From Pineapple Residue to Precision Biocontrol: UAV-Assisted Release of the Predator Euborellia annulipes Using Biodegradable Capsules

The large-scale release of natural enemies remains a major challenge in biological control. This study evaluated the viability of using biodegradable capsules produced from pineapple (Ananas comosus) leaf fibers for the release of the predator Euborellia annulipes. The objectives of the current research were: (I) to evaluate the viability of these capsules for predator release; (II) to validate the effectiveness of aerial release by drone (Agras T40); and (III) to evaluate the behavioral repertoire and performance of the predator after exiting the capsule in maize plants infested with susceptible and resistant Spodoptera frugiperda larvae. Predator-induced opening (in the absence of moisture) required a median time of 33 h (77.5% success, mortality ≤ 7.5%), whereas autonomous opening reached 100% in soil at field capacity. Aerial release achieved a 95.04% success rate. Under semi-field conditions, moisture facilitated rapid capsule opening (220 to 269 min); the predator exhibited active search behavior and achieved a higher predation rate on the resistant pest population (40%) than on the susceptible one (25%). The technology is therefore functional, compatible with the predator’s biology, and promising for sustainable integrated pest management strategies.