An online resource based on the award-winning nature guide

Flies

Bloodroot A Fair-weather Friend

bloodroot in rain 336Bloodroot (Sanguinaria canadensis), utilizes contrasting white (petals) and yellow (pollen-bearing stamens) colors to attract insects and achieve pollination. The blossoms have no nectar, only pollen, and in order to protect the pollen, the petals of this member of the Poppy family close on overcast days and nights, a time when most pollinators are inactive. The reopening of the flowers depends on temperature and cloud cover. If it’s sunny out, the flowers will open when the temperature reaches 47°F. Native bees, which are Bloodroot’s main pollinators, don’t usually fly until it is 55°F., so flies, capable of flying at slightly lower temperatures, do most of the cool weather pollinating.

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White-tailed Deer Scavengers

deer carcass2  028According to NPR, each year Americans waste 33 million tons of food (and much of this ends up in landfills where it produces methane, a potent greenhouse gas). This situation is totally alien to that of other animals in the natural world, which seem to find a use for any and every organic particle. Great crested flycatchers incorporate shed snake skins into their nests, beavers build dams and lodges with branches they have eaten the bark off of, ermine line their nests with the fur and feathers of prey — the list goes on and on. When it comes to food, there is equally little waste. The carcasses of animals do not linger long, as almost every atom of their bodies is recycled. Fishers, coyotes, foxes, raccoons, opossums, bald eagles, hawks, woodpeckers, ravens, crows and many other animals make short work of a dead deer in winter. Come spring, if there’s anything left, the final clean-up crew consists of legions of turkey vultures, beetles, flies and bacteria, among others. How unfortunate we’ve strayed so far from a process that’s worked for so many for so long.

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.


Willow Beaked-Gall Midge

10-30-13 willow beaked-gall midge   047Now that most of the leaves have fallen, it’s a good time to look for galls that form on woody plants. Willows are host to a great number of gall-making insects, including tiny flies called midges. The most common species of willow gall midge is the Willow Beaked-Gall Midge, Rabdophaga rididae. In the spring, after mating, the adult female midge lays an egg in a willow bud (often terminal) that is just starting to expand. The egg soon hatches and the larva burrows deeper into the bud, which causes the bud tissue to swell and form a gall, usually with a “beak” at the top. The larva remains inside the gall through the winter, where it has a constant supply of food (the interior of the gall) and shelter. In the spring the larva pupates, and an adult midge emerges and begins the cycle all over again. Some gall midges are crop pests, but willows are not significantly damaged by the Willow Beaked-Ball Midge.

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.


Jewelweed Gall Midges

10-4-13 jewelweed gall  277Abnormal plant growths called galls come in all sizes and shapes, are found on leaves, buds and stems, and are caused by a number of agents, including insects. A majority of insect galls are caused by the eggs and developing larvae of flies, wasps and midges. Jewelweed, or Touch-Me-Not (Impatiens capensis), has a very distinctive looking aborted bud gall that is produced by a midge (Schizomyia impatientis). While some galls provide shelter and food for a lone resident, the Jewelweed Gall Midge is colonial, and several orange larvae can be found residing in separate cavities within the gall. These midge larvae are now emerging and will overwinter as adults.

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.


Clean Antennae Necessary for Sensory Perception

8-9-13 conehead katydid cleaning antenna 098Insect antennae are among the most sensitive and selective chemical-sensing organs in the animal kingdom. They detect information crucial to an insect’s survival, including odors, sounds, humidity, changes in water vapor concentration and air speed. Antennae are capable of these feats because of the sensory receptors covering them which bind to free-floating molecules. Experiments with cockroaches, ants and flies confirm that insects engage in antennal grooming — removing foreign materials from the surface of their antennae with their mandibles — primarily to maintain acute olfactory reception. Pheromones, chemical signals that are vital to insect communication, are used to convey alarm, attract a mate, mark territory and lay out trails, among other things, and clean antennae enhance these messages. (Photo is of a Sword-bearing Conehead Katydid cleaning its antenna.)

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.


Stinky Squid Fungus

7-16-13  Pseudocolus fusiformis 225There is no way you can walk by the fruiting body of Pseudocolus fusiformis, a member of the Stinkhorn family Phallaceae, without noticing it. Its shape is markedly different from most fungi, in that it has three or four separate orange “arms” which are fused at the top. If your eyes don’t detect it, your nose most certainly will. Also known as “Stinky Squid,” this fungus emits a strong, putrid odor which comes from the dark green, spore-bearing slimy material (gleba) that is found on the inner surfaces of the arms. This smell attracts insects, primarily flies, which inadvertently disperse spores after visiting the fungus. Look for round egg-like whitish structures at the base of Pseudocolus fusimormis – these are young fruiting bodies that have yet to develop arms. (Thanks to Shiela Swett for photo op.)


Hepatica Blooming

4-18-13 hepatica DA8A9542Hepatica has finally opened its hairy buds and greeted the world with its beautiful white, pink, blue and lavender blossoms. Typically the only wildflowers to appear earlier than this member of the Buttercup family are skunk cabbage and coltsfoot. Like many flowers, hepatica blossoms open on sunny days, and close at night and on cloudy days. This prevents rain from washing out the pollen and nectar which help attract pollinating insects, including early-flying bees and flies.


Goldenrod Ball Gall Fly Larva

3-22-13 goldenrod ball gall fly larva IMG_6182The round “ball” that is often present on the stem of goldenrod plants contains the overwintering larva of a fly (Eurosta solidaginis). A year ago an adult female fly laid an egg in the stem of the goldenrod plant. The egg hatched and the larva proceeded to eat the interior of the stem. As it did so, the larva excreted chemicals which caused the plant to grow abnormally, creating a ball-shaped “gall.” If you were to open a goldenrod ball gall today, you would probably find an overwintering larva (if a downy woodpecker or parasitic wasp hadn’t gotten there before you). Within the next few weeks the larva will pupate, and as early as April the adult fly will emerge from the gall, having crawled out the passageway that it chewed last fall. An inflatable “balloon” on its forehead allows the fly to burst through the remaining outermost layer of tissue at the end of the passageway. The adult fly lives about two weeks, just long enough to mate and begin the process all over again.


Mating Flies

3-18-13 mating flies IMG_6645 (2)It’s hard to believe that flies are not only active but mating now, given the snow and low temperatures that Vermont is still experiencing, but these two flies were perched atop coyote scat doing just that. They are in the Heleomyzidae family, whose members are often found in dark or cold places, and are most likely to be encountered in the spring or late fall. There are species associated with caves, mammal burrows, carrion and birds’ nests, in addition to scat.


A Great Christmas Present!

If you’re looking for a present for someone that will be used year round, year after year, Naturally Curious may just fit the bill.  A relative, a friend, your child’s school teacher – it’s the gift that keeps on giving to both young and old!

One reader wrote, “This is a unique book as far as I know. I have several naturalists’ books covering Vermont and the Northeast, and have seen nothing of this breadth, covered to this depth. So much interesting information about birds, amphibians, mammals, insects, plants. This would be useful to those in the mid-Atlantic, New York, and even wider geographic regions. The author gives a month-by-month look at what’s going on in the natural world, and so much of the information would simply be moved forward or back a month in other regions, but would still be relevant because of the wide overlap of species. Very readable. Couldn’t put it down. I consider myself pretty knowledgeable about the natural world, but there was much that was new to me in this book. I would have loved to have this to use as a text when I was teaching. Suitable for a wide range of ages.”

In a recent email to me a parent wrote, “Naturally Curious is our five year old’s unqualified f-a-v-o-r-I-t-e  book. He spends hours regularly returning to it to study it’s vivid pictures and have us read to him about all the different creatures. It is a ‘must have’ for any family with children living in New England…or for anyone that simply shares a love of the outdoors.”

I am a firm believer in fostering a love of nature in young children – the younger the better — but I admit that when I wrote Naturally Curious, I was writing it with adults in mind. It delights me no end to know that children don’t even need a grown-up middleman to enjoy it!


Pine Cone Willow Gall

Galls are abnormal plant growths that can be caused by insects, fungi, bacteria, nematode worms and mites.  Insects cause the greatest number of galls and induce the greatest variety of structures.  Galls provide both food and shelter for the organisms living within them.  Galls develop during the growing season, often in buds and on leaves.  Pine Cone Willow Galls, named for their resemblance to small pine cones, are found on willows, typically in terminal buds.  A gall midge (Rhabdophaga strobiloides) is responsible for the willow bud going haywire and developing  abnormally. (No-one has determined exactly how insects cause galls, whether it’s the act of laying eggs in or on the plant, or if it’s somehow connected to the chewing of the larvae into the plant.)    Each gall-making insect has a specific host plant, or small group of related plant.  The galls that each insect species induces and lives in while developing into an adult has a recognizable shape and size.  When you think you’re seeing pines cones on willow trees, you’re not hallucinating, you’ve just discovered the temporary home and food supply of a tiny fly, known as a midge.


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.)


White-tailed Deer Fawn

White-tailed Deer fawns are close to two months old now, and will retain their spots until their gray winter coat grows in this fall. The dappling of the spots enhances a fawn’s ability to remain camouflaged up until it is large enough and strong enough to outrun most predators. However, it doesn’t hide them from biting insects. During the summer months, when White-tailed Deer, including fawns, have a relatively thin, cool coat of hair, they are very vulnerable to biting insects such as female horse flies and deer flies. These flies make tiny slices with their blade-like mouthparts in their host’s skin in order to have access to their blood. This fawn was being constantly bothered by such flies.


Moose Flies and Moose

My recent quest for finding moose was successful – and my most striking observation, other than their imposing size, was the presence of a multitude of flies on and around the hindquarters of every moose I saw. I assumed they were deer flies, but they didn’t appear to be bothering the moose and research revealed that, in fact, they were moose flies, Haematobosca alcis. These flies can be seen throughout the spring and summer in dense swarms over and on the rumps of moose — five hundred or more may accompany a single moose. Unlike most other biting insects, both male and female moose flies feed on their host’s blood. Although not considered a serious pest (moose tend to pay little attention to them), moose flies may be responsible for sores often found on the hind legs of moose. It is thought that female moose flies may be stimulated by gases released by the moose when it is defecating, after which the female flies descend and deposit eggs into crevices in the moose’s scat.


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”.)

 


Winter Crane Fly

Earlier this week, when temperatures were in the 40’s and the sun was shining in the late afternoon, there were clusters of male winter crane flies (Trichocera sp.) hovering two or three feet above the snow, bobbing up and down as they did their mating dance. Females are on the surface of the snow most of the time, but join a swarm in order to find a mate. Winter crane flies are active throughout the winter, as their name implies, and are a source of food for resident songbirds.  The larvae feed on decaying vegetation, and can be found in leaf litter, shelf fungi and compost heaps.


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!

   


Naturally Curious wins National Outdoor Book Award

I am delighted to be able to tell you that this morning I learned that NATURALLY CURIOUS won the Nature Guidebook category of the 2011 National Outdoor Book Awards.  I’m honored and humbled by this recognition.   http://www.noba-web.org/books11.htm


Netted Stinkhorn

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The way I discovered this netted stinkhorn fungus (Dictyophora duplicata) was the same way flies find it – the odor emanating from it is much like that of a decomposing body.  This odor comes from the spores of the stinkhorn – the  slimy, olive-green matter on the head, or top portion of the fungus.  When mature, the spores have a fetid odor which successfully lures insects to the stinkhorn.  They eventually depart from the fungus, and procede to disperse the spores that stuck to them far and wide.   Although it’s not too discernible in these photographs, netted stinkhorns derive their name from a fishnet-like veil, or skirt, below the head of the fungus.

 


Robber Fly

Robber flies have been covered in a previous posting, but their beak, or proboscis, deserves its own post, in my opinion.  These predators perch and scan the sky for prey. When they see it they  anticipate the prey’s direction and speed of flight and fly out and intercept it mid-air.  Their objective is to paralyze the prey and  liquify its insides so that the fly can drink it.  The tip of the robber fly’s beak is covered with microscopic stiff bristles, designed to secure it within the wound it creates. Once this is achieved, a dagger-like shaft hidden inside the beak is used to stab its victim in the head or thorax and inject the paralyzing  neurotoxic and digestive enzymes.  The resulting fluid is sucked up by the fly’s beak, or proboscis.


Goldenrod Visitors

If you want to get an idea of the number and variety of wasps, bees, beetles and bugs that reside in your area, go to the nearest goldenrod patch sit for a spell – this member of the Aster family is a magnet for insects. You’ll find many foliage- eating bugs and beetles, leaf-mining  larvae, nectar and pollen feeders, and flower and seed-eaters.  In addition, many predatory spiders (jumping and crab, especially) and insects (ambush bugs, ladybug beetles, flower bugs etc.) have discovered that goldenrod  is a goldmine for them, as well. Researchers have found nearly 250 species of insects feeding on one species of goldenrod (Solidago canadensis).   Pictured from left to right are a long-horned beetle (locust borer, Megacyllene robiniae  – pollen eater), a fly (nectar feeder) and bee (nectar and pollen feeder).

 


Robber Flies

Robber flies often perch on the leaves or stems of low plants waiting until suitable prey flies by, and then attack it in the air.  They have long, strong, spiny legs for grabbing prey, and piercing-sucking mouthparts for consuming it.  Robber flies prey on a variety of insects, including bees, beetles, bugs, dragonflies, grasshoppers, flies, leafhoppers and wasps. Once they capture an insect, they pierce it with their short, strong proboscis, or mouthpart, and inject  their saliva into it.  The saliva of robber flies contains enzymes that paralyze the insect and digest its insides, which the robber fly then drinks. The pictured robber fly is feasting on the innards of a stink bug it just captured.


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