Kseniya D. DYATLOVA¹⁾ and Andrei N. FROLOV^2)
1)Nizhny Novgorod Agricultural Academy, Nizhny Novgorod, 603093 Russia;
²⁾All-Russian Institute for Plant Protection, Pushkin  St. Petersburg, 189620 Russia;

The European corn borer (ECB), Ostrinia nubilalis (Hbn.) is one of the most important pest of maize. However, it is capable to infest very many other plants including sorghum (Painter, Weibel, 1951; Atkins et al., 1983; Wiseman, 1992). During 1994-1998 we compared maize and sorghum infestations at the scientific crop rotation of the Kuban Experimental Station, Krasnodar Territory, Russia (two-generation zone of the pest). Overall number of fields inspected was 11 for sorghum and 21 for maize. Periodical surveys of plants grown at 7-23 constant plots (averaged in size 2.5 m2) per field were done at regular (5-7 days) intervals during a period of egg-laying to estimate numbers, survival and mortality of eggs. We summed over all estimates of egg numbers per plot to obtain absolute scores of egg and 1st instar larval densities per m2 for each field. After a week upon completion of egg-laying period we sampled late instar larvae by dissecting plants grown at 10-36 randomized plots sized in average of 1.4 m2. The following means characterize insect densities and survival:

The deductions made are as follows:

1. Overwintered adults strongly prefer maize for egg-laying contrary to sorghum.
2. During the first-generation flight maize is not favored for egg-laying over sorghum.
3. Larval mortality at early instars is much higher when feeding on sorghum, especially during the second generation. It seems plausible that sorghum can be used as trap crop to beat borers.

Acknowledgments: The study was partly supported by RFBR grants # 94-04-11328, 97-04-48015, and 99-04-48053.