Energy comparison in three cases of pesticide versus bio-control pest management

Abstract

The deletrious effects of chemical pesticides on many plant and animal populations have been described. Rapidly increasing costs of convenient energy sources have increased cost-benefit ratios of chemical pesticides used. We compared biological control techniques versus chemical pesticides for inputs of human labor, machinery, and fuel per hectare at each pertinent step of the production procedure. Three pest-crop systems were selected and all applicable factors converted into kilocalories of energy required. These were: (1) citrus-red scale ( Aonidiella aurantii), using oil as a chemical and the predator wasp, Aphytis melinus as a biological control; (2) greenhouse cucumbers-white fly ( Trialeurodes vaporariorum), using Orthene or the wasp, Encarsia formosa; (3) tomato-hornworm ( Manduca quinquemaculata) using Sevin or the bacterium, Bacillus thurengiensis. For citrus-red scale, the pesticide required 5 248 405 kcal, the use of A. melinus 100 793 kcal; for cucumber-white fly the pesticide required 29 300 kcal, E. formosa 154 500 kcal; for tomato-hornworm the pesticide 26 693, B. thurengiensis 207 240 kcal.