Pests
Chaetocnema breviuscula Fald. - Beet Flea Beetle.
Systematic position.
Class Insecta, order Coleoptera, family Chrysomelidae, genus Chaetocnema. Closely related to Ch. tibialis Ill.Biological group.
This is a pest of sugar-beet, mangold and red beet.Morphology and biology.
The body length is 1.4-2 mm, some females are bigger than males. The body is short-oviform, upper side dark-green in color with metallic shine, tarsus, tibia and base of antennae russet. Antennae include 11 segments. Frons smooth with 3-5 punctures near both of eyes. The stria of elytra has regular punctures. Middle and hind tibia in apical 1/3 part of length emarginated and covered in this part with short hairs. Hind femur thickened, adapted for jumping. Adults appear in spring with an average air temperature of 8-9°C long before beet seedlings and they feed on weeds. Adults fly to beet fields with the appearance of cotyledons and first leaves. Beetles eat parenchyma up to cuticle and plant may be destroyed after growing-points are injured. Mating and oviposition occur from the beginning of May. Fertility is about 40-50 eggs, female puts eggs around food plants. Egg development continues for 8-14 days, larvae for 24-36 days, pupae for 8-14 days. Larva in last instar are white in color, head and legs foxy, body length is 4.4 mm. Pupae white, with 2 spines on the apex of abdomen. Adults of the first generation emerge in June-July, the second in August-September. Most beetles migrate to woodland belts for hibernation after additional feeding in the fall. Some of them stay in fields.Distribution.
This is a European-Siberian species. Inhabits Western Europe, Asia Minor, Iraq, Mongolia. In the former USSR it is widely distributed in the south of the European part, in the Caucasus, in the south of Western Siberia, in Kazakhstan and Middle Asia without high mountains. Absent in Far East.Ecology.
Moderately xerophilous polyzonal species, distributed throughout mixed forests to semi-desert territories. They develop on Chenopodiaceae (Atriplex, Beta, Chenopodium, Haloxylon, Salsola) and Amaranthaceae. Adults prefer Chenopodium, Beta and to a lesser degree Salsola, Amaranthus. Larvae develop in the soil on roots of the same plants but their damage to agricultural plants is inessential. Damage of adults is most discernible during hot days, but at night and after the fall of temperatures beetles are inert. It is monovoltine in most areas and bivoltine in southern regions.Economic significance.
Greatest damage is caused to beet seedlings in the spring before a few pair of leaves develop; significant not discernible in the summer and autumn. Most damage is caused to late sowing beet seedlings. Irrigation of fields during the pre-imaginal phase of the pest development causes a decrease in its abundance.Reference citations:
Dobrovol'skii B.V. 1951. Harmful beetles. Rostov-na-Donu: Rostizdat. 455 p. (In Russian)Dubeshko L.N., Medvedev L.N. 1989. Ecology of leaf beetles from Siberia and Far East. Irkutsk: Izd. Irkutskogo Universiteta. 224 p. (In Russian)
Konstantinov A.S. 1988. Landscape-zonal peculiarities of the Chaetocnema beetles distribution (Coleoptera, Chrysomelidae). Vestnik Zoologii. N. 6. Kiev. 44-47 p. (In Russian)
Lakhidov A.I., ed. 1976. The system of estimation and forecast of development of pests and diseases of field crops in Central-Chernozem Region. Voronezh: Tsentral'no-Chernozemnoe Publishing House. 136 p. (In Russian)
Lopatin I.K. 1977. Leaf beetles (Chrysomelidae) from Middle Asia and Kazakhstan. Leningrad: Nauka. 289 p. (In Russian)
Lopatin I.K., Kulenova K.Z. 1986. Leaf beetles (Coleoptera, Chrysomelidae) from Kazakhstan. Alma-Ata: Nauka. 199 p. (In Russian)
Markov F.I. 1962. Ecological foundation of control beet flea-beetles on the irrigated area of Kirgizstan and Kazakhstan. Questions of ecology of land invertebrates. V. 4. Moscow: Vysshaya shkola. 45-46 p. (In Russian)
Minoranskii V.A. 1976. Harmful insects in the beet fields. Rostov: Rostov University. 112 p. (In Russian)
Palii V.F. 1961. Fauna of the pest flea beetles from USSR. Frunze: Izd. AN Kirgiz. SSR. 101 p. (In Russian)
Putele V. 1970 a. Fauna of the flea beetles from Latvian SSR. Materials of 7th Baltic meeting on plant protection, part 2. Pests of agricultural and forest plants and their control. Elgava: Latvian Ministry of Agriculture. 17-20 p. (In Russian)
Putele V. 1970 b. Flea beetles of the genus Chaetocnema from Latvian SSR. Materials of 7th Baltic meeting on plant protection, part 2. Pests of agricultural and forest plants and their control. Elgava: Latvian Ministry of Agriculture. 20-25 p. (In Russian)
Zverezomb-Zubovskii E.V. 1956. Pests of sugar-beet. Kiev: AN Ukr. SSR. 276 p. (In Russian)