Gymnandrosoma consists of seven species, all restricted to the New World. Adults are dark brown to black, usually with indistinct markings. Diagnostic genitalic characters include: male with uncus and socii undeveloped, valva with moderately constricted neck, cucullus with rounded apex and short stout setae evenly distributed along distal margin, and medial surface with ridge of stout setae near ventral margin from neck to anal angle; female with two large thornlike signa in the corpus bursae and extensive wrinkling of the membrane near the juncture with the ductus bursae. Most males have secondary sex scaling on the abdomen, terga, hind tibia, and/or anal margin on the hindwing. Adamski and Brown (2001) provide the most recent revision of the genus.
Larvae are similar to other species in the Cryptophlebia-Ecdytolopha group, with an enlarged L-pinaculum on the prothorax that extends beneath (and usually beyond) the spiracle. Larvae of Gymnandrosoma can be separated from those of Ecdytolopha by the distance between the V setae on A9: approximately the same as the distance between Vs on A8 in Ecdytolopha and 1.2-2.0 times the distance between Vs on A8 in Gymnandrosoma.
Gymnandrosoma larvae (including G. aurantianum) are intercepted frequently on a variety of imports from Central America, South America, and the Caribbean. As most species were placed in Ecdytolopha prior to Adamski and Brown's revison (2001), many interception records for Gymnandrosoma are listed under Ecdytolopha. Target species
Adamski, D. and J. W. Brown. 2001. Systematic revision of the Ecdytolopha group of genera (Lepidoptera: Tortricidae: Grapholitini) in the New World. Entomologica Scandinavica Supplement 58. 86 pp.
Blanco-Metzler, H. A. D. Watt and D. Cosens. 2009. The effect of parasitism on the population dynamics of the macadamia nutborer Gymnandrosoma aurantianum (Lepidoptera: Tortricidae). Revista de Biologia Tropical. 57: 1245-1252.
Gilligan, T. M., D. J. Wright and L. D. Gibson. 2008. Olethreutine moths of the midwestern United States, an identification guide. Ohio Biological Survey, Columbus, Ohio. 334 pp.