Date of Award

8-2014

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Entomology

Advisor

Morse, John C

Committee Member

Hains , John

Abstract

A key feature of the order Lepidoptera is the coilable proboscis, present in over 99% of lepidopteran species. The proboscis is used to obtain liquid nutrition, usually floral nectar. The proboscis is assembled from two elongate galeae immediately after emergence of the adult from the pupa. What happens if the galeae become separated? I studied the process of repair of the proboscis, behaviorally and functionally, at the organismal level. My research questions were as follows: 1) is the proboscis capable of repair, 2) is saliva necessary to proboscis repair, and 3) is the repaired proboscis able to acquire fluids? Test organisms were Danaus plexippus (Linnaeus) (Lepidoptera: Nymphalidae: Danainae) and Vanessa cardui (Linnaeus) (Lepidoptera: Nymphalidae: Nymphalinae). To assess repair capability, at 24 hours after eclosion the galeae were separated totally and compared to control specimens without galeal separation. Both species were able to accomplish repair of the proboscis, with 10-100% achieving reunion of the galeae and recovery of the coiled resting state. The role of saliva in repair of the proboscis was tested for D. plexippus, with the hypothesis that removal of saliva would impede repair. Three groups were compared: 1) the proboscis was manipulated with a capillary tube to remove saliva for five minutes, 2) the proboscis was similarly manipulated for five minutes but no saliva was removed, and 3) the proboscis was not manipulated and no saliva was removed. Both manipulated groups were similarly impeded, indicating that manipulation impeded repair, rather than removal of saliva. To test functionality of the repaired proboscises, at 24-48 hours after separation of the galeae all butterflies were offered dyed sucrose-water, with the hypothesis that the repaired proboscis can acquire fluids. After feeding, butterflies were placed in separate cages lined with filter paper. Successful feeding was confirmed by the presence of dye in the gut exudate on the filter paper or in the gut by dissection for 64-100% of all groups. Physical and functional self-repair of the butterfly proboscis could provide a model for artificially engineered microfluidic devices.

Included in

Entomology Commons

Share

COinS