Resistance of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), larvae in Michigan to insecticides with different modes of action and the impact on field residual activity

BACKGROUND: The codling moth is one of the principal pests of apple in the world. Resistance monitoring is crucial to the effective management of resistance in codling moth. Three populations of codling moth in neonate larvae were evaluated for resistance to seven insecticides via diet bioassays, and compared with a susceptible population. In addition, apple plots were treated with labeled field rate doses of four insecticides. Treated fruit were exposed to neonate larvae of two populations from commercial orchards. RESULTS: Two populations of codling moth expressed two‐ and fivefold resistance to azinphos‐methyl, seven‐ and eightfold resistance to phosmet, six‐ and tenfold resistance to lambda‐cyhalothrin, 14‐ and 16‐fold resistance to methoxyfenozide and sixfold resistance to indoxacarb, but no resistance to acetamiprid and spinosad. The impact of the resistance to azinphos‐methyl, measured as fruit damage, increased as the insecticide residues aged in the field. In contrast, fruit damage in methoxyfenozide‐ and lambda‐cyhalothrin‐treated fruit was observed earlier for resistant codling moth. No differences in efficacy were found for acetamiprid. CONCLUSIONS: Broad‐spectrum insecticide resistance was detected for codling moth. Resistance to azinphos‐methyl, lambda‐cyhalothrin and methoxyfenozide was associated with reduced residual activity in the field. Broad‐spectrum resistance presents serious problems for management of the codling moth in Michigan. Copyright © 2008 Society of Chemical Industry     

Geographic variability in response to azinphos‐methyl in field‐collected populations of Cydia pomonella (Lepidoptera: Tortricidae) from Argentina

BACKGROUND: Resistance to insecticides has been related to application history, genetic factors of the pest and the dynamic within the treated area. The aim of this study was to assess the geographic variation in azinphos‐methyl response and the role of esterase and cytochrome P450 monooxygenase enzymes in codling moth populations collected within different areas of the Río Negro and Neuquén Valley, Argentina. RESULTS: Diapausing field‐collected populations showed resistance ratios at the LC₅₀ that were 0.7–8.7 times higher than that of the susceptible strain. Mean esterase (EST) and cytochrome P450 monooxygenase activities (expressed as α‐N min^?1 mg^?1 prot^?1 and pg 7‐OHC insect^?1 min^?1 respectively) were significantly correlated with LD₅₀ values from the field‐collected populations. In addition, azinphos‐methyl response was associated with the geographic area where the insect population was collected: populations from isolated and more recent productive areas presented significantly lower resistance ratios in comparison with populations from older and more intensive productive areas. CONCLUSION: The populations assayed presented different resistance levels to azinphos‐methyl. The response was highly correlated with the orchard's geographic location. EST and ECOD activities were involved in azinphos‐methyl response in the given region. Copyright © 2012 Society of Chemical Industry     

Toxicological and biochemical response to azinphos-methyl in Cydia pomonella L. (Lepidoptera: Tortricidae) among orchards from the Argentinian Patagonia

BACKGROUND: Azinphos‐methyl is the main insecticide used to control codling moth on apple and pears in Northern Patagonia. The aim of this study was to evaluate the toxicological and biochemical response of diapausing larvae of codling moth in orchards subjected to different insecticide selection pressure. RESULTS: Dose–mortality assays with azinphos‐methyl in diapausing larvae of Cydia pomonella L. showed significant differences between the LD₉₅ from a population collected in one untreated orchard (2.52 µg moth^?1) compared with that in a laboratory‐susceptible population (0.33 µg moth^?1). Toxicity to azinphos‐methyl in field populations of diapausing larvae collected during 2003–2005 was evaluated by topical application of a discriminating dose (2.5 µg moth^?1) that was obtained from larvae collected in the untreated orchard (field reference strain). Significantly lower mortality (37.71–84.21%) was observed in three out of eight field populations compared with that in the field reference strain. Most of the field populations showed higher esterase activity than that determined in both the laboratory susceptible and the field reference strains. Moreover, there was a high association between esterase activity and mortality (R² = 0.64) among the field populations. On the other hand, a poor correlation was observed between glutathione S‐transferase activity and mortality (R² = 0.33) among larvae collected from different orchards. CONCLUSIONS: All the field populations evaluated exhibited some degree of azinphos‐methyl tolerance in relation to the laboratory susceptible strain. Biochemical results demonstrated that esterases are at least one of the principal mechanisms involved in tolerance to this insecticide. Copyright © 2008 Society of Chemical Industry     

Adding microencapsulated pear ester to insecticides for control of Cydia pomonella (Lepidoptera: Tortricidae) in apple

BACKGROUND: The possibility of improving the efficacy of various insecticides for codling moth, Cydia pomonella (L.), by the addition of a microencapsulated formulation of pear ester, ethyl (2E, 4Z)‐2,4‐decadienoate (PE‐MEC, 5% AI), was evaluated in field trials in apple from 2005 to 2009. RESULTS: The addition of PE‐MEC (<3.0 g AI ha^?1) significantly lowered fruit injury with low rates of organophosphate and neonicotinoid insecticides. The addition of PE‐MEC (1.48 g AI ha^?1) to maximum label rates of insecticides with moderate activity for codling moth, such as ebamectin benzoate, spinosad and methoxyfenozide, significantly improved their effectiveness. However, PE‐MEC did not consistently improve the activity of maximum label rates of either rynaxypyr or spinetoram. The addition of PE‐MEC with seasonal spray programs of acetamiprid and azinphos‐methyl in combination with the use of sex pheromones for mating disruption provided the most effective control. CONCLUSION: The addition of PE‐MEC can improve the effectiveness of some insecticides for codling moth in apple. Insecticides active via dermal toxicity are more strongly improved by the addition of PE‐MEC. Season‐long use of PE‐MEC can also augment the effectiveness of mating disruption. Adding PE‐MEC to variable integrated management programs for C. pomonella should be further investigated. Published 2012 by John Wiley & Sons, Ltd.     

Targeting Cydia pomonella (L.) (Lepidoptera: Tortricidae) adults with low‐volume applications of insecticides alone and in combination with sex pheromone

BACKGROUND: Studies surveyed the toxicity of several insecticides against adult codling moth, Cydia pomonella (L.), and examined the field effectiveness of applying low‐volume (12 L ha^?1) sprays alone or in combination with a microencapsulated (MEC) sex pheromone formulation. RESULTS: Neonicotinyls, organophosphates and synthetic pyrethroids significantly reduced fecundity at concentrations nearly 100‐fold lower than their maximum labeled field rate. Field studies in 2005 demonstrated that six applications of esfenvalerate resulted in > 90% reduction in fruit injury versus the untreated check. The addition of the MEC pheromone formulation did not further improve control. Five sprays of esfenvalerate, phosmet and acetamiprid all significantly reduced levels of fruit injury compared with the untreated control in 2006. Esfenvalerate and acetamiprid mixed with the MEC pheromone significantly reduced fruit injury compared with the MEC‐only treatment. Significant increases in pest and decreases in predator mite densities occurred in plots treated with esfenvalerate in both years. Low‐volume sprays of phosmet and acetamiprid did not disrupt mites. CONCLUSION: Low‐volume insecticide sprays can effectively manage codling moth and are less disruptive of integrated mite management. Developing an effective ‘attract and kill’ technology with this approach will require optimization of the attractant(s) to maximize moth exposure to insecticide residues. Published 2010 by John Wiley & Sons, Ltd.     

Development of a rapid resistance monitoring bioassay for codling moth larvae

BACKGROUND: The codling moth, Cydia pomonella (L.), is one of the most important pests of apple worldwide. Use of insecticides for management of this insect has been extensive and has resulted in resistance development. There are a number of different bioassay methods to monitor for codling moth resistance; however, many are not applicable to new insecticides and most are time consuming. A novel 16‐well plasticware bioassay plate containing lyophilized diet was developed for rapid resistance monitoring of codling moth. RESULTS: The contact insecticides acetamiprid and azinphosmethyl were significantly more toxic to neonates than to fourth instars. However, there was no significant difference in LC₅₀ values between neonates and fourth instars to the ingestion insecticides chlorantraniliprole, methoxyfenozide, novaluron and spinetoram. Field colonies of codling moth were significantly more resistant to methoxyfenozide than susceptible populations. A diagnostic dose of 20 µg mL^?1 (LC₉₉) was established to monitor for codling moth resistance to methoxyfenozide. CONCLUSIONS: The results presented here demonstrate that a novel and rapid bioassay can be used to monitor for codling moth resistance to methoxyfenozide. The bioassay method is relevant to both ingestion and contact insecticides, but a single diagnostic dose, regardless of larval age, is only relevant to ingestion insecticides. Age‐dependent diagnostic doses are likely necessary for contact insecticides. Copyright © 2011 Society of Chemical Industry     

Plant volatile compounds shorten reaction time and enhance attraction of the codling moth (Cydia pomonella) to codlemone

BACKGROUND: The codling moth is the most serious pest of deciduous tree fruit (apples, pears, crabapples, walnuts, quince) worldwide. The high frequency of insecticide treatments per season has resulted in breakdown of codling moth control owing to insecticide resistance. As an alternative, integrated pest management includes mating disruption to achieve population suppression in orchards. Under this scheme, the sex pheromone of the codling moth, (E, E)‐8,10‐dodecadien‐1‐ol (codlemone), is released from dispensers in crops to hinder mating by luring males. Increasing the attractiveness of codlemone formulations to codling moth males can be regarded as a key to increasing the efficacy of mating disruption. With this aim, the effects of adding plant volatiles on the behavioural responses of codling moth males to codlemone were tested. RESULTS: Adding R(+)‐limonene, linalool, (E)‐β‐farnesene or ethyl (E, Z)‐2,4‐decadienoate to codlemone significantly increases the proportion of males flying to the pheromone source in a wind tunnel. The response level is equivalent to that of males responding to females releasing codlemone. Using real‐time recordings, it is shown how these four plant products also shorten the response time of males to codlemone under the behavioural criteria time to activation, time till upwind flight is induced and time to pheromone source contact. CONCLUSION: Shortening the response time and increasing source location by males of dispensers releasing codlemone with R(+)‐limonene, linalool, (E)‐β‐farnesene or ethyl (E, Z)‐2,4‐decadienoate added would enhance mating disruption through better engagement of males with dispensers, to the detriment of females. Copyright © 2011 Society of Chemical Industry     

Evaluating sex-pheromone- and kairomone-based lures for attracting codling moth adults in mating disruption versus conventionally managed apple orchards in Pennsylvania

BACKGROUND: Effectiveness of different types of commercial sex‐pheromone‐ and kairomone‐based lures for attracting codling moth adults may vary under different pest management practices. The attractiveness of four types of codling moth (CM) lures (CM L2 Long‐Life^®, CM 10X Megalure^®, Pherocon CM DA^® and Pherocon CM‐DA Combo^®) was evaluated in commercial apple orchards either treated with sex pheromone mating disruption (MD) or only conventional insecticides (non‐MD) in Adams County, Pennsylvania, in 2006 and 2007. RESULTS: CM DA Combo lure was most effective in terms of mean seasonal weekly moth capture as well as mean cumulative moth capture in MD orchards. In both years, the CM L2 lure was as attractive to adult moths as the CM DA Combo lure in non‐MD orchards. The CM DA and CM 10X lures caught significantly fewer moths in both MD and non‐MD orchards compared with the CM DA Combo lure. CONCLUSIONS: ON the basis of mean seasonal weekly moth capture as well as mean cumulative moth capture, the CM DA Combo and CM L2 lures were found to be significantly more effective for monitoring CM adults in both MD and non‐MD orchards. In contrast, the CM DA and CM 10X lures were not as effective in either type of orchard. Copyright © 2011 Society of Chemical Industry     

Toxicity of azinphos-methyl to various development stages of the codling moth Cydia pomonella (Lepidoptera: Tortricidae)

The response to azinphos-methyl of different life-stages of the codling moth Cydia pomonella (L.) was studied. A similarity in response to azinphos-methyl (LC(50), LC(90)) was observed in neonate larvae obtained from the first and second generations of field populations. Mortality rates for neonate larvae of a field population cross-bred with a laboratory colony were lower (by a factor of 1.2-2.2) in comparison with field neonate larvae. The mortality rate of larvae from a laboratory colony exposed to artificial diet containing azinphos-methyl gradually decreased at older instars. The mortality rates of fifth-instar larvae were remarkably low when exposed to artificial diet mixed with azinphos-methyl or when topically treated with the insecticide. One- to three-day-old females were more sensitive than males of the same age, whereas the opposite was observed in 14-to 17-day-old adults. Mortality rates of 14- to 17-day-old adults were higher than those under 10 days old. No significant difference in sensitivity to the organophosphorus compound was noticed between the sexes of 7- to 10-day-old adults. Neonate larvae of the codling moth can serve as a target life-stage for various groups of pesticides, and the importance of using such a stage as a standardized methodology for monitoring resistance in the codling moth is discussed.     

Toxicities and sublethal effects of seven neonicotinoid insecticides on survival, growth and reproduction of imidacloprid-resistant cotton aphid, Aphis gossypii

BACKGROUND: Imidacloprid has been a major neonicotinoid insecticide for controlling Aphis gossypii (Glover) (Homoptera: Aphididae) and other piercing–sucking pests. However, the resistance to imidacloprid has been recorded in many target insects. At the same time, cross‐resistance of imidacloprid and other insecticides, especially neonicotinoid insecticides, has been detected. RESULTS: Results showed that the level of cross‐resistance was different between imidacloprid and tested neonicotinoid insecticides (no cross‐resistance: dinotefuran, thiamethoxam and clothianidin; a 3.68–5.79‐fold cross‐resistance: acetamiprid, nitenpyram and thiacloprid). In the study of sublethal effects, imidacloprid at LC₂₀ doses could suppress weight gain and honeydew excretion, but showed no significant effects on longevity and fecundity of the imidacloprid‐resistant cotton aphid, A. gossypii. However, other neonicotinoid insecticides showed significant adverse effects on biological characteristics (body weight, honeydew excretion, longevity and fecundity) in the order of dinotefuran > thiamethoxam and clothianidin > nitenpyram > thiacloprid and acetamiprid. CONCLUSION: The results indicated that dinotefuran is the most effective insecticide for use against imidacloprid‐resistant A. gossypii. To avoid further resistance development, the use of nitenpyram, acetamiprid and thiacloprid should be avoided on imidacloprid‐resistant populations of A. gossypii. Copyright © 2011 Society of Chemical Industry     

Insecticide resistance status of the codling moth Cydia pomonella (Lepidoptera: Tortricidae) from Greece

The codling moth Cydia pomonella L. is controlled mostly with chemical insecticides in Greece and control failures have been reported. However, there are no insecticide resistance studies in the country as yet. We examined the insecticide resistance status of 33 and 38 populations of fifth-instar non-diapausing and diapausing larvae, respectively by applying bioassays, biochemical and DNA diagnostics. Diagnostic concentrations of azinphos-methyl, phosalone, deltamethrin, thiacloprid, fenoxycarb, tebufenozide, methoxyfenozide and diflubenzuron were used in bioassays. Almost all populations showed reduced susceptibility to at least one insecticide and approximately half of them to all insecticides examined compared to a laboratory susceptible strain used as reference. However, only one out of six populations tested showed reduced susceptibility in ovicidal tests with fenoxycarb. Cross-resistances were observed among most insecticides, except from the pairs fenoxycarb–phosalone and thiacloprid–phosalone, in non-diapausing larvae. The more obvious biochemical marker associated with the reduced susceptibility observed in both larval instars was elevated cytochrome P₄₅₀ polysubstrate monooxygenases activity, followed by elevated glutathione-S-transferase activity and reduced carboxylesterases activity. Neither sodium channel nor AChE known resistance mutations were found in any of the approximately 1000 individuals of each larval instar screened with diagnostic PCR. Actions for Integrated Resistance Management and application of alternative control methods are discussed.     

Biological characterization of sulfoxaflor, a novel insecticide

BACKGROUND: The commercialization of new insecticides is important for ensuring that multiple effective product choices are available. In particular, new insecticides that exhibit high potency and lack insecticidal cross‐resistance are particularly useful in insecticide resistance management (IRM) programs. Sulfoxaflor possesses these characteristics and is the first compound under development from the novel sulfoxamine class of insecticides. RESULTS: In the laboratory, sulfoxaflor demonstrated high levels of insecticidal potency against a broad range of sap‐feeding insect species. The potency of sulfoxaflor was comparable with that of commercial products, including neonicotinoids, for the control of a wide range of aphids, whiteflies (Homoptera) and true bugs (Heteroptera). Sulfoxaflor performed equally well in the laboratory against both insecticide‐susceptible and insecticide‐resistant populations of sweetpotato whitefly, Bemisia tabaci Gennadius, and brown planthopper, Nilaparvata lugens (Stål), including populations resistant to the neonicotinoid insecticide imidacloprid. These laboratory efficacy trends were confirmed in field trials from multiple geographies and crops, and in populations of insects with histories of repeated exposure to insecticides. In particular, a sulfoxaflor use rate of 25 g ha^?1 against cotton aphid (Aphis gossypii Glover) outperformed acetamiprid (25 g ha^?1) and dicrotophos (560 g ha^?1). Sulfoxaflor (50 g ha^?1) provided a control of sweetpotato whitefly equivalent to that of acetamiprid (75 g ha^?1) and imidacloprid (50 g ha^?1) and better than that of thiamethoxam (50 g ha^?1). CONCLUSION: The novel chemistry of sulfoxaflor, its unique biological spectrum of activity and its lack of cross‐resistance highlight the potential of sulfoxaflor as an important new tool for the control of sap‐feeding insect pests. Copyright © 2010 Society of Chemical Industry     

Involvement of a sodium channel mutation in pyrethroid resistance in Cydia pomonella L, and development of a diagnostic test

Populations of the codling moth, Cydia pomonella L (Lepidoptera, Tortricidae) have developed resistance to several classes of insecticide such as benzoylureas, juvenile hormone analogues, ecdysone agonists and pyrethroids, but the corresponding resistance mechanisms have not been extensively studied. Knockdown resistance (kdr) to pyrethroid insecticides has been associated with point mutations in the para sodium channel gene in a great variety of insect pest species. We have studied two susceptible strains (S and Sv) and two resistant strains (Rt and Rv) of C pomonella that exhibited 4- and 80-fold resistance ratios to deltamethrin, respectively. The region of the voltage-dependent sodium channel gene which includes the position where kdr and super-kdr mutations have been found in Musca domestica L was amplified. The kdr mutation, a leucine-to-phenylalanine replacement at position 1014, was found only in the Rv strain. In contrast, the super-kdr mutation, a methionine-to-threonine replacement at position 918, was not detected in any C pomonella strain. These data allowed us to develop a PCR-based diagnostic test (PASA) to monitor the frequency of the kdr mutation in natural populations of C pomonella in order to define appropriate insecticide treatments in orchards.     

Cross‐resistance,mode of inheritance and stability of resistance to emamectin in Spodoptera litura (Lepidoptera: Noctuidae)

BACKGROUND: Spodoptera litura (F.) is a cosmopolitan pest that has developed resistance to several insecticides. The aim of the present study was to establish whether an emamectin‐selected (Ema‐SEL) population could render cross‐resistance to other insecticides, and to investigate the genetics of resistance. RESULTS: Bioassays at G₁ gave resistance ratios (RRs) of 80‐, 2980‐, 3050‐ and 2800‐fold for emamectin, abamectin, indoxacarb and acetamiprid, respectively, compared with a laboratory susceptible population Lab‐PK. After three rounds of selection, resistance to emamectin in Ema‐SEL increased significantly, with RRs of 730‐fold and 13‐fold compared with the Lab‐PK and unselected (UNSEL) population respectively. Further studies revealed that three generations were required for a tenfold increase in resistance to emamectin. Resistance to abamectin, indoxacarb, acetamiprid and emamectin in UNSEL declined significantly compared with the field population at G₁. Furthermore, selection with emamectin reduced resistance to abamectin, indoxacarb and acetamiprid on a par with UNSEL. Crosses between Ema‐SEL and Lab‐PK indicated autosomal and incomplete dominance of resistance. A direct test of a monogenic model and Land's method suggested that resistance to emamectin was controlled by more than one locus. CONCLUSION: Instability of resistance and lack of cross‐resistance to other insecticides suggest that insecticides with different modes of action should be recommended to reduce emamectin selection pressure. Copyright © 2010 Society of Chemical Industry     

Toxicity of emamectin benzoate to Cydia pomonella (L.) and Cydia molesta (Busck) (Lepidoptera: Tortricidae): laboratory and field tests

BACKGROUND: Emamectin benzoate is a novel macrocyclic lactone insecticide derived from naturally occurring avermectin molecules isolated by fermentation from the soil microorganism Streptomyces avermitilis Kim & Goodfellow. The present study aims to evaluate the toxicity of emamectin benzoate to codling moth, Cydia pomonella (L.), and oriental fruit moth, C. molesta (Busck), under laboratory and semi‐field conditions. RESULTS: Dose response bioassays showed that emamectin benzoate had a high level of intrinsic toxicity to early‐stage larvae of both species, and that contact activity might contribute significantly to mortality. In the semi‐field trials, residual toxicity lasted for more than 1 week. Ovicidal activity was recorded only for C. pomonella (approximately 30%), irrespective of the concentrations tested. Field trials confirmed the efficacy of emamectin benzoate on codling moth when applied at 7 day intervals. Fruit damage, both from the first and second generations, was comparable with that on treatment with chlorpyrifos‐ethyl, used as a chemical reference. CONCLUSION: Emamectin benzoate may be considered a valuable tool for the control of codling moth as a component of an IPM programme. Its collective advantages are: high efficacy, lack of cross‐resistance with currently used products, control of secondary pests such as oriental fruit moth and selective toxicity that spares beneficials. Copyright © 2008 Society of Chemical Industry     

Control of the codling moth (cydia pomonella) in apple and pear orchards in Israel by mating disruption

Control of the codling moth,Cydia pomonella (L.) (Lepidoptera: Tortricidae), by pheromone-mediated mating disruption, was studied in Israel using two types of dispensers: Shin-Etsu twist-tie (normal and long-life) and TNO matrix formulation (square wafers). Factors affecting mating disruption: initial pest population density, timing of the pheromone application, early season insecticide treatments and monitoring of the pest, were evaluated. Efficacy of mating disruption was assessed by comparing catch of males in pheromone traps located in pheromone-treated and chemically sprayed control plots. Fruit infestation during the season and at picking time was the major criterion to assess mating disruption. The preferred time for pheromone application was before the first flight of the moth. When pheromones were applied at a later stage, one or two early insecticide sprays had to be used to reduce the initial level of the codling moth population. In all tests, trap catch in pheromone-treated plots was drastically reduced as compared with respective control plots. In pheromone-treated plots where total seasonal trap catch (after pheromone application) was less than 12 males/trap, fruit infestation was less than 1.5%; zero trap catch resulted in 0.1-0.3% infestation. At high population levels, mating disruption was ineffective, with the rate of infestation at picking-time being similar in pheromone-treated and control plots. All the field tests indicated that mating disruption with either Shin-Etsu ropes or TNO squares can control codling moth infestations in apple and pear orchards, at relatively low densities of the pest, as efficiently as commercial insecticide sprays.     

Assessment of insecticide resistance in eggs and neonate larvae of Cydia pomonella (Lepidoptera: Tortricidae)

Spanish Cydia pomonella (L.) field populations have developed resistance to several insecticide groups. Diagnostic concentrations were established as the LC₉₀ calculated on a susceptible strain (S_Spain) for five and seven insecticides and tested on eggs and neonate larvae field populations, respectively. The three most relevant enzymatic detoxification systems (mixed-function oxidases (MFO), glutathione S-tranferases (GST) and esterases (EST)) were studied for neonate larvae.In eggs, 96% of the field populations showed a significantly lower efficacy when compared with the susceptible strain (S_Spain) and the most effective insecticides were fenoxycarb and thiacloprid. In neonate larvae, a significant loss of susceptibility to the insecticides was detected. Flufenoxuron, azinphos-methyl and phosmet showed the lowest efficacy, while lambda-cyhalothrin, alpha-cypermethrin and chlorpyrifos-ethyl showed the highest. Biochemical assays showed that the most important enzymatic system involved in insecticide detoxification was MFO, with highest enzymatic activity ratios (5.1-16.6 for neonates from nine field populations). An enhanced GST and EST activities was detected in one field population, with enzymatic activity ratios of threefold and fivefold for GST and EST, respectively, when compared with the susceptible strain. The insecticide bioassays showed that the LC₉₀ used were effective as diagnostic concentrations. Measures of MFO activity alongside bioassays with insecticide diagnostic concentrations could be used as tools for monitoring insecticide resistance in neonate larvae of C. pomonella.     

The importance of forecasting and warning systems in implementation of integrated pest management in apple orchards in Turkey*

Integrated Pest Management (IPM) has been widely implemented in apple orchards in various regions of Turkey. Between 1995 and 1999, in Central Anatolia and the Aegean Region, apple scab (Venturia inequalis) and codling moth (Cydia pomonella) were key pests, and implementation of pest control was based on forecasting and warning systems. During the project, orchards in which IPM was implemented and in which farmers applied conventional practices were compared. In nine provinces in which IPM projects were carried out in 1999, the damage due to codling moth was 0–1.3% in IPM orchards while it was 0.4–21.8% in nearby non‐IPM orchards. It is clear that damage did not reach the acceptable threshold level of 2% in any of the IPM orchards, while damage was much higher than the threshold in conventionally‐farmed orchards. The number of fungicide applications against apple scab decreased to 5–6 applications from 10–15 applications in the Eğirdir district of the Isparta Province in 1996 as a result of IPM implementation. No insecticides were applied against codling moth in IPM orchards in the Nigde Province in 1998 and 1999 because population levels of the pest were low and under the economic threshold. Apple producers received training and 1200 producers from Central Anatolia became experts in IPM for their own orchards, learning to make appropriate decisions about pest control. The Apple IPM Guideline was prepared and disseminated. In Turkey modern equipment for forecasting and warning systems was employed and, in the last decade, forecasting and warning networks have been improved. Computer‐based systems have increased the speed and accuracy of forecasting as well as decreasing its costs. A computerized national forecasting network in apple orchards now transmits data from the field to system headquarters automatically. The national forecasting network has been expanded and covered 12 208 800 apple trees in 34 provinces in 2006, using 115 electronic forecasting and warning stations.     

Disruption of mating in codling moth (Lepidoptera: Tortricidae) by chlorantranilipole, an anthranilic diamide insecticide

The influence of the anthranilic diamide insecticide chlorantranilipole (DPX-E2Y45; Rynaxypyr against the adult stage of codling moth, Cydia pomonella L., was examined. Insecticide residues in plastic cups sprayed with 56 mg AI L(-1) (equivalent to the recommended field rate) had a minimal effect on adult survival or fecundity, but significantly fewer female moths were mated in treated than in untreated cups. Similar results were found in field studies with adults placed in screened cages on treated apple foliage for up to 3 weeks. Mating was disrupted when either sex was topically dosed with technical material (0.01-0.1 microg). Males were more sensitive to the disruptive effects of chlorantranilipole than females. A 2 h exposure significantly reduced male activity (walking and wing fanning), but not female calling. A 25 h exposure significantly reduced the activity of both sexes. The proportion of males landing near a sex pheromone source in a flight tunnel was significantly reduced following exposures of 2-4 h and completely eliminated following a 17 h exposure. Male moths partially recovered from either topical or residual exposure to chlorantranilipole, but the extent of their recovery was dose and time dependent. Male response to sex pheromone recovered within 2 h following a 4 h exposure, but following a 17 h exposure only a partial recovery occurred after 48 h. Mating by moth pairs exposed to chlorantranilipole residues for 24 h did not significantly increase during recovery periods of 24-96 h, except in cups treated with 10% of the standard concentration. The proportion of field-collected female codling moths caught in pear ester-baited traps that were mated was significantly lower in apple orchards treated season-long with chlorantranilipole compared with females caught in either untreated orchards or those treated with sex pheromones to cause mating disruption.     

Sex-related differences in the tolerance of Oriental fruit moth (Grapholita molesta) to organophosphate insecticides

In vivo toxicity assays have shown that organophosphate insecticides are less toxic to male than to female Oriental fruit moths Grapholita molesta. While male moths have higher levels of acetylcholinesterase and general esterase activities, female moth acetylcholinesterase enzymes are less sensitive to aromatic and aliphatic organophosphates than male enzymes. Elevated esterase and acetylcholinesterase activities in male moths explain their greater tolerance to aromatic and aliphatic organophosphates. Male and female acetylcholinesterase enzymes are equally tolerant to heteroaromatic organophosphates, the most widely used of this class of insecticides in G molesta control. This observation, in contrast to the greater sensitivity of male acetylcholinesterases to aromatic and aliphatic organophosphates, shows the potential for the evolution of insensitive target sites in male moths, which would increase male G molesta tolerance to these insecticides. Significant sex-linked differences in insecticide tolerance have not been reported previously in lepidopterans. The practical implications of the observed differences in tolerance in male and female G molesta question the practice of using pheromone traps to monitor populations of these moths in orchards.