An online resource based on the award-winning nature guide

Invertebrates

Common Green Darners Appearing

6-20-17 common green darner 021The Common Green Darner (Anax junius) is one of our most common dragonflies. often seen near ponds. The family of dragonflies known as “darners” consists of species with large eyes and long abdomens that tend to rest infrequently and when they do rest, usually hang vertically. The Common Green Darner is the only North American darner in which the male and female usually fly in tandem when the female is laying her eggs on emergent vegetation.

Up to 50 of the world’s 5,200 dragonfly species migrate and the Common Green Darner is one of them. In the fall most (but not all) adult Common Green Darners migrate south to Florida, eastern Mexico and the West Indies. Huge clouds of migrating dragonflies have been seen along the East Coast, Gulf Coast and the Great lakes in autumn. Transmitters weighing 1/100th of an ounce that have been attached to migrating dragonflies confirm that they migrate much like birds. Just like avian migrators, they build up their fat reserves prior to migrating; they follow the same flyway as birds, along the Atlantic Coast; and like birds, dragonflies don’t fly every day but stop and rest every three days or so.

Some dragonflies mate and lay eggs along the way, while others do so when they reach their destination. The eggs hatch, larvae develop and the adults head north in the spring. Unlike birds, migration is only one-way for dragonflies. It is the offspring of the fall migrating generation that migrate north in the spring. Here in the Northeast, most arrive before any resident Common Green Darners have emerged. (photo:  female Common Green Darner)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.

 


Millipedes Meandering

6-16-17 millipede IMG_0682

How do you distinguish a millipede from a centipede – both multi-segmented arthropods that have a lot of legs? Although there are many less obvious differences, centipede bodies are relatively flexible and they have one pair of legs per body segment. Most of a millipede’s segments have two legs, and their tubular body is quite rigid.

Depending on the species, millipedes have between 80 and 750 legs, with most having fewer than 100, but they didn’t start out their lives with this way. When they hatch, millipedes only have three pairs of legs; every time they molt, they add more body segments and legs. When threatened, millipedes quickly coil their body into a spiral, protecting their legs and fragile underbody with their armor-like body plates (tergites).

If you come across a millipede, know that you’re looking at one of the earliest animals to breathe air and make the move from water to land. Pneumodesmus newmani, a fossil found in Scotland, dates back 428 million years and is the oldest fossil specimen with spiracles for breathing air.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Where Do Grasshoppers Go In Winter?

1-19-17-red-legged-grasshopper2-img_4112Everyone knows that grasshoppers disappear once cold weather arrives. Where do they go and what is their strategy for surviving the winter?  Most grasshoppers overwinter as eggs.  They mate, lay eggs and die in the fall. The female Red-legged Grasshopper, New England’s most abundant species of grasshopper, deposits clusters of eggs one to two inches deep in the soil in the late summer and early fall. During this process, a glue-like secretion cements soil particles around the egg mass, forming a protective “pod.” Each pod is roughly three-quarters to one-inch long and curved. The top third is dried froth, the bottom two-thirds contain 20 to 26 eggs. Each egg is just over 1/10th of an inch long and pale yellow.

In the spring, nymphs hatch out of the eggs, crawl up to the surface of the soil and start to feed on grasses and other herbaceous plants. It takes about three months for them to mature and begin the cycle all over again. (Photo: gravid female Red-legged Grasshopper  in late summer)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.

 


Greater Fritillaries

9-23-16-gs-fritillary-036

There is a group of butterflies known as greater fritillaries, or silverspots (their underwings often have multiple silver spots). Three species of greater fritillaries can be found in the Northeast: Great Spangled, Atlantis and Aphrodite. All three are similar in appearance, with differences so subtle that the butterfly in a Naturally Curious post last month was mis-identified as a Great Spangled Fritillary, when it was actually an Atlantis Fritillary. Thanks to a sharp-eyed reader, Sue Elliott, this was brought to my attention. If you can approach a fritillary close enough to see the color of its eye, identification is a snap! Great Spangled Fritillaries have amber-colored eyes, Atlantis Fritillaries have blue-gray eyes, and Aprhrodite Fritillaries have yellow-green eyes. Can you identify the two species of fritillaries that are pictured? (Upper right, on thistle – Great Spangled Fritillary; main photo, on Joe-Pye Weed – Atlantis Fritillary)

Naturally Curious is supported by donations. If you choose to contribute, you may go tohttp://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.

 


American Crow Bills Used As Tools

1-13-16  American crow tracks 147American crows obtain most of their food on the ground as they walk along in search of seeds, insects, frogs, snakes, bird nests and small mammals. Their hunting techniques are varied and most involve the use of their bill. In search of invertebrates, crows will probe the soil with their bill, flick aside leaves, dig in the soil and even lift cow paddies. They fish for tadpoles and dig nearly an inch deep with their bill for clams. In winter, their foraging continues and as these tracks indicate, when the snow is only a few inches deep they will walk around and around in a given area, probing tufts of grass for hibernating insects, mice, voles, or any other form of life these opportunists find.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Ambush Bugs Courting

8-19-15  ambush bugs IMG_2887Ambush Bugs are true bugs, in the order Hemiptera. (Although insects are often referred to as “bugs,” technically, only insects in this order are considered and referred to as bugs by entomologists.) All true bugs have piercing and sucking mouthparts, and wings which are membranous and clear at the tips, but hardened at the base.

Ambush Bugs are usually brightly colored (yellow, red or orange) and have thickened front legs which are used to capture prey up to ten times their own size. They live up to their name, patiently lying in wait, motionless, often in goldenrod flowers where they are very well camouflaged, for unsuspecting prey. The Ambush Bug, upon sighting prey, suddenly seizes the prey in its powerful forelegs and quickly dispatches it with a stab from its sharp beak. It then injects digestive enzymes into its prey, after which it drinks the resulting liquid innards.

This time of year you often see the smaller males riding around on the backs of the larger females while the females continue to feed. This behavior is part of the courtship ritual – males actively guard their mate prior to and following copulation. Mating takes place side by side, after which the female deposits her eggs among the leaves or on the stems of flowering plants. Look for Ambush Bugs in yellow and white flowers, especially goldenrod.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Mossy Rose Gall Wasp Larvae Cease Feeding

10-31-14 mossy rose gall IMG_0404In the spring, the 4mm-long cynipid gall wasp, Diplolepis rosae, lays up to 60 eggs (through parthenogenesis) inside the leaf bud of a rose bush. A week later, the eggs hatch and the larvae begin feeding on the leaf bud. This stimulates the abnormal growth of plant tissue, and a Mossy Rose Gall, covered with a dense mass of sticky branched filaments, is formed. The gall provides the larvae with food and shelter through the summer. In late October, when the Mossy Rose Gall is at its most colorful, the larvae stop eating and pass into the prepupal stage, in which they overwinter inside the gall. In February or March, the prepupae undergo a final molt and become pupae. If the pupae aren’t extracted and eaten by a bird during the winter or parasitized by another insect, adult wasps exit the gall in the spring and begin the cycle all over again.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.