ANALYSIS OF GUT CONTENTS AND FEEDING-BEHAVIOR OF TIPULID LARVAE (DIPTERA, TIPULIDAE) USING A NEW ROOT-STAINING TECHNIQUE

To determine whether first-instar Tipula oleracea L. preferentially fe ed on either grass roots or leaves, we developed a differential staini ng technique for grass roots. A 0.15% aqueous solution of trypan-blue stained the root-system of ryegrass sufficiently to identify root tiss ue in the gut system of leatherjackets. It did not stain leaf tissue o f the same plants. Using stained grass plants, it was shown that young larvae of T. oleracea in grasslands preferentially feed on leaf tissu e and not on root tissue as previously assumed.