Time-lapse tracing of biological events in an endophytic schizophoran fly, Atherigona soccata Rondani (Diptera: Muscidae)

Atherigona soccata Rondani known as shoot fly is an endophytic pest of cultivated sorghum in the Old World. In our study, we demonstrate all critical biological events of the fly on a real-time basis using time-lapse imaging, including the endophytic larval and puparial stages. The most critical biological events in A. soccata are egg-hatching, first instar larva, pupariation, eclosion and post-eclosion phases. All these stages are critical because of their time-boundedness from initiation to completion. Any kind of lapse in terms of time delay in completion of an event prevented the insect from advancing to the next phase of life and eventually proved fatal. After hatching from egg, first instar larva took a mean time of 34 min to enter the plant through the gap between leaf sheath and growing central shoot. From this moment of larval entry into the plant until total extrication of adult fly during eclosion, A. soccata passed its life endophytically. After larval entry, it took a mean time of 33.7 h for the plant to show first visible symptoms of withering of central growing leaf whorl. From larval hatching to first take-off of adult fly required an average of 309.6 h (12.9 days). The critical periods in the life cycle of A. soccata are less resilient to changes and therefore more vulnerable to external influences. Such phases in the life history can be targeted for managing A. soccata in sorghum.