The Beetle Eggs Have Started Hatching! Blog Post 2

On Wednesday of last week (June 19th), I examined the dry grass stems where the longhorned milkweed beetles oviposited and discovered that many were filled with eggs and a few hatched larvae! Each of the nine beetle habitats, which are ventilated rearing boxes in the greenhouse containing the stems, sand, fresh milkweed leaves, and the beetles, contained approximately twenty stems and between ten and fourteen beetles. Each box contained an average of just over 500 eggs, which is much more than we originally expected.  I transferred the stems from the beetle habitats to a kiddy pool containing over thirty-five, small (25-35 cm tall) milkweed plants. The larvae will feed on the roots of these plants in order to grow a little bit bigger before they are introduced to our experimental plants.

In addition to continuing to monitor and care for our longhorned milkweed beetles and common milkweed plants in the greenhouse, I have been learning to code in R, reading scientific articles, and uploading and organizing data from field research. Our lab traveled to the Norfolk Botanical Garden to take some demographic data on several different species of milkweed plants and to take some absorbance readings of milkweed leaves using the spectroradiometer. We collaborated again with Professor Williamson’s lab on the experiment to see if cardenolides have antimicrobial properties. We grew the bacterial cultures in beakers of broth this time instead of on plates of nutrient agar and used only the bacteria P. fusiformis. We are going to repeat this experiment in the upcoming weeks but use E. Coli instead of P. fusiformis to see if/how the results differ between the two bacteria.




  1. emdavies says:

    This is really interesting! My lab also works with milkweed. What will the implications be if cardenolides do have antimicrobial properties? Does this affect the usefulness of the plant or would it give the plant a increased variety of uses? Or would this have negative implications? I’m interested to see the results!

  2. mrdonnan says:

    If cardenolides in the milkweed nectar have anti-microbial properties, they may have an important anti-microbial function that prevents the inversion of sucrose to fructose and glucose, thereby altering pollinator behavior, and, ultimately, seed production for the plant.