The effect of urea on the oviposition behaviour of culicine vectors of Japanese encephalitis was studied in rice fields. Gravid females had a strong preference for oviposition in urea treated areas in rice fields, while no such preference was exhibited in untreated areas. The egg laying declined in the area where urea treated water surface had a mechanical barrier, which allowed volatile fractions to escape, but prevented contact with the water. Urea was shown to act as an oviposition attractant/stimulant for Culex tritaeniorhynchus, but its role was not clear for Cx. vishnui, as the number of egg rafts obtained for the latter species was low.
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http://dx.doi.org/10.1590/s0074-02762003000600014 | DOI Listing |
Acta Trop
October 2024
Núcleo PReV Amazônia - Instituto Leônidas e Maria Deane - Fiocruz Amazônia; Programa de Pós-Graduação em Biologia Parasitária, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.
Proposing substitutes for Pyriproxyfen (PPF) in the auto-dissemination strategy is essential to ensure the continuity of the strategy in the field, especially in the case of the emergence of populations resistant to this larvicide. One possible substitute among the compounds already in use in Brazil is the larvicide Diflubenzuron (DFB). The equation that defines the proportion of oviposition sites (habitats) contaminated by the auto-dissemination strategy was modified to account for the number of visits required to reach the necessary concentration of DFB for contamination, considering scenarios with varying numbers of oviposition sites and mosquito densities.
View Article and Find Full Text PDFFront Physiol
April 2023
Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China Jiliang University, Hangzhou, China.
The brown planthopper, (Stål), is a major pest of rice crops, and its control is critical for food security. Pymetrozine has been recommended as an alternative to imidacloprid for controlling , but the pest has developed high resistance to it, making its prohibition and restriction urgent. To address this issue, we conducted a study using a mixture of pymetrozine and zhongshengmycin with the effective ratio of 1:40, to evaluate the fitness costs in .
View Article and Find Full Text PDFiScience
December 2022
School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
Intraspecific competition drives ecological specialization, and niche expansion. In holometabolous insects, larval intraspecific competition ("crowding") has lasting fitness consequences for individuals and shapes adaptive responses. However, our understanding of the molecular profile of larval crowding responses remains allusive.
View Article and Find Full Text PDFMalar J
June 2022
Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
Background: Nutrient acquisition and allocation integrate foraging and life-history traits in insects. To compensate for the lack of a particular nutrient at different life stages, insects may acquire these through supplementary feeding, for example, on vertebrate secretions, in a process known as puddling. The mosquito Anopheles arabiensis emerges undernourished, and as such, requires nutrients for both metabolism and reproduction.
View Article and Find Full Text PDFCommun Biol
November 2021
Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea.
Ammonia and its amine-containing derivatives are widely found in natural decomposition byproducts. Here, we conducted biased chemoreceptor screening to investigate the mechanisms by which different concentrations of ammonium salt, urea, and putrescine in rotten fruits affect feeding and oviposition behavior. We identified three ionotropic receptors, including the two broadly required IR25a and IR76b receptors, as well as the narrowly tuned IR51b receptor.
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