Carp ( Cydia Pomonella ), an insect of the order Lepidoptera, is one of the main orchard pests and mainly attacks pome plants. It is not for nothing that it is commonly called “apple worm”, although its damage affects not only apple trees but also pears, quinces and walnuts.
The term “worm” refers to the larvae that penetrate the fruit, causing the actual damage that the insect brings to the crops, in the affected trees, the carrapse can lead to the total loss of the harvest.
Fortunately, today there are several methods of defense against this parasite, and even the organic, amateur and professional arborist can choose between different solutions. As for the defense against other adversities in the organic garden, also in the case of Carpocapsa, the important thing is to act quickly and constantly, possibly through various combined intervention strategies.
Contents [Ocultar]
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Know the codling moth
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Prevent and capture this lepidopterist
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Codling moth traps
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Monitoring with traps
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DIY traps against overwintering larvae
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food traps
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slime trap
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Insecticides and biological control of carpocapsa
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sex pheromones
Contents
Know the codling moth
To get the best results, you must first know the insect and its life cycle. This is the only way to identify the threat in time and apply preventive or corrective measures at the right time. The adult carpocapsa is a small butterfly with a wingspan of 15-22 mm, with grayish forewings and transverse bronze stripes. Young larvae are white with a dark head, then turn yellowish and finally pinkish. The instars are 5 in number and the final length of the larva at the last instar is about 20 mm.
The adult individuals of these lepidoptera blink between April and May, after having spent the winter in the larval stage protected in cocoons, under the plates of the bark of the trees. After flashing, when average temperatures are 15-16°C, the carpopod lays its eggs on the leaves and fruits, from which the dreaded larvae hatch, responsible for crop damage. Indeed, the larvae penetrate the fruits and dig tunnels in the pulp, eating it and deteriorating it. Once their development is complete, they leave the fruit to be stung on the branches or the trunk and carry out their metamorphosis which goes through the chrysalis stage and then reaches the adult stage. The attached fruits fall or remain attached to the plant, but in no case are they no longer edible.
Carpocapsa reaches two or three generations per year, the last of which develops between late summer and early autumn. During her life, each female generates an average of 60-80 eggs, which are laid separately.
Considering the biology and behavior of this insect, it is obvious that a good phytosanitary defense is important in order to be able to harvest healthy and abundant fruits and not to frustrate all the previous work of planting, pruning and fertilizing the orchard. . So let’s see what are the most effective and ecological methods to monitor and control this insidious insect.
Prevent and capture this lepidopterist
Once the carpapsa eggs have been deposited in the fruit, there is not much more to do, the advice that can be given is therefore centered on prevention: to avoid finding the larvae in the apples or pears of our orchard we must therefore intervene before they hatch and we can only do this by fighting the adult insect.
Insect nets
Mosquito nets, installed to completely cover the foliage after fruit set, provide an excellent barrier to egg laying. The cost of purchasing them and possibly setting up an effective row cover and uncovering system is quite significant, but in professional organic arboriculture it is an investment that must be evaluated, also because it is durable and can be combined with weather protection. hail.
If you have few plants, the nets are wrapped around the foliage using a ladder.
Codling moth traps
Insect traps basically serve two purposes: to monitor and reduce the minnow population.
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Monitoring of their presence, which makes it possible to identify the right moment to carry out the treatments.
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The capture itself, also called “mass capture”, which aims to significantly reduce the presence of the insect.
load monitoring
Surveillance systems are very helpful in giving us a timely view of the insect’s presence. Monitoring traps should be set early, around the end of April, in quantities of 2 to 3 per hectare. These traps can be pheromone traps, food traps or chromotropy traps. Once installed, catches should be monitored weekly and when two adults of carpapsa per trap are seen in a week, it is time to start intervening, i.e. the “damage threshold” has been reached .
An example of a trap suitable for both surveillance and mass trapping is the Sfera trap, a yellow chromotope trap with a spherical shape. The sphere is equipped with an LED in which two 1.5 V batteries are inserted, and in this way it lights up at night and operates continuously. Before hanging it, it must be covered with a transparent film and sprayed with glue. Harmful insects (carpapse but also wasps, flies and bumblebees) will remain attached to it. For monitoring purposes, we will be able to observe the catches and identify the carp.
An alternative and simpler type of monitoring is that of the fruit: the damage threshold in this case is 1% of the fruit showing larval penetration holes. Obviously this monitoring begins with fruiting and therefore after capture.
DIY traps against overwintering larvae
In ornamental orchards with a few examples of apple and pear trees in late summer, it is advisable to wrap the trunk of the plants with a strip of corrugated cardboard, as the larvae preparing for winter will cocoons and in this way they can be removed. At the end of winter, the cardboard can be wrapped in a 3mm mesh net because this allows harmless insects to escape and retains those of the carpape. It can be a good DIY method to get rid of lots of bugs without using products.
food traps
Food traps, such as Tap Traps, are very effective in controlling many insect pests and carpapsa is one of them.
Tap Trap is a yellow plastic trap cap that attaches to the neck of a plastic bottle previously filled with food bait. Insects, already approaching the yellow color, are attracted by the smell given off by the bait, they enter the bottle but can no longer get out and drown in it.
What bait to use for carpocapsa . In the bottles that are used with Tap Trap to catch carp, it is advisable to put bait prepared with the following recipe: take 1 liter of wine, add 6-7 tablespoons of sugar, flavor with 15 cloves and half a cinnamon stick. Let everything macerate for about 15 days then dilute it with 3 liters of water. In this way, a total of 4 liters of bait is obtained, to be used for 8 trap bottles, i.e. half a liter each.
Trash can
The alternative to the classic Tap Trap is the Trap Glass, yellow cap, with a slightly different shape because it is designed to be used with a glass jar instead of the bottle. For this, 1 kg jars of honey are excellent. The recommended recipe is the same for Tap Trap, only in this case many more trap pots can be filled, around 11.
Insecticides and biological control of carpocapsa
Against winter forms of codling moth, fall treatments can be done with entomoparasitic nematodes , that is, they parasitize the insect like Steinernema carpocapsae or Steinernemafeltiae. This method allows a significant reduction of insects the following season. It is an effective type of treatment, especially in conditions of high air and vegetation humidity. The ideal is to do it after a rain, and it is important to do it at night, because the nematodes are sensitive to ultraviolet rays. .
Another ecological and proven product against carpocapsa is the granulosis virus which acts specifically on Lepidoptera and is very selective because there are several specific strains, including the one adapted to the defense against codling moths. The commercial products are suspensions which are diluted in water and sprayed on the plants at the start of the hatching of carpopod eggs, because it acts on the larvae. Monitoring traps and local plant pathology bulletins are used to identify the right time to perform the treatment, but towards the end of May the larvae are usually present. The first glimmering codling moth adults lay their eggs primarily on the leaves, so treatment at this stage can be very beneficial.
Ultimately, spinosad It is an insecticide authorized in organic farming and effective against various insect pests of the orchard and the garden. This treatment also acts against the carpape. Generally, the commercial product is quite expensive, but it must be used very diluted (about 15 ml in 100 liters of water), it has multiple uses and is very successful.
In a context of biological defense, sweet orange essential oil can also be used, which is an ecological method less effective than spinosad but more natural.
sex pheromones
The mating disruption method prevents males from finding females, through the spread of synthetic sex pheromones in the environment. This has a negative impact on the multiplication of the insect and therefore allows . Indeed, when the males fail to locate the females, mating does not take place. In professional orchards of at least one hectare, it is certainly an effective and long-standing method.
There are also pheromone traps for mass trapping, which attract insects with the pheromone and are sprayed with glue. These are very selective traps because the diffuser only emits the specific pheromones of the target insect, avoiding all others.