James E. Cilek

Acaricidal activity of Satureja thymbra L. essential oil and its major components, carvacrol and γ-terpinene against adult Hyalomma marginatum (Acari: Ixodidae)

The acaricidal activity of a volatile essential oil hydrodistillate of Satureja thymbra L. (Lamiaceae) and its major constituents, carvacrol and gamma-terpinene, were evaluated against field-collected unfed adult Hyalomma marginatum. The distillate was tested against this tick species at 5, 10, 20, and 40 microL/L while the two major components were each tested at 10 microL/L. Generally, tick mortality to the S. thymbra distillate increased with concentration and exposure time. Ticks exposed to vapors from cotton wicks containing at least 40 microL/L resulted in complete (100%) mortality at 3h. The lower concentrations provided >or=90% mortality at 3h post treatment with complete mortality at 24h. Knockdown was observed only in the carvacrol and gamma-terpinene treatments. Ticks exposed to carvacrol-treated wicks produced >93% knockdown at 3h but at 24h approximately 57% were dead. The gamma-terpinene treatment produced >or=90% knockdown at 105 min through 3h but at 24h only about 87% of the ticks were dead.

Acaricidal effects of the essential oil of Origanum minutiflorum (Lamiaceae) against Rhipicephalus turanicus (Acari: Ixodidae)

The acaricidal effects of the volatile essential oil Origanum minutiflorum O. Schwarz & P.H. Davis (Lamiaceae) against adult Rhipicephalus turanicus was evaluated at a variety of concentrations and exposure times. Generally tick mortality increased with concentration and exposure. Ticks exposed to vapors from cotton wicks containing at least 10mul/L resulted in complete (100%) mortality at 120min. The major constituent of essential oil obtained from the plant material of O. minutiflorum was carvacrol.

Efficacy of diflubenzuron, a chitin synthesis inhibitor, against Culex pipiens larvae in septic tank water.

ABSTRACT The mosquito Culex pipiens L. is an important pest in urban and suburban areas in many parts of the world. Septic tanks are the most important habitats supporting the production of this species in the city of Antalya, southwestern Turkey. Diflubenzuron, in a 25% wettable powder (Du-dim® 25 WP), and a 4% granular formulation (Du-dim® 4 G) was evaluated against late 2nd to early 3rd instars of Cx. pipiens in single-family septic tanks. Both formulations were tested at 0.01, 0.02, and 0.03 mg (AI)/liter. The results indicated that both formulations applied at the rate of 0.02 and 0.03 mg (AI)/liter achieved 100% adult inhibition, at intervals of 7, 14, 21, and 28 days after treatment. Septic tanks treated with 0.01 mg (AI)/liter WP formulation resulted in complete (100%) adult inhibition through 14 days, whereas the G formulation gave the same effect through 21 days posttreatment at this rate.

Comparative efficacy of spinosad with conventional acaricides against hard and soft tick populations from Antalya, Turkey.

The acaricidal efficacy of ceramic tiles treated at field application rates with either spinosad (Mozkill 120 SC, 0.01 g ai/m(2)), deltamethrin (Impotek Deltamethrin EW, 0.01 g ai/m(2)), permethrin+esbiothrin (Chrysamed, 0.1 g ai/m(2)), chlorpyrifos-methyl (Chlortoks EC 50, 0.2 g ai/m(2)) or a mixture of alpha-cypermethrin/tetramethrin/piperonyl butoxide (Ecorex Alfa SE, 0.01 g ai/m(2)), against larval Rhipicephalus turanicus and Argas persicus ticks was determined in laboratory bioassays. All ticks were initially exposed to treated tiles for 15 min then removed to non-treated containers and mortality evaluated for 15 min, 1 h, 6 h, and 24 h postexposure. Generally, A. persicus proved to be the most susceptible of the two species to all treatments. The alpha-cypermethrin/tetramethrin/piperonyl butoxide mixture was the quickest acting acaricide against larval A. persicus where 100% mortality was observed 15 min postexposure. For the rest of the treatments complete mortality was obtained at 1 h except for permethrin/esbiothrin which occurred at 6 h postexposure. Complete mortality of larval R. turanicus occurred to deltamethrin and spinosad at 1 h postexposure with all acaricides providing 100% control at 6 h except permethrin/esbiothrin which only achieved 92% control through the end of the study (i.e. 24 h). Our results showed that spinosad would be a useful addition in a tick control program as an alternative for pyrethroids and organic phosphorus acaricides against both tick species.

Effects of Carbon Dioxide, an Octenol/Phenol Mixture, and Their Combination on Tabanidae (Diptera) Collections from French 2-Tier Box Traps

Abstract The French 2-tier box trap was evaluated in northwestern Florida to determine its attractiveness to host-seeking tabanids (Diptera) when baited with either CO2 alone; a 4:1:8 mixture of octenol, 3-n-propylphenol, and 4-methylphenol; or a combination of CO2 plus 4:1:8 mixture. Six genera representing 43 species were obtained from this trap. Chrysops and Tabanus made up 10.3 and 87.4% of the total, respectively, with Chrysops celatus Pechuman and Tabanus pallidescens Philip as the predominate species from these two genera. CO2 alone and in combination with the octenol/phenol mixture enhanced overall tabanid collections three- to four-fold compared with no odor. Generally, more species were collected in the top tier of the French 2-tier trap regardless of treatment. Those species that showed a significant difference between top and bottom tiers in traps without odors continued this trend when traps were baited with the semiochemicals. However, Tabanus mixis Philip showed no tier preference in traps baited by CO2 alone, whereas Tabanus lineola F. showed no stratification difference with or without odors.

Operational Evaluation Of Vectomax® WSP (Bacillus thuringiensis Subsp. israelensis + Bacillus sphaericus) Against Larval Culex pipiens in Septic Tanks1

Abstract The residual effectiveness of VectoMax® WSP (a water-soluble pouch formulation containing a combination of Bacillus thuringiensis subsp. israelensis strain AM65-52 and B. sphaericus strain ABTS 1743) when applied to septic tanks against 3rd- and 4th-stage larvae of Culex pipiens L. was evaluated in this study. This formulation was evaluated at operational application rates of 1 pouch (10 g) and 2 pouches (20 g) per septic tank. Both application rates resulted in >96% control of larvae for 24 days. Operationally, VectoMax WSP has proven to be a useful tool for the nonchemical control of Culex species in septic tank environments.

Evaluation of Temephos and Chlorpyrifos-Methyl Against Culex pipiens (Diptera: Culicidae) Larvae in Septic Tanks in Antalya, Turkey

Abstract The larvicidal activity of chlorpyrifos-methyl and temephos was evaluated against Culex pipiens L. (Diptera: Culicidae) in septic tanks in Antalya, Turkey. Chlorpyrifos-methyl (Pyrifos MT 25 emulsifiable concentrate [EC]) was evaluated at application rates of 0.04, 0.08, and 0.12 mg active ingredient (AI)/liter, and temephos (Temeguard 50 EC) was evaluated at 0.02, 0.04, and 0.06 mg (AI)/liter during a 21-d study. Generally, overall larval reduction in septic tanks from single- and multifamily dwellings treated with either larvicide was significantly greater than pretreatment levels and control tanks for the duration of the study. At 14 d posttreatment, duration of control was greatest in multifamily tanks treated with chlorpyrifos-methyl at the highest application rate with similar levels of control through 21 d for single-family dwellings (range 97–100%). Septic tanks from both types of family dwellings treated at the highest application rate of temephos resulted in >90% reduction through day 21 (range 91–100%). Laboratory bioassays of septic tank water treated at field application rates, without daily dilution, revealed that complete larval mortality was achieved for 21 d at each application rate and formulation. It is thought that daily addition of water and organic matter to the septic tanks in the single and multifamily dwellings influenced the duration of effectiveness of the larvicides.

Comparison of Mosquito Abundance From Biogents Sentinel 2.0 Traps With and Without Rain Covers1

Abstract Biogents Sentinel (BGS) traps have rapidly become a standard for adult Aedes aegypti surveillance. Several investigators have found that trap collections can be damaged easily by heavy dew or rain entering the trap intake port. In addition, water entering the trap may temporarily stop the fan, thus reducing the collection potential of the trap. We evaluated the effectiveness of a rain cover designed to minimize damage to mosquito trap collections from BGS 2.0 traps in a residential backyard in Jacksonville, FL. Rain covers consisted of white fiberglass 51-cm2 sheets positioned 19, 29, and 39 cm above the air intake of the traps. One BGS trap did not have a rain cover and was used as a control standard for comparison. All traps were baited with the BG-Lure. Generally, traps with rain covers resulted in higher mosquito counts when compared with collections from uncovered traps. Overall mosquito abundance was greater from traps with the rain cover positioned at 29 cm, but this difference was not significantly different when compared with the other cover heights. Covers spaced 29 or 39 cm collected significantly more Culex quinquefasciatus compared with traps at 19 cm and no cover. Species diversity was greatest for BGS traps with the rain cover positioned at 29 cm followed by 39 cm, 19 cm, and no cover; however, differences in diversity among the traps, with or without covers, were not significant.

Comparative Efficiency of Biogents Gravid Aedes Trap, Cdc Autocidal Gravid Ovitrap, and CDC Gravid Trap in Northeastern Florida1

Abstract We conducted a study to compare the effectiveness of the Biogents Gravid Aedes Trap (BG-GAT) and Centers for Disease Control and Prevention (CDC) Autocidal Gravid Ovitrap (AGO) with that of the CDC Gravid Trap (CDC-GT) (as a standard) for their proficiency to collect mosquitoes in an urban residential neighborhood in northeastern Florida. Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus were collected from each trap, with the latter species being predominant. Significantly more Cx. quinquefasciatus were collected from CDC-GT traps compared with the other 2 traps. Pairwise comparison of the efficiency of the CDC-GT revealed that this trap collected 6.7- to 21.5-fold more mosquitoes than the BG-GAT, depending on species. The BG-GAT collected overall more mosquitoes (3- to 6-fold) than the AGO, with the exception of Ae. aegypti, where both traps were nearly equal in effectiveness.

Application Efficacy of Vectobac WDG Against Larval Aedes aegypti Using Thermal Fog Technology

ABSTRACT The effectiveness of thermal fog application of Bacillus thuringiensis israelensis (Vectobac® WDG) against larval Aedes aegypti was evaluated in open and forest canopied environments in northeastern Florida, using a handheld IGEBA® TF34 thermal fogger (with water conversion kit). The product was applied at the maximum label rate of 1 kg/ha to linear transects, in each environment, containing empty 0.5-liter cups. After application, late-2nd to early-3rd instars of Ae. aegypti were added to each cup. Complete larval mortality occurred 48 h after treatment, 8 m away from the spray line in the open field while 63.4% larval mortality was achieved at this same distance in the forest canopy at 72 h posttreatment. Operational efficacy was then evaluated in an urban tropical environment in Key West, FL. In this study, empty plastic cups were placed in cryptic areas of a commercial lobster and crab trap yard. The 0.1-ha area was treated with Vectobac WDG at the maximum label rate using the same equipment. Aedes aegypti larval mortality from treated cups was >99% at 24 h posttreatment, whereas complete mortality was achieved at 48 h after application.