Insecticide resistance is an informative model for studying the appearance of adaptive traits. Simultaneously, understanding how many times resistance mutations originate is essential to design effective resistance management. In the mosquito Culex pipiens, target–site resistance to the insecticide diflubenzuron (DFB) has been recently found in Italian and Turkish populations. Three point mutations confer it at the codon 1043 of the chitin synthase 1 gene (chs-1): I1043L, I1043M, and I1043F. Whether the resistant mutations originated independently from different susceptible alleles or sequentially from resistant alleles and whether resistant alleles from Italy and Turkey have originated once or multiple times remain unresolved. Here, we sequenced a fragment of the chs-1 gene carrying the resistant mutations and inferred the phylogenetic relationships among susceptible and resistant alleles. Confirming previous findings, we found the three mutations in Italy and the I1043M in Turkey. Notably, the I1043F was also found for the first time in Turkish samples, highlighting the need for extensive monitoring activities. Phylogenetic analyses are consistent with an independent origin of the I1043F, I1043M, and I1043L mutations from different susceptible alleles and with multiple independent origins of the Italian and Turkish I1043M and I1043F alleles.
Several plant species and their compounds are well-known to have some pesticidal properties against a wide range of insect pests. Potential of two water plant extracts, Azadirachta indica A. Juss and Melia azedarach L., in comparison with the synthetic pyrethroid bifenthrin against sucking insect pests and their associated predators, as well on the yield in Bt cotton, was evaluated. The population of the sucking insect pests was found lowest in the positive control (only bifenthrin application). The A. indica extract reduced the pest population equivalent to the positive control, but the highest populations were observed in both negative controls (only water and 0.1% soap with water application). The M. azedarach did not show any harmful effect on the insect population. The predators' abundance was higher in the plots where botanicals were applied, while the lowest population was observed in the bifenthrin treatment. In comparison to the negative control (only water application), (63.4%) cotton yield was increased by the application of A. indica and (58.8%) by the application of the synthetic insecticide. Using plant extracts of A. indica to control sucking insect pests of cotton can be as effective as synthetic insecticides in terms of crop yield beside they are safer for natural enemies in the field.
The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important insect pest of the citrus crop worldwide. It vectors the pathogen ‘Candidatus Liberibacter asiaticus’ (CLas) that causes a serious disease known as citrus greening. Here, we tested the infection frequency of Wolbachia and CLas from 100 D. citri individuals collected from two host plants belonging to families Rutaceae (Citrus reticulata Blanco) and Boraginaceae (Cordia myxa L.) using molecular methods. The following trend of endosymbionts infection in adult D. citri was found; 85.4% (35/41) by Wolbachia, and 19.5% (8/41) by CLas collected from C. reticulata plants and 65.4% (17/26) by Wolbachia, and 15.4% (4/26) by CLas in case of C. myxa plant. However, 61.5% (8/13) nymphs collected from C. reticulata and 20.0% (4/20) collected from C. myxa plants were infected by Wolbachia, while no nymph was infected by CLas collected from either host plants. Findings from this work represent the first report of CLas presence in D. citri feeding on C. myxa plants. By studying the presence of CLas with other endosymbiotic bacteria, future basic and applied research to develop control strategies can be prioritized.
Isparta elma bahçelerinden toplanan
SummaryThe spider mites are the second pest group which is tried to be managed in apple orchards following codling moth. The chemical control is generally preferred against spider mites. However, chemical control may lead to resistance in pests in the long time. The resistance development may lead to increase the pesticide usage. Because the dose and spray frequency of pesticides for the management of resistant pest population has been increased mostly. This study was conducted to determine the resistance against abamectin, chlorpyrifos ethyl and bifenthrin in Panonychus ulmi Koch (Acari: Tetranychidae) populations from apple orchards in Isparta. The LC50 values were determined in mentioned populations. The resistance ratios were determined dividing the LC50 values of susceptible population to the LC50 values of orchard populations. According to LC50 value, the resistance ratios against abamectin, chlorpyrifos ethyl and bifenthrin of P. ulmi orchards populations are 0.75-2.25, 0.57-1.76 and 1.19-3.78 fold, respectively.
Key words: P. ulmi, apple, bifenthrin, abamectin, chlorpyrifos ethyl
ÖzetElma bahçelerinde elma içkurdundan sonra en fazla savaşım yapılan zararlılar arasında kırmızıörümcekler yer almaktadır. Kırmızıörümceklere karşı genellikle kimyasal mücadele tercih edilmektedir. Fakat, kimyasal mücadele zaman içerisinde zararlılarda direnç sorununa yol açabilmektedir. Zararlılarda direnç gelişimi, dirençli zararlıları kontrol altına almak için daha yüksek dozlarda ve daha sık uygulamalar yüzünden daha fazla kimyasal kullanımına neden olmaktadır. Bu çalışma, Isparta ilindeki elma bahçelerinden toplanan Panonychus ulmi Koch (Acari: Tetranychidae) popülasyonlarında abamectin, chlorpyrifos ethyl ve bifenthrin'e karşı direnç düzeylerinin belirlenmesi amacıyla yapılmıştır. Toplanan popülasyonlarda bu akarisitlere karşı LC50 değerleri belirlenmiştir. Direnç oranları, bahçe popülasyonları için belirlenen LC50 değerlerinin hassas popülasyonun LC50 değerine bölünmesiyle elde edilmiştir. LC50 değerleri dikkate alındığında, bahçelerden alınan P. ulmi popülasyonlarının abamectin, chlorpyrifos ethyl ve bifentrin'e karsı göstermiş olduğu direnç oranları sırasıyla 0.75-2.25, 0.57-1.76 ve 1.19-3.78 kat arasında değişmiştir.Anahtar sözcükler: P. ulmi, elma, bifenthrin, abamectin, chlorpyrifos ethyl.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.