Brutal Sunflower Thornbearer

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

The sunflower, or sunflower thorn beetle is found everywhere on the territory of Russia, especially often it can be observed in the steppe regions. The harmfulness of this unceremonious scoundrel lies not only in the fact that its larvae, in addition to sunflower, are capable of damaging various essential oil and industrial crops, but also in the fact that the beetles of the sunflower thorn beetle are carriers of pathogens of various viral and fungal ailments. Therefore, if an uninvited guest is found on the site, everything possible should be done in order to get rid of her as soon as possible

Meet the pest

The sunflower spikelet is a malicious black beetle, the size of which ranges from 2.5 to 3.3 mm. The entire body of the pests is densely covered with hairs. Their chairpersons are usually wider than the anterior edges of the pronotum, the abdomen protrude beyond the tips of the elytra, and the hind tibia are equipped with a pair of rather long notches.

The larvae of sunflower thorns are colored lemon-yellow. Their body is covered with short, sparse bristles, and on the last segments of the abdomen there are a pair of large cone-shaped spines. The heads of the larvae are always brownish. As for the tops of the anal segments, they are equipped with hairs and small spines arranged in the form of oval rings. All segments of the bodies of the larvae are characterized by sawtooth sides and are clearly delineated. And the pupae of the pests are rather small in size and have a brilliant yellow color.

Approximately in May-June, adults begin to appear, laying eggs under the skin of sunflower stalks. Eggs are laid by females mainly in the leaf sinuses. The larvae hatching from the eggs (their hatching occurs about a week and a half after laying the eggs) begin to feed on the cores of the stalks, in which they gnaw through the winding narrow passages. By the way, in these passages they will hibernate later. And with the onset of spring, voracious larvae will continue their march closer to the outer sides of the stalks attacked by them. Their pupation will also occur there. Each sunflower stalk can contain several dozen harmful larvae (sometimes up to ninety pieces). In addition to sunflower, they also choose various Compositae crops as food.

Sunflower thorn beetles are incredibly mobile. If something threatens them, they either strive to fly away as soon as possible, or, bending their front and middle legs to the body and tucking their head, sharply push off with their hind legs in order to fall down from the plants. During the fall, they can roll over their heads several times. As soon as they reach the soil surface, they will make a few more somersaults and again push off with their legs, hiding in nearby shelters and falling into a state of thanatosis there.

Immediately after emerging from the soil in spring, bugs are usually quite slow. Their mass release starts with the beginning of sunflower flowering. The years of harmful parasites lasts until the end of July, and sometimes until the end of August.

The bugs have a lifespan of about two months. Usually males start to die off first. Especially dangerous are sunflower thorns, when there are more than fifteen individuals per stalk - the productivity of growing crops in this case is significantly reduced.

How to fight

Plant residues from the plots must be promptly eliminated and immediately destroyed, and deep autumn plowing should be carried out on the plots themselves. When harvesting, sunflower stalks should be cut close to the ground.

But it is not recommended to use insecticides in order to get rid of sunflower thorns. Only in the most extreme cases is it permissible to carry out the treatment with "Fufanon", "Danadim Stable" or "Vantex".