Mechanosensory neurons located on the body surface show somatotopic organization in their projections into the central nervous system and elicit diverse behavioral responses, from relatively simple stimulus location-aimed movements to complex movement sequences. How mechanosensory neurons and their postsynaptic circuits influence such diverse behaviors remains unclear. We previously identified nearly all mechanosensory neurons around the Drosophila head whose individual stimulation elicit aimed grooming of specific head parts (e.g. eyes or mouthparts) while their simultaneous stimulation elicits a whole head grooming sequence. Here, we define how these somatotopically-organized mechanosensory neurons are synaptically connected with a lineage of interneurons that also elicit head grooming. The lineage consists of subpopulations of morphologically distinct neurons that each elicit grooming of a different head part. Interestingly, these subpopulations show preferential synaptic connectivity with mechanosensory neurons from particular parts of the head. Activation of a set of mechanosensory neurons or its corresponding postsynaptic subpopulation elicits aimed grooming of the same head part. Our results indicate that head grooming behavior is produced by developmentally related and somatotopically organized parallel circuits that each elicit grooming of specific parts of the head. This provides the first synaptic resolution view of the interface of neural circuitry and the somatotopic map of a head, and defines the parallel-projecting mechanosensory pathways that elicit head grooming.