Stem cabbage angiosperm – fighting
The stem cabbage angiosperm is distributed throughout Ukraine. Food specialization – cabbage, namely cabbage, rutabaga, spring rapeseed, mustard, radish, turnip.
The stem cabbage angiosperm (Ceutorhynchus quadridens Panz.) is a small beetle with a size of only 2.5 – 3.2 mm. It can also be recognized by the following signs: grayish-brown in color, with a white quadrangular spot near the shield. It has geniculate-shaped antennae, a thin and long cephalothorax. Females lay transparent,oval eggs 0.8 mm in size, from which legless yellowish-white larvae up to 5 mm in size develop. Over time, they turn into pupae up to 4 mm in size, also yellowish in color.
Adult beetles of the stem cabbage angiosperm remain for the winter, for this they hide under the remains of plants in parks, gardens, forest belts, on the edges of forests. In the first half of April, when the soil temperature rises to 8-9 ° C, the beetles wake up. At the beginning, they feed on wild plants, but over time they switch to cultivated ones, both in fields and in greenhouses. Their pity lies in the fact that first they gnaw through the petioles and thick veins of the epidermis, and then eat away the pulp – thus, chambers are formed inside the leaf, and “warts” on the surface.
Despite the small size of the stem cabbage powderworm, its females are highly fertile – 40-60 eggs, which lay 3-4 pieces each. Such places swell and outwardly resemble warts. After half a week or a week, larvae appear, gnawing through the passages in the petioles of the leaf, sometimes reaching the root collar. Gnawed by the stem cabbage hidden-bodied can be easily recognized by the brown stripes that are translucent. There can be 15-20 larvae in one leaf at the same time, such leaves lag behind in growth and subsequently die. The development of larvae lasts 20-30 days, they burrow into the soil to a depth of 2-3 cm and turn into pupae. In June, beetles come to the surface, which feed for a short time and switch to wintering.
See also:ORCHIDS – ORCHID CARE
The economic threshold of harmfulness (EPS) is 1 beetle per plant at the stemming phase.
The stem cabbage powder borer has natural enemies, in particular, Tersilochus obscurator Aubert (Hymenoptera: Ichneumonidae) parasitizes on the larvae.
Protection measures against stem cabbage angiosperm
Agrotechnical protection measures: deep autumn plowing. Careful selection of seedlings – only intact ones can be used.
Destruction of weeds. If beetles populate a fifth of the excess EPS, it is necessary to spray the area with an insecticide.
Testes are best sprayed at the beginning of budding.
