A Stick-y Situation

Two paths diverged in the Nature Conservancy’s Sandyland Sanctuary; as I stood, deciding which to follow, I noticed some pretty, ruffled foliage. I didn’t recognize the plant, but I liked the way the twig lying across it had provided the third side of a natural triangle.

Then, I realized that the twig seemed to be looking at me. It wasn’t a twig at all, but an insect: a Giant Walkingstick (Megaphasma denticrus). If you enlarge the photo, you can see what I imagine to be an appraising look in its eye.

Officially the longest insect species in North America, the creatures can reach six inches or more in length; from toe to outstretched toe, this one measured about eight inches long. It may have been a female, since female walkingsticks typically are larger than the males.

Found in woods, forests, and grasslands of the Southern United States, Giant Walkingsticks are common in Texas, but can be found as far north as Indiana and Iowa. They prefer a moist environment,  and generally are found on trees or shrubs.

A wonderful example of mimicry in nature, walkingsticks closely resemble twigs of the plants where they choose to rest. When motionless, they’re far less obvious to predators; their nearly undetectable presence has led to their continued reproduction and expansion throughout the Southern United States.

Both male and female adults are wingless and slow moving. Adults tend to be greenish to reddish brown, sometimes with pale legs. Immature nymphs, though smaller, resemble adults;  they’re often green, and sometimes resemble juniper twigs.

Noturnal creatures, Giant Walkingsticks feed on leaves throughout the night. When I found this one at a relatively early hour of the morning, it may have just settled in for a post-dinner nap.

Comments always are welcome.

Incoming!

Pseudodoros clavatus visiting a spring ladies tresses orchid

 

Not only humans enjoy ladies tresses orchids. Their small flowers present no obstacle to the variety of bees, flies, and beetles that visit them, nor to the tiny spiders that lurk among their folds.

Here, a syrphid fly with the impressive name Pseudodoros clavatus comes in for a landing. As an interesting side note, this little fly has no common name, unless you’re willing to count “that thing that looks like a wasp.”  Johan Christian Fabricius, a Danish zoologist, named the species Dioprosopa clavata  in 1794, but a 1903 revision resulted in Pseudodoros clavatus.

It’s been suggested that the wasp-like shape may help to protect the insect from predators. Taking on a syrphid fly is one thing: attacking a wasp quite another.

Can you see the infinitesimal headphones the little fly’s wearing? No? Well, if you could, and if it shared them with you for a moment, you might find it’s listening to perfect music for visiting a Spiranthes — Spyro Gyra’s Morning Dance.”

 

Comments always are welcome.

Gulf Coast Autumn: Orange

A gathering of the clan
(click image for more detail)

The large milkweed bug, Oncopeltus fasciatus,  feeds on the seeds, leaves and stems of assorted milkweeds. Here, at least three instars, or developmental stages, of the bug have gathered on Asclepias asperula, the antelope horn milkweed: adults, near-adults with little black wing buds, and the very small, mostly orange nymphs.

Milkweed bugs not only resemble monarch butterflies, they’re just as distasteful to predators because of toxic compounds contained in the milkweed sap they ingest. The easily recognizable orange-and-black color scheme common to these nasty-tasting insects, called Müllerian mimicry after German naturalist Fritz Müller, offers the bugs a degree of protection.

In late summer or early autumn,  the number of milkweed bugs in coastal Texas begins to burgeon as result of another similarity to monarchs. After spending the summer in northern states and southern Canada, the bugs begin to migrate toward southern states and Mexico, where milkweed still is available. According to entomologist Michael J. Raupp:

Their annual migration south is triggered by shortening day length, cooling temperatures, and declining quality of milkweed plants as food. Titers of a glandular product called juvenile hormone signal the milkweed bug’s ovaries to take a “time-out”, and trigger flight behavior that transports the milkweed bug to warm southern lands where milkweeds grow.
Once the southward migration is complete, juvenile hormone levels rise, ovaries are switched on, and reproduction resumes. In spring, the migratory pattern reverses and generations of large milkweed bugs leap-frog their way northward to colonize milkweeds as far north as Canada.

Clearly, the milkweed bug needs a better press agent. Its migratory habits are fully as impressive as those of the monarch, but most people tend to prefer a butterfly over a bug. Still, milkweed bugs, interesting and handsome in their way, are worth seeking out where autumn milkweed continues to thrive.

 

Comments always are welcome.