A SOLID CARBON DIOXIDE (DRY ICE) COOLING SYSTEM FOR THE MECHANIZED AERIAL RELEASE OF STERILE MALE CERATITIS CAPITATA

摘要

One alternative to chemical treatment in the fight against Ceratitis capitata is the liberation of sterilized male insects to compete with wild flies in mating. This method decreases the number of fertilized females in each generation, maintaining a reduced population so as to prevent crop damage. A system for insect storage and a method for the mechanized aerial release of insects are proposed in this article. The system cools the mass of stored insects by convection, using an external flow of air passing through a bed of solid carbon dioxide, sublimated at -79°C. To control the system, three parameters have been determined: the airflow necessary to maintain latency for a specific volume of insects, the relationship between the volumes of sublimated CO2 and external air necessary to obtain air at a specific temperature, and the volume of solid carbon dioxide (dry ice) necessary to cool a specific volume of insects for the duration of the treatment. A prototype has been built to validate the system, in which insects are released with worm screws located on the bottom of the storage module. The prototype allows for the release of 1000 to 4000 flies per second with no injury to the insects, which maintain their ability to fly and mate. With this prototype, between 2000 and 8000 insects per week per hectare can feasibly be released by airplane, covering an area between 200 and 250 m in width with each pass at speeds of 160 to 180 km/h