How Do Insects Feed on this Plant with Sticky White Latex?
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Amy Berkov is an Honorary Research Associate with The New York Botanical Garden’s Institute of Systematic Botany; she studies interactions between wood-boring beetles and trees in the Brazil nut family. Photo of Amy Berkov by Chris Roddick. |
When I was in graduate school I decided to turn my East Village community garden plot over to the insects. I was an NYBG/CUNY Ph.D. candidate hoping to study plant-animal interactions. By happy accident I ended up in an entomology course at the American Museum of Natural History. The revelation that plants produce a huge variety of chemicals capable of manipulating insect behavior captured my imagination, so I planted six native species: three milkweeds (Asclepias) and three goldenrods (Solidago) to attract specific beetles.
Fifteen years later, one goldenrod species is still hanging on, but common milkweed (Asclepias syriaca) is clearly the winner—and it’s now making furtive advances into neighboring plots (the original plant probably spread by underground rhizomes). My observations have convinced me that the common milkweed is anything but common!
Plants in the genus Asclepias are called milkweeds because of the sticky white latex that pours out of wounded tissues. Asclepias latex is rich in toxic cardiac glycosides, and the scientific genus name comes from Asklepios, the ancient Greek physician.
Some milkweed-feeders actually sequester the toxins to defend themselves from predators, but how do they avoid getting their mouthparts hopelessly gummed up? Some slice right through leaf midribs, which diverts the latex flow and enables the “trencher” to feed downstream of the cut. For a video clip of the best-known trencher, the monarch caterpillar, click here. read more »
When life hands you three giant pumpkins, you might as well carve them into jack-o’lanterns! Really, really big jack-o’-lanterns.