Aedes aegypti is an important mosquito species that can transmit several arboviruses such as dengue fever, yellow fever, chikungunya and zika. Because these mosquitoes are becoming resistant to most chemical insecticides used around the world, studies with new larvicides should be prioritized. Based on the known biological profile of imidazolium salts (IS), the objective of this study was to evaluate the potential of six IS as larvicides against Ae. aegypti, as tested against Ae. aegypti larvae. Larval mortality was measured after 24 and 48 h, and residual larvicidal activity was also evaluated.
RESULTS
Promising results were obtained with aqueous solutions of two IS: 1‐n‐octadecyl‐3‐methylimidazolium chloride ( C 18 MImCl ) and 1‐n‐hexadecyl‐3‐methylimidazolium methanesulfonate ( C 16 MImMeS ), showing up to 90% larval mortality after 48 h exposure. C 18 MImCl was more effective than C 16 mIMeS , causing mortality until day 15 after exposure. An application of C 18 MImCl left to dry under ambient conditions for at least 2 months and then dissolved in water showed a more pronounced residual effect (36 days with 95% mortality and 80% mortality up to 78 days).
Arboviroses such as dengue, Zika and chikungunya represent a serious public health issue as a consequence of the absence of approved vaccines or specific antiviral drugs against the arboviruses that cause them. One way to prevent these diseases is by combating the vector mosquito, Aedes aegypti (Diptera), which has serine proteases in the midgut. Protease inhibitors are molecules that can block enzyme activity, impairing digestion and nutrition, which can lead to death. Thus, we purified and characterized a novel chymotrypsin‐trypsin inhibitor (LsCTI) from Lonchocarpus sericeus seeds and investigated its effect upon Ae. aegypti egg hatching, larval development and digestive proteases.
RESULTS
LsCTI showed a single protein band in sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE), and the molecular mass determined by matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) was 8870.45 Da. Kinetics analyses revealed a noncompetitive type of inhibition and low inhibition constant (Ki) for chymotrypsin (8.24 x 10‐8 m ). The thermal resistance was remarkable, even at 100 °C for 180 min. The inhibitor concentration required for 50‐percent enzyme inhibition (IC50) of LsCTI was 4.7 x 10‐7 m for Ae. aegypti midgut larval enzymes. LsCTI did not affect egg hatchability at 0.3 mg mL‐1, but caused a high larval mortality rate (77%) and delayed development (37%).
The control of Aedes aegypti (L.), the main urban vector that causes arboviral diseases such as dengue, Chikungunya and Zika, has proved to be a challenge because of a rapid increase in insecticide resistance. Therefore, adequate monitoring of insecticide resistance is an essential element in the control of Ae. aegypti and the diseases it transmits. We estimated the frequency and intensity (Resistance Frequency Rapid Diagnostic Test [F‐RDT] and Resistance Intensity Rapid Diagnostic Test [I‐RDT]) of pyrethroid resistance in populations of Ae. aegypti from Mexico using the bottle bioassay and results were related to the frequencies of knockdown resistance (kdr) mutations V1016I and F1534C.
RESULTS
All populations under study were resistant to the pyrethroids: bifenthrin (99%), d‐(cis–trans)‐phenothrin (6.3% cis, 91.7% trans) and permethrin (99.5%) according to F‐RDT, and showed moderate to high‐intensity resistance at 10× the diagnostic dose (DD) in I‐RDT. Frequencies of the kdr mutation V1016I in Ae. aegypti populations were correlated with moderate permethrin resistance at 10× DD, whereas F1534C mutation frequencies were correlated with high bifenthrin resistance at 5× DD. Both I1016 and C1535 were highly correlated with high‐intensity phenothrin resistance at 1× to 10× DD.
This standard describes the procedures for official control with the aim of containing and eradicating Bursaphelenchus xylophilus in areas where infestation of susceptible coniferous species by B. xylophilus leads to wilt symptoms.
Specific approval and amendment
First approved in 2002–09. Revision approved in 2009‐09. 相似文献
This standard describes national regulatory control systems for Heracleum mantegazzianum, Heracleum sosnowskyi and Heracleum persicum. In the text the three species are referred to as Heracleum spp. in order to reduce repetitions.
This standard describes diagnostic protocols for Anisogramma anomala1 1 Use of brand names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable. .
This standard describes a diagnostic protocol for Globodera rostochiensis and Globodera pallida1 1 Use of brand names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable. .
Specific approval and amendment
This Standard was developed under the EU DIAGPRO Project (SMT 4‐CT98‐2252) by partnership of contractor laboratories and intercomparison laboratories in European countries. Approved as an EPPO Standard in 2003–09. Revision approved in 2009–09. 相似文献
This standard describes a diagnostic protocol for Curtobacterium flaccumfaciens pv. flaccumfaciens.1 1 Use of names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable.
This standard is intended for use in association with the EPPO Standards series PM 3 on phytosanitary procedures for consignment inspection, inspection of places of production and area‐wide surveillance. It includes elements common to inspection of consignments, places of production and area‐wide surveillance, and lot identification.
Specific approval and amendment
First approved in 2008–09. Revised in 2009–09. 相似文献
This standard describes a diagnostic protocol for Gremmeniella abietina1 1 Use of brand names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable.
This standard describes a diagnostic protocol for Ceratitis capitata. 1 1 Use of brand names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable.
The cover image of a droplet containing active ingredient applied to the thorax of a female Aedes aegypti adult mosquito is based on the Research Article Synthesis and insecticidal activity of novel pyrimidine derivatives containing urea pharmacophore against Aedes aegypti, by Xing‐Hai Liu et al., DOI: 10.1002/ps.4370 .
This standard describes a diagnostic protocol for Gibberella circinata1 1 Use of brand names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable. .
This standard describes a diagnostic protocol for the genus Hirschmanniella1 1 Use of names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable. .
This standard describes a diagnostic protocol for Xiphinema americanum sensu lato1 1 Use of names of chemicals or equipment in these EPPO Standards implies no approval of them to the exclusion of others that may also be suitable. .
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