Emre Oz

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 activity of Origanum bilgeri P.H. Davis (Lamiaceae) essential oil and its major component, carvacrol against adults Rhipicephalus turanicus (Acari: Ixodidae)

The acaricidal activity of an essential oil obtained from aerial parts of Origanum bilgeri P.H. Davis (Lamiaceae), an endemic species in Turkey, and its major constituents, carvacrol was evaluated against unfed adults Rhipicephalus turanicus Pomerantzev (Acari: Ixodidae) collected from Kepez, Antalya. The composition of the essential oil was analyzed by GC/MS. The major compound identified in the oil was carvacrol (93.02%). Generally, tick mortalities to the O. bilgeri distillate and carvacrol increased with concentrations. O. bilgeri oil produced >83% mortality at 48h at a concentration of 0.8% and mortality was higher than 63% at a carvacrol concentration of 0.4%. Our results have shown that O. bilgeri essential oil and its major component, carvacrol, may have potential as acaricidal agents against R. turanicus.

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.

Larvicidal activity of the extract of seaweed, Caulerpa scalpelliformis, against Culex pipiens.

Abstract The larvicidal efficacy of the acetone extract of the thalli of Caulerpa scalpelliformis var. denticulata was determined against late 2nd to early 3rd instars of Culex pipiens at concentrations ranging from 100 to 2,000 parts per million (ppm). At 1,200 ppm, the extract caused >70% larval mortality at 24-, 48-, and 72-h exposure. The LC50 (lethal concentration) and LC90 values of C. scalpelliformis were 338.91 and 1,891.31 ppm, respectively. Our data showed that this species of seaweed contains components with larvicidal properties against mosquitoes.

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.

Chemical composition and larvicidal activity of essential oils from Nepeta cadmea Boiss. and Pimpinella anisum L. on the larvae of Culex pipiens L.

Culex pipiens L. (Diptera: Culicidae) is an important vector of West Nile virus in many parts of the world. In this research, the essential oils obtained from Nepeta cadmea Boiss. (endemic for Turkey) and Pimpinella anisum L. were examined for larvicidal activity against second-third instar larvae of Cx. pipiens. The essential oils were distilled from aerial parts of N. cadmea and seeds of P. anisum by water distillation. The chemical composition of these oils was determined by gas chromatography-mass spectrometry (GC-MS). The lethal concentration 50 and 90 values of these essential oils were 28.7 and 49.51 ppm, and 39.82 and 74.57 ppm, respectively. As a result, both essential oils were found highly toxic to larvae of Cx. pipiens. Our results showed that the essential oils obtained from N. cadmea and P. anisum may be suitable for the development of potential new botanical insecticides.

Larvicidal activity of Cyclamen (Myrsinaceae) extracts against the larvae of West Nile virus vector Culex pipiens L. (Diptera: Culicidae)

OBJECTIVE To evaluate the larvicidal activity of the tuber extracts isolated from two species of Cyclamen Cyclamen mirabile Hildebr. and Cyclamen alpinum Dammann ex. Sprenger) against Culex pipiens L. (Diptera: Culicidae). METHODS Twenty young (first-second) or older (third-fourth) instars of the Culex pipiens were exposed to various concentrations (100 to 1000 ppm) of the extracts. Mortality was recorded after 12-, 24-, 48-, 72- and 96-h of exposure. RESULTS We determined that the young larval stages were more susceptible to the extracts in comparison with the older larval stages. A comparison of LC 50 and LC 90 values has shown that Cyclamen mirabile was more active than Cyclamen alpinum. CONCLUSIONS This study is the first to report on the larvicidal activity of the extracts of Cyclamen species against Culex pipiens. More studies are needed to isolate and identify the active components involved, their mode of action, and effects on other mosquito and pest species.