PROC. ENTOMOL. SOC. WASH. 106(2), 2004, pp. 478-480 Note Larval Development of Cylindrotoma distinctissima americana Osten Sacken, 1865 (Tipulidae: Cylindrotominae) on Maianthemiim dilatatum (Liliaceae) in California The genus Cylindrotoma Macquart is unique among North American crane flies because its members feed on the developing leaves of higher plants. Other members of the nearly worldwide subfamily Cylindro-tominae feed on moss as well as higher plants (Alexander and Byers 1981), One of us (GP) had the opportunity to collect the larvae of Cylindrotoma distinc-tissima americana Osten Sacken on leaves of the false-lily-of-the-valley (or mayber-ry), Maianthemum dilatatum (Wood) Nels. & Macbr (Liliaceae) in northern California. This report discusses this find and briefly describes the larvae and pupae. This is the first record of this crane fly species, and of the subfamily Cylindrotominae, in Califor-nia. The previously known distribution of Cylindrotoma distinctissima americana was from British Columbia to Oregon (Alex-ander 1967, Oosterbroek 2002). This is also the first record of this crane fly species feeding on Maianthemum dilatatum. Pre-viously recorded host plants in North America are Allium, Anemone, Trautx'etter-ia, Stellaria, and Viola (Brodo 1967). The host plant, M. dilatatum, is native to western North America from Alaska to Cal-ifornia (Hitchcock and Cronquist 1973). It is especially abundant along the Pacific Northwest coast, where it normally grows in the shade of large trees, but can be found completely exposed, even almost adjacent to the high tide level. It is a perennial nor-mally not reaching over 40 cm tall, that dies back in the fall and grows anew in the spring from slender rhizomes (Hitchcock and Cronquist 1973). Populations of M. dilatatum harboring Cylindrotoma larvae were discovered in a moist forest of Sitka spruce {Picea sitch-ensis (Bong.) Can; (Pinaceae) near Lake Earl in Humboldt County, northwestern California, on April 13, 2001. The larval and pupal stages (n = 8) were observed and photographed at the site. The mature larvae were unlike any other leaf-feeding insects found on this plant. They were green and relatively smooth except for a pair of small protuberances on the dorsum of each abdominal segment except the last (Fig. 1). The larvae fed on the dorsal and ventral sides of the leaves, leaving large holes very similar to damage caused by sawfly larvae feeding on the same plant species in Oregon. When mature (length = 12 mm), the larvae pupated on the upper surface of the leaves in a very peculiar manner. The last molt was incompletely shed, with the posterior portion of the pupa remaining within the anterior part of the last larval skin (Fig. 2). The skin served as a holdfast to the leaf surface and could not be removed without tearing it apart. This was the only portion of the pupa attached to the leaf surface. The pupae were smooth, green, 13 mm in length, with a pair of tho-racic respiratory horns as the only body projections (Fig. 2). Both the larvae and pu-pae were well camouflaged on the leaves. The adults (length 13 mm) emerged within two weeks after pupation (Fig. 3). Observations reported here are similar to those reported by Cameron (1918), who studied the same species of Cylindrotomi-nae (under the name of C. splendens Doane, 1900) developing on the leaves of Traut-vetteria caroliniensis (Walt.) Vail (= T. grandis Nutt.) (Ranunculaceae) in British Columbia. It is interesting that this species can develop on both monocots and dicots. In both cases (California and British Co-lumbia) the host plants were understory herbs in damp, well shaded, forested areas.
Larval development of Cylindrotoma distinctissima americana Osten Sacken, 1865 (Tipulidae: Cylindrotominae) on Maianthemum dilatatum (Liliaceae) in California
BioStor
