On most farms, Diabrotica beetles are only severe in certain years, a pattern for which there is yet no analysis. Therefore, for most organic farms these beetles are tolerable in most years. However, in certain seasons some help in reducing numbers may mean the survival of many crops, particularly where beetle damage to seedlings essentially destroys the crop. Example crops are beans and early season cucumbers. Sweet corn is also such a crop, although the damage only interferes with the proportion of kernels which are fertilized. Where destruction of the crop is likely, the extra effort given to building and operating these traps could be important. Since the larvae develop in the roots of grasses and the adults overwinter in a wide variety of places, mass trapping can be used where the standard contact insecticides are not applied. For small plots handpicking may be possible as described elsewhere (Olkowski et al, 1991) but a trap offers adult beetle reductions on a large scale. All sticky traps currently on the market have a limited trapping capacity and are costly. These characteristics make mass trapping unlikely to be tried by growers. However, a low cost trap with a high capacity could bring mass trapping within the reach of many small growers.
