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3. The L1014F Knockdown Resistance Mutation Is Not a Strong Correlate of Phenotypic Resistance to Pyrethroids in Florida Populations of Culex quinquefasciatus

Author

Estep, Alden S., primary, Sanscrainte, Neil D., additional, Stuck, Jason, additional, Unlu, Isik, additional, Prasauskas, Agne, additional, Mundis, Stephanie J., additional, Cotter, Nicholas, additional, Romero-Weaver, Ana L., additional, Fedirko, Troy J., additional, Kendziorski, Natalie L., additional, Kosinski, Kyle J., additional, Ramirez, Daviela, additional, and Buckner, Eva A., additional

Published
2024
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5. The L1014F Knockdown Resistance Mutation Is Not a Strong Correlate of Phenotypic Resistance to Pyrethroids in Florida Populations of Culex quinquefasciatus

Author

Estep, Alden S, primary, Sanscrainte, Neil D, additional, Stuck, Jason, additional, Unlu, Isik, additional, Prasauskas, Agne, additional, Mundis, Stephanie J, additional, Cotter, Nicholas, additional, Romero-Weaver, Ana L, additional, Fedirko, Troy J, additional, Kendziorski, Natalie L, additional, Kosinski, Kyle J, additional, Ramirez, Daviela, additional, and Buckner, Eva A, additional

Published
2024
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6. Biological evaluation of a series of benzothiazole derivatives as mosquitocidal agents

Author

Sever Belgin, Altıntop Mehlika Dilek, Özdemir Ahmet, Tabanca Nurhayat, Estep Alden S., Becnel James J., and Bloomquist Jeffrey R.

Subjects
mosquito control, aedes aegypti, benzothiazole, piperidine, docking studies, Chemistry, QD1-999
Abstract

Aedes aegypti is associated with the transmission of numerous human and animal diseases, such as yellow fever, dengue fever, chikungunya, and more recently Zika virus. Emerging insecticide resistance has created a need to develop new mosquitocidal agents for effective control operations. A series of benzothiazole-piperidine derivatives (1-24) were investigated for their larvicidal and adulticidal effects on Ae. aegypti It was observed that compounds 2, 4, 6, 7, 8, 11 and 13 showed notable larvicidal activity. Furthermore, compounds 6 and 10 showed promising adulticidal activity. Based on the mosquitocidal properties of these compounds, docking studies were also carried out in the active site of the AeSCP2 enzyme to explore any insights into further in vitro enzyme studies. Docking results indicated that all these active compounds showed reasonable interactions with critical residues in the active site of this enzyme. This outcome suggested that these compounds might show their larvicidal and adulticidal effects via the inhibition of AeSCP2. According to in vitro and in silico studies, compounds 2, 4, 6, 7, 8, 10, 11 and 13 stand out as candidates for further studies.

Published
2019
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11. Insecticide resistance of Miami-Dade Culex quinquefasciatus populations and initial field efficacy of a new resistance-breaking adulticide formulation.

Author

Unlu, Isik, Buckner, Eva A., Medina, Johanna, Vasquez, Chalmers, Cabrera, Aimee, Romero-Weaver, Ana L., Ramirez, Daviela, Kendziorski, Natalie L., Kosinski, Kyle J., Fedirko, T. J., Ketelsen, Leigh, Dorsainvil, Chelsea, and Estep, Alden S.

Subjects
CULEX quinquefasciatus, WEST Nile virus, SUBURBS, PYRETHROIDS, DELTAMETHRIN
Abstract

Sporadic outbreaks of human cases of West Nile virus (WNV), primarily vectored by Culex quinquefasciatus Say in suburban and urban areas, have been reported since introduction of the virus into Florida in 2001. Miami-Dade County, Florida is part of one of the largest metropolitan areas in the United States, supports Cx. quinquefasciatus year-round, and recently experienced over 60 human cases of WNV during one outbreak. To facilitate more effective integrated vector management and public health protection, we used the Centers for Disease Control and Prevention (CDC) bottle bioassay method to evaluate the susceptibility of adult Cx. quinquefasciatus collected from 29 locations throughout Miami-Dade County to pyrethroid and organophosphate adulticide active ingredients (AIs) used by Miami-Dade County Mosquito Control. We also determined the frequency of the 1014 knockdown resistance (kdr) mutation for Cx. quinquefasciatus from a subset of 17 locations. We detected resistance to two pyrethroid AIs in all tested locations (permethrin: 27 locations, deltamethrin: 28 locations). The 1014F allele was widely distributed throughout all 17 locations sampled; however, 29.4% of these locations lacked 1014F homozygotes even though phenotypic pyrethroid resistance was present. Organophosphate resistance was more variable; 20.7% of the locations tested were susceptible to malathion, and 33.3% of the populations were susceptible to naled. We subsequently conducted a field trial of ReMoa Tri, a recently approved multiple AI adulticide formulation labelled for resistant mosquitoes, against a mixed location field population of Miami-Dade Cx. quinquefasciatus. Average 24-hr mortality was 65.1 ± 7.2% and 48-hr mortality increased to 85.3 ± 9.1%, indicating good control of these resistant Cx. quinquefasciatus. This current study shows that insecticide resistance is common in local Cx. quinquefasciatus but effective options are available to maintain control during active disease transmission in Miami-Dade County. [ABSTRACT FROM AUTHOR]

Published
2024
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13. The insecticidal activities of Erica manipuliflora Salisb. Extracts in the flowering and fruiting periods and their evaluation in term of chemical profiles of active extracts

Author

Sen, Burcu, primary, Gurdal, Bahar, additional, Estep, Alden S., additional, Tabanca, Nurhayat, additional, Kurkcuoglu, Mine, additional, Goger, Fatih, additional, Gul, Zulfiye, additional, Bardakci, Hilal, additional, Becnel, James, additional, Mat, Afife, additional, and Baser, Kemal Husnu Can, additional

Published
2022
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15. Larvicidal constituents from Poncirus trifoliataroot extracts

Author

Meepagala, Kumudini M and Estep, Alden S

Abstract

In the search for effective and environmentally friendly mosquito control agents, we have examined natural sources, such as microbes and plants, and the synthetic analogs of natural products. These plants and microbes have evolved in their ecological niches to produce defensive compounds against other competing organisms in their surroundings such as microbes, plants, and insects as a means to enhance their survival. Thus, some of these plants and microbes have bioactive compounds with insecticidal, fungicidal, and phytotoxic activities. In our previous research, we successfully isolated bioactive constituents from natural sources. We have carried out synthetic modifications and total synthesis of marginally active isolated compounds to achieve significantly higher active compounds. We have focused on plants in the Rutaceae family as the members of this family are known to possess bioactive compounds with algicidal, antifungal, insecticidal, and fungicidal activities. In this article, we report the isolation and structure elucidation of mosquito larvicidal constituents from Poncirus trifoliata(Rutaceae) root extract.

Published
2023
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18. Chemical composition and biological activities of Valeriana dioscoridis SM. roots

Author

Sen-Utsukarci, Burcu, primary, Kessler, Sonja M., additional, Akbal-Dagistan, Ozlem, additional, Estep, Alden S., additional, Tabanca, Nurhayat, additional, Kurkcuoglu, Mine, additional, Demirci-Kayiran, Serpil, additional, Eroglu-Ozkan, Esra, additional, Gul, Zulfiye, additional, Bardakci, Hilal, additional, Becnel, James, additional, Kiemer, Alexandra K., additional, Mat, Afife, additional, and Baser, Kemal Husnu Can, additional

Published
2021
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21. Additional file 1 of Spatial variation in the frequency of knockdown resistance genotypes in Florida Aedes aegypti populations

Author

Mundis, Stephanie J., Estep, Alden S., Waits, Christy M., and Ryan, Sadie J.

Abstract

Additional file 1: Table S1. Collection sites and their respective counties and count of collected and genotyped Ae. aegypti. Table S2. Coefficients and their associated level of statistical significance for the top variables in the top 20 models (without spatial lag or spatial error terms), and AICc and R2 metrics of model evaluation.

Published
2020
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23. Field evaluation of commercial off-the-shelf spatial repellents against the Asian Tiger Mosquito, Aedes albopictus (Skuse), and the potential for use during deployment

Author

Lloyd, Aaron M., Farooq, Muhammad, Diclaro, Joseph W., Kline, Daniel L., and Estep, Alden S.

Subjects
Mosquitoes -- Control, Aedes albopictus -- Health aspects -- Control -- Methods -- Usage, Soldiers -- Health aspects -- Methods -- Usage, Insect baits and repellents -- Usage -- Health aspects, Health
Abstract

Humans have used repellents to protect themselves from pestiferous blood-feeding insects since prehistoric times. The most probable primitive repellent is the use of smoke to mask kairomones (odors from humans [...]

Published
2013

27. Insecticidal and repellent properties of novel trifluoromethylphenyl amides II

Author

Tsikolia, Maia, Bernier, Ulrich R., Agramonte, Natasha M., Estep, Alden S., Becnel, James J., Tabanca, Nurhayat, Linthicum, Kenneth J., Gross, Aaron D., Guerin, Patrick M., Krober, Thomas, Bloomquist, Jeffrey R., and Entomology

Subjects
Aedes aegypti, Drosophila melanogaster, Mosquito, fungi, Anopheles gambiae
Abstract

This project focused on the design, synthesis, and testing of trifluoromethylphenyl amides (TFMPAs) as potential mosquitocides and repellents. Fourteen compounds were evaluated for toxicity against larvae and adults of Aedes aegypti. Several compounds were toxic against Aedes aegypti (larval, adult and feeding bioassays) and Drosophila melanogaster (glass-surface contact assay), but were much less toxic than fipronil, with toxicity ratios ranging from 100-fold in the larval assay to 100,000-fold for topical application to adult insects. In repellency bioassays to determine minimum effective dosage (MED), compound N-(2,6-dichloro-4(trifluoromethyl)phenyl)-2,2,3,3,3-pentafluoropropanamide (7b) repelled Ae. aegypti females at lower concentration, 0.017 (+/- 0.006) mu mol/cm(2), than N, N-diethyl-meta-toluamide (DEET) 0.026 (+/- 0.005) mu mol/cm(2). 2-Chloro-N-(3-(trifluoromethyl)phenyl)acetamide (6a) performed better than DEET against two species of mosquitoes: it repelled Ae. aegypti females at 0.013 (+/- 0.006) mu mol/cm(2) and Anopheles gambiae females (in a warm body repellent assay), at a standard exposure of 2 nmol/cm(2). These studies revealed novel active structures that could further lead to compounds with better repellent activity. Deployed War-Fighter Protection Research Program; United States Department of Defense through the Armed Forces Pest Management BoardUnited States Department of Defense [60-0208-4-001]; United States Department of Defense through the Armed Forces Pest Management Board [USDA] [58-0208-0-068, 58-0208-5-001] This work was supported by the Deployed War-Fighter Protection Research Program and funded by the United States Department of Defense through the Armed Forces Pest Management Board [Agreement 60-0208-4-001 and under USDA Specific Cooperative Agreements 58-0208-0-068 and 58-0208-5-001]. Public domain – authored by a U.S. government employee

Published
2018

30. Chemical composition and antioxidant, cytotoxic, and insecticidal potential of Valeriana alliariifolia in Turkey

Author

Sen-Utsukarci, Burcu, primary, Taskin, Turgut, additional, Goger, Fatih, additional, Tabanca, Nurhayat, additional, Estep, Alden S., additional, Kessler, Sonja M., additional, Akbal-Dagistan, Ozlem, additional, Bardakci, Hilal, additional, Kurkcuoglu, Mine, additional, Becnel, James, additional, Kiemer, Alexandra, additional, and Mat, Afife, additional

Published
2019
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33. Insecticidal and repellent properties of novel trifluoromethylphenyl amides II

Author

Entomology, Tsikolia, Maia, Bernier, Ulrich R., Agramonte, Natasha M., Estep, Alden S., Becnel, James J., Tabanca, Nurhayat, Linthicum, Kenneth J., Gross, Aaron D., Guerin, Patrick M., Krober, Thomas, Bloomquist, Jeffrey R., Entomology, Tsikolia, Maia, Bernier, Ulrich R., Agramonte, Natasha M., Estep, Alden S., Becnel, James J., Tabanca, Nurhayat, Linthicum, Kenneth J., Gross, Aaron D., Guerin, Patrick M., Krober, Thomas, and Bloomquist, Jeffrey R.

Abstract

This project focused on the design, synthesis, and testing of trifluoromethylphenyl amides (TFMPAs) as potential mosquitocides and repellents. Fourteen compounds were evaluated for toxicity against larvae and adults of Aedes aegypti. Several compounds were toxic against Aedes aegypti (larval, adult and feeding bioassays) and Drosophila melanogaster (glass-surface contact assay), but were much less toxic than fipronil, with toxicity ratios ranging from 100-fold in the larval assay to 100,000-fold for topical application to adult insects. In repellency bioassays to determine minimum effective dosage (MED), compound N-(2,6-dichloro-4(trifluoromethyl)phenyl)-2,2,3,3,3-pentafluoropropanamide (7b) repelled Ae. aegypti females at lower concentration, 0.017 (+/- 0.006) mu mol/cm(2), than N, N-diethyl-meta-toluamide (DEET) 0.026 (+/- 0.005) mu mol/cm(2). 2-Chloro-N-(3-(trifluoromethyl)phenyl)acetamide (6a) performed better than DEET against two species of mosquitoes: it repelled Ae. aegypti females at 0.013 (+/- 0.006) mu mol/cm(2) and Anopheles gambiae females (in a warm body repellent assay), at a standard exposure of 2 nmol/cm(2). These studies revealed novel active structures that could further lead to compounds with better repellent activity.

Published
2018

34. Reduction in Musca domestica fecundity by dsRNA-mediated gene knockdown

Author

Sanscrainte, Neil D., Arimoto, Hanayo, Waits, Christy M., Li, Lucy Y., Johnson, Dana, Geden, Chris, Becnel, James, Estep, Alden S., Sanscrainte, Neil D., Arimoto, Hanayo, Waits, Christy M., Li, Lucy Y., Johnson, Dana, Geden, Chris, Becnel, James, and Estep, Alden S.

Abstract

House flies (Musca domestica) are worldwide agricultural pests with estimated control costs at $375 million annually in the U.S. Non-target effects and widespread resistance challenge the efficacy of traditional chemical control. Double stranded RNA (dsRNA) has been suggested as a biopesticide for M. domestica but a phenotypic response due to the induction of the RNAi pathway has not been demonstrated in adults. In this study female house flies were injected with dsRNA targeting actin-5C or ribosomal protein (RP) transcripts RPL26 and RPS6. Ovaries showed highly reduced provisioning and clutch reductions of 94±99% in RP dsRNA treated flies but not in actin-5C or GFP treated flies. Gene expression levels were significantly and specifically reduced in dsRNA injected groups but remained unchanged in the control dsGFP treated group. Furthermore, injections with an Aedes aegypti conspecific dsRNA designed against RPS6 did not impact fecundity, demonstrating species specificity of the RNAi response. Analysis of M. domestica tissues following RPS6 dsRNA injection showed significant reduction of transcript levels in the head, thorax, and abdomen but increased expression in ovarian tissues. This study demonstrates that exogenous dsRNA is specifically effective and has potential efficacy as a highly specific biocontrol intervention in adult house flies. Further work is required to develop effective methods for delivery of dsRNA to adult flies.

Published
2018

36. Quantification of permethrin resistance and kdr alleles in Florida strains of Aedes aegypti (L.) and Aedes albopictus (Skuse)

Author

Estep, Alden S., primary, Sanscrainte, Neil D., additional, Waits, Christy M., additional, Bernard, Sarah J., additional, Lloyd, Aaron M., additional, Lucas, Keira J., additional, Buckner, Eva A., additional, Vaidyanathan, Rajeev, additional, Morreale, Rachel, additional, Conti, Lisa A., additional, and Becnel, James J., additional

Published
2018
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37. Insecticidal and repellent properties of novel trifluoromethylphenyl amides II

Author

Tsikolia, Maia, primary, Bernier, Ulrich R., additional, Agramonte, Natasha M., additional, Estep, Alden S., additional, Becnel, James J., additional, Tabanca, Nurhayat, additional, Linthicum, Kenneth J., additional, Gross, Aaron D., additional, Guerin, Patrick M., additional, Kröber, Thomas, additional, and Bloomquist, Jeffrey R., additional

Published
2018
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38. Quantification of permethrin resistance andkdralleles in Florida strains ofAedes aegypti(L.) andAedes albopictus(Skuse)

Author

Estep, Alden S., primary, Sanscrainte, Neil D., additional, Waits, Christy M., additional, Bernard, Sarah J., additional, Lloyd, Aaron M., additional, Lucas, Keira J., additional, Buckner, Eva A., additional, Vaidyanathan, Rajeev, additional, Morreale, Rachel, additional, Conti, Lisa A., additional, and Becnel, James J., additional

Published
2018
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41. Composition & biological activity of Cyperus rotundus L. tuber volatiles from Saudi Arabia

Author

Al-Massarani, Shaza, Al-Enzi, Fedha, Al-Tamimi, Maram, Al-Jomaiah, Nourah, Al-amri, Roaa, Başer, Kemal Hüsnü Can, Tabanca, Nurhayat, Estep, Alden S., Becnel, James J., Bloomquist, Jeffrey R., and Demirci, Betül

Abstract

The present study was conducted to investigate the composition of the oil of Cyperus rotundus L. rhizomes collected in Saudi Arabia, and to evaluate in vitro cytotoxic, antimicrobial and mosquito mortality activities of both the oil and the alcoholic extract of the aforementioned plant. Nineteen compounds were identified by GC-FID and GC-MS, of which α-cyperone (21.1%) and 4-oxo-α-ylangene (12.8%) were the major components. The essential oil recovered with diethyl ether demonstrated potent cytotoxic activities against colon (HCT-116), hepatocellular (Hep G-2) and breast (MCF-7) human cancer cell lines with IC50s of 1.06, 1.17 and 2.22 μg/mL, respectively. This oil also showed a comparable zone of inhibition against the gram positive bacteria Staphylococcus epidermidis and the gram negative bacteria, Klebsiella pneumoniae, Shigella flexneri and Salmonella enteritidis when compared to the standard drugs ampicillin and gentamycin. The ethanolic extract showed moderate activity against human cancer cells and pathogens. The essential oil was significantly more toxic to 1st instar Aedes aegypti larvae than the ethanol extract; however, the ethanol extract was more toxic to adult Ae. aegypti than the essential oil. Based on the results obtained, C. rotundus collected from Riyadh city could provide a potential and cheap source of biologically active compounds.

Published
2016

42. Nosema maddoxi sp. nov. (Microsporidia, Nosematidae), a Widespread Pathogen of the Green Stink Bug Chinavia hilaris (Say) and the Brown Marmorated Stink Bug Halyomorpha halys (Stål)

Author

Hajek, Ann E., primary, Solter, Leellen F., additional, Maddox, Joseph V., additional, Huang, Wei‐Fone, additional, Estep, Alden S., additional, Krawczyk, Grzegorz, additional, Weber, Donald C., additional, Hoelmer, Kim A., additional, Sanscrainte, Neil D., additional, and Becnel, James J., additional

Published
2017
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43. Synthesis and structure–activity relationships of carbohydrazides and 1,3,4‐oxadiazole derivatives bearing an imidazolidine moiety against the yellow fever and dengue vector, Aedes aegypti

Author

Tok, Fatih, primary, Kocyigit‐Kaymakcioglu, Bedia, additional, Tabanca, Nurhayat, additional, Estep, Alden S, additional, Gross, Aaron D, additional, Geldenhuys, Werner J, additional, Becnel, James J, additional, and Bloomquist, Jeffrey R, additional

Published
2017
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47. Cover Image, Volume 73, Issue 5

Author

Liu, Xing-Hai, primary, Wang, Qiao, additional, Sun, Zhao-Hui, additional, Wedge, David E, additional, Becnel, James J, additional, Estep, Alden S, additional, Tan, Cheng-Xia, additional, and Weng, Jian-Quan, additional

Published
2017
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