Pests
Otiorhynchus asphaltinus Germar - Crimean Vine Weevil
Systematic position.
Class Insecta, order Coleoptera, family Curculionidae, genus Otiorhynchus Germar. Closely related to O. atronitens Form., differing from latter in structure of male hind tibia.Synonyms.
O. asphaltinus creticola Arnoldi.Biological group.
Pest of vine.Morphology and biology.
Body sub-glabrous, shiny and coal-black; antennae and tarsus occasionally lighter. Vestiture with thin, tiny and sparse hairs, without scales. Body length 6.2-10 mm, width 2.6-5 mm. Rostrum weakly transverse, rostral dorsum flattened. Eyes large, somewhat convex. First and 2nd funicular segments elongated, with the first somewhat shorter; 3rd to 7th segments less elongated, or sub-squared. Disk of pronotum distinctly punctated, interspace between punctures somewhat convex. Beetle is wingless. Elytra long-ovate, intervals flat or slightly convex, distinctly punctated. Femora with a tooth, which is the largest on hind legs. Male femora somewhat thickened. Anterior margin of hind tibia indented, with deep excision and elongated prominence in preapical part. Adults are active mainly at night. The beetle.s activity depends on the weather and phase of vine growth. Emergence of overwintered adults starts 2 weeks before swelling of buds and continues for 25 days. Mating starts soon after the beginning of additional feeding. Oviposition occurs from May until the end of July. Egg develops 9-20 days. The first larvae hatch the end of April. Larva has 7 instars. It lives in the soil, eating vine roots. Adults and larvae of the last instars hibernate. Majority of larvae perish in 1st and 2nd instars during hibernation. Pupation begins the end of May at the soil temperature 18-20°C. Pupae occur in abundance the end of May until mid-July at depth of 5-15 cm. The pupa development lasts 9-15 days, with 16.5-22°C as the optimal temperature for its development. Appearance of the first young beetles begins the end of May and coincides with the ripening of early-maturing sweet cherry. Emergence of young beetles begins the first of October. Mating occurs all season and before hibernation. Adult longevity is 3 years, but most of them perish before autumn in the second year of their life. Fertility is about 2000 eggs in the 1st year and about 600 eggs in the 2nd year.Distribution.
Distributed in southern regions of Ukraine and European part of Russia. Imported specimens are known from St. Petersburg, Baikal and Western Europe.Ecology.
Polyphage, feeding on plants of 85 species. Vine, almond tree, apple, ash tree, maple, dog-rose, pear, apricot and alfalfa are the main host plants for adult. Figured injury of leaf margin is typical of adult. Diapause begins at the soil temperature about 9.2° and day length duration 10-11 hours. Vineyard is defoliated after early frost in autumn, and most adults perish before spring due to nutrient deficiency. Population density in nature depends on the activity of predators Calosoma sycophanta L., Procerus tauricus Boh. and insectivore mammals. Adults and larvae may be infected by white and red muscardine respectively.Economic significance.
Both adults and larvae cause damage. About 44% of buds per 1 vine shrub may be injured by 5 specimens of adults. Damage of the apical part of the bud is more dangerous because the growing point is destroyed. Harmfulness increases during long spring. In Crimea, crop losses of vine sometimes run 50%. Control measures include treatment of the ground with a cultivator at depth to 12 cm in period of mass pupation. Pesticide treatment is necessary in spring after mass emergence of the beetles.Reference citations:
Korotyaev, B.A. 1984. Family Curculionidae. In: Kopaneva L.M., ed. Key to harmful and useful insects and mites of fruit and berry cultures in the USSR. Leningrad: Kolos, 120-125 (in Russian).Lipetskaya, A.D. & Ruzaev, K.S. 1958. Pests and diseases of vineyard. Moscow: Izd. sel'skokhozyaistvennoi literatury, 279 p. (in Russian).
Mashchenko, N.D. 1972. Significance of the ecological factors on the diurnal activity of Otiorhynchus asphaltinus. In: Dudnik, N.A. Viticulture. Odessa: Proceedings of SKHI, 183-185 (in Russian).
Mashchenko, N.D. 1973. Control measures substantiation against Otiorhynchus asphaltinus // In: Dudnik, N.A. Viticulture. Odessa: Proceedings of SKHI, 130-137 (in Russian).
Mashchenko, N.D. 1975. Biology of Otiorhynchus asphaltinus and control measures in vineyard // PhD Thesis. Kishinev: Kishinevskii SKhI, 21 p. (in Russian).
Slavgorodskaya-Kurpieva, L.E. 1982. Otiorhynchus asphaltinus and control measures in vineyard. Kiev: AN Ukr.SSR. 39 p. (in Russian).