Lixus junci Boheman
Taxonomic placing: Insecta, Holometabola, Coleoptera, Curculionidae.
Common name: Beet weevil
Geographical distribution: The Mediterranean region.
Host plants: Various cultivated forms of Beta vulgaris L., including sugar beet and red beet.
Morphology: Body of adults about 10-12 mm long, elongated, brown with darker head, covered with reddish powder, elytra striated and finely punctated. Larva whitish with a brown head, about 15 mm in length.
Life cycle: Females excavate small holes in the host petioles wherein they place their eggs (about 200/female). The emerging larvae gnaw at the petiole, later moving into the taproot in which they form galleries, wherein they pupate. The calculated threshold of development is around 10ºC. The adult may live for several months, raising 2 annual generations (in spring and in late summer).
Economic importance: The feeding of the larvae on the petioles causes their withering, and burrowing in the taproot affects plant growth and provides invasion portals for rot microorganisms. A heavy infestation may reduce beet weight by 75%.
Management
Horticultural methods: Heavy damage may be avoided by early beet harvesting.
Chemical control: Organophosphates](entry/Organophosphate) controlled the pest.
Biological control: The braconid Bassus mediator (Nees) (formerly known as Microdus lugubrator (Ratzeburg)) parasitized the pest in Israel.
References
Ocete, R. and Ocete, M.E., Pérez Izoquierdo, M.A. and Rubio, I.M. 1994. Aproximación a la fenología de Lixus junci Boheman (Coleoptera: Curculionidae) en La Rioja Alta: estimación de las pérdidas que causa. Boletín de Sanidad Vegetal Plagas 20: 611-616.
Rivnay, E. 1962. Field Crop Pests in the Near East. W Junk, The Hague, 450 pp.