The aphid (Myzus cerasi Fabricius, 1775) is currently the main pest in cultivation of the cherry tree .
It belongs to the Aphidoidea family, popularly known as aphids, they are between 1 and 10 mm long and can be colored black (cherry tree ), yellow, brown and green.
Like the other aphids, the black cherry aphid (1.8-2.6 mm) feeds on the sap and has similar reproductive cycles.
Aphid biological cycle
During the cycle of the aphid, it mainly feeds on the sap of young shoots. At the same time that the aphid sucks the sap, it injects toxic enzymes with its saliva. After the digestion of the sap, the aphid excretes sugars, these sugars can be the substrate of fungi like the Bold.
Aphids have two ways to multiply. In an amphonic or parthenogenetic form,
Amphibonic: they need to mate to fertilize the eggs.
Parthenogenetic: during this phase they can lay unfertilized eggs that recombine genetically, in the case of Myzus cerasi, the progeny are female.
During the parthenogenetic phase the black aphid of the cherry tree and other species of aphids, have a enormous capacity of multiplication.
Damage caused by aphids
The activity of the aphid in the cherry tree weakens and reduces the growths of the tree. In the new cherry plantations delays the formation of trees.
The fruits infected by the aphid colonies take longer to mature and reach a size smaller than that of a healthy cherry. In addition, the molasses excreted by the aphids permeates the surface of the cherry, depreciating its value and complicating the collection.
Predators of aphids
The popular ladybug (Coccinella septempunctata Linnaeus, 1758) is the most popular aphid predator. Their larvae need to feed on a large amount of aphids during their development. They also help control other pests as mites and black scale.
The syrphids (Syrphidae Latreille, 1802), with three major species on the peninsula Eupeodes corollae, Episyrphus balteatus and Sphaerophoria rueppellii. They are an excellent ally against the aphid.
Aphidius colemani (Dalman, 1820) is a parasitoid wasp of different species of green, black, white and yellow aphids.
The earwig (Dermaptera DeGeer, 1773), is an insectivore with a regular presence in stone fruit trees (cherry, almond, plum tree …).
The larvae of Cristop (Chrysoperla carnea Stephens, 1836) are also aphid predators.
Other coleoptera such as Scymnus apetzi (Mulsant, 1846), parasitoids such as Ephedrus cerasicola (Stary, 1962) and insects of the family Chamaemyiidae.
There are now research to select and cultivate the most effective aphid predators. The results will be applied for the biological control of the aphid, both in the open field and in the greenhouse. The biological fight is the main weapon that has organic farming in the fight against the aphid and other pests.
The performance of these and other predators of the aphid is limited when there are populations of ants defending the aphids.
How to fight the aphid?
Combating or eliminating aphids can be a complex task. Even by applying authorized systemic insecticides, ant populations can help infect trees again. In addition, the application of insecticides reduces the presence of aphid predators that need more time to recover.
As we have seen, the activity of aphids is important during the growth phase of the cherry tree. It affects tender shoots especially so we should be attentive to this stage of development.
Studying the behavior of the different ant species in our growing area, can help control the pest partially. The most probable is that we meet the ant (Lasius grandis Forel, 1909), with great addiction to the sugary secretions of flies, aphids, scale insects or other pests.
How to eliminate ants?
In crops it is very important to know how we should eliminate ants. It is necessary to do it in a selective way that causes the least possible disorder in the ecosystem.
The species of ants establish competences among themselves for the existing resources. For this reason, if we try to eliminate all the anthills that we find without identifying them, the resources of our area will increase fostering the new invasion of the crop.
Maybe we managed to keep the ant populations at bay for a few months, but they ended up returning quickly.
Therefore, when we perform control over ants, we want to reduce the populations of those species that have a greater fondness for the aphid.
Ants that feed on insects and weeds such as grass favor the balance of the ecosystem of our plantation.
Summing up, ants have an important significance for the balance of the ecosystem. When we grow fruit trees, we encourage an increase in species that feed on sugar excreted by aphids, on other native species that benefit us. Our fight against ants should therefore be aimed at promoting the populations of ants that do not “graze” the aphid. To favor these species, we must simply eliminate the anthills that cause damage, the biological niche they leave, will end up being occupied by new ant colonies.
There are several products (poisons, baits, repellents, sprays, insecticides, traps…) against ants. For home, homemade baits with boric acid + sugar are very effective. In agricultural crops, we can used treatments authorized by the ministry to fumigate ants.
Control and treatments against cherry aphid
As we have seen, cultural measures should be aimed at increasing predator populations and preventing ants from pasturing aphids. Within the measures to avoid the action of the ants, we can surround the trunks with entomological tail.
Treatments for cherry aphid
Although cultural practices are a good way to reduce the number of treatments needed. The use of systemic insecticides for aphids ends up being necessary in most plantations. Some treatments against the aphid have been authorized by the ministry.
Imidacloprid 20%, trade name Confidor 20 LS, 28 days of security.
Acetamiprid 0.005% (trade name Polysect Ultra Al, 14 days and a single annual application).
Other insecticide treatments such as those applied against the cherry fly and Drosophila suzukii (Matsumura, 1931), can also help control the aphid.