Among the traits listed by Daniel K. Young for the larva of genus Synchroa (and presumably other members of the family share most of these):
- Body approximately cylindrical and sides essentially parallel
- A few setae on each segment
- Color whitish to yellowish
- Abdominal segments 1-5 with darkened rough patches
- Head not retracted, mouthparts projecting forward
- Prothorax a little wider than the head
- Mandibles asymmetric
- Five-segmented legs vested with stout setae
- The abdominal apex with a pair of upturned appendages
