Gardening

Cochineal on pine


Question: What affects my hedge?


I have a hedge with about fifty pine trees, and on more than half of them there is the cochineal as I have to fight this parasite thanks

Cochineal on pine: Answer: cochineal on conifers


Dear Gabriele,
the cochineal is a typical parasite of conifers, often difficult to notice because the small specimens tend to nest beneath the needles, or at the point where they are attached to the branches, and therefore are almost invisible; infestations are only noticed when they are large and when they lead to symptoms on plants. Generally it is a fall of honeydew from the foliage of the plants, but with the passing of the months it can happen that the needles turn yellow, and the plants remain little thick. This type of parasite generally, however, very rarely causes serious damage to conifers, unless they are very young specimens, or specimens cultivated with bonsai. In all other cases the cochineal is usually left undisturbed, as it tends not to give great problems to an adult and large conifer. If you have noticed the insects, then it means that your hedge was not very well, and therefore it shows some strange and worrying symptoms. The treatments against cochineal, to be effective, must be practiced in late winter or early spring, in order to eradicate even the juvenile stages of the insect. Since it is always better to use insecticides when there are no bees or other useful insects in the garden, it would be advisable to practice treatments against cochineal in late winter, when the plants around the hedge are not yet in bloom. Typically white oil is used, as it is able to dissolve the waxy layer that scale insects build around it, which protects them from the outside. White oil can be mixed with other insecticides, which make it more effective; the white oil therefore works only as a carrier for an insecticide, to which it is mixed. Pyrethroid or pyrethroid based insecticides are often used, which seem to work against cochineal.