BIOLOGY AND CONTROL OF TANYMECUS-DILATICOLLIS GYLL (COL, CURCULIONIDAE)

T. dilaticollis has long been a member of the Hungarian fauna, but pub lication on its damage only appeared in 1952. In South-Eastern Europea n countries first of all in Rumania, it caused damages to maize in the 1940s already, a definitely polyphagous species. In Hungary it has do ne greater or smaller damages to Beta-, Medicago-, Triticum-, Helianth us-, Citrullus-, Persica- and Amygadalus species besides maize. Many w eed plants are also chewed by it. It has a single generation a year. T he adult overwinters in the soil. In May the adults feed on young maiz e leavae. The larvae develop on the roots, and do not cause damage. In August they enter the pupa state in the cocoon prepared in the soil, then transform into adults which do not emerge but overwinter in oblig ate diapause. The average number of eggs per female is 103. Of the egg s 11.9% were laid in April, 11.0% in May, 40.0% in June and 37.1% in J uly, under glasshouse-laboratory conditions. The number of eggs is inf luenced by the photoperiod and temperature. Its mass reproduction in H ungary was caused - in our opinion - by the single-crop production of maize. In warm, rainy years the individual number is higher. The distr ibution of a forat-containing granulate (18-25 kg/ha) before sowing ha s proved to be a successul method of control. Seed-drills (e.g. John-D eer, Becker, etc.) furnished with granulate distributor carry out the work of sowing and pest control in one go (5-10 kg/ha).