THE FREQUENCY OF INVERTEBRATES IN FIELDS OF POTATOES AND CARROTS GROWN UNDER INTENSE CONDITIONS IN A HIGHLAND AREA OF PANAMA

Studies were conducted from June to November, 1994, in the Cerro Punta area (Chiriqui, Panama) on volcanic soils at altitudes of 1.800 to 2. 300 m above sea level, in the rainy season (May to December). Inverteb rates were monitored by pitfall traps. The intensity of pesticide spra ying was inquired from the farmers at the end of the study period and compared with data published so far. In potatoes (50 % of the agricult ural area) per 120 days from planting to harvest, one nematicide, one herbicide, 13 fungicides and 19 insecticides were applied at the avera ge. Every field in tile area received more than 26 insecticidal sprays per year, but an examined farmer (Ing. agr.) sprayed insecticides at maximum 15 times, only. Collembola were by far the mast common inverte brates. Of predatory arthropods, six orders were present in the fields , but all at very low frequency (with no significant difference betwee n crops, adding up to 0.25 specimens per trap per day). Studies from o ther regions of partly high insecticide input confirm the negative eff ects of a high frequency of insecticidal sprays on the beneficial arth ropods. The necessity of training Farmers in plant protection is stres sed.