Systematics and biology of a new, polyphagous species of Marmara (Lepidoptera : Gracillariidae) infesting grapefruit in the southwestern United States

A new species of Marmara (Lepidoptera: Gracillariidae), M. galosa Guillen a nd Davis, from the southwestern United States, is described and illustrated . This species, the citrus peelminer, which Was previously misidentified as M. salictella Clemens, is a cyclical pest in xeric areas of California and Arizona. Larvae mine the surface of citrus fruits, with grapefruit, Citrus paradisi Macfadyen, as a preferred host, and with oleander, Nerium oleande r L., cotton, Gossypium hirsutum L., and avocado, Persea americana Mill., a s alternate hosts. Salix lasiolepis Benth is probably the primary host. Bas ed on two nuclear gene regions, 28S-D2 and ITS2, almost no genetic differen ces were found between populations of peelminer on oleander and grapefruit (0-0.4%), whereas both populations had a 6.8-9.2% divergence from an undesc ribed, sympatric species of Marmara on tree tobacco. Thus at the morphologi cal and genetic level the populations-on oleander and grapefruit appear to be panmictic. On grapefruit in the laboratory, females laid 48.5 +/- 7.2 eg gs and developmental time (egg-adult) at 26 degreesC was 28.8 +/- 0.4 days.