Codling moth

The codling moth or (especially Australia ) codlin moth (Cydia pomonella) is a member of the Lepidopteran family Tortricidae. They are major pests to agricultural crops, mainly fruits such as apples and pears, and a codling moth larva is often called an "apple worm". Along with the apple maggot, it is the worm that people encounter when biting into an infested apple. Because the larvae are not able to feed on leaves, they are highly dependent on fruits as a food source and thus have a significant impact on crops. The caterpillars bore into fruit and stop it from growing, which leads to premature ripening. Various means of control, including chemical, biological, and preventive, have been implemented. This moth has a widespread distribution, being found on six continents. Adaptive behavior such as diapause and multiple generations per breeding season have allowed this moth to persist even during years of bad climatic conditions.

The codling moth or (especially Australia ) codlin moth (Cydia pomonella) is a member of the Lepidopteran family Tortricidae. They are major pests to agricultural crops, mainly fruits such as apples and pears, and a codling moth larva is often called an "apple worm". Along with the apple maggot, it is the worm that people encounter when biting into an infested apple. Because the larvae are not able to feed on leaves, they are highly dependent on fruits as a food source and thus have a significant impact on crops. The caterpillars bore into fruit and stop it from growing, which leads to premature ripening. Various means of control, including chemical, biological, and preventive, have been implemented. This moth has a widespread distribution, being found on six continents. Adaptive behavior such as diapause and multiple generations per breeding season have allowed this moth to persist even during years of bad climatic conditions. ]] When the caterpillar first hatches from the egg, it is about 2 mm long and 0.5 mm in diameter. The body is divided up into twelve segments, and the color is usually pale yellow. As the caterpillar undergoes development through five instar phases, it grows to become 18–20 mm long and more reddish in color. By the time the caterpillars are fully grown, they are light brown in color and have dark brown spots. The sex of the moth is determined during the larval stage. The karyotype of codling moths has shown a diploid system (2n=56), which means the offspring receives two sets of chromosome, one from each parent. Females have a WZ sex chromosome system, while males have ZZ. Males have two brown spots near the end of the dorsal side, which become the gonads. The eggs can hatch at night or day, depending on humidity. Because direct sunlight can dry up the caterpillar and increases the temperature, the caterpillar moves into a shade or crawls to the bottom of the leaf if it hatches during the day. The eggs are glued onto the leaf by the sticky substance secreted by the female, but the caterpillars are small and light enough to be washed away by rain or blown off the tree by wind. Especially because the caterpillars are so small when they first emerge from the egg, they are more susceptible to rainy summers, and data have shown that crops were attacked less by the moths in rainy summers. ==Pest control== Because the caterpillar of the codling moth bore into fruits and stop their growth, codling moths are major agricultural pests. They are widespread and attack a wide range of fruits. In order to control these pests, insecticide has been used extensively. Case study done in British Columbia in the late 1980s and early 1990s showed that damage from codling moths ranged from 25% to 50% of crops being damaged. Another case study at Codling Moth Areawide Management (CAMP) project sites in Washington, California, and Oregon showed that the number of hectares of farms treated with mating disruption insecticides to control codling moths has grown exponentially from 1990 to 2000. ===Chemical control=== ===Biological control=== The codling moth is not a great candidate for biological pest control, as the larvae are well protected within the fruit for the majority of development. However, their eggs are susceptible to biological control by Trichogramma wasps. The wasps deposit their eggs into codling moth eggs, and the developing wasp larvae consume the moth embryo inside. Another candidate for a biological control agent is the parasitoid wasp Mastrus ridens, also known as the Mastrus ridibundus. This wasp has exhibited a positive response to higher densities of codling moth larvae, a short generation time compared to other parasites of the codling moth, and a high number of female offspring per host larva. These 3 characteristics improve M. ridibundus 's ability to control codling moth populations. Parasitism of overwintering codling moth cocoons has reached up to 70%, but most field tests have not demonstrated a dramatic result. M. ridibundus as a biological control is recommended as part of a broader management strategy. ==References== ==External links== Codling moth on UKmoths Codling Moth Information Support System (CMISS) UC IPM Pest Management Guidelines – Apple Codling Moth Lepiforum.de

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