An online resource based on the award-winning nature guide – maryholland505@gmail.com

Posts tagged “Invertebrates

Twelve-spotted Skimmers

Twelve-spotted Skimmers are classified as “King Skimmers,” all members of which are large and conspicuous, often with distinctive wing patterns.   Male Twelve-spotted Skimmers (pictured) have a grayish bloom on their abdomens and each wing has three dark spots with white spots in between them.  Females have brown abdomens and no white spots on their wings.  All summer you can see males flying back and forth short distances along the shores of ponds and over water, hovering as well as perching.  They are territorial and patrol over water, loop-de-looping with competing males.  A small number of Twelve-spotted Skimmers occasionally take part in Atlantic Coast migrations.


American Lady Larva

The American Lady larva is very distinctive with its branched spines and white bands across its abdomen.  One of its favorite foods is Pussytoes, a member of the Aster family.  The larva feeds inside a shelter it makes by tying up several leaves with silk.  In the photograph, the larva has incorporated the flower heads of Pussytoes into its shelter.  Not only is the larva feeding and growing inside this 1 ½ ”-long  cavity, it also shed its skin.  To see an adult American Lady butterfly, go to https://naturallycuriouswithmaryholland.wordpress.com/2012/07/08/american-lady-common-milkweed-pollinia/ .  Soon after the larva forms a chrysalis and pupates, a butterfly emerges and starts its migration south for the winter.


Earwigs

People used to believe that earwigs crawled into people’s ears while they were sleeping and proceeded to bore into their brains, thereby causing insanity and/or death. Fortunately, this isn’t, and never has been, true. Earwigs feed on leaves, flowers, fruits, mold and insects, but not human brains. Because they are nocturnal, during the day we often find them secreted away in some dark, damp crevice, often on a plant. These flat, elongated insects have a pair of pincers, or cerci, at the end of their abdomen which they use to capture prey, defend themselves and arrange their hind wings, if they have them. (Earwigs that possess wings can, but rarely do, fly.) You can actually determine the sex of an earwig, should you be so inclined, by the shape of its cerci – those of a male (pictured) are unequal in length, strongly curved and larger than the straight cerci of females.


Ant Mandibles

Ants go through complete metamorphosis, passing through four stages (egg, larva, pupa, adult). Like honeybees, there are queens, female workers and male drones in an ant colony. The female worker ants have a series of “jobs” that they perform in a certain order. A young worker spends the first few days of its life caring for the queen and young. After that she maintains the nest and eventually forages for food. Like most insects, ants lack grasping forelegs and compensate for this by using their mandibles as “hands.” When the nest is disturbed, workers rush to rescue the eggs, larvae (depicted in photograph) and pupae by clasping them in their mandibles and transporting them to safety. They also use their mandibles to carry food, construct nests, and for defense.


Common Milkweed Pollination

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The structure of the Common Milkweed (Asclepias syriaca ) flower is such that its pollen, produced in two saddlebag-like sacs with a black appendage joining them, snaps onto an insect’s leg when the two come in contact with each other. To assure that the chances of this are high, the pollen sacs (pollinia) hang inside a slit that is located between each of the five cups, or hoods, that contain nectar. An insect lands on the slippery flower, attracted by both the scent and availability of nectar, and inadvertently one or more of its six legs slips down between the hoods into a slit, where the pollinia automatically attach to the leg. The insect withdraws the leg upon leaving to find more milkweed nectar, and the attached pollinia eventually falls off onto another milkweed flower, pollinating it. Unfortunately, about 5% of milkweed flowers visited trap insects because they cannot extract their legs from the slit. It is not uncommon to see an insect dangling from a Common Milkweed flower – during a 30 minute visit to a milkweed patch recently I released 2 flies, 3 skippers (butterflies) and one honeybee that were caught, but hadn’t yet perished.


Broad-necked Root Borer

This impressive egg-laden, 2-inch long female Broad-necked Root Borer (Prionus laticollis) was attempting to lay her eggs when I discovered her. She repeatedly extended and retracted her ovipositor (pointed, egg-laying structure at tip of abdomen) in an attempt to probe the packed dirt in my driveway, but finally moved on to softer soil. Female Broad-necked Root Borers insert clumps of eggs into the ground. When the eggs hatch, the larvae tunnel downward to feed on the roots of a variety of shrubs and trees. In the spring they pupate, and adults, such as this female, emerge. This whole life cycle is thought to take three years.


Red Grasshopper Mites

The next time you’re in a field, stop and take a close look at a few of the grasshoppers you find there. Chances are great that you will see tiny, red mites on some of them. These Red Grasshopper Mites, close relatives of ticks and spiders, go through three stages: larva, nymph and adult. The larvae (6-legged) attach to the base of a grasshopper’s wings, where they suck the grasshopper’s blood. The nymphs and adults (both 8-legged) are free-living and feed on grasshopper eggs. Each Red Grasshopper Mite nymph requires more than two grasshopper eggs to become an adult. An adult male Red Grasshopper Mite requires three grasshopper eggs for reproducing, and each female, seven to eight eggs. After breeding, a female mite deposits up to 4,000 eggs. Entomologists believe that mites reduce grasshopper survival and reproduction dramatically.


Beaverpond Baskettail

Beaverpond Baskettail dragonflies have an early flight season, first appearing in May in the Northeast.  The males (pictured) cruise over the water (often beaver ponds, hence their name) as well as the shore in sexual patrol flight, flying back and forth over the same area repeatedly.  After mating, the female accumulates a large egg cluster at the tip of her abdomen, and as she drags it along the surface of the water, a long string of eggs is draped over plants.  Once these strings expand, they can be several feet in length and an inch or more in diameter.


Brown Creepers Nesting

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The Brown Creeper is so well camouflaged that there are many people who don’t even know of its existence. This diminutive bird gets its name from its habit of creeping along tree trunks and spiraling upwards while it probes for insects and spiders hidden in bark crevices with its curved, sharp bill.  At this time of year, brown creepers have already made their fibrous nest behind a loose flap of bark on a tree, and the 5 – 6 nestlings are constantly demanding food.  Unlike some species, both adults care for their young.  These photos illustrate how the male goes off and finds an invertebrate, flies back to the nest and gives it to the female, who then disappears behind bark to feed it to her nestlings.


Delayed Greening of Young Leaves

Many plants practice “delayed greening” of their leaves, including this Red Maple (Acer rubrum).  An initial lack of chlorophyll prevents the leaves from photosynthesizing and making food, which means they have little nutritive value, and thus, appeal, to an herbivore.  Most plants that delay greening have reddish leaves due to the presence of anthocyanin, a pigment which appears reddish.  A majority of herbivorous insects and invertebrates cannot detect colors in the red range of the color spectrum. Young leaves suffer the greatest predation from invertebrate herbivores.  Red leaves would be perceived by these leaf eaters as somewhat dark and possibly dead – not a choice food material.  It is possible that the red coloration of new leaves allows the plant to make them unappealing to the herbivores that would otherwise eat them.


Invertebrate Signs

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A quick look recently at the underside of a wooden bench sitting in the middle of a nearby field revealed a multitude of signs of insects and spiders that sought shelter in this protected spot.  They included the empty chrysalis of a monarch butterfly, the flat, red egg  sac of a Phrurotimpus  antmimic  spider (look closely and you’ll see bumps in the middle  made by the eggs underneath the silk), the silk and twig case of a bagworm moth larva , and a cocoon which is housing the pupa of a moth.