Organophosphate resistance in vector Populations of the complex of Culex Pipiens L. (Diptera: Culicidae)

1981 ◽  
Vol 71 (1) ◽  
pp. 153-161 ◽  
Author(s):  
C. F. Curtis ◽  
N. Pasteur
Keyword(s):  
Sri Lanka ◽  
High Activity ◽  
Culex Quinquefasciatus ◽  
Urban Areas ◽  
Culex Pipiens ◽  
Single Gene ◽  
Field Studies ◽  
Susceptible Strain ◽  
Organophosphate Resistance ◽  
Closely Linked Group

AbstractResistance to chlorpyrifos and other commonly used organophosphate larvicides was found in Culex quinquefasciatus Say from several urban areas in Tanzania. Lower levels of resistance were found in laboratory strains of the complex of C. pipiens L. collected in Sri Lanka, Egypt, Liberia and Brazil. Crosses of the Tanzanian strains to a more susceptible strain gave results consistent with causation of the resistance by a single gene or closely linked group of genes. Electrophoresis of one of the Tanzanian stocks indicated two esterase bands of high activity. The resistance in Tanzania did not prevent larval killing by freshly sprayed chlorpyrifos, but it is suggested that a spraying would probably no longer remain effective for three months as reported in earlier field studies.

Inheritance and activity of some esterases associated with organophosphate resistance in mosquitoes of the complex of Culex pipiens L. (Diptera: Cnlicidae)

1983 ◽  
Vol 73 (1) ◽  
pp. 153-170 ◽  
Author(s):  
F. Villani ◽  
G. B. White ◽  
C. F. Curtis ◽  
S. J. Miles
Keyword(s):  
Sri Lanka ◽  
High Intensity ◽  
Culex Pipiens ◽  
Resistance Mechanisms ◽  
Enzyme Assays ◽  
Resistance Level ◽  
Organophosphate Resistance ◽  
Esterase Pattern ◽  
Resistant Strains ◽  
Low Activity

AbstractEighteen strains of the complex of Culex pipiens L. from Africa, Asia and Europe were bioassayed for resistance to chlorpyrifos and electro-phoresed and stained for esterases. Susceptible strains showed only low activity esterase bands. The resistant strains of C. quinquefasciatus Say from hot countries (Liberia, Nigeria, Sri Lanka, Tanzania, Thailand) all showed the same two high intensity esterase bands (Rm 0·60 + 0·82). Different patterns of high esterase were found in resistant C. pipiens strains from cooler localities in Nairobi, Kenya (Rm 100), and Mont-pellier, France (Rm 0–50). Selection experiments on strains originally polymorphic for resistance and esterase pattern showed, without exception, that high esterase remained associated with resistance, and it is concluded that the association is almost certainly causal and not merely due to genetic linkage. The high intensity esterase bands were probably due to alleles of the loci Est-l, Est-2 and Est-3, separated by crossover distances of approximately 2·4 and 5·5 units, respectively. Strains monomorphic for what appeared to be the same high esterase pattern varied markedly in resistance level. Enzyme assays showed a direct relationship between levels of enzyme activity and resistance. Bioassays with fenthion and chlorpyrifos revealed differences in the relative resistance of C. quinquefasciatus from Colombo (Sri Lanka) and Dar-es-Salaam (Tanzania). Despite these differential degrees of cross-effectiveness, it is concluded that high intensity esterases are reliable indicators of organophosphate resistance in mosquitoes of the C. pipiens complex, although the possibility of other resistance mechanisms means that the lack of abnormally active esterases does not necessarily indicate the absence of resistance.

scholarly journals Gonoactivity of Culex (Culex) (Diptera: Culicidae) Mosquitoes During Winter in Temperate Argentina

2021 ◽  
Author(s):  
María Florencia Branda ◽  
Magdalena Laurito ◽  
Andrés Mario Visintin ◽  
Walter Ricardo Almirón
Keyword(s):  
Developmental Stage ◽  
Culex Quinquefasciatus ◽  
Culex Pipiens ◽  
Life Cycles ◽  
Morphological Identification ◽  
Dry Ice ◽  
Culex Pipiens Pipiens ◽  
Host Seeking ◽  
Baited Traps ◽  
The City

Abstract The subgenus Culex L. includes species involved in summer–autumn arbovirus transmission but studies during winter are scarce in temperate Argentina. Female specimens were collected host-seeking at dry-ice-baited traps during autumn–winter–spring at two sites in Córdoba City during 2016 and 2017. The specimens were morphologically identified and dissected to determine the follicular developmental stage (gonotrophic activity). Females with advanced follicular stages (≥III) were subjected to molecular procedures to confirm or re-identify previous morphological identification. Five species (Culex apicinus Philippi (Diptera: Culicidae), Culex dolosus (Lynch-Arribálzaga) (Diptera: Culicidae), Culex maxi Dyar (Diptera: Culicidae), Culex pipiens pipiens L. (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae)) were collected and found gonoactive during winter; showing that a high proportion of Culex (Culex) females remain reproductively active during the unfavorable season for mosquito populations. Among them, it is worth noting the collection of Cx. quinquefasciatus, vector of the St. Louis encephalitis virus (endemic in the city), a specimen of Cx. p. pipiens, and a hybrid of Cx. p. pipiens/Cx. quinquefasciatus (during autumn). The study of this community during winter should continue because a high gonoactive female proportion with advanced follicular stages was found: 29.12 and 13.07% in 2016 and 2017, respectively. Local studies such as this one provide evidence about ornithophilic Culex species with active year-round life cycles, species that could favor arbovirus overwintering.

scholarly journals Polygenic and single gene responses to selection for resistance to diazinon in Lucilia cuprina.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 613-620 ◽  
Author(s):  
J A McKenzie ◽  
A G Parker ◽  
J L Yen
Keyword(s):  
Resistant Strain ◽  
Single Gene ◽  
Natural Populations ◽  
Susceptible Strain ◽  
Selection Line ◽  
Base Population ◽  
Gene Response ◽  
Biochemical Profiles ◽  
Resistant Strains ◽  
Selection For

Abstract Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.

scholarly journals ANALISIS TINGKAT KETEPATAN WAKTU KRL COMMUTER LINE LINTAS TANAH ABANG-RANGKASBITUNG (STUDI KASUS: STASIUN CISAUK)

2020 ◽  
Vol 3 (3) ◽  
pp. 625
Author(s):  
Giovanni Bintang ◽  
Dewi Linggasari ◽  
Hokbyan Angkat
Keyword(s):  
Urban Areas ◽  
Research Method ◽  
Gap Analysis ◽  
Field Studies ◽  
Individual Characteristics ◽  
Tolerance Limit ◽  
Green Line ◽  
Tolerance Limits ◽  
Online Surveys ◽  
Delay Tolerance

Commuter Line trains are one of the modes of transportation that are very popular with the Jabodetabek community. KRL Commuter Line is capable of reducing the level of congestion in urban areas, so it is expected that the KRL Commuter Line is able to meet the needs of the community with punctuality in performance. This study’s purpose is to identify the timeliness of Green Line KRL departures by scheduling it and classify the level of Green Line KRL departure delays and determine solutions that can be applied to reduce the level of KRL Green Line departure. The research method used to collect data by online surveys and field studies. Then analyzed with Gap Analysis in order to obtain information about individual characteristics, characteristics of travel, and perceived delays according to KRL Green Line users. From the results of the analysis, it was found that KRL users have 3 late tolerance limits according to the Ministerial Regulation set a delay tolerance limit of 5 minutes while the results of the perception of KRL users on the Green Line lane tolerance limit of 5 minutes and finally according to KRL users at Cisauk Station tolerate delays by 10 minutes.  ABSTRAKKereta Commuter Line adalah salah satu moda transportasi yang sangat diminati masyarakat Jabodetabek. KRL Commuter Line juga dinilai mampu mengurangi tingkat kemacetan di perkotaan, sehingga diharapkan KRL Commuter Line mampu memenuhi kebutuhan masyarakat dengan ketepatan waktu dalam kinerjanya. Tujuan penelitian ini adalah untuk mengindentifikasi ketepatan waktu keberangkatan KRL Green Line dengan penjadwalannya serta mengklasifikasikan tingkat keterlambatan keberangkatan KRL Green Line dan menentukan solusi yang dapat diterapkan untuk mengurangi tingkat keterlambatan keberangkatan KRL Green Line. Metode Penelitian yang digunakan untuk mengumpulkan data adalah dengan survey online dan studi lapangan. Lalu dianalisis dengan Gap Analysis agar didapatkan informasi mengenai karateristik individu, karateristik perjalanan, dan persepsi keterlambatan menurut pengguna  KRL Green Line. Dari hasil analisis, didapat bahwa pengguna KRL mempunyai 3 batasan toleransi keterlambatan yaitu menurut Peraturan Menteri ditetapkan batas toleransi keterlambatan sebesar 5 menit sedangkan hasil dari persepsi pengguna KRL jalur Green Line batas toleransi keterlambatan sebesar 5 menit dan yang terakhir menurut pengguna KRL di Stasiun Cisauk menoleransikan keterlambatan sebesar 10 menit.

Mechanisms of insecticide resistance in a temephos selected Culex quinquefasciatus (Diptera: Culicidae) strain from Sri Lanka

1990 ◽  
Vol 80 (4) ◽  
pp. 453-457 ◽  
Author(s):  
H.T.R. Peiris ◽  
J. Hemingway
Keyword(s):  
Cytochrome P450 ◽  
Sri Lanka ◽  
Culex Quinquefasciatus ◽  
Resistant Strain ◽  
Resistance Mechanism ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Biochemical Assays ◽  
Significant Difference ◽  
Naphthyl Acetate

AbstractCulex quinquefasciatus Say from Peliyagoda, Sri Lanka, has larval resistance to temephos, malathion, fenitrothion and chlorpyrifos. Biochemical assays on individual resistant and susceptible mosquitoes of this strain showed that there was a good correlation between this resistance and increased esterase activity with both 1-and 2-naphthyl acetate, which appears to be the major resistance mechanism in this multiple organophosphate resistant strain. There was no significant difference in malaoxon, bendiocarb or propoxur sensitivity of the acetylcholinesterase from the resistant and susceptible strains, indicating that the sensitivity of the target site has not been altered. Biochemical assays on mass homogenates of the resistant and susceptible strains showed no correlation between resistance and the level of glutathione s-transferase activity, or the amount of cytochrome P450 present.

scholarly journals North American Culex pipiens and Culex quinquefasciatus are competent vectors for Usutu virus

2018 ◽  
Vol 12 (8) ◽  
pp. e0006732 ◽  
Author(s):  
Christian L. Cook ◽  
Yan-Jang S. Huang ◽  
Amy C. Lyons ◽  
Barry W. Alto ◽  
Isik Unlu ◽  
...  
Keyword(s):  
Culex Quinquefasciatus ◽  
North American ◽  
Culex Pipiens ◽  
Usutu Virus

Impact of Age and Social Class on Individual Music Preference in Selected Urban and Sub-urban Areas of Sri Lanka

2021 ◽  
Author(s):  
Palihaderu P.A.D.S ◽  
Mendis B.I.L.M. ◽  
Premarathne J.M.K.J.K ◽  
Dissanayake A.S. ◽  
IRajapaksha H. ◽  
...  
Keyword(s):  
Social Class ◽  
Sri Lanka ◽  
Urban Areas ◽  
Music Preference

Simulation of the Cooking Organic Aerosol Concentration Variability in an Urban Area

2021 ◽  
Author(s):  
Evangelia Siouti ◽  
Ksakousti Skyllakou ◽  
Ioannis Kioutsioukis ◽  
Giancarlo Ciarelli ◽  
Spyros N. Pandis
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Temporal Distribution ◽  
Late Summer ◽  
Field Studies ◽  
Organic Aerosol ◽  
Basis Set ◽  
Cooking Times ◽  
The City ◽  
Lunch Time

<p>Cooking operations can be an important fine PM source for urban areas. Cooking emissions are a source of pollution that has been often ignored and are not included or are seriously underestimated in urban emission inventories. However, several field studies in cities all over Europe suggest that cooking organic aerosol (COA) can be an important component of the total organic PM. In this study we propose and evaluate a methodology for the simulation of the COA concentration and its variability in space and time in an urban area. The city of Patras, the third biggest in Greece is used for this first application for a typical late summer period. The spatial distribution of COA emissions is based on the exact location of restaurants and grills, while the emissions on the meat consumption in Greece. We estimated COA emissions of 150 kg d<sup>-1</sup> that corresponds to 0.6 g d<sup>-1</sup> per person. The temporal distribution of COA was based on the known cooking times and the results of the past field studies in the area. Half of the daily COA is emitted during dinner time (21:00-0:00 LT), while approximately 25% during lunch time (13:00-16:00 LT). The COA is simulated using the Volatility Basis Set with a volatility distribution measured in the laboratory and is treated as semivolatile and reactive. The maximum average COA concentration during the simulation period is predicted to be 1.3 μg m<sup>-3</sup> in a mainly pedestrian area with a high density of restaurants. Peak hourly COA concentrations in this area exceed 10 μg m<sup>-3</sup> during several nights. The local production of secondary COA is predicted to be slow and it represents just a few percent of the total COA.</p><p> </p>

Classifying Outdoor Recreation Opportunities in Urban and Semi-Urban Areas: A Case of Sri Lanka

2020 ◽  
Vol 10 (10) ◽  
pp. 714-730
Author(s):  
GMG Sampath ◽  
K Jayantha ◽  
DLIHK Peiris ◽  
RPDD Rajapaksha ◽  
AMSJP Abeykoon
Keyword(s):  
Sri Lanka ◽  
Urban Areas ◽  
Outdoor Recreation ◽  
Recreation Opportunities
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