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

Posts tagged “insects

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.


Tobacco Hornworms & Brachonid Wasps

Tobacco Hornworms, Manduca sexta (often found feeding on tomato plants and confused with Tomato Hornworms, Manduca quinquemaculata) are often the target of a species of Brachonid wasp that parasitizes beetle, moth, fly and sawfly larvae. The adult wasp lays her eggs inside the hornworm with her long ovipositor. The eggs hatch and the wasp larvae feed on the caterpillar. Eventually the wasp larvae emerge and form white pupa cases on the skin of the dying hornworm larva, inside of which they transform into winged adults. Braconid wasps are extremely good at locating hornworms, even when there are very few to find. Because they parasitize hornworm, cabbage worm, aphid and gypsy moth larvae, Braconid wasps are considered important biological control agents. If you want to discourage Tobacco Hornworms in your tomato patch, allow the wasps to complete their metamorphosis – this accomplishes both the demise of the hornworm, as well as an increased population of Braconid wasps.


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.


Monarch Butterfly Eggs Hatching

It appears that this may be a good year for monarchs in the Northeast, as with very little looking, you can find their eggs as well as young monarch caterpillars. Look on the underside of the top leaf or two on young milkweed plants – these leaves are tender and monarchs often lay their tiny, ribbed eggs there (usually one per plant) as they (leaves) are ideal food for young larvae. The first meal a monarch larva eats is its egg shell. It then moves on to nearby milkweed leaf hairs, and then the leaf itself. Often the first holes it chews are U-shaped, which are thought to help prevent sticky sap (which can glue a monarch caterpillar’s mandibles shut) from pouring into the section of leaf being eaten.


Close-up of Entire Organ Pipe Mud Dauber Nest

The images in a slideshow are smaller than if they were posted individually, so I thought I would include a single shot of the first image, showing all of the cells in the nest’s three tubes.


Weevils

A weevil is a type of beetle whose mouthparts are formed into a long snout, with one antenna on either side of it. The snout is used not only for feeding but also for making cavities in buds, fruits, seeds, stems, and roots of plants, where eggs are laid. When the weevil larvae emerge, they feed within the plant. There are 60,000 species of weevils, all of which are herbivorous and most of which are less than ¼ ” long. The species of weevil in the photograph was on many of the black-eyed Susans that were blooming in an unmowed field, and all of them appeared to be feasting on pollen. Many weevils are pests of plants such as cotton, alfalfa and wheat. You may have even found them inside your house devouring your cereal or flour.


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.


Leafcutter Bee Cell Leaf Sections

At the risk of boring readers, I wanted to include one final Leafcutter Bee post, showing the two basic shapes that these bees chew out of leaves in order to make their incubator/nursery cells.  There are oblong pieces, roughly an inch long, as well as perfectly round, ¼-inch diameter pieces.  Each cell consists of several layers of oblong pieces rolled lengthwise which are sealed at one end with a round piece of leaf.  The round end pieces appear to be glued into place (perhaps with the pollen/nectar mixture?) at one end of the cell, leaving the opposite end open.  The cells are arranged end-to-end, with the open end of the cell placed against the sealed end of the next cell.  Together they form a nest that is somewhat cigar-shaped and is typically located a few inches down in the soil, or in a cavity.


Inside View of Leafcutter Bee Cell – Larva and Pollen Supply


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.


Mystery Photo

This is the larval stage of a very common insect. Do you know what it turns into? (I.D. provided 6-13-12)


Spittlebugs

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Have you ever poked around inside one of those masses of bubbles that you see on grass and other plant stems? If so, chances are that you have discovered that an insect actually lives inside this frothy home – the immature stage (nymph) of a Spittlebug. It hangs head down while piercing the stem of the plant and ingests the sap. Because the sugar content is often very low, the nymph must drink a lot of sap in order to get the nutrition it needs. As a result, the Spittlebug pumps out the excess water from the tip of its abdomen, which amounts to 150 – 300 times its weight every 24 hours. During this process, oxygen and nymphal secretions cause the water to have a sticky, bubbly quality, and these sticky bubbles pour down over the nymph, creating a moist home that prevents the Spittlebug nymph from drying out and that discourages predators as it tastes bad. Once it has matured, the nymph metamorphoses into an adult Spittlebug (also called a Froghopper) and flies away.  (Photographs are of:  spittlebug “spit,” spittlebug nymph and adult spittlebug emerging from nymphal skin.)


Eastern Tiger Swallowtail

The male Eastern Tiger Swallowtail butterfly (pictured) is yellow with four “tiger stripes” on each of its forewings. The female can be yellow or black, and has more blue on the hind wings than the male. Eastern Tiger Swallowtails are currently mating and laying eggs on plants which their larvae eat, which include black cherry, red maple and American hornbeam. When the caterpillars first hatch, they resemble bird droppings – an effective way of decreasing predation. As they get older, the larvae turn green and have a large head and bright eyespots.


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.


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.


Rusty Tussock Moth Egg Case

There are many species of tussock moths, and in their larval, or caterpillar, stage, most are covered with tufts of hair-like setae, some impressively long.  The female rusty tussock moth, Orgyia antiqua, is flightless, so after emerging from her cocoon, she stays put, releasing alluring pheromones and awaiting the arrival of a male suitor.  After mating, she lays up to several hundred eggs on top of her empty cocoon and then dies.  The flat-topped, cylindrical eggs (with a dark depression on their top) overwinter, and as soon as leaf buds start opening, the eggs hatch, with ready-made meals inches away.  Larvae feed on the leaves of birches, oaks, crabapples and black cherry, among others.  Pictured is an egg mass on an apple leaf.

 


Mourning Cloak Butterflies

With the warm temperatures this week, mourning cloak butterflies have been seen gliding through the leafless woods.  Like eastern commas, question marks and red admirals, mourning cloaks overwinter as adults.  They resemble dead leaves so much that from a distance the entire insect seems to disappear.  Up close you can see the velvety texture of the wing scales, said to resemble the clothing mourners used to wear; hence, their common name. Mourning cloaks live up to ten months — an impressive life span for a butterfly.  As they age, the yellow border of their wings fades to an off-white.


Northern Green-striped Grasshopper Nymph

Hard as it is to believe with half a foot of snow remaining in the woods, this northern green-striped grasshopper (Chortophaga viridifasciata) was hopping around in the dry grass of a south-facing field in Hartland, Vermont yesterday.   Most grasshoppers overwinter as eggs.  They hatch in the spring, and the immature grasshopper nymphs look like miniature versions of their parents, except they lack wings and sexual organs. Northern green-striped grasshoppers, however, overwinter as nymphs in the northeast, which is why the one in the photograph is as large as it is (1/2-inch) this early in the season.  (This grasshopper is one of the “band-winged grasshoppers,” which typically possess bands, or stripes, on their wings, as does the adult northern green-striped grasshopper.)


Snow Flies

It always comes as a surprise to see tiny creatures moving nimbly over the surface of the snow.  However, there are quite a few insects and spiders that do, thanks to the glycerol that they produce in their body fluids that keep them from freezing.  The Snow Fly (Chionea sp.) is wingless, probably because at sub-freezing temperatures, it would be very hard to generate enough energy for maintaining flight muscles.  They (along with other flies, mosquitoes and gnats) do have two vestigial wings called halteres, the little knobs on the fly’s thorax.  They inform true flies about the rotation of their body during flight, and are thought to act as sensory organs for the flightless Snow Flies.  Throughout most of the year Snow Flies can be found in leaf litter, but come winter the adults emerge, mate and lay up to 200 eggs.  The lack of predators such as dragonflies and most insect-eating birds makes winter a relatively safe time for Snow Flies to be out and about.  Their life span is about two months, during which time they drink by pressing their proboscis against the snow, but don’t eat.   (Snow Fly in photograph is a female, measuring less than ½”.)

 


Larvae-seeking Downy Woodpeckers

12-3-11  Larvae-seeking Downy Woodpeckers

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When cooler days arrive and adult insects become relatively scarce, insect-eating birds are very clever at gleaning the twigs, trunks and buds of trees and shrubs for overwintering eggs, larvae and pupae.  Certain galls (abnormal plant growths that house and provide food for a variety of insects) are sought by specific birds.  Downy woodpeckers seek the larvae of the Goldenrod Gall Fly (Eurosta solidaginis), which overwinter inside Goldenrod Ball Galls (formed on Canada Goldenrod, Solidago canadensis) before emerging as adults in the spring.  A tiny1/4” to 3/8”-wide hole (and an empty gall) is evidence that a downy woodpecker had itself a meal!

   


Sulphur Butterflies

It’s hard to believe, but even after Irene, several inches of snow and an occasional night that’s below freezing, there are still butterflies and moths to be seen. Yesterday this sulphur butterfly (probably clouded, Colias philodice) was flying from dandelion to dandelion, sucking up nectar with its long, black proboscis.  Clouded sulphur and orange sulphur butterflies, two different species, are similar looking, and on top of that, they even hybridize, so distinguishing between the two is often difficult, at best.  Both species have several broods in a summer; you can see them flying in fields and along roadsides from spring to fall.


Bald-faced Hornet Nest

If you find a  football-size (or larger), gray, papery structure attached to the branches of a tree or shrub, you’ve probably discovered the nest of a bald-faced hornet. (The only other hornets that build a similar nest are aerial hornets, and their nests usually have wider strips, and less of a scalloped appearance than those of bald-faced hornets.)   This structure is actually a nursery, filled with several horizontal layers of hexagonal cells, in which eggs are laid and larvae are raised.  These horizontal layers are surrounded by a multi-layered envelope, which, like the cells, is made of masticated wood fiber from weathered wood such as fence posts and hornet saliva. The different colors reflect the different sources of wood that have been used.  Although only the queen bald-faced hornet survives over winter (in a rotting log or other protected spot), the workers do not die until  freezing  temperatures have really set in, so wait for another month before approaching a nest!