Tag Archives: Georgia

Golden Silk Orb-weaver

Golden silk orb-weaver - Nephila clavipes - 07.20.2014 - 10.22.49Literally ran into a few of these recently… here’s a large (probably about four inches or the size of your hand’s palm) female Nephila sp. (I’m guessing N. clavipes from Google searches of nearby orbweavers) and one of her hopeful mates. I counted three males associated with this web, and Wikipedia claims that these spiders are often parasitized by kleptoparastic Argyrodes spiders that steal captured prey from her web.

Wild Sage

Flowers, fruits, and vegetative characteristics of wild sage Lantana camara.

While the florescence here only displays orange and dark orange or red, flower color varies widely in a single florescence, and changes in individual flowers once pollinated. The change in color signals to pollinators that a flower is no longer producing nectar, and, since the function of flowers, including their nectar production, is to attract animal pollinators to move pollen around, pollinated flowers tend to halt nectar production once pollinated. It does seem odd that a plant would communicate to pollinators as promptly (color change can occur within minutes) and directly as occurs here, given that the flower ‘has what it needs’. The hypothesis explaining this claims conservation of pollinator energy, presumably allowing improved visitation efficiency, which must benefit the host plant. Why not keep the pollinator guessing a little, especially in monoecious flowers where pollen could still move away from the host? (I don’t know if Lantana is monoecious – that is, has both male and female parts in the same flower)

Visible flower color change after pollination occurs in other plants too, and there are likely other changes that are not quite as striking to us, non-pollinating, humans, but are evident to pollinators.

Marsh periwinkle

The Marsh Periwinkle Litoraria irrorata has been well-studied and is a conspicuous, dominant-player in the ecology of salt marshes along the East Coast of the United States. I took these photographs to prepare for a mark-recapture exercise that my Coastal Ecology course performed. Unfortunately, I couldn’t attend the exercise, and it was run by my department chair, who is co-teaching the course with me. From the images the students captured, and have posted, the activity seemed productive and fun.