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1.
The purpose of this study was to analyse the radiosensitivity of codling moth Cydia pomonella (L.) strains from different elevations, 850 and 2000 m above the sea level. The level of sterility of parental males and inherited sterility of F1 males in the strain from the higher elevation at all radiation doses (80, 100 and 150 Gy) was significantly lower, than in the strain from the lower elevation. The frequency of chromosomal aberrations in the F1 generation in the strain from the higher elevation was significantly lower at 80 and 150 Gy than that in strain from the lower elevation. The average number of eupyrene sperm in the F1 males descended from irradiated males was higher in the strain from the higher elevation than in the strain from the lower elevation. Inheritance of the resistance/susceptible to ionizing radiation were examined by standard genetic cross‐breeding analysis confirming the polygenic nature of the differences in radiosensitivity. The implications of these findings for the implementation of area‐wide integrated pest management programmes that integrate the use of sterile insects are discussed.  相似文献   

2.
Spread pachytene nuclei of codling moth Cydia pomonella (Linnaeus) (Lep., Tortricidae) females of a Syrian strain (SY) were used to investigate chromomere patterns of chromosome bivalents and determine their length. The karyotype of female codling moths consists of 28 chromosome bivalents, of which seven are clearly distinguishable using chromosome length and the number and size of the chromomeres in the pachytene stage. One autosome bivalent has two nucleolar organizing regions (NORs) that are located at the opposite ends of the chromosome and appear as distinct structural landmarks. In female codling moths, the WZ sex chromosome bivalent was easily identified in pachytene oocytes according to the heterochromatic thread of the W chromosome. This study contributed to the knowledge and identification of pachytene chromosomes of female codling moths.  相似文献   

3.
The morphology of Nosema carpocapsae and its development in experimentally infected codling moth larvae are described. Spherical uninucleate meronts were the first stages. Nuclear division produced binucleate meronts which were the most abundant vegetative stage, although additional uninucleate and a few tetranucleate meronts were also observed at this time. All meronts were spherical and ranged from 2.8 to 5.8 μm in diameter. Uninucleate and binucleate fusiform sporonts then appeared followed by some tetranucleate and dividing forms. Oval sporoblasts developed after these and did not divide before maturing into spores. Sporonts were approximately 5.0 to 7.9 × 2.4 to 3.0 μm. Spores developed in all host tissues except the nervous tissue. The binucleate spores showed considerable variation in spore size, 2.4 to 3.9 × 1.3 to 3.1 μm (alcohol fixed, Giemsa stained). The polar filament was usually coiled 11 times (range 9 to 13) at an angle of 53° to the long axis of the spore. Its maximum observed length was 75 μm.  相似文献   

4.
The attract and kill technique has been formulated in a product under the trade name `Sirene CM®'. It consists of a viscous paste containing 0.16% codlemone to attract the male moths and 6.0% permethrin to kill them. The formulation is applied by hand twice per season using a specially developed system which can be calibrated for application of the paste to the host plant in small droplets of either 100 l or 50 l. Between 1995 and 1997, 15 trials on control of the codling moth were conducted in isolated orchards in the Lake Geneva region. In each plot, depending on tree size, two applications varying between 52 and 537 g ha–1 of Sirene CM were made. In 14 trials, the larval attack of the codling moth on fruit was below the economic threshold of 1% and the hibernating population stayed at a low level. One single plot (0.4 ha) had to be treated with a curative spray in 1995, because the initial population was much too high. According to the reductions in trap catch and of mating frequency measured by tethered codling moth females, efficiency of the attract and kill droplets lasted 5–7 weeks, after which it decreased slowly.  相似文献   

5.
A viscous formulation based on castor oil containing the pyrethroid insecticide cyfluthrin and E8, E10-dodecadienol, the main component of the codling moth sex pheromone, (Cydia pomonellaL.: Tortricidae, Olethreutinae) was developed. The insecticidal performance of the formulation was evaluated in the laboratory using a tarsal-contact bioassay. The pheromone dosage required to attract male moths to the formulation was determined in behavioural tests performed in a wind tunnel. The efficacy of formulations applied to seedlings of the host plant was further investigated in glasshouse experiments conducted with male moths in small wire-gauze cages. The laboratory tests resulted in a formulation for preliminary field trials containing 4% cyfluthrin and 0.1% pheromone. During the 1995 growing season, experiments were conducted in apple orchards at three locations in Germany. The formulation was first applied to the bark of apple trees (Malus domestica) in mid May and then again in late July. A good level of control, comparable with a spray treatment using the insect growth regulator Alsystin was achieved. The potential of the attract and kill strategy, combining selective attraction of a pest species with the efficacy associated with a pyrethroid insecticide treatment, as a means of controlling the codling moth in commercial apple growing, is discussed.  相似文献   

6.
The biocontrol potential of South African isolates of Heterorhabditis zealandica, Steinernema citrae, S. khoisanae, S. yirgalemense, and Steinernema sp., was evaluated against codling moth, Cydia pomonella. Codling moth was susceptible to all six nematode isolates at a concentration of 50 infective juveniles/insect (78–100% mortality). Low temperatures (10 h at 17°C; 14 h at 12°C) negatively affected larvicidal activity (≤3%) for all isolates. All tested isolates were most effective at higher levels of water activity (a w=1). The average a w50-values for all isolates tested was 0.94 (0.93–0.95), except S. khoisanae 0.97 (0.97–0.98). Regarding host-seeking ability, no positive attraction to host cues could be detected amongst isolates, except for H. zealandica. Three of the isolates, H. zealandica, S. khoisanae, and the undescribed Steinernema sp., were selected for field-testing and proven to be effective (mortality >50%). Insect containment methods used during field experimentation was shown to influence larvacidal activity, as different levels of mortality were obtained using various containment methods (wooden planks vs. pear tree logs vs. mesh cages). Pear tree logs were impractical. Predictive equations were subsequently developed, enabling future trials to be conducted using either planks or cages, enabling the prediction of the expected level of control on tree logs. All tested isolates therefore showed a certain degree of biological control potential, however, none of the experiments showed clear efficacy-differences amongst isolates. The study highlighted the importance of environmental factors to ensure the successful application of these nematodes for the control of diapausing codling moth larvae in temperate regions.  相似文献   

7.
The codling moth Cydia pomonella (L.) (Lepidoptera Tortricidae) is a key pest of pome fruit (apple, pear and quince) and walnut orchards in most temperate regions of the world. Efforts to control the codling moth in the past mostly relied on the use of broad spectrum insecticide sprays, which has resulted in the development of insecticide resistance, and the disruption of the control of secondary pests. In addition, the frequent reliance and use of these insecticides are a constant threat to the environment and human health. Consequently, there have been increased demands from the growers for the development of codling moth control tactics that are not only effective but also friendly to the environment. In that respect, the sterile insect technique (SIT) and its derivative, inherited sterility (IS), are, together with mating disruption and granulosis virus, among the options that offer great potential as cost‐effective additions to available control tactics for integration in area‐wide integrated pest‐management approaches. In support of the further development of the SIT/IS for codling moth control, the Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture implemented a 5‐year Coordinated Research Project (CRP) entitled ‘Improvement of codling moth SIT to facilitate expansion of field application’. Research focussed on sterile codling moth quality and management (e.g. mobility and life‐history traits in relation to rearing strategy, dispersal, flight ability, radiosensitivity and mating compatibility) and a better understanding of the basic genetics of codling moth to assist the development of genetic sexing strains (e.g. cytogenetics, the development of dominant conditional lethal mutations, molecular characterization of the sex chromosomes, sex identification in embryos and cytogenetic markers). The results of the CRP are presented in this special issue.  相似文献   

8.
Codling moth (CM) and oriental fruit moth (OFM) are very important orchard pests worldwide, and particularly in Victoria, Australia, where both species damage pome fruit. Individually CM and OFM have been controlled successfully by pheromone‐mediated mating disruption, but treatment of pome fruit with full registered rates of two individual hand‐applied dispensers for CM and OFM could be uneconomical for growers. Field trials conducted over three seasons in plots sprayed with insecticides consistently demonstrated that dual Isomate C/OFM TT dispensers, designed to disrupt both CM and OFM, were as effective as Isomate CTT and Isomate OFM Rosso dispensers applied individually in pears for control of CM and OFM respectively. The dual‐ and individual‐species dispensers reduced moth catches and fruit damage to a similar degree. The results suggest that combined control of CM and OFM in pears by applying dual Isomate C/OFM TT dispensers at the full‐recommended rate of 500 dispensers per hectare will be more economical than use of individual species dispensers, because the price and application cost of dual dispenser is about half that for individual dispensers.  相似文献   

9.
The codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is a serious pest of pome fruit worldwide and the sterile insect technique (SIT) provides an environmentally acceptable approach for its control. As the pest is present in both the southern and northern hemispheres it would be possible for a rearing facility in the northern hemisphere to supply sterile moths to an SIT programme in the southern hemisphere during the northern winter and vice versa. This could greatly improve the economics of moth production and the running costs of rearing facilities. However in order to develop this concept, it is important to assess if populations of codling moth from different geographical regions share mating compatibility. Twelve different laboratory and field populations from both hemispheres were sampled and field cage bisexual mating compatibility tests were carried out between selected combinations. The index of sexual isolation (ISI) and the female and male relative performance index (FRPI and MRPI, respectively) were calculated for each mating combination. In only two of the combinations was there a slight but significant deviation from random mating. There were also some significant differences in mating duration between the homotypic matings and the duration of a particular homotypic mating seemed to depend on the origin of the other population in the cage. It was concluded that there exist no barriers to mating between populations of codling moth from many parts of the world and that it would be feasible for sterile moths to be shipped from one rearing facility to SIT programmes in other parts of the world.  相似文献   

10.
Two different methods were tested to identify the sex of the early developmental stages of the codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) with a WZ/ZZ (female/male) sex chromosome system. First, it was shown that the sex of all larval stages can be easily determined by the presence or absence of sex chromatin, which is formed by the female‐specific W chromosome in interphase nuclei. This trait can also be used to identify the sex of newly hatched larvae but it does require care and accuracy. Secondly, a new sexing technique was developed based on a molecular marker of the codling moth W chromosome. Flanking regions of an earlier described W‐specific sequence (CpW2) were isolated and sequenced and a 2.74 kb sequence (CpW2‐EcoRI), specific for the W chromosome, was obtained. Several PCR tests were conducted, which confirmed that the CpW2‐EcoRI sequence is a reliable marker for the sex identification in codling moth samples of different geographical origin. In addition, a fragment of a codling moth gene, period (Cpper) was isolated and sequenced. Results of southern hybridization of the Cpper probe with female and male genomic DNA suggested that the Cpper gene is located on the Z chromosome. Then a multiplex PCR assay was developed, which co‐amplified the CpW2‐EcoRI sequence to identify the W chromosome and the Z‐linked Cpper sequence, which served as a positive control of accurate processing of tested samples. The multiplex PCR provides an easy and rapid identification of the sex of embryos and early larval instars of the codling moth.  相似文献   

11.
The non-insecticidal control strategies currently being implemented in South African orchards for the control of codling moth, Cydia pomonella (L.) may be hampered by wooden fruit bins being infested with diapausing codling moth larvae, acting as a potential source of re-infestation. Key factors contributing to the success or failure of an entomopathogenic nematode application were investigated using the SF 41 isolate of Heterorhabditis zealandica in laboratory bioassays with wooden minibins. Under operational conditions, an application rate of 100 IJs/mL (LD90=102 IJs/mL) effectively controlled codling moth larvae in these bins, and for further laboratory bioassays, the LD50 value of 18 IJs/mL (?25 IJs/mL) was identified as the discriminating dosage. Maximum mortality was attained when bins were pre-wet for at least 1 min (>90% RH) and maintained at maximum humidity (>95% RH) post-treatment for at least 3 days (LT90=73 h), to ensure nematode survival and subsequent satisfactory infection of diapausing codling moth larvae. Tarping bins achieved the desired high level of humidity required. Furthermore, adjuvants (specifically Reverseal 10?) also improved an application. The study conclusively illustrated that if all the above-mentioned conditions are met, H. zealandica has the potential to successfully disinfest wooden fruit bins of codling moth.  相似文献   

12.
The pathogenicity of Nosema carpocapsae for codling moth was studied using dose-infectivity experiments. The IC50 (median infective concentration) was similar for the five larval instars (range 4.0 × 103 to 6.7 × 104 spores/ml). Spore loads in moths ranged from 6.0 × 106 to 7.1 × 107 spores per moth and varied with dose and with larval age at infection. The infection does not cause mortality but does reduce the fecundity and fertility of infected moths. Nosema carpocapsae is transmitted transovarially as well as horizontally. Infected eggs were not produced by healthy females mated with infected males, although such pairs generally produced fewer eggs than healthy pairs.  相似文献   

13.
In order to preserve key activities or improve survival, insects facing variable and unfavourable thermal environments may employ physiological adjustments on a daily basis. Here, we investigate the survival of laboratory-reared adult Cydia pomonella at high or low temperatures and their responses to pre-treatments at sub-lethal temperatures over short time-scales. We also determined critical thermal limits (CTLs) of activity of C. pomonella and the effect of different rates of cooling or heating on CTLs to complement the survival assays. Temperature and duration of exposure significantly affected adult C. pomonella survival with more extreme temperatures and/or longer durations proving to be more lethal. Lethal temperatures, explored between −20 °C to −5 °C and 32 °C to 47 °C over 0.5, 1, 2, 3 and 4 h exposures, for 50% of the population of adult C. pomonella were −12 °C for 2 h and 44 °C for 2 h. Investigation of rapid thermal responses (i.e. hardening) found limited low temperature responses but more pronounced high temperature responses. For example, C. pomonella pre-treated for 2 h at 5 °C improved survival at −9 °C for 2 h from 50% to 90% (p < 0.001). At high temperatures, pre-treatment at 37 °C for 1 h markedly improved survival at 43 °C for 2 h from 20% to 90% (p < 0.0001). We also examined cross-tolerance of thermal stressors. Here, low temperature pre-treatments did not improve high temperature survival, while high temperature pre-treatment (37 °C for 1 h) significantly improved low temperature survival (−9 °C for 2 h). Inducible cross-tolerance implicates a heat shock protein response. Critical thermal minima (CTmin) were not significantly affected by cooling at rates of 0.06, 0.12 and 0.25 °C min−1 (CTmin range: 0.3-1.3 °C). By contrast, critical thermal maxima (CTmax) were significantly affected by heating at these rates and ranged from 42.5 to 44.9 °C. In sum, these results suggest pronounced plasticity of acute high temperature tolerance in adult C. pomonella, but limited acute low temperature responses. We discuss these results in the context of local agroecosystem microclimate recordings. These responses are significant to pest control programmes presently underway and have implications for understanding the evolution of thermal tolerance in these and other insects.  相似文献   

14.
Codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is the key pest of pome fruit in South Africa, and it’s control in apple and pear orchards relies on the application of insecticides and pheromone‐mediated mating disruption. Development of resistance to insecticides and placement of restrictions on the use of certain insecticides has made control of codling moth in South Africa increasingly problematic. The use of the sterile insect technique (SIT) as a control tactic for codling moth is under investigation as a potential addition to the current control strategy. We investigated the radiosensitivity of a laboratory strain of codling moth that was established from moths collected from commercial and organic orchards in the Western Cape, South Africa. Fecundity and fertility of this strain following radiation were consistent with values for the codling moth strain in the Canadian rearing facility in British Columbia. For both strains, the female codling moth was considerably more radiosensitive than the male. At a radiation dose of 100 Gy or higher, treated females were 100% sterile. The fertility of the South African strain was higher (86.3%) than for the Canadian strain (71.9%). This difference in fertility between the two strains was maintained when the dose of radiation was 100 Gy. However, the level of fertility was very similar between the two strains for doses ≥150 Gy. Therefore, based upon previously published work and the data from this study, an operational dose of 150 Gy is recommended for future codling moth SIT programmes in South Africa.  相似文献   

15.
Seasonal changes in the fatty acid composition of the total lipid extracted from the whole body of Cydia pomonella L. larvae were determined by gas chromatography. The six most abundant fatty acids in both non-diapause and diapause larvae of codling moth were oleic (35%-39%), palmitic (23%-33%), linoleic (16%-30%), palmitoleic (5%-10%), stearic (1.5%-3.0%) and linolenic acids (1.0%-2.5%). This represents a typical complement of Lepidopteran fatty acids. The fatty acid composition of total lipid of C. pomonella larvae was related to diapause. In similarity to most other reports, the proportion of unsaturated fatty acids increased in diapause initiation state. The total lipid of diapause larvae contained more linoleic acid (25.8% vs. 16.1%) and less palmitic acid (24.7% vs. 33.4%), than that of non-diapause larvae. The weight percentage of linoleic acid (C 18:2) increased from 16% to 26% from early-August through early-September during transition to diapause, while palmitic acid (C16:0) decreased from 33% to 25% at the same time. These changes resulted in an increase in the ratio of unsaturated to saturated fatty acids (UFA/SFA) from 1.72 in non-diapause larvae to 2.63 in diapause larvae.  相似文献   

16.
Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most important insect of apple, will contribute to the development of safe control techniques. Synthetic apple volatiles in two doses were tested for antennal and behavioural activity in codling moth. Female antennae strongly responded to (Z)3‐hexenol, (Z)3‐hexenyl benzoate, (Z)3‐hexenyl hexanoate, (±)‐linalool and E,Eα‐farnesene. Two other compounds eliciting a strong antennal response were the pear ester, ethyl (E,Z)‐2,4‐decadienoate, and its corresponding aldehyde, E,E‐2,4‐decadienal, which is a component of the larval defence secretion of the European apple sawfly. Attraction of codling moth to compounds eliciting a strong antennal response was tested in a wind tunnel. Male moths were best attracted to a blend of (E,E)‐α‐farnesene, (E)‐beta‐farnesene and ethyl (E,Z)‐2,4‐decadienoate. The aldehyde E,E‐2,4‐decadienal had an antagonistic effect when added to the above mixture.  相似文献   

17.
The effect of four prediapause temperatures (18, 22, 26 and 30°C) on the photoperiodic response of the codling moth, Cydia pomonella (L.), was studied under controlled conditions. The highest rates of diapause were recorded, for all day-lengths, at temperatures of 22 and 26°C while relatively lower rates of diapause were elicited at 18 and 30°C. The same trend was demonstrated by projecting the values of the critical photoperiod which induces 50% diapause (=CPhP50) over the prediapause temperature. The change in diapause incidence as a function of photoperiod, at all prediapause temperatures, exhibited a response characteristic of long-day insects, i.e. high rates of diapause at short days (12–13.5 h) and a decrease in diapause incidence at long days (14–15 h). The results for temperatures 22, 26 and 30°C support the view that lower prediapause temperatures enhance diapause induction, at a give photoperiod, while higher temperatures tend to avert or diminish the process. On the other hand, the low rates of diapause obtained at 18°C contradict this view. Nevertheless, high correlation was found between the laboratory evidence and field data, indicating the adaptability of the Israeli codling moth to subtropical climate.  相似文献   

18.
The effect of larval diet on diapause induction in the Israeli strain of the codling moth, Cydia pomonella (L.), was studied in a field trial using intact apple fruits of two varieties: Ana (early-ripening, in the end of June) and Granny Smith (late-ripening, in October). Diapause incidence increased as fruit age (determined as days from fruit-set) progressed. These results corroborate former studies on other strains of the codling moth, where excised fruits were used.The combination of 80-day-old, fully ripe, Ana fruit treatment with the longest days of the year, yielded 38% diapause. This result demonstrates that mature fruit (inducing diapause) cannot completely override the effect of long day (averting diapause), but does confirm that larval diet modifies the photoperiodic induction of diapause in the codling moth.Deceased, October 1988  相似文献   

19.
A method for screening codling moth granulovirus (CpGV) formulation sensitivity to sunlight using specially prepared half apples and a solar simulator is described. The half apple preparation allows an even coverage of virus over the surface of the fruit that would not be possible using whole apples. Leaves and artificial medium were not usable for extended periods of exposure in the solar simulator due to excess drying. Fruit was sprayed with 10−3 and 10−5 dilutions of three commercial formulations of CpGV (Carpovirusine, Cyd-X, and Virosoft) and infested with codling moth neonates. Half of the sprayed fruit was exposed to 650 W/m2 for 4 h in an Atlas Suntest CPS solar simulator resulting in an accumulated radiant energy of 9.36 × 106 J/m2 before they were infested with neonate codling moth larvae. Spraying non-irradiated fruit with the 10−3 dilution of Cyd-X and Virosoft resulted in nearly 100% mortality of neonate larvae. Irradiation reduced viral activity by 71-98% at the 10−3 dilution and by up to 32% at the 10−5 dilution relative to non-irradiated fruit. The procedures utilized enabled good preservation of the fruit throughout the incubation period and minimized invasion of the fruit by plant pathogens and saprophytic organisms. This laboratory method for screening candidate formulations and potential UV protectants could conserve time and resources by eliminating adjuvants with less potential in laboratory tests and field testing only the most promising candidates. It also enables year-round testing.  相似文献   

20.
The codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is a serious pest of pome fruit worldwide. In an effort to reduce the use of pesticides to control this pest, the sterile insect technique (SIT) is used or considered for use as a component of area‐wide integrated pest management programmes. Rearing codling moths through diapause has been shown to improve the competitiveness of sterile moths released in orchards, and provides management alternatives that would allow mass‐rearing facilities to increase their yearly production of sterile moths. Because radiosensitivity in insects can be influenced by numerous biological factors, laboratory tests were conducted to examine whether the response to increasing doses of radiation, as expressed in the fecundity and fertility of cohorts of moths, is similar for adult moths mass‐reared through diapause or through standard (non‐diapause) production protocols. Our data revealed that the effect of increasing doses of radiation on fecundity and fertility of codling moths reared through both rearing strategies was similar. In the case of fertility, this is a particularly important finding for the expanded application of codling moth SIT. If mass‐rearing facilities use year‐round diapause rearing, the dose required to treat the insects prior to release will be similar to that used when codling moths are reared through standard production protocols.  相似文献   

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