Painted lady butterfly (Vanessa cardui) preferences for amino acids in solution Elliot Martin* & Brad Rehnberg, Department of Biology, York College Introduction Flowers provide nectars with specific ratios of sugars and amino acids to attract certain pollinators. Some insects such as ants have been able to detect specific balances of amino acids (Lanza and Kraus Oecologia 63: 423). Butterflies only use the nectar in their adult stage when feeding on flowers. Amino acids are especially necessary for females during oogenesis (Mevi-Schütz et al American Naturalist 165: 411). Amino acids were chosen based on the different chemical properties of their constituent side chains. Abstract Flowers pollinated by butterflies contain nectars which are rich in sugars and amino acids. Nectar amino acids are nutritionally important for oogenesis and spermatogenesis in painted lady butterflies (Vanessa cardui). Six structurally diverse amino acids commonly found in nectars were tested at 16 mM: alanine, phenylalanine, glycine, asparagine, glutamic acid, and serine. Groups of 2-11 butterflies were presented with three solutions in 1 mL centrifuge tubes. Two of the centrifuge tubes contained different amino acid solutions while the third contained water. Amino acid solutions and water were replaced daily and the amounts consumed were measured as a mass difference. Preferences for the six amino acids were highly variable with glycine most favored (P<0.001, Kruskal-Wallis Test) and serine least favored (P<0.001, ANOVA). Methods Painted lady butterflies n=100 Present a choice of 6 different amino acids throughout testing. Each test tank contains 2 different 16 mM amino acid solutions and water Switch out the 2 amino acids with a different pair Find mass difference of solutions from before and after feeding Complete a One-way Anova or Kruskal-Wallis test to find a statistical preference for an amino acid Results serine<water<asparagine<glycine Conclusions The painted lady butterflies consumed the single amino acid solutions. They can differentiate the serine hydroxyl and the asparagine carboxamide functional groups. The hydroxyl of the serine may be distasteful. The butterflies may have special receptors that bind to these constituent side chains of the amino acids. Glycine was favored most. It may be favored because it is used in a gamma- aminobutyric acid (GABA)/glycine receptor, which is involved in phagostimulation (Mullin et al Journal of Insect Physiology 40: 913). Structures of Amino Acids AsparagineSerineAlanine Phenyl- alanine Glycine Glutamic Acid Water Asparagine- Serine Asp 1 P< AlanineN.S. - Phenyl- alanine N.S. - Glycine Gly 2 P<0.001 N.S. - Glutamic Acid N.S. - Water Asp 1 p<.001 N.S. - Amino Acid Preference Matrix Progression of Preference : ANOVA with post test 1 Kruskal-Wallis test with post test 2 Significance based on Bonferroni correction (α= 0.002). Results Objectives Determine if solutions of single amino acids are consumed. Determine which amino acids the butterflies prefer from least to greatest Future Studies All 20 amino acids should be tested to determine ultimate preference. Determine if butterflies prefer a certain ratio of amino acids. Ratios of sugars could also be mixed with amino acid solutions. Glycine’s skeleton structure could be a potential building block for other amino acids and therefore make it a significant preference over the other two amino acids. A nutritional study may answer this.