Larvicidal and repellent effects of essential oils on the brown dog tick (Rhipicephalus sanguineus Sensu lato) with description of new larval repellent activity test method.

The aim of this research was to investigate the larvicidal and repellent effects of essential oils (EOs) obtained from two Lamiaceae plant species, Origanum minutiflorum O. Schwarz & P.H. Davis and Dorystoechas hastata Boiss. & Heldr. ex Bentham, both endemic to Turkey, on Rhipicephalus sanguineus s.l. Latreille (Acari: Ixodidae). The study also introduces a new test method that can be used to assess the repellent effects against ticks. Both plant EOs exhibited the highest larvicidal activity against brown dog tick larvae after 24 h and LC50 and LC90 values were determined as 0.101% and 0.125% for O. minutiflorum essential oil and 0.937% and 2.1% for D. hastata essential oil, respectively. In this study, we have described a detailed protocol for a novel larval repellent activity test (LRAT) for essential oils and extracts, using simple equipment. The advantages and limitations of LRAT, when compared to other tests commonly used to determine repellent effect against ticks, are also included in this study. The LRAT was developed with modifications of the larval immersion test (LIT) and proves to be a highly efficient and easily observable method. It can be used to test any active substance that may be toxic to humans and animals. According to the LRAT, at the end of 3 h, O. minutiflorum essential oil showed a high repellent effect, varying between 84.14% and 100% at 1% concentration. This result was not statistically different from the DEET, the positive control. When comparing the larvicidal and repellent activities, O. minutiflorum essential oil was found to be more effective than D. hastata essential oil.

Exploring the Larvicidal and Repellent Potential of Taurus Cedar (Cedrus libani) Tar against the Brown Dog Tick (Rhipicephalus sanguineus sensu lato).

This study investigated the potential acaricidal and repellent effects of tar obtained from the Lebanon cedar (Cedrus libani A. Rich.) against the brown dog tick species Rhipicephalus sanguineus sensu lato Latreille (Acari: Ixodidae). The goal was to find an alternative, safe, and effective way to eliminate ticks. Tar is traditionally extracted from cedar trees in the Antalya region of Türkiye. The composition of the tar is primarily characterized by a diverse mixture of terpenes, with ß-himachalene (29.16%), α-atlantone (28.7%), ar-turmerone (8.82%), longifolene-(V4) (6.66%), α-himachalene (5.28%), and ß-turmerone (5.12%) emerging as the predominant constituents. The toxic effects of tar on tick larvae were studied through larval immersion tests (LIT), and its repellent activity was evaluated using a new larval repellent activity test (LRAT). The results revealed significant acaricidal effects, with mortality rates of 77.7% and 82.2% for the Konyaalti and Kepez strains of the brown dog tick, respectively, in response to a 1% concentration of tar. LC50 and LC90 values were determined as 0.47% and 1.52% for the Kepez strain and 0.58% and 1.63% for the Konyaalti strain, respectively. When comparing the repellent effect of tar to the widely used synthetic repellent DEET, repellency rates of up to 100% were observed. As a result, this study establishes, for the first time, the larvicidal and repellent effects of C. libani tar on ticks.

Pathogenicity of an Entomopathogenic Nematode, Steinernema carpocapsae on Alphitobius diaperinus (Coleoptera: Tenebrionidae) Strains From Turkey.

Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae) is an insect pest in poultry production systems. This insect has developed resistance to many chemical insecticides. As an alternative to chemicals, entomopathogenic nematodes (EPNs) are one of the most commonly used agents against several pest arthropods. The pathogenicity of the EPN Steinernema carpocapsae Weiser on four field strains of lesser mealworm, A. diaperinus, from Turkey was studied. In the experiments, larvae of A. diaperinus were found to be more sensitive than adults to S. carpocapsae infection. In terms of LC50 values in both larval and adult insects, Balikesir strain was found to be the most susceptible, Manisa strain the most resistant. The calculated LC50 values for adults were 85.9, 205.6, 135.4, and 418.8 IJs/ml, and for larvae 31.2, 39.8, 34.8, and 70.9 IJs/ml for the Balikesir, Canakkale, Izmir, and Manisa strains, respectively. This is the first report about the pathogenicity of EPNs against larvae and adults of lesser mealworm A. diaperinus strains from Turkey. We conclude that S. carpocapsae can be used as a control agent for lesser mealworms.

Evaluation of Some Plant Fruit Extracts for the Control of West Nile Virus Vector Culex pipiens (Diptera: Culicidae).

BACKGROUND: The extracts of different parts of plants were found very effective against various pests. The aim of this research was to determine the insecticidal activity of fruit methanol extracts obtained from Melia azedarach (Meliaceae), Phoenix theophrasti (Arecaceae), Styphnolobium japonicum (Fabaceae) and Pyracantha coccinea (Rosaceae) against the larvae of Culex pipiens (Diptera: Culicidae). METHODS: The fruits of test plants were collected from the Campus of Akdeniz University, Antalya, Turkey in 2013. A series of concentrations of the extracts ranging from 62.5-1000 ppm were tested against second instar larvae. RESULTS: Only the extracts of Me. azedarach and Ph. theoprasti showed significant larvicidal activity against Cx. pipiens and the LC50 values of these extracts were found to be 169.48 and 220.60 ppm, respectively. This is the first research investigating the insecticidal or larvicidal activity of Ph. theophrasti, St. japonicum and Py. coccinea extracts on mosquitoes. CONCLUSION: The methanol extract of fruits of Me. azedarach and Ph. theophrasti showed significantly higher larvicidal activity against Cx. pipiens.

Tick species (Acari: Ixodida) in Antalya City, Turkey: species diversity and seasonal activity.

Ticks (Acari: Ixodida) are an important group of ectoparasites of vertebrates. Most species are known vectors of diseases including Lyme disease, Q fever, and Crimean-Congo hemorrhagic fever. A 3-year research was conducted in Antalya, Turkey, to determine tick species composition, seasonal abundance, and spatial distribution. The study was carried out in five districts (Aksu, Dosemealti, Kepez, Konyaalti, and Muratpasa) of Antalya Metropolitan Municipality area in Turkey, between May 2010 and May 2013, where 1393 tick specimens were collected from domestic and wild animals (cattle, goats, sheep, hedgehogs, tortoises, dogs, cats, chickens) and from the environment. The collected ticks were preserved in 70 % alcohol and then were identified. Five genus and eight hard and soft tick species were identified, including Argas persicus, Rhipicephalus annulatus, R. sanguineus, R. turanicus, Hyalomma aegyptium, H. marginatum, Haemaphysalis parva, and Dermacentor niveus. Rhipicephalus sanguineus, R. turanicus, and H. aegyptium were the most common tick species in Antalya city. Rhipicephalus turanicus and R. sanguineus were the most abundant tick species infesting dogs in the city. The hosts of H. aegyptium are primarily tortoises in Antalya. The results of this research will contribute to establishing appropriate measures to control tick infestations on animals and humans and their environment in the city of Antalya.

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.

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.

Acaricidal activity of the essential oils from three Lamiaceae plant species on Rhipicephalus turanicus Pom. (Acari: Ixodidae).

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.

Repellent activities of some Labiatae plant essential oils against the saltmarsh mosquito Ochlerotatus caspius (Pallas, 1771) (Diptera: Culicidae).

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.