CUTICULAR SENSILLA ON NEWLY-HATCHED LARVAE OF GASTEROPHILUS-INTESTINALIS AND ESTRUS-OVIS

Cuticular sensilla on newly hatched larvae of Gasterophilus intestinal is De Geer (Diptera: Gasterophilidae) and Oestrus ovis (L.) were studi ed by scanning electron microscopy. Two types of trichoid sensilla, tw o types of coeloconic sensilla and a pit sensillum were present on the thoracic and abdominal segments of G.intestinalis larvae. Sensilla on larvae of O.ovis were similar although only one type of trichoid sens illum was present. Total number of sensilla were higher for O.ovis tha n for G.intestinalis (248 v. 214). Variation in numbers of sensilla is consistent with the concept that increasing numbers of sensilla are a ssociated with increasingly complex searching behaviour required to lo cate suitable habitats for development.