EFEITO DA POSIÇÃO DO RECIPIENTE DE CRIAÇÃO NO CONSUMO E UTILIZAÇÃO DE ALIMENTO POR Spodoptera frugiperda ( J.E. SMITH, 1797) E Helicoverpa zea (BODDIE, 1850) (LEPIDOPTERA: NOCTUIDAE) EFFECT OF THE POSITION OF THE REARING CONTAINER IN THE FOOD CONSUMPTION AND UTILIZATION FOR Spodoptera frugiperda (J.E. SMITH, 1797) AND Helicoverpa zea (BODDIE, 1850) (LEPIDOPTERA: NOCTUIDAE)

The objective of the work was to verify the effect of the position of the creation container, in the consumption and utilization of the food for Spodoptera frugiperda and Helicoverpa zea for better utilization of its biological potential. Caterpillars of S. frugiperda and adults of H. zea, were collected in corn farms in Pelotas (RS). Fifty (50) caterpillars recently emerged, were individualized in tubes of glass of flat bottom containing artificial diet, being maintained in the positions vertical, sloping and horizontal, in controlled conditions of temperature (25 ± 1oC), relative humidity (70 ± 15%) and photofase (14 hours). Dry weights were determined for caterpillar in the maximum development, the food consumation and the eliminated faeces, being calculated the nutritional indexes: relative consumption rate (RCR), relative metabolic rate (RMR), relative growth rate (RGR), approximate digestibility (AD), efficiency of conversion of the ingested food (ECI), efficiency of conversion of the digested food (ECD) and metabolic cost (100-ECD). The most appropriate tube position for S. frugiperda were sloping and horizontal, because in the vertical position, the insects didn't reach the maximum physiologic potential, presenting a low weight gains (B). For H. zea the vertical position, was the most appropriate, because the largest efficiency of conversion of the ingested food (ECI), the insects presented smaller consumption tax (RCR), ingesting less food (I).