Local feeder (Diptera: Cecidomyiidae) in stems of Phryma

Where the larva of this cecidomyiid dwells within the stem of the host, the stem exterior becomes locally discolored -- it blackens and may also show pale areas with dark spots. Furthermore, the discolored tissue sometimes assumes a sunken appearance. Examples I examined as part of the current study displayed the local discoloration of the stem but no visible swelling; however, in some cases, when the discoloration extended into a node, one of the leaves attached at the node was dead and shriveled. Larvae occurred in subsurface tissues within these blackened areas of the stem in late September. In one example, the blackened area contained a parasitoid wasp larva instead. The cecidomyiid has been identified as Neolasioptera sp. by R. J. Gagné (pers. comm.).