Otiorhynchus ligustici L. - Alfalfa Snout Beetle

Systematic position.

Class Insecta, order Coleoptera, family Curculionidae, genus Otiorhynchus Germar.

Biological group.

Pest of perennial legumes and hop.

Morphology and biology.

Body length, 8.5-11.5 mm. Body convex, black in color, covered with moderately dense, gray vestiture. Eyes large and convex, distinctly protruding beyond contour. Rostrum conically narrowed toward pterygia, 1.5 times as long as wide. Rostral dorsum with thin median carina, frons slightly depressed. Scape extended to the apical margin of pronotum. 2nd funicular segment as long as the 1st, or slightly longer; 3rd is somewhat longer than weakly elongated 4th; 5-7th segments equal, subrounded. Club is short, widely spindle-shaped. Pronotum transverse, covered with convex, slightly flattened and weakly shining granules. Elytron widely ovate, its apical declivity rather steep, descending with negative curvature. Elytral striae weakly distinguished, intervals covered with dense and small granules. Each femur moderate in size, subequal tooth. Tibia strongly dilated apicad, tarsal claws free. Elytral pubescence comprises oblong-oval or fusiform adpressed scales and thin, pointed, slightly subrecumbent setae, which mostly arranged in few irregular rows on the intervals. It is a parthenogenetic species in most of the area. Males are known from Kherson Region of Ukraine. Larvae of last instars and adults hibernate in the soil at depth about 20-60 cm. Larva pupates in vertical soil cradle at the end of May-June. Pupa stage lasts 3-4 weeks. In Ukraine adults appear the end of June until the beginning of August, but they leave cradle next spring only during the first half of April. Mass emergence of adults occurs at soil temperature 7-12°C at depth 10 cm. Young beetles are distinguished by mandibular processes, which they lose in a few days. Adults feed during sunny days in morning and evening only, and the whole daytime on cloudy days. Oviposition begins after additional feedings and continues 1-2 months. Before oviposition female buries itself near host plant and lays down eggs one by one or by groups. Fertility is about 900 eggs. At first the egg is whitish and transparent, after 1-3 days it becomes light-brownish. Embryonal development lasts 12-30 days. Larva feeds by roots; it molts 6 times before autumn. Length of last instar larva, 16-20 mm.


Europe, Asia Minor, introduced to the North America. Inhabits the European part of the former USSR northward to Leningrad Region, the whole Caucasus, the south of Western Siberia, Middle Asia and Kazakhstan.


Generation development continues about 2 years. Polyphage, feeding on alfalfa, clover, haricot, lupine, hop, currants, vine, strawberries, nettle, beet, Siberian pea shrub. Full generation development occurs on alfalfa and hop. Larvae feed mainly on roots of perennial leguminous and hop, and vine with rosaceous plants, to a lesser degree. Abundance of the larvae sometimes reaches 100-200 specimens per sq. m. Early in spring, beetles devour buds and leaves of alfalfa and apical buds of hop. At first larvae devour thin roots and later gnaw grooves on the thick roots. Megaselia (Apiochaeta) rufipes (Diptera) is a parasite of adults. Many beetles are sometimes infected with white and green muscardine (Beauweria bassiana Bals., Metarrhizium anisopliae Metsch.).

Economic significance.

Both adults and larvae cause damage. Species is more abundant and harmful in the southern part of area. It damages vine at the nurseries, which were arranged on fields after alfalfa. Alfalfa growing in crop rotation is not desirable for more than 3 years. Pesticide treatment is necessary in spring after mass emergence of the beetles.

Reference citations:

Ioannisiani, T.G. 1972. The weevils (Coleoptera, Curculionidae) of Byelorussia. Minsk: Nauka i Tekhnika, 352 p. (in Russian).
Likventov, A.V. 1949. Some peculiarities in development of Otiorrhynchus ligustici L. in forest belts in the Lower part of the Volga River. In: Polyakov, I.Ya., ed. Proc. VIZR (2). Moscow & Leningrad: Selkhozgiz., p. 69-71 (in Russian).
Lipetskaya, A.D. & Ruzaev, K.S. 1958. Pests and diseases of vineyard. Moscow: Izd. sel'skokhozyaistvennoi literatury, 279 p. (in Russian).
Tribel, S.A. 1969. Biological peculiarities of the Otiorhynchus ligustici L. and control measures on hop crops in Ukraine. PhD Thesis. Kiev: Ukr.ASKhN, 26 p. (in Russian).
Vasil.ev, I.V. 1914. The major pests of alfalfa. Part 2. Otiorrhynchus (Cryphiphorus) ligustici L., its description, mode of life and control measures. Proc. Bureau of Entomology, 8(2). St. Petersburg: Bureau of Entomology, 40 p. (in Russian).

© David'yan G.E. (text & picture)


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