PUPAL DEVELOPMENT AND ADULT EMERGENCE PATTERNS OF THE MEXICAN RICE BORER (LEPIDOPTERA, PYRALIDAE)

Pupal development times and thermal unit requirements, daily adult ecl osion patterns, and the durations of phases of emergence of the Mexica n rice borer, Eoreuma loftini (Dyar), adult sexes were observed under reversed photoperiodic and thermoperiodic conditions. Female pupae req uired fewer days and thermal units for development than did males. Bot h sexes eclosed early in the scotophase; eclosion of adult males femal es was complete within almost-equal-to 1.7 and 4.5 h of last light, re spectively. Newly emerged males required less time than females to inf late and dry their wings and less time for the entire emergence proces s (eclosion to wings dried and folded in a normal resting position). T he temporal patterns of emergence suggest that efforts to observe emer gence in sugarcane fields should be concentrated in the early scotopha se. The short duration of the emergence process will limit the time du ring which newly emerged moths can be identified. Therefore, cage stud ies of emergence may offer a greater likelihood of success than studie s relying on direct observation, especially under the usual conditions of low E. loftini population intensity and high crop biomass.