Pest Type: Pest
Row: Diptera – Diptera
Family: Gall midges – Cecidomyiidae
It is widespread in the south of Russia, damaging clary sage.
The adult is 2-3 mm in size, has 14 segments, antennae, and long legs; the female differs from the male in large body size, well-developed abdomen and the presence of an ovipositor.
A freshly laid egg 0.34 × 0.10 mm in size has a light brown color, oval, the egg is similar in shape, on the second day after laying the chorion of the egg becomes dull, the embryo is clearly visible through it.
Larva orange-black, oblong, narrowed, densified, segmented. Forms a white spider web cocoon in which pupates. Pupa – 3 mm, free, with the rudiments of the head, legs, wings, antennae and orange-black abdomen.
Winters in the larval stage in the surface soil layer. Years of imago occur in May, at a temperature of 18-19 ° C, in the initial period of budding of sage. The female sexual index is 0.6, and the male is 0.4. Egg-laying occurs in buds, in groups or one at a time, on bracts protected from direct sunlight. The fertility of females – 17-205 eggs. Embryonic development at 20-22 ° C is completed within 2-3 days. Reborn larvae penetrate into the bud to flower twigs and flowers. Most (up to 37 individuals) are concentrated inside the calyx of flowers. When feeding, the larvae damage the ovary, which subsequently darkens and dries. The walls of the cups of flowers grow and deform.
Damaged flower branches are shortened and often dry out. In the case of a significant settlement of inflorescences, it stops growing, is deformed and does not bloom. The mass of damaged inflorescences decreases by 15-70%, and the number of healthy flower cups, which contain the largest amount of essential oil, by 30-90%. Mass fraction of essential oil is reduced by 1.5-8 times. In May – June, most larvae pupate in inflorescences. During the year, the sage gall midge develops in four to five generations. In August – September, the larvae of the last generation pass into the soil, where they remain until the spring of next year.
Protective measures. Sage cultivation on the same field for only two years. Spatial isolation of sage plantations of different years of vegetation and varieties with different flowering periods. Deep plowing of sage fields. In conditions of high pest populations of plantations – processing in the initial period of budding with insecticides.