C. POPOV, A. BÃRBULESCU, C. ROIBU, A.A. ALEXANDRI, V. PREOTEASA
Research Institute for Cereals and Industrial Crops, 8264 Fundulea, Nicolae Titulescu str., no.1, District Calarasi, Romania, e-mail: fundulea@ns.ricic.ro

The main poliphagous pests of almost all field crops in Romania, are wireworms which belong to Elateridae species. The significant species are: Agriotes ustulatus (40.1%), A. obscurus (17.3%), A. sputator (11.3%), A. flavicornis (10.9%), A. pilosus (6.9%). Annually, the wireworms attack 800.000 ha. aproximately. The recorded densities in different crops vary from 5-10 larvae/mp up to 70-100 larvae/mp, which can induce attack levels up to 25-30% in wheat and barley crops, and 40-65% in maize and sunflower crops. The researches regarding the utilization of seed treatment are very important now, when organochlorine insecticides applied, for many years, as dusts have been prohibited.
The experiments were performed in the field, in plots cropped with wheat, barley, maize and sunflower. The efficacy of the chemicals was established on the basis of the attack frequency. The seed treatment of the winter spiked cereals, was realized with lindan-based products. The efficacy of the different formulations against wireworms was about 85%. Due to the good experimental results, numerous insectofungicide mixtures based on lindan and one or more fungicides (carbendazim, carboxin, diniconazol, miclobutanil, prochloraz, tebuconazol, thiophanate methyl, thiram, triadimenol) were obtained, and registred in Romania. Using one of these mixtures, a good simultaneous protection against both wireworms and some specific pathogens (Tilletia spp., Fusarium spp. in wheat, and Ustilago nuda, Pyrenophora graminea in barley) was assured.
For maize and sunflower seed treatment, different active ingredients (acetamiprid, bifenthrin, carbofuran, fipronyl, furatiocarb, imidachlopride, thiamethoxam) have been experimented. As a result of their good efficacy, up to 80%, many products were registered and promoted into production.
The seed chemical treatment method represents the most important, efficient, economic and almost unpolluted measure for the control of wireworms in various field crops, and for the prevention of the diseases spreaded by seed and soil, in wheat and barley crops only.

Acknowledgments: The authors thank to I.Voinescu, E.Trotus, E.Bucurean, S.Vasilescu, L.Petcu, T.Manole, V.Brudea for their contibution to this work.