Acetylcholinesterase (AChE), encoded by the Ace gene, is the primary target of organophosphates (OPs) and carbamates (CBs) in insects. Ace mutations have been identified in OP and CB resistant strains of Musca domestica. In this study, the Ace gene was partially amplified and sequenced at amino acid positions 260, 342, and 407 to determine the frequencies of these mutations in housefly samples collected from farms and garbage disposal sites of 16 provinces in the Aegean and Mediterranean regions of Turkey. In addition, the percent remaining AChE activities in these samples were assayed by using three OPs (malaoxon, paraoxon, and dichlorvos) and one CB (carbaryl) compound as inhibitors. In all the analyzed samples, 13 different combinations at the three amino acid positions were identified and the L/V260-A/G342-F/ Y407 combination was found in the highest frequency. No susceptible individual was detected. The highest mean percent remaining AChE activities were detected in the individuals having the L260-A/G342-F/Y407 genotype when malaoxon and paraoxon were used as inhibitors and in the individuals with the L260-A342-F/Y407 combination when dichlorvos and carbaryl were used as inhibitors. The obtained data were heterogeneous and there was no exact correlation between the molecular genetic background and the resistance phenotypes of the flies. The findings of this study at the molecular and biochemical levels indicate the presence of significant control problems in the field. Journal of Vector Ecology 36 (2): 248-257. 2011.

House flies were collected from 16 different provinces in the Aegean and Mediterranean regions of Turkey, and the frequencies of pyrethroid resistance-associated mutations in Vssc1 and CYP6D1 in these field-collected populations were studied. Although there is no organized resistance management program for house fly control in Turkey, it is known that different groups of insecticides, including pyrethroids, are used. The frequencies of both Vssc1 and CYP6D1 alleles were weighted toward the susceptibles, with Vssc1-susceptible alleles having higher frequencies in both regions (0.75 in Aegean and 0.69 in Mediterranean populations) than CYP6D1-susceptible alleles (0.65 in Aegean and 0.56 in Mediterranean populations). The frequencies of kdr-his alleles were higher than the frequencies of kdr alleles in these populations. While the frequencies of kdr-his alleles were close to each other in the Aegean (0.23) and Mediterranean (0.17) populations, the frequencies of kdr alleles remarkably differed in these two regions, with values of 0.02 and 0.14, respectively. In contrast to Europe, Asia, and the U.S.A., no super-kdr allele was detected in the samples from both regions. We identified six and eight different Vssc1 + CYP6D1 genotype classes in the Aegean and Mediterranean regions, respectively. The three most common genotype classes in the regions were susceptible Vssc1 with heterozygous CYP6D1v1 (29%), sus/kdr-his1 with heterozygous CYP6D1v1 (23%), and susceptible Vssc1 with CYP6D1 (22%). The total frequencies of these three most common genotype classes (approximately 75%) obtained in our study were very close to the value obtained in Florida in a previous study, which was related by the similarity of temperature patterns between Florida and the corresponding regions of Turkey. This may reflect the lack of overwintering fitness cost associated with resistance alleles in both climates. Journal of Vector Ecology 36 (2): 239-247. 2011.

In the present study, the frequencies of three organophosphate (OP) resistance-associated mutations in acetylcholinesterase gene of Bactrocera oleae (BoAce) populations collected from 8 different important olivegrowing areas in the west part of Turkey were determined. Populations were sampled from the areas that have been treated with only the pyrethroid α-cypermethrin; pyrethroids plus OPs; deltamethrin with pheromone eco-traps, and no insecticide treatment applied areas for many years. For Ile214Val and Gly488Ser point mutations PCR-RFLP and for Δ3Q deletion mutation PCR diagnostic tests were carried out. Seventy-two percent of the total individuals analyzed in the study were exhibited heterozygous genotype (RS) for both Ile214Val and Gly488Ser point and homozygous susceptible genotype (SS) for Δ3Q deletion mutations. This RS/RS/SS combination together with RS/RR/SS with the frequency of 13% were the most common two combinations observed in all of the populations under different insecticide regimes, even in the populations under no insecticide pressure for many years. Independent evaluation of the three mutations resulted in 0.450, 0.534 and 0.037 frequency values for the resistant alleles of 214Val, 488Ser and Δ3Q mutations, respectively. Among the studied populations, the frequencies of resistant alleles for the positions of 214 and 488 were not differed from each other. However, in 3 of the populations the frequency of the R allele of Δ3Q was zero and it changed between 0.025 and 0.100 in the remaining five populations. Results of this study contributed to the distribution pattern of the two point mutations in Europe and a pattern for Δ3Q mutation was determined for the first time in the field collected olive fly samples.