Emperors, admirals and giants, zebras, tigers and woolly bears: casting a broader net in exploring heparin effects on Lepidoptera wing patterns [version 3; peer review: 2 approved]

Abstract

Background: Studies of heparin effects on Lepidoptera wing patterns have been restricted to a small number of species. I report observations from experiments on a broader range of taxa, including first results from swallowtails, tiger moths and microlepidoptera. Methods: Heparin injections were made in prepupae and pupae of Junonia coenia (common buckeyes), Agraulis vanillae (gulf fritillaries), Heliconius charithonia (zebra longwings), Asterocampa clyton (tawny emperors), Danaus plexippus (monarchs), Vanessa atalanta (red admirals); Heraclides cresphontes (giant swallowtails), Pterourus troilus (spicebush swallowtails), Protographium marcellus (zebra swallowtails), Battus polydamas (polydamas swallowtails); Hypercompe scribonia (giant leopard moths), Estigmene acrea (acrea moths), Hyphantria cunea (fall webworm moths), Utetheisa ornatrix (ornate bella moths); Glyphodes sibillalis (mulberry leaftier). Results: Heparin sometimes altered the entire pattern in a dramatic way, sometimes caused changes locally. In buckeyes, the previous heparin study conducted on pupae was compared to injections made at a prepupal stage. In gulf fritillaries, zebra longwings and tawny emperors, the dramatic changes occurred throughout their wings, while in monarchs, changes were restricted to wing margins. Changes achieved in red admirals, show that heparin action is unrelated to the original color. In swallowtails, transformations were restricted to border system, indicating higher levels of stability and compartmentalization of wing patterns. In mulberry leaftier, changes were restricted to the marginal bands. In tiger moths, elongation of black markings led to merging of spots; in the ornate bella moth, it was accompanied by an expansion of the surrounding white bands, and results were compared to the effects of colder temperatures. Conclusions: Using pharmaceutical intervention demonstrates that there are many similarities and some very significant differences in the ways wing patterns are formed in different Lepidoptera lineages. By creating a range of variation one can demonstrate how one pattern can easily evolve into another, aiding in understanding of speciation and adaptation processes.