Доклади на Българската академия на науките Comptes rendus de l’Acad´emie bulgare des Sciences
Tome 68, No 1, 2015
SCIENCES AGRAIRES
Culture des plantes
THE TOXICITY OF ESSENTIAL OILS OF SOME PLANT SPECIES AGAINST ADULTS OF COLORADO POTATO
BEETLE, LEPTINOTARSA DECEMLINEATA SAY (COLEOPTERA: CHRYSOMELIDAE)
Memis Kesdek, Saban Kordali∗, Ayse Usanmaz∗∗, Sezai Ercisli∗∗∗
(Submitted by Academician A. Atanassov on November 4, 2014)
Abstract
In the present study, the essential oils obtained from 14 plant species including 5 species of Achillea, 4 species of Origanum, 3 species of Artemisia and 2 species of Thymus were tested for their toxicity against adults of Colorado potato beetle (CPB), (Leptinotarsa decemlineata Say). The bioassays were performed in laboratory conditions. After exposure, mortality of the adults was determined at 24, 48, 72 and 96 h. The majority of tested essential oils were found to be toxic to the adults of CPB. The toxicity degrees were found to be variable ranging from 2.22 to 100% mortality. Essential oils obtained from Achillea wilhelmsii, Artemisia santonicum, Achillea biserrata, Origanum acutidens and Origanum vulgare subsp. hirtum were the most effective at the end of the first 24 h in the lowest dose applications. However, at the end of the 96th h, the most effective essential oils were obtained from Achillea millefolium, Achillea biebersteinii, Artemisia absinthium, Origanum onitesand Thymus sipyleus. The insecticidal effect was influenced by the doses of the essential oils and the exposure time.
Key words: essential oil, plants, Leptinotarsa decemlineata, insecticidal activity, toxicity
Introduction. In recent years, scientists have focused on increasing of food production due to the rapid expanding of world population. Unfortunately, crop loss is still keeping on due to plant diseases caused by insects, plant pathogen fungi, bacteria and viruses. The Colorado potato beetle (CPB), (Leptinotarsa
decemlineata Say) is the most destructive pest of potatoes, eggplants and some tomato species in the world [1]. Synthetic chemical insecticides and fumigants are commonly used in the pest control. However, there is a considerable problem in the use of these chemicals due to their residual toxicity in the post-harvest prod-ucts and occurrence of insecticide resistance [2]. Synthetic pesticides also cause environmental pollution owing to their slow biodegradation in the environment [3]. Hence, there is a need to develop natural and safe bio-pesticides. Thus, there is an increasing interest in research concerning the development of new alternative pesticides, such as toxic natural products including plant essential oils, extracts and secondary metabolites for pest control in agricultural production [4, 5]. The natural products are relatively less damaging to environment and mammalian health, as compared with synthetic chemicals [6].
CPB appeared in Europe in the 1920’s and since colonized the whole conti-nent except the British Isles and Scandinavia. Currently, it is also found in the Middle East and in Western Asia [7]. CPB is an economically important pest de-foliating potatoes and reducing drastically tuber yields. During the larval stage, while a larvae of CPB can ingest up to approximately 40 cm2 of foliage, an adult of CPB can consume an average of 10 cm2 of potato leaves per day. Despite their high fecundity (a mature female lays between 300 and 800 eggs), CPB has a short life cycle and under optimal conditions may complete two or three generations per season [8].
Essential oils are natural plant products that contain natural flavours and fragrances grouped as monoterpenes (hydrocarbons and oxygenated derivatives), sesquiterpenes (hydrocarbons and oxygenated derivatives) and aliphatic com-pounds (alkanes, alkenes, ketones, aldehydes, acids and alcohols) that provide characteristic odours. Many essential oils isolated from various plant species belonging to different genera contain relatively high amount of monoterpenes. Insecticidal properties of numerous essential oils and some monoterpenes have been extensively studied against various insects [5, 9].
Actually, CPB is still a destructive pest of potatoes, eggplants and some tomatoes species and causes an important loss in the yield of crop. The toxicities of several sesquiterpenes against CPB have been recently reported [10]. However, no report has been found on the toxicity of plant essential oils. Therefore, the aim of the present study is to assess the toxicity of 14 essential oils and izoldesis, an insect control agent against adults of CPB.
Materials and methods. Biological material. The adults of CPB were collected from potato fields in eastern Anatolia (Erzurum) and reared in labora-tory at 25±1◦C, 64±5 relative humidity in the Department of Plant Protection at Ataturk University. The adults obtained from laboratory cultures were stored in separate insect cages including appropriate potato leaves. Tests were also carried out under the same conditions and in the same laboratory.
Achil-lea wilhelmsii, AchilAchil-lea millefolium, AchilAchil-lea biebersteinii, AchilAchil-lea biserrata, Artemisia absinthium, Artemisia santonicum, Artemisia spicigera, Origanum onites, Origanum acutidens, Origanum syriacum, Origanum vulgare subsp. hir-tum, Thymus sipyleus and Thymus fallax were collected from different localities of Turkey. Voucher specimens have been deposited in the herbarium of Ataturk University, Faculty of Agriculture, the Department of Plant Protection, Erzurum, Turkey. Aerial parts of the plants were dried in shade and ground in a grinder. The dried plant samples (500 g) were subjected to hydrodistillation for 4 h using a Clevenger-type apparatus. The oil yields of Achillea gypsicola, A. wilhelmsii, A. millefolium, A. biebersteinii, A. biserrata, Artemisia absinthium, A. santonicum, A. spicigera, Origanum onites, O. acutidens, O. syriacum, O. vulgaresubsp. hir-tum, Thymus sipyleus and T. fallax were 0.65, 0.85, 0.90, 0.63, 0.78, 0.15, 0.30, 0.25, 3.67, 0.60, 4.0, 2.2, 0.98 and 1.95% (w/w, dry weight basis), respectively. The oils were dried over anhydrous Na2SO4 and stored under N2 in a sealed vial until required, and then stored at 4◦C until used for toxicity bioassays.
Bioassays using essential oils. Glass Petri dishes (9 cm wide × 1.5 cm deep, corresponding to 120 ml volume) were used as exposure chambers to test the toxicity of essential oils of 14 plants against adults of CPB. To determine the contact toxicity effects of the oils they were dissolved in DMSO–water solution (10%, v/v). The final concentration of the treatments was 10, 15 and 20 µl/ml. A filter paper was placed in bottom of each of the Petri dishes (9 cm × 1.5 cm deep) and 15 adults of CPB were placed on this filter paper, containing the appropriate amounts of potato leaves. Thus, there was direct contact between the oils and the adults. The emulsions were sprayed to Petri dishes (9 cm diameter) and two layers of filter paper were placed in the bottom (1 ml/Petri dish). Afterwards, 15 adults were placed on the filter paper. 10, 15 and 20 microliters of the essential oils were sprayed to adults of CPB by using spray equipment. The Petri dishes were covered with a lid and transferred into incubator, and then kept under standard conditions of 25±1◦C, 64±5 relative humidity and 16:8 (light: dark) photoperiod for 4 days. The treatments were arranged in a completely randomized design with three replications including controls. ˙Izoldesis 2.5 EC (Deltametrin) (10, 15 and 20 µl/petri plates) was used as positive control in the same above mentioned conditions. After exposure, the mortality of the adults was counted at 24, 48, 72 and 96 h. Sterile water and DMSO were used as a control in the same way. Each experiment was replicated for three times at each dose.
Data analysis. The results of mean mortality were subjected to one-way variance analyses (ANOVA), using SPSS 10.0 software package. Differences be-tween means were tested through Duncan and values of p < 0.05, 0.01 and 0.001 were considered significantly different.
Results and discussion. The toxicities of fourteen oils obtained from Achillea gypsicola, A. wilhelmsii, A. millefolium, A. biebersteinii, A. biserrata, Artemisia absinthium, A. santonicum, A. spicigera, Origanum onites, O.
acu-T a b l e 1
The toxicity of essential oils obtained from 14 different plants against adults of Leptinotarsa decemlineata (Say)
Treatment Dose Mortality (%)
Essential oils (µl/Petri) Exposure time(h)
24 48 72 96
A. gypsicola 10 0.0 ± 0.0a 15.5 ± 2.22cd 26.6 ± 3.84de 37.7 ± 4.44gh 15 4.44 ± 2.22abc 15.5 ± 5.87cd 53.3 ± 6.66f 66.6 ± 3.84ı 20 11.1 ± 5.87bcd 17.7 ± 5.87d 64.4 ± 2.22g 75.5 ± 4.44j 10 0.0 ± 0.0a 0.0 ± 0.0a 0.0 ± 0.0a 8.89 ± 2.22a A. wilhelmsii 15 2.22 ± 2.22ab 2.22 ± 2.22ab 2.22 ± 2.22a 11.1 ± 2.22ab
20 8.89 ± 4.44abcd 11.1 ± 2.2bcd 20.0 ± 3.84bc 28.8 ± 4.44ef 10 48.8 ± 2.22g 73.3 ± 3.84gh 93.3 ± 3.84hij 100 ± 0.0l A.millefolium 15 86.6 ± 3.84klm 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l 20 91.1 ± 3.84lmn 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l 10 75.5 ± 8.01ij 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l A.biebersteinii 15 95.5 ± 4.44mn 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l 20 100 ± 0.0n 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l 10 71.1 ± 9.68ı 93.3 ± 3.84kl 100 ± 0.0j 100 ± 0.0l A. absinthium 15 77.7 ± 2.22ıjk 97.7 ± 2.22kl 95.5 ± 4.44ij 100 ± 0.0l 20 88.8 ± 2.22lm 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l 10 0.0 ± 0.0a 2.22 ± 2.22ab 8.89 ± 5.87ab 17.7 ± 4.44bc A.biserrata 15 0.0 ± 0.0a 4.44 ± 4.44ab 13.3 ± 0.0bc 20.0 ± 0.0cd
20 2.22 ± 2.22ab 6.67 ± 3.8abc 22.2 ± 2.2cde 31.1 ± 2.22efg 10 0.0 ± 0.0a 0.0 ± 0.0a 6.67 ± 3.84ab 20.0 ± 3.84cd A. santanicum 15 0.0 ± 0.0a 0.0 ± 0.0a 6.67 ± 3.84ab 26.6 ± 3.84d
20 40.0 ± 3.84f 68.8 ± 2.22g 88.8 ± 8.01hı 100 ± 0.0l 10 0.0 ± 0.0a 11.1 ± 3.84bcd 31.1 ± 4.44e 35.5 ± 2.22fgh A. spicigera 15 15.5 ± 5.87d 11.1 ± 2.22bcd 22.2 ± 4.44cde 37.7 ± 2.22gh 20 4.44 ± 2.22abc 20.0 ± 3.84d 20.0 ± 0.0cd 42.2 ± 2.22h 10 57.7 ± 2.22h 93.3 ± 6.66ab 100 ± 0.0j 100 ± 0.0l O. onites 15 62.2 ± 2.22h 95.5 ± 4.44ab 100 ± 0.0j 100 ± 0.0l 20 86.6 ± 7.69klm 97.7 ± 2.22kl 100 ± 0.0j 100 ± 0.0l 10 0.0 ± 0.0a 0.0 ± 0.0a 2.22 ± 2.22a 4.44 ± 4.44a O.acutidens 15 0.0 ± 0.0a 6.67 ± 3.8abc 31.1 ± 4.44e 80.0 ± 3.84jk
20 6.67 ± 3.84abcd 37.7 ± 2.22e 64.4 ± 2.22g 84.4 ± 8.01k 10 73.3 ± 3.84ı 80.0 ± 7.69hı 88.8 ± 5.87hı 95.5 ± 2.22l O. syriacum 15 73.3 ± 6.66ı 82.2 ± 5.87ij 91.1 ± 4.44hij 97.7 ± 2.22k
20 84.4 ± 8.88jkl 88.8 ± 4.44jk 95.5 ± 4.44ij 97.7 ± 2.22l O. vulgare 10 0.0 ± 0.0a 0.0 ± 0.0a 8.89 ± 2.22ab 17.7 ± 2.22bc subsp. hirtum 15 13.3 ± 3.84cd 20.0 ± 3.84d 28.8 ± 4.44de 42.2 ± 4.44h
20 33.3 ± 3.84ef 37.7 ± 2.22e 66.6 ± 0.0g 95.5 ± 4.44l 10 75.5 ± 4.44ij 84.4 ± 2.22ij 95.5 ± 2.22ij 100 ± 0.0l T. sipyleus 15 93.3 ± 3.84lmn 97.7 ± 2.22kl 100 ± 0.0j 100 ± 0.0l 20 95.5 ± 2.22mn 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l
T a b l e 1 Continuation
Treatment Dose Mortality (%)
Essential oils (µl/Petri) Exposure time(h)
10 11.1 ± 2.22bcd 37.7 ± 5.87e 60.0 ± 3.84fg 93.3 ± 3.84l T.fallax 15 26.6 ± 3.84e 46.6 ± 3.84f 64.4 ± 2.22g 93.3 ± 3.84l 20 28.8 ± 2.22e 68.8 ± 2.22g 84.4 ± 8.01h 95.5 ± 2.22l Positive control 10 77.7 ± 2.22ıjk 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l (izoldesis) 15 88.8 ± 2.22lm 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l 20 95.5 ± 2.22mn 100 ± 0.0l 100 ± 0.0j 100 ± 0.0l Control – 0.0 ± 0.0a 2.22 ± 1.83a 2.22 ± 1.83a 4.44 ± 1.83a Values followed by different letters in the same column differ significantly at P ≤ 0.05 according to Duncan Multiple test.
a Mean±SE of three replicates, each set up with 15 adults.
tidens, O. syriacum, O. vulgare subsp. hirtum, Thymus sipyleus and T. fallax were determined against adults of CPB. These essential oils in the 10, 15 and 20 µl doses in the petri dishes were applied for toxicity tests and their toxicities were compared with toxicity of Izoldesis, a commercial insecticide in the 10, 15 and 20 µl doses in petri dishes (Table 1). Results show that the essential oils exhibited various toxicities against the adults depending on exposure time and the essential oil doses. In general, the mortality increased with increasing doses of the essential oils and exposure times.
Among the tested fourteen plant essential oils, the highest toxicity (100%) for the adults of CPB was shown by A. biebersteinii in the 20 µl dose and at all exposure times (24, 48, 72 and 96 h). Furthermore, the essential oils of A. millefolium, A. biebersteinii and O. onites showed the most toxic effect (100%) in all doses (10, 15 and 20 µl) after 72 and 96 h against the adults of CPB. However, the least mortality (2.22%) for the adults of CPB after 24 h was shown by A. wilhelmsii and A. biserrata oils in the 15 and 20 µl doses, respectively (Table 1). There was no mortality in the 10 µl dose after 24 h for the essential oils of A. gypsicola, A. wilhelmsii, A. santonicum, A. biserrata, A. spicigera, O. acutidens and O. vulgare subsp. hirtum, against the adults of CPB. However, the highest mortality rate after 24 h of treatment with the minimum dose (10 µl) of A. biebersteinii and T. sipyleus oils were determined as 75.50% for the adults of CPB (Table 1). Separately, the highest mortality rates after 24 h of treatment with the 15 µl dose of A. biebersteinii and T. sipyleus oils were determined as 95.50 and 93.30%, respectively. There was no mortality treatment with 15 µl dose after 24 h of essential oil treatment of A. santonicum, A. biserrata and O. acutidens against adults of CPB. Controls did not show any mortality (Table 1).
Although the highest mortality rate (100%) after 48 h of treatment with the minimum dose (10 µl) of A. bibersteinii oil was determined against adults of CPB, there was no mortality for essential oils of O. acutidens, O. vulgare subsp. hirtum, A. wilhelmsii and A. santonicum in the same exposure time and dose. Also, there was no mortality for treatment with 15 µl dose in the 48 h of essential oil of A. santonicum. Furtheremore, the highest mortality rate (100%) occured for treatment after 48 h with 15 µl dose of essential oils of A. biebersteinii and A. millefolium (Table 1). The lowest mortality rate (2.22%) was observed after 48 h the 15 µl dose of A. wilhelmsii and A. biserrata oils. In addition, the lowest mortality rates after 48 h of treatment with the 20 µl dose of essential oils of A. biserrata and A. wilhelmsii (6.67; 11.1%, respectively) were determined but the highest mortality rate was found as 100% for the adults of CPB using 20 µl of essential oils of T. sipyleus, A. absinthium, A. biebersteinii and A. millefolium (Table 1). There was no mortality after 72 h treatment with the 10 µl dose of A. wilhelmsii oil. Also, the lowest mortality rates were determined after 72 h of treatment with the 10 µl dose of essential oils of O. acutidens and A. santonicum (2.22, 6.67%, respectively). The highest mortality (100%) after 72 h in the 10 µl dose was found for the essential oils of A. biebersteinii, A. absinthium and O. onites (Table 1).
The mortality was obtained after 72 h of treatment with the 15 µl of the essential oils of all plants for adults of CPB. The highest mortality rate (100%) occured with essential oils of A. millefolium, A. biebersteinii, O. onites and T. sipyleus after 72 h in the 15 µl against adults of CPB, whereas in the same time and dose the essential oils of A. wilhelmsii and A. santonicum occurred the lowest (2.22, 6.67%, respectively). On the other hand, the mortality was shown after 96 h treatment with all doses for essential oils of all plants tested against adults of CPB. The least mortality rates were found for essential oils of O. acutidens (4.44%, 10 µl) and A. wilhelmsii (8.89%, 10 µl). However, the mortality rates increased with increasing doses and exposure times of essential oils of all the plants on adults of CPB (Table 1).
Furthermore, according to LD values, the highest toxicity to adults of CPB was established for the essential oils of T. fallax as 0.000 (LD25, LD50) and A. spicigera (LD90), while the essential oils of A. spicigera (LD25) and O. syriacum (LD25) had the lowest toxicity as 8715.716 and 3999.000, respectively. However, the least toxicity effect in the LD50value was found by the essential oil of O. syriacum as 917.278 against adults of CPB. Also, the least toxicity effect in the LD90value was determined using the essential oil of A. biserrata as 396.648 (Table 2).
Comparisons between all the essential oils showed that the highest insecti-cidal effect had essential oils of A. millefolium, A. biebersteinii, A. absinthium, O. onites, O. syriacum and T. sipyleus with 48.80% as minimum and 100% as maximum of mortality rates against adults of CPB. Whereas, essential oils of A.
T a b l e 2
The LD values of essential oils obtained from 14 plants against adults of Leptinotarsa de-cemlineata (Say) Treatments LD25 LD50 LD90 X 2 Slope ± SE A. gypsicola 28.142 17.497 7.093 4.190 3.268 ± 0.931 A. wilhemsii 19.599 34.665 102.441 3.216 2.723 ± 1.131 A. millefolium 2.283 3.244 6.322 3.178 4.422 ± 5.822 A. biebersteinii 186.243 103.888 34.268 5.705 2.661 ± 5.365 A. biserrata 16.346 49.090 396.648 1.938 1.412 ± 0.984 A. absinthium 119.412 79.358 36.510 4.536 3.801 ± 6.132 A. santanicum 11.879 14.515 21.242 27.591 7.749 ± 1.132 A. spicigera 8715.716 0.109 0.000 0.978 0.138 ± 0.889 O. onites 119.412 79.358 36.510 4.536 3.801 ± 6.132 O. acutidens 77.281 19.959 1.524 76.352 1.147 ± 0.897 O. syriacum 3999.000 917.278 55.915 5.193 1.055 ± 1.820
O. vulgare subsp. hirtum 11.564 14.138 20.712 11.131 7.728 ± 1.127 T. sipyleus 3381.893 867.464 65.389 10.853 1.141 ± 1.985
T. fallax 0.000 0.000 0.001 5.843 0.069 ± 1.381
wilhelmsii and A. biserrara gave the lowest mortality (Table 1).
Some of the previous studies showed that O. acutidens oil had a toxic ef-fect against Sitophilus granarius and Tribolium confusum adults (68.3 and 36.7% mortality, respectively) [11]. In this study, we have found that essential oil of O. acutidens has an insecticidal effect (after 72 h in the 10 µl min. 2.22%, and 96 h in the 20 µl max. 84.40% mortality) on adults of CPB, while there is no mortality after 24 h in the 10 and 15 µl doses (Table 1).
In our present study, it was found that the essential oil obtained from O. onites had a toxic effect between 57.70% and 100% for adults of CPB (Table 1). The essential oil from O. onites (oregano) had a toxic effect on Taumetopoea pityocampa and three stored-product insects, Acanthoscelides obtectus, Plodia in-terpunctella and Ephestia kuehniella adults [12, 13]. It was stated that the essen-tial oil from O. syriacum had a nematicidal effect on the root-knot nematode, Meloidogyne javanica [14]. In the present study, we found that the essential oil from O. syriacum had an insecticidal effect between 73.33 and 97.70% (after 24 h in the 10 µl dose and 96 h in the 20 µl, respectively) for adults of CPB (Table 1). It was stated that the essential oil from O. hirtum and some of its main constituents, carvacrol and thymol had impact on insecticidal and genotoxic activities on Drosophila [15]. In this study, the essential oil of O. hirtum has the highest mortality rate (95.50%) after 96 h in the 20 µl dose, while there is no mortality after 24 and 48 h in the 10 µl dose against adults of CPB (Table 1).
plants against CPB was related to their main components, which were β-pinene, γ-terpinene, 3-carene, myrcene, fenchone, linalool, terpinen-4-ol, borneol, fenchol, geranyl acetate, menthol and nerol acetate, and the main components were found to be toxic to the larvae and the adults, with variable degree of toxicity ranging from 20 to 100% mortality [16]. In our study, A. gypsicola oil contained camphor, 1,8-cineole, piperitone, borneol and α-terpineol as major components and it was determined that the essential oil of A. gypsicola had a toxic effect between 4.44 and 75.50% against adults of CPB (Table 1).
In this study, the mortality rates were established 2.22% as minimum after 24, 48, 72 h in the 10 µl and 28.8% as maximum after 96 h in the 20 µl for adults of CPB (Table 1).
The essential oil of A. millefolium had a low toxicity, but a strong repellency and reduced the emergence of offspring [17]. In addition, the mortality rate of A. millefolium oil at 250 ppm dose was shown as 63.3% against the larvae of the Culicidae mosquito and Aedes albopictus [18]. In the present study, it was found that A. millefolium oil had a toxic effect between 48,8% and 100% for adults of CPB (Table 1). The A. biebersteinii oil and its major components have a larvacidal effect on Aedes aegypti first instar larvae [19]. In this study, we determined that A. biebersteinii oil had an important insecticidal effect with 100% mortality rate for all doses and exposure times against adults of CPB (except after 24 h in the 10 µl 75.50%, and in the 15 µl 95.50%) (Table 1).
The present results showed that the highest mortality rate (31.10%) of A. biserrata oil was obtained after 96 h in the 20 µl for adults of CPB, whereas the lowest effect (2.22%) was noted after 24 h in the 20 µl (Table 1). In this study, we determined that A. absinthium oil had an insecticidal effect with a minimum 71.10% and a maximum 100% mortality rates on adults of CPB (Table 1).
There are several studies using A. santonicum oil for some bacteria species, while there is only one study for insects. It was fixed that A. santonicum oil had a toxic effect (85%) against the large diamondback moth, Plutella xylostella [20]. We found that this oil had an insecticidal effect (between 6.67 and 100% mortality rates) for adults of CPB (Table 1). In the present study, the essential oil of A. spicigera has a toxic effect between 4.44 and 42.20% with mortality rates in all exposure times and treatment with all doses for adults of CPB (Table 1). Yildirimet al. [21] noted that T. sipyleus oil had an insecticidal effect against adults of S. granarius. In this study, it was determined that T. sipyleus oil had a toxic effect between 75.50 and 100% mortality ratio in all exposure times and treatment with all doses against adults of CPB (Table 1). The mortality rate of T. fallax oil was found after 96 h of treatment with the 20 µl dose as 88.88% for S. granarius [21]. In the present study, it was determined that the mortality rates of T. fallax oil after 24 h in the 10 µl and 96 h in the 20 µl was between 11.10 and 95.50% for adults of CPB, respectively (Table 1).
estab-lished after 24 h in the 10, 15 and 20 µl doses as 77.70, 88.88 and 95.50% for adults of CPB, respectively. Furthermore, the mortality rates after 48, 72 and 96 h of treatment with all doses (10, 15 and 20 µl) of izoldesis were found as 100% for adults of CPB. There was no mortality (except 2.22% 48 h, 72 h; and 4.44% 96 h) in sterile water used as control for adults of CPB (Table 1).
Conclusions. In conclusion, the development of natural or biological in-secticides will help to decrease the negative effects of synthetic chemicals such as residues in products, insect resistance and environmental pollution. In this respect, natural insecticides may also be effective, selective, easily bio-degradable and relatively low polluting for environment. In the present study, the essential oils obtained from A. millefolium, A. biebersteinii, A. absinthium, O. onites, O. syriacum and T. sipyleus were found to be more toxic against adults of CPB, but the essential oils of A. wilhelmsii and A. biserrara were less effective. In many cases, their toxicities were also identical with the toxicity of widely used commercial insecticdes, to protect potatoes against CPB. Therefore, in the light of the present results, it can be suggested that these plant essential oils can be used as new insecticidal reagents against adults of CPB. However, further studies need to be conducted to evaluate the cost and safety of these reagents.
REFERENCES
[1] Puttler B., Sh. Long (1983) Proc. Entomol. Soc. Washington, 85, 383–387. [2] Gelman D. B. R. A. Bell, L. C. Liska, J. S. Hu (2001) J. Insect. Sci, 1, 1–11. [3] Barnard C., M. Padgitt, N. D. Uri (1997) Int. Pest Control, 39, 161–164. [4] Ercan F., H. Bas, M. Koc, D. Pandir, S. Oztemiz (2013) Turk. J. Agric. For.,
37, 719–723.
[5] Bashir M. H., M. D. Gogi, M. Ashfaq, D. M. Afzal, M. A. Khan, M. Ihsan (2013) Turk. J. Agric. For., 37, 585–594.
[6] Misra G., S. G. Pavlostath.
is(1997) Appl. Microbiol. Biotechnol., 47, 572–577. [7] Weber E. J. (2003) “The Misuse of Central Bank Gold Holdings”. In: Moon Joong
Tcha (ed.) Gold and the Modern World Economy, London. Routledge, 64–80. [8] Harcourt D. G. (1971) Can. Entomol., 103, 1049–1061.
[9] Lee S., C. J. Peterson, J. R. Coats (2003) J. Stored Prod. Res., 39, 77–85. [10] Gonzalez-Coloma A., F. Valenc.
ia, N. Mart.
in, J. J. Hoffman, L. Hutter, J. A. Marco, M. Re.
ina(2002) J. Chem. Ecol., 28, 117–129.
[11] Kordali S., A. Cakir, H. Ozer, R. Cakmakci, M. Kesdek, E. Mete (2008) Bioresour. Technol., 99, 8788–8795.
[12] Cetin H., F. Erler, A. Yanikoglu (2006) Folia Biol., 54, 153–157.
[13] Ayvaz A., O. Sagdic, S. Karaborklu, I. Ozturk (2010) J. Insect. Sci., 10, 1–13.
[14] Oka Y., S. Nacar, E. Putievsky, U. Ravid, Z. Yaniv, Y. Spiegel (2000) Phytopathology, 90, 710–715.
[15] Karpouhtsis I., E. Pardali, E. Feggou, S. Kokkini, Z. G. Scouras, P. M. Tsipidou(1998) J. Agric. Food Chem., 46, 1111–1115.
[16] Kordali S., M. Kesdek, A. Cakir (2007) Ind. Crop Prod., 26, 278–297. [17] Jovanovic Z., M. Kostic, Z. Popvic (2007) Ind. Crop Prod., 26, 100–104. [18] Conti B., A. Canale, A. Bertoli, F. Gozzini, L. Pistelli (2010) Parasitol.
Res., 107, 1455–1461.
[19] Tabanca N., B. Demirci, I. Gurbuz, F. Demirci, J. J. Becnel, D. Wedge, E. Baser, H. Kemal(2011) Nat. Prod. Commun., 6, 701–706.
[20] Erturk O., O. Kara, E. Sezer, G. San (2004) Ekoloji, 13, 18–22.
[21] Yildirim E., S. Kordali, G. Yazici (2011) Rom. Biotech. Lett.,16, 6702–6709.
Department of Environment Protection and Technologies
Fethiye Ali SıtkıMefharet Kocman Vocational School Mugla SıtkıKocman University
48300 Fethiye, Mugla, Turkey e-mail: memiskesdek@mu.edu.tr
∗Department of Plant Protection
Agriculture Faculty Ataturk University 25240 Erzurum, Turkey e-mail: skordali69@gmail.com
∗∗Department of Plant Protection
Agriculture Faculty Igdir University 76100 Igdir, Turkey e-mail: ayseusanmaz@hotmail.com ∗∗∗Department of Horticulture Agriculture Faculty Ataturk University 25240 Erzurum, Turkey e-mail: sercisli@gmail.com
