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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.

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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.

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.

The repellent activities of the essential oils of two Thymus (Thymus sipyleus Boiss. subsp. sipyleus and Thymus revolutus Celak) and two Mentha (Mentha spicata L. subsp. spicata and Mentha longifolia L.) species against Ochlerotatus caspius (Pallas, 1771) (Diptera: Culicidae) are presented. The essential oils were obtained by hydrodistillation of the aerial parts of the plants in flowering period and repellency tests were done with a Y-tube olfactometer. All essential oils showed repellency in varying degrees and exhibited no significant time-dependent repellent activities. When all test oils compared for repellent activities there was no significant activity detected within 15 min exposure period. Mentha essential oils had better activity than Thymus essential oils, producing high repellency (73.8-84.2%) at 30th min on Oc. caspius. Mentha longifolia has the best mosquito repellent activity among the plants tested at the 25th min. Th. sipyleus subsp. sipyleus essential oil produced >85% repellent activity at the 15th min, but the effect decreased noticeably to 63.1% and 68% at 25th and 30th min, respectively.

Acaricidal effects of three Labiatae essential oils extracted from ariel parts of Thymus sipyleus Boiss. subsp. sipyleus, Mentha longifolia L., and Dorystoechas hastata Boiss. & Heldr. ex Bentham on 10-day-old Rhipicephalus turanicus Pom. (Acari: Ixodidae) larvae were evaluated by using the larval packet test bioassay. Serial dilutions of the three essential oils were tested from a starting concentration of 1-0.1% (1.0, 0.5, 0.25, and 0.1% w/v). Results showed that all essential oils had very similar activity, producing complete mortality (100%) in all tested concentrations on 10-day-old R. turanicus tick larvae.