Caterpillars eating into the central whorl of my maize and leaving wet sawdust

Ragged whorl feeding with moist sawdust like droppings and caterpillars sitting deep in the central whorl is the typical sign of an armyworm in maize, most often fall armyworm these days. Look for a caterpillar with an upside down pale Y mark on the head and four spots in a square on the second last segment to help identify it, and send a photo to your KVK or agri officer to confirm. Scout early in the morning across the field and decide on action based on how many plants show fresh whorl damage rather than spraying the whole field blindly. Useful non chemical steps are handpicking and crushing the egg masses and young larvae, putting a pinch of dry sand or ash into the whorl, and setting up pheromone traps to track the moths. If a spray is justified, recommended actives include spinetoram, emamectin benzoate or chlorantraniliprole directed into the whorl, but follow the label dose, the pre-harvest interval and local KVK recommendation and rotate the mode of action since this pest builds resistance fast. Treat early when larvae are small, as big larvae hide deep and are hard to reach.