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

Posts tagged “Metamorphosis

Hickory Tussock Moth

 

Most tussock moths, such as this Hickory Tussock Moth (Lophocampa caryae), are densely covered with hair-like structures called setae that bear microscopic barbs.  Many people are sensitive to these setae and get an itchy rash if they handle a Hickory Tussock Moth.   Even touching the cocoon of a tussock moth can cause irritation, as the setae are woven into it.  Many tussock moths display warning coloration with their black, white, red, orange or yellow setae.  What looks like two Hickory Tussock Moth larvae in the photograph is actually one adult caterpillar (left) and its shed skin (right).   You can find these larvae feeding on hickory, walnut, ash, oak and many other trees in the woods right now.  After spending the winter pupating in a cocoon in the leaf litter, a small spotted, tan moth emerges.


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.


Monarch Butterfly Chrysalis

Of the multitude of discoveries that every summer offers us, one of the most magical is that of  a Monarch Butterfly chrysalis.  While locating a Monarch larva is not all that difficult, especially when they are as prolific as they are this summer, finding a chrysalis doesn’t happen all that often. Most butterfly chrysalises are a rather drab brown, but the Monarch’s is a beautiful green which serves to camouflage it in fields where the caterpillars feed on milkweed and eventually pupate (form a chrysalis).  The Monarch caterpillar, when mature, usually seeks a sheltered spot under a leaf or branch where rain will not cause the silk button by which it hangs to disintegrate.  The chrysalis in the photograph is attached to a blade of grass which was anchored with silk to another blade of grass in order to make it more secure.  No matter how many I’ve seen, each one still takes my breath away.


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.


Spongilla Fly Cocoon

If you’ve never heard of a Spongilla Fly, you’re not alone. We don’t see its larval stage, as it lives under water, where it feeds exclusively on fresh water sponges. You can find these sponges living in the still waters of large rivers, lakes and wetlands. The beautiful silken net, as well as the small cocoon inside the net, are created by a Spongilla Fly larva after it crawls out of the water and chooses a spot on land on which to pupate (in this case on a seat cushion). The entire structure is less than ¼” in diameter.


Botfly Puparium

Congratulations on some very creative guesses!  Yesterday’s post  was a botfly puparium – a hard case made from an insect’s larval exoskeleton (skin) that covers and protects the pupa.  Most insects that go through complete metamorphosis (egg, larva, pupa, adult) don’t have this added protection for their pupal stage, but certain flies, including botflies, do.  Botflies are fairly large, hairy flies that resemble bumblebees and are internal parasites of many species of mammals, including humans. Depending on the species, the botfly deposits its eggs on or near the host animal, or on another insect, such as a mosquitoe or housefly, which carries them to their host. The eggs of some species of botflies are ingested or inhaled; those of other species hatch and the larvae bore into their host. After entering and crawling around inside of the host animal for a week or so, most species of botfly larvae settle in a spot just under the host’s skin and remain there for three to ten weeks, consuming the flesh of its host.  The lump, or “warble,” that forms just under the host’s skin where the botfly resides increases in size as the larva grows. A tiny hole chewed in the skin allows the larva to breathe, and eventually it exits through this hole.  The larva falls to the ground, where it pupates in the soil and later emerges as an adult botfly. (The two yellow bumps at one end of the puparium are spiracles, through which the pupa breathes.) The whole story of this particular puparium is that Jeannie Killam  found it in her old farmhouse’s kitchen cupboard, where it probably popped out of a visiting mouse.  (Illustration is of a human botfly.)


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.


Inside Look at Organ Pipe Mud Dauber Wasp Cells

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Each “pipe” of the Organ Pipe Mud Dauber nest consists of several sealed cells (four, in this photograph), each stuffed with spiders (typically orb-spinning spider species) and one wasp egg. When the egg hatches, the white wasp larva consumes the paralyzed spiders, which are still fresh because they are still alive. Eventually, upon finishing the spiders, the larva will form a pupa case, and spend the winter inside it. In the spring the adult wasp will emerge from the case and chew its way out of the mud cell. If you look closely at the open, back side of these three “pipes” you can see that the oldest pipe is on the left, and contains cells with wasp larvae, whereas you can see mud dauber eggs lying on top of the spiders in two of the cells on the far right, in the most recently built pipe.


Inside View of Leafcutter Bee Cell – Larva and Pollen Supply


Ladybug Metamorphosis

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Much to my delight, many of you knew that yesterday’s mystery photo was none other than the larval stage of a ladybug (referred to as a “ladybird beetle” by entomologists, as it is not a true bug, but a beetle). I remember when I first learned what the different stages of a ladybug’s life cycle looked like – I couldn’t believe that this miniature alligator-like creature turned into a sweet little ladybug. Approximately 88% of all insects pass through four separate stages (complete metamorphosis: egg, larva, pupa, adult) by the time they reach adulthood. Ladybugs are one of these insects. The first three stages of a ladybug’s life each last anywhere from 7 to 21 days, depending on weather and food supply. An adult ladybug lives for 3 to 9 months. The larvae of all ladybug species (there are approximately 450 in New England) have a similar appearance. Yesterday’s larva, as well as today’s pupa (and accompanying shed larval skin) and adult, are  Multicolored Asian Ladybugs.


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)


Cecropia Moth

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Who would ever associate a lime green caterpillar with colored knobs with a large, brown moth? Thanks to someone’s keen observation, we know that these are both stages of one and the same insect — a Cecropia Moth. It is North America’s largest native moth — individuals with a wing span of over six inches have been documented. Cecropia Moths are emerging from their 3-inch cocoons this month, as are other giant silk moths, including the Luna Moth and Prometheus Moth.
NOTICE: I will be away for the next week in northern Maine, trying to photograph the largest member of the deer family. Blogs will resume on Monday, June 11.


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.)


Spotted Salamander Larvae

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A few short weeks ago spotted salamanders gathered at vernal pools to breed and lay eggs.  Since then their eggs have started hatching, and gilled spotted salamander larvae can now be found in these pools. The larvae are major predators and consume many insects and crustaceans, including mosquito larvae and fairy shrimp.  During the next two or three months, these larvae will develop lungs, absorb their feathery gills and begin life as terrestrial amphibians, assuming the temporary pool they’re in doesn’t dry up prematurely. (The two appendages, one on either side of its body in front of the gills, help the larva balance itself until its legs develop.)

 


Blinded Sphinx

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Sphinx moths (also known as hawk moths, and the larvae as hornworms) are a group of long-tongued moths that possess the most acute color vision of any animal. The larvae possess a “horn”, eyespot or hard button on their abdomen. (The tobacco hornworm and tomato hornworm are sphinx moth larvae.) The larva of the Blinded Sphinx moth (Paonias excaecatus) is the most common sphinx moth larva in many of New England’s woods.  Its bright green color and granulated skin may camouflage it amongst the leaves of the oak, hop hornbeam, cherry and poplar trees that it eats, but when crawling on the forest floor, as this one was, it’s hard to miss.  The larva burrows into the soil in the fall and pupates. An adult moth emerges the following summer and mates, but does not feed. This moth ‘s name refers to the fact that the small blue spot (or “iris”) on the hindwing has no central black spot (or “pupil”)  and is therefore “blind.”  The spots of the similar Twin-spotted Sphinx (Smerinthus jamaicensis)  has a black “pupil” which allows it to see.  p.s. Old habits die hard — I will continue to post whenever time allows!


Gray Treefrog (Hyla versicolor)

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A gray treefrog starts life off as a ¼”, yellow tadpole. Eventually it may reach 2 ½” in length, and its body will have turned olive green with a red tail. Upon metamorphosing into a frog, the gray treefrog turns a bright emerald green and gradually develops into a mottled gray adult. The two color phases of the maturing frog are so different it’s hard to believe that they are the same species. However, a glance at their large, rounded toe pads tells you that they are at least related. All members of the treefrog family (which includes spring peepers) possess these toe pads, which enable them to cling to rough and smooth surfaces, and to climb up verticle structures, from tree trunks to house windows.


Dragonfly Eclosion – Emergence of Adult

8-4-11 Dragonfly  Eclosion – Emergence of Adult

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At the end of its larval stage, a dragonfly larva crawls out of the water where it’s been living and climbs up onto emergent vegetation, or a nearby rock, where it clings as its skin splits along its back and head.  The adult winged dragonfly pulls itself out of its larval skin through this hole, and grasps the skin (or vegetation or rock) while it pumps its body full of air and sends fluid into its wing veins.  This fluid causes the wings to enlarge — the wing expansion that is evident in these two photographs took place in less than ten minutes.  When it first emerges from its skin, a dragonfly is pale and soft, and the wings have a characteristic pearlescent sheen, as in these photographs.  Within a day or so the wings lose this sheen, the body hardens and colors start to develop.


Monarch Butterflies

The third and fourth generations of the monarchs that migrated from New England to central Mexico last fall are arriving in New England, mating and laying eggs.  The eggs are hatching, and some of the larvae, or caterpillars, are well on their way to adulthood.  This larval stage of their metamorphosis lasts about two weeks, and is the only stage during which monarchs have chewing mouth parts. The caterpillars take advantage of this by consuming both the leaves and flower buds (see photograph) of common milkweed practically non-stop, increasing their body mass up to 2,000 times.

 


American Toadlet

American toads mated and laid their eggs in ponds about a month ago.  Those eggs hatched and now the tadpoles are beginning to transform into tiny toadlets. For several days after developing legs and lungs they can be found in clusters on the shore of the pond from which they emerged. Gradually they disperse to the surrounding land.  No bigger than your smallest fingernail, they look like miniature adults, warts and all.