The "windows", scales, and bristles of the tropical moth Rothschildia lebeau (Lepidoptera: Saturniidae).
The common Spanish name of the moth Rothschildia lebeau (Saturniidae) is cuatro ventanas (four 'windows'), because it exhibits a transparent oval path in each wing. The scales of the colored areas and the bristles from the "window" were analyzed. We developed a simple device to measure transmittance across the "windows" with an spectrophotometer. A square section of "window" was mounted onto a flat black card and placed onto a clamp that hung in the path of the light - beam of the spectrophotometer. Absorbance was measured at 350 and 550 nm, with the "window" positioned perpendicular to the light beam (incidence of 90 degrees); then the measurements were repeated with the "window" moved at an angle of 45 degrees. Each measurement was replicated 5 times. Wing color spots were analyzed with a light dissection microscope (stereoscope) and with scanning electron microscopy. The scales have a minimum of 4 morphological types, 3 of them showed the typical appearance of unspecialized scales described for other butterflies; whereas the fourth has features particular to this species. On the "window" the scales are transformed in hair-like bristles that do not interfere with light, conferring the transparency that characterizes the "windows". However, if the wing is illuminated at an almost grazing-incidence, they reflect the light as a mirror. Two hypothetical functional explanation for the windows are mimicry and interspecies communication.
Hernández-Chavarría
Francisco
F
Facultad de Microbiologia, Universidad de Costa Rica, San José, Costa Rica. hchavarr@cariari.ucr.ac.cr
Hernández
Alejandro
A
Sittenfeld
Ana
A
D000818:Animals; D002980:Climate; D017753:Ecosystem; D007915:Lepidoptera / Q000502:physiology* / Q000648:ultrastructure; D008027:Light; D008855:Microscopy, Electron, Scanning; D010858:Pigmentation / Q000502:physiology*; D014921:Wings, Animal / Q000502:physiology* / Q000648:ultrastructure