LIFE HISTORY OF DYSODIA SICA 
(LEPIDOPTERA: THYRIDIDAE) 
IN PANAMA 1 
By Annette Aiello 
Smithsonian Tropical Research Institute 
P.O. Box 2072, Balboa, Panama 
Thyrididae is a widespread tropical and subtropical family of 
moths, generally thought to be related to the Pyralidae, from which 
they differ in a number of ways (see Whalley, 1971). Possibly the 
group is not monophyletic, but so little is known concerning the 
immature stages, that few conclusions can be reached regarding the 
relationships among the four subfamilies. 
Dysodia (Thyrididae: Pachythyrinae) is a pantropical genus found 
on all continents except Australia (Whalley, 1971). Aside from 
scattered foodplant records for several species, little is known about 
the immature stages of any of the approximately thirty species. The 
present paper describes the egg, larvae, pupa, and larval behavior of 
Dysodia sica Druce (Figure 1) reared on Barro Colorado Island 
(BCI), Panama, during May through August 1977 and 1980. Seven 
other species of Dysodia are listed for BCI by Forbes (1942). 
Adult Behavior 
Adults of Dysodia spp. fly during early evening, and are seen 
frequently at lights on BCI. At rest, the wings are horizontal to the 
substrate, with the fore wings almost completely covering the hind 
wings (Figure 2). This resting posture, triangular in outline, is also 
common among many pyralid moths. When alert or about to fly, the 
fore wings are drawn forwards, exposing the hind wings, and 
bringing the markings of the fore and hind wings into alignment 
(Figure 3). The two “windows” on each hind wing show just behind 
the posterior margin of the fore wings. The fore wings are curved 
longitudinally so as to be somewhat concave above. 
'Manuscript received by the editor December 4, 1980. 
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