Meeting Abstract
Milkweed are latex producing plants that are familiar perennials in the grasslands of North America, and serve as an excellent model for the study of host/herbivore interactions. Leaves of Asclepias curassavica, viridis, asperula, stenophylla, tuberosa, and viridiflora, each being a native milkweed species in Texas, were used to construct a lipid profile that will allow an analysis of the assimilation of fatty acids to milkweed bugs and monarch butterfly larvae, two predators of Asclepias. Lipids were extracted from leaf samples using a mixture of chloroform/methanol/water in a 4:2:1 ratio. The fatty acids were then converted to fatty acid methyl esters (FAMEs) to be further analyzed by gas chromatography-mass spectrometry (GC-MS). The fatty acid within milkweed that was found in highest abundance was linolenic acid (18:3) followed by palmitic acid (16:0) and stearic acid (18:0). Interestingly, linolenic acid was seen in very high abundance in some leaves from the same plant but completely absent in others. Further testing will be conducted to analyze if linolenic acid production is a response to insect predation. This information will be utilized to provide a more thorough understanding of the transition of fatty acids from the milkweed plant to specialist predators.
