Pine sawfly: methods of struggle

Pine sawfly is a dangerous enemy for all kinds of coniferous trees. It lives in forests where such tree species meet. It spreads quickly, is capable of affecting a large area of forest tracts. Insects inflict huge damage on trees.

They are found not only in Russia (the European part, Siberia, the Caucasus), but also in Japan and other Asian countries. Even in North America, outbreaks were observed when the beetle infested huge areas of coniferous trees. A place where an insect has never been seen - the Arctic.

What does the pest of a pest look like?

There are several types of such insects:

• Sawfly ordinary;

• Red pine sawfly.

Despite the external differences, damage to insects causes the same, since they have identical habits. The only difference is reproduction. An ordinary sawfly gives at least two generations during the summer season, thereby causing more harm.

To see exactly which insect damages the tree, it is necessary to know what a pine sawfly looks like. The size of the larva is no more than 2.5 centimeters. The color can vary from light yellow to green. The head is brown. There is a false pair of legs, marked with black spots.

The larvae of the red sawfly differ in the color of the calf and head. They have a light gray shade with a characteristic white strip along the back, black spots with light patches can be seen on the sides. Head shining, black.

Appearance of an adult

The appearance of adult insects of both species of sawflies is almost identical. Differences exist only between the female and the male.

The female has a light yellow, sometimes rusty, color of calf. There are black spots along the entire perimeter. The size is small, the length does not exceed 1 centimeter.

The appearance of the sawfly female is very similar to the pupa of this insect. It is in the cocoon of the same yellow color, and the length is not more than one centimeter.

Males are painted black, except for the paws (red tint). The mustache resembles a wave crest in its shape.

How does a harmful insect appear?

Female beetles lay eggs in a special way, as if cutting through the needles. Thus, the eggs immediately fall into the soft tissues of the tree. If you take a good look, you can see convex bulges (galls) on pine trees affected by this pest.

Depending on the climatic conditions in mid-April-early May, larvae appear from the eggs, which begin to destroy the young needles at the sides, and adults eat it whole. They are holding in packs, creeping from one branch to another. Scientists have estimated that one larva is capable of completely destroying up to 40 pine needles on a pine tree.

The development of larvae takes a long time and includes 6 stages. On average, they ripen for several months, then pupate in the branches of the tree, and after 15 days a pine sawfly appears on the light.

But this does not always happen. Very often caterpillars descend the trunk into the litter of grass, moss, fallen pine needles. Carefully disguised in it and plunged into hibernation. The larva can stay in this state for up to 2 years, and it does not need additional nutrition. Some individuals can hide in the bark of a tree at its base.

What damage does the pest do?

Lesnichestvo, in which coniferous trees are planted, the term "pine sawfly" is well known. Measures to combat it are different, the main thing is to find the problem in time, otherwise the damage from the insect can be huge.

Harm causes both larvae and adults. Even if the first eat the needles on the sides, leaving the middle untouched, it shrinks, turns yellow and eventually falls off. In addition, adult caterpillars eat it whole, and if there is a shortage of food, they can reach the bark and young shoots. And this already leads to the fact that the branches in the crown are drying up. After a while the plant weakens, begins to ache, which leads to the death of the tree.

If the pine sawfly reaches the young pine, then it dies within 4 years. It often happens that in addition to the described insect a weak tree is attacked by other pests. In this case, the pine dies during wintering.

Pine sawfly: how to fight and win in the forests

In coniferous forests, it is very problematic to deal with this type of pest. But still the methods of getting rid of an insect are:

1. Use of special glue rings. On the lower part of the barrel a thin layer of glue is applied, which is not prone to drying and is resistant to moisture. At a time when the larvae descend to form a cocoon, they fall into the created trap.

2. Chemical spraying of infected and trees.

3. If the area of damage is large, aviation processing is carried out.

4. The use of a viral drug ("Virine-diprion"). When using it, the pH of the medium should be taken into account.

Dangerous pine sawfly: measures of pest control on the backyard

If you found this evil pest at the dacha, you need to save the trees. The struggle will be as follows:

1. Planting next to the infected pine bushes is a tomato. The enzymes produced by this plant repel insects.

2. Digging up an infected tree.

3. Before planting a young pine, it is recommended to pour a specially prepared ash solution with water into the well.

4. Sprinkle with tincture of mustard, tomatoes, wormwood, tobacco.

5. Application of biologics.

6. If the pine is small, collect the larvae by hand. Always wear gloves and goggles. The insect in case of danger regurgitates its blood, which can cause a strong allergic reaction in humans.

Methods of prevention

If at least one tree in the forest has been hit by a pine sawfly, the methods of fighting must be taken immediately. But not always they have the proper effect. Each method is good for application at a specific time (maturation of larvae, pupa formation, breeding period, etc.). Therefore, it is better not to allow the appearance of a harmful insect. For this, there are special preventive measures:

• In many respects the spread of the pine sawfly is facilitated by favorable weather. If weather forecasters forecast hot and dry May and June, with a certainty of 80%, it can be said that the trees will face the invasion of the pest. If there is enough rain in these months, you can not worry about pine trees. At high humidity, the larvae of the insect perish.

• If possible, it is better to plant mixed forests (coniferous and deciduous). The presence of shrubs makes it difficult for adults to search for food.

• Pine sawfly - a tasty morsel for birds. Build the birdhouses, provide lure for the birds, which are the natural sanitarians of the forests.

Pine sawfly quickly multiplies and affects a large number of trees. It is necessary to fight against it in order to prevent extinction of forest tracts.