Carpocapsa pomonella (Linnaeus)
(Sometimes placed in the genus Cydia)
Taxonomic placing: Holometabola, Lepidoptera, Tortricidae.
Common name: Codling moth.
Geographic distribution: Wherever apples and pears are grown.
Host plants: Apple, pear and other stone fruits, as well as quince, walnuts and various uncultivated Rosaceae.
Economic importance: A major pest of apples and pears around the world. Small infested apples drop, whereas larger fruits, attacked later in the season, may remain on the trees but are unmarketable. Unless the pest is controlled, damage to pome fruits and to walnuts may reach 50% or more.
Morphology: The female is about 0.8 mm long, with grayish forewings that are transversed by brown zigzag lines and have large copper-colored circular marking near thire tips. Hindwings brown, with a fringe of paler setae. The larva may reach 20 mm in length, initially whitish, later becoming pink to red. The head and the terminal segment dark; each segment bears small tubercles with short setae.
Life Cycle: Each female lays 60 eggs or more, on leaves or on and around the developing fruits. After hatching the larvae enter fruits to feed on the pulp and seeds, and develop there during summer for about 3-5 weeks.If a small fruit is insufficient, the larva may invade, and damage, a second fruit. Before pupating the mature larva crawls down the tree to hide in bark cracks or similar protected sites. The adults, unless in winter diapause, emerge a few weeks later. They are most active around dusk, when temperatures are at least 15°C. The moth lives for 3-5 weeks, annually raising 3-4 partially overlapping generations. The winter diapause is induced by shortening days and lowering temperatures during late summer. Some larvae may enter diapause even under benign summer conditions. The codling moth occurs in two races, the apple and pear race, and the walnut race; both respond to apple odors.
Management
Monitoring: In order to reduce the numbers of the pest’s first generation, its populations are monitored in early spring. Sex pheromone traps (often using the Shin-Etsu twist-tie rope dispensers) are used to capture male moths in order to establish the biofix, which indicates the time of first male catch (beginning of the emergence from diapause). The development of the pest’s population may then be determined by using the PETE (Predictive Extension Time Estimator) model. By using information about the pest’s biology along with meteorological data, PETE forecasts when the various stages of the pest will appear, and thereby indicates the optimal time for spraying against its first generation. Later in the season pheromone traps are used to monitor moth populations; the finding of 4 or more moths per trap within two weeks triggers chemical control measures. Another method, used later in the season to determine the results of control measures, consists of establishing the rate of fruit infestation, samples being collected every week or during the population peaks of the moth. Individual apples are examined for the presence of dark brown frass, which is the excrement of the larva.
Physical control: Corrugated cardboard strips covered with sticky glue are placed around the trunk (‘trunk banding”) to trap larvae crawling down to overwintering sites. The strips may then be removed and burned. Other methods include bagging each fruit individually, removing dropped fruit (which may include larvae) and any nearby potential hosts.
Mating disruption: Several hundred dispensers of a commercial pheromone preparation, when placed in an apple orchard, may significantly reduce the level of moth damage. However, the efficacy of mating disruption is density dependent, providing insufficient control against very large populations and/or when an invasion of gravid females occurs. A similar method is baiting traps by a combination of pear ester and acetic acid, which in Hungary outperformed pheromone lures in mating disruption and in sampling pest populations.
Chemical control: Various pesticides, such as organophosphates and pyrethroids were applied in the past. The pest has developed resistance to many of these pesticides, and neonicotinoids and synthetic insect growth regulators are now in use. Pesticides are also used in “attract-and kill” systems, in which the sex pheromone (codlemone) attractant is combined with a pesticide. This approach has successfully been applied in Syrian apple orchards. Another option is applying nontoxic kaolin clay-based sprays, which cause tiny clay particles to attach to the pests’ bodies, disturbing and repelling them, and render clay-covered trees less recognizable as suitable habitats.
Sterile male technique (SIT): An “FAO/IAEA Coordinated Research Project on Improvement of Codling Moth SIT to Facilitate Expansion of Field Application” is currently underway in several countries. It focuses on recent advances in the SIT intended to improve control of C. pomonella.
Biological control: Various organisms affect the codling moth, attacking the eggs or larvae in different parts of the world. In England the woodpecker Parus feeds on larvae that hide under the tree bark. Parasitoids include Trichogrammatidae, which attack the eggs, and members of the families Braconidae and Ichneumonidae in many countries, as well as a tachinid, Elodia, that parasitize the larvae in Sweden. In addition, several Entomopathogenic fungi were isolated from overwintering larvae. Entomopathogenic nematodes (EPNs) have some potential for controlling overwintering larvae, provided temperatures are above 15°C and there are adequate moisture conditions. A recent mode of codling moth control is by applying the codling moth granulosis virus (CMGV) in water-based formulations. This virus occurs naturally in all major pome fruit growing regions and is much used in organically grown orchards in Europe and North America, the widely used brand being Virosoft CP4. It is applied when the eggs begin to hatch; infested larvae die within 3–7 days.
Area-wide control: SIT and its derivative, inherited sterility (IS), together with mating disruption and CMGV, are among the options that offer great potential, as cost-effective components of an area-wide integrated pest management strategy to control the pest.
References
Basheer, A.M., Alhaj, Sh.I. and Asslan, L.H. 2016. Parasitoids on codling moth Cydia pomonella (Lepidoptera: Tortricidae) in apple and walnut orchards in Syria. EPPO Bulletin 46: 295-297.
Botto, E. and Glaz, P. 2010. Potential for controlling codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) in Argentina using the sterile insect technique and egg parasitoids. Journal of Applied Entomology 134: 251–260.
Dyck, V.A. 2010. Rearing codling moth for the sterile insect technique. FAO Plant Protection and Protection Papers 199, pp.198.
Lacey, L.A. and Unruh, T.R. 2005. Biological control of codling moth (Cydia pomonella, Lepidoptera: Tortricidae) and its role in integrated pest management, with emphasis on entomopathogens. Vedalia 12: 33-60.
Maalouly, M., Franck, P., Bouvier, J.-C., Toubon, J.-F. and Lavigne, C. 2013. Codling moth parasitism is affected by semi-natural habitats and agricultural practices at orchard and landscape levels. Agriculture Ecosystems & Environment 169: 33-42.
Mansour, M. 2010. Attract and kill for codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) control in Syria. Journal of Applied Entomology 134: 234-242.
Mills, N. 2005. Selecting effective parasitoids for biological control introductions: Codling moth as a case study. Biological Control 34: 274-282.
Palevsky, E., Oppenheim, D. and Steinberg, S. 1991. Use of the PETE model for timing chemical control of the codling moth, Cydia pomonella, in Israel. Hassadeh 71: 1189-1193 (in Hebrew with an English abstract).
Pluciennik, Z. 2013. The control of codling moth (Cydia pomonella L.) population using mating disruption method. Journal of Horticultural Research 21: 65-70.
Reuveny, H. and Cohen, E. 2004. Resistance of the codling moth Cydia pomonella (L.) (Lep., Tortricidae) to pesticides in Israel. Journal of Applied Entomology 128: 645-651.
Reuveny, H., Oppenheim, D., Dunkelblum, E. and Akunis, O. 2001. Control of the codling moth (Cydia pomonella) by mating disruption and monitoring the pest population levels under these conditions. Alon Hanotea 55: 143–147 (in Hebrew with an English abstract).
Solomon, M.E. and Glen, D.M. 1979. Prey density and rates of predation by tits (Parus spp.) on larvae of codling moth (Cydia pomonella) under bark. Journal of Applied Ecology 16: 49-59.
Subinprasert, S. 1987. Natural enemies and their impact on overwintering codling moth populations (Laspeyresia pomonella L.) (Lep., Tortricidae) in south Sweden. Journal of Applied Entomology 103: 46-55.
Toth, M., Jósvai, J. (and 9 co-authors). 2014. Pear ester based lures for the codling moth Cydia pomonella L. — A summary of research efforts in Hungary. Acta Phytopathologica et Entomologica Hungarica 49: 37-47.
Vreysen, M.J.B., Carpenter, J.E. and Marec, F. 2010. Improvement of the sterile insect technique for codling moth Cydia pomonella (Linnaeus) (Lepidoptera Tortricidae) to facilitate expansion of field application. Journal of Applied Entomology 134: 165–181.
Witzgall, P., Stelinski, L., Gut, L. and Thomson, D, 2008. Codling moth management and chemical ecology. Annual Review of Entomology 53: 503–522.