.

An analysis of gene flow was conducted among collections of Aedes aegypti from 7 localities along the southwestern and southeastern coasts in Taiwan. Markers include 7 types of scaling patterns and 23 random amplified polymorphic DNA (RAPD) loci amplified by the polymerase chain reaction. Differences in scaling pattern and in the frequencies of RAPD markers were detected among populations and cluster analyses revealed 2 main groups on each side of the Central Mountain Range.

Voltage-dependent calcium channels in the corpora allata of the adult male loreyi leafworm, Mythimna loreyi.

In the corpora allata (CA) of the adult male loreyi leafworm, Mythimna loreyi, juvenile hormone acid (JHA) biosynthesis and release show a dose dependence on extracellular Ca(2+) concentration. Maxima are obtained with Ca(2+) concentrations of 2-10 mM, and synthesis and release are significantly inhibited under a Ca(2+)-free condition. The Ca(2+)-free inhibition of JHA release can be reversed by returning the glands to medium at 5 mM Ca(2+).