Thursday, August 31, 2017

Peewee Leggy Bugs--Water Striders

Jesus! A bug type that can walk on water!

A neighbor walking with us spotted a bug he considered a "leggy bug", like several I had written about the last few months. From looking at images and diagrams of proportionally for legs vs. body length, I could agree. However, after peering more into the water strider (aka pond skater), I'd characterize the bug as a peewee leggy bug. These striders' body lengths measure only about 1/2". Their legginess, however, helps them navigate on water surfaces.

From Osborn School site "Water Strider"—"½ of an inch long … sometimes called 'Pond Skater', can run across the surface of the water, very sensitive to movement".

Enchanted Learning's site "Water Strider" has similar information with a descriptive diagram.
The water strider (also known as the pond skater) is a true bug that can run across the surface of water … The underside of the body is covered with water-repellent hair. … Most water striders are over 0.2 inch (5 mm) long. … The long, middle legs move this bug across the surface on the water like paddles. The long hind legs steer them and act as brakes. The short front legs are used to catch prey.
Coincidentally, I wrote about a "true bug" previously—the leaf-footed bug that visited me at one of my porch columns "Leaf-footed Bug Visitor". The commonality—piercing mouth parts: In the case of the water strider in BugFact's "Water Strider (True Bug)" site, using the bug POV, "[I] use my piercing mouth parts to suck the juices primarily from other insects or spiders, alive or dead."

Is the water strider a leggy bug like several I have written about recently? Yep, if considering ratios of body parts. "Water Strider (True Bug)" emphasis on legs—"I am able to slide along the surface of the water by distributing my weight evenly on my long legs. … I have two antenna and six long thin legs. My front legs are shorter than my back legs."

Bugguide.net's "Family Gerridae - Water Striders", shows the size to be a puny (3-16 mm, about .12 to .63 inches)—not as impressive as walking sticks, crane flies, or huntsman spiders.

An informative site, seemingly hostile to water striders, is PestWiki's "Water Strider: 8 General Facts and How to Get Rid of Them". (The descriptive illustration is pretty cool.)
They have short front legs which help them to capture aquatic insects in ponds. They also have wings on dorsal sides. They use their middle pair of hydrophilic legs for propulsion and their hind pairs for steering. The adult water striders come in two species i.e. one with wings n (sic) the other without wings.
How It Works' "How do water striders walk on water?" provides another description of mechanics and water-coping ability of this bug:
Despite being denser than water, a water strider doesn’t doesn’t sink; … The forces of attraction between all the molecules in the water pull the molecules at the surface together so that they lock like a thin elastic membrane of slightly denser molecules.…

The middle pair of legs, lying ?at on the water, are used as oars to ‘row’ over the surface while the rear pair act like rudders for steering. Long, splayed legs enable the pond skater to distribute its weight evenly over a greater surface area, further helping it to float.
Some TouTube Videos About Water Striders with Emphasis on Water-walking Talents
A Male Water Strider Species with Captivating Courtship

"Male water striders evolved antennae to grab females by the eyes" describes a study of rheumatobates rileyi species of water strider. The male bug mates with the female, first using his antennae to physically capture her eyes. Besides vivid descriptions, the article includes a video of the couple in action.

Sunday, August 27, 2017

Molting Cicada Visitor at My Doorstep



Last month, on my way back from a morning walk around 8 AM, I spied a cicada partially emergent from its exoskeleton at my front door. It looked to be trapped and unable to have exited. Took pix, natch. Checked later, and found it had moved. In the course of the day (about 4 1/2 hours), the two of us took series of pix and videos. (View the finished YouTube video.)

Around mid-day, the other pictaker took a last shot of the cicada, fully extended, still drying out. Shortly thereafter, we saw it had departed, leaving the exuviae that had a more slender exit cavity than I'd seen of other vacated shells. The video is time-sequenced for cropped stills and clips. Most amazing is capturing stages of emergence and the stunning mask-like look on its back.

Note: Somehow, I missed the shelly cicada on my way out for my walk (7-ish, maybe). I either didn't spot it, or it approached the doorstep during my walk. View "Cicada Molting - Nature Time Lapse (Cicala fa la muta)" to see a couple of shelly cicadas undulating and splitting the shell backs, starting the emerging process, then completing the molting process.

Bugguide.net and Cicada Mania
Bugguide.net has been my most frequent go-to site for bugs. For this article about cicadas, Cicada Mania's "The most interesting 17 year cicada facts" bubbled to the surface as a compelling site to visit.
More worthy Cicada Mania sites:
Some images from Bugguide.net's "Subfamily Cicadinae" page resemble my visitor cicada. The genus might be neotibicen ("Genus Neotibicen - Annual or Dogday Cicadas") or megatibicen ("Genus Megatibicen").
From "Genus Megatibicen"
Identification
Most members of the Megatibicen are >2.5 inches long (incl. wings). Megatibicen are often "stockier in appearance" & characteristically more pruinose (white powdery wax) than are most members of the Genus Neotibicen.
Pee Ew
One of the clips in my YouTube video shows the emergent cicada spraying a fluid. Did it pee? Sure looked like it did! Found some info and a video, although these cicadas were already free of their shells.

At Massachusetts Cicadas site (slogan: Dedicated to the Study of the Cicadas of Massachusetts and New England), "Cicada Molting/Eclosing Process" shows a timeline a timeline of the cicada's emergence. For ick factor, view the closeup of cicada pee. Cicada Mania's "Do cicadas pee?" mentions cicadas after they molt, not during. The site includes YouTube video "Cicadas - Drinking & Peeing (01Apr2012a)" of branch with emerged cicadas on it spraying away. (The spray resembles the emission as from my molting cicada visitor.)

Cicada articles:
Related Posts Plugin for WordPress, Blogger...