Anatomy and histology of the alimentary canals of the antlion larvae Furgella infermedia Markl and Palpares annulatus Stitz (Neuroptera : Myrmeleontidae), with reference to their feeding physiology

The anatomy and histology of the alimentary canal, mouthparts and mandibula r-maxillary glands of larvae of Furgella intermedia Markl and Palpares annu latus Stitz were studied to determine the mechanisms involved in feeding an d the adaptations for optimal use of ingested food during non-feeding perio ds. A scletorized canal was observed within the maxilla of the larva of Cra mbomorphus sinuatus (Olivier). Palpares annulatus and F. intermedia have se veral anatomical features that are characteristic of Myrmeleontidae and ena ble antlion larvae to exploit periods of food abundance and to survive long periods of food shortage. When food is ingested, the intima of the crop an d rectal pouch, and the regulatory effect of the proventriculus prevent the disruption of the osmotic balance in these larvae. Food is retained in the midgut, as the midgut is discontinuous with the hindgut. Six of the eight Malpighian tubules are cryptonephric and end in a pear-shaped organ that is laterally displaced on the rectal pouch. The cryptonephric system, Malpigh ian tubules and the modified cuboidal epithelium of the rectal fold regulat e the water balance of these larvae.