Posts Tagged ‘insects’

Wednesday, July 1, 2009

The Hover Fly: A Sheep in Wolf’s Clothing

There you are, enjoying a pleasant stroll among the flowers, when your eyes suddenly land on a black and yellow banded insect getting a meal on a flower. “A bee!” your mind screams, and you hastily blunder your way out of the garden in full panic mode. When you reach the safety of the house, you contemplate grabbing a can of Raid and eliminating the unwanted insect. If, however, you had taken the time to look at the insect, you might have noticed two things. One, the “bee” only had two wings (most insects have four; flies have two), and two, the body was not fuzzy. This is no bee. It is a beneficial insect called a Syrphid, or Hover, Fly.

Syrphids are nifty, harmless flies. Although they may look like a bee or yellowjacket, they have no stingers. Their cryptic coloration fooled you, though, as it was supposed to. By looking like a bee or wasp, this insect is able to trick predators that might otherwise want to make it a meal.

Like our friend the housefly, Syrphids are equipped with sponge-like mouthparts, which they use to mop up meals of pollen and nectar. As such, they are very important pollinators, flying from blossom to blossom and transferring pollen as they go. But the benefits of these boldly colored insects don’t end here. Their larvae are also important.

The larvae of some species of Syrphids feed on decaying vegetation and fungi, making them important cogs in nature’s recycling system. Others seek out the nests of ants, termites and bees. But the ones that are dear to the naturalist’s (and gardener’s) heart are the ones that seek out and destroy aphids. In these species, the female adults lay their eggs singly near a herd of aphids. In days the egg hatches and the legless, slug-like larva oozes its way towards its prey. When an aphid is encountered, the larva raises its head, clamps onto the juicy body, and sucks it dry. Over the course of its short life, the larva can consume upwards of 400 aphids (provided their ant protectors don’t evict it first), providing relief to the host plant the aphids were draining.

The next time you find yourself walking through a field of flowers, along a roadside, or in your garden, keep your eyes peeled for these bright, bi-winged insects as they hover over the blossoms. Take a few moments to observe their behavior. You never know what else you might discover.


Saturday, June 27, 2009

Wild and Woolly Adirondack Aphids

While hustling a group of first and second graders along the trail to get them back to their bus on time, I hit the breaks when my eye was caught by masses of white fuzz in the alders along the boardwalk. I zoomed in on the fuzz, with the kids right beside me. What could it be? When I got close enough, I knew what we had: woolly alder aphids (Paraprociphilus tesselatus).

Usually we see these insects in late summer and early fall when the bits of white fuzz start flying around. They are kind of pretty, in a fluffy faerie sort of way, with just a hint of pale blue showing through the fuzz. But, they are aphids, after all, and we all know that aphids tend to be bad news for plants.

In preparation for writing this post, I read up on woolly alder aphids, and it turns out that, like so many things on this planet, they are pretty interesting characters. For example, let’s look at that glorious white fuzz. It’s more than just a pretty covering. This cottony fluff is actually a waxy substance that the aphids exude to protect their juicy grey bodies from predators. After all, if you were looking for a mouthful of tender insect, and instead you got a mouthful of waxy fuzz, you might think twice about snacking at this location.

But every problem has a solution, and indeed there are two major predators of these aphids: the larvae of green lacewings (Chrysopa slossonae) and the caterpillar of a butterfly appropriately known as the Harvester (Feniseca tarquinius). This caterpillar, by the way, is one of the world’s only predaceous butterfly caterpillars. Both these predators adapt a pretty interesting hunting strategy: they cover themselves with the aphids’ own waxy fuzz. Thus disguised, they become veritable wolves in sheep’s clothing, hunkering down among the aphid colony and munching away.

But wait…the story doesn’t end here. The disguise adapted by these larvae isn’t so much to hide them from the aphids as it is to hide them from the aphids’ body guards. Like many aphids worldwide, woolly alder aphids have an arrangement with Ant Protective Services. If you find a colony of aphids, look closely and you will surely find ants nearby. These ants may look like simple shepherds, herding flocks of aphids and “milking” them for honeydew, but the arrangement isn’t quite so bucolic. Sure, the aphids squeeze out droplets of super sweet liquid (a by-product of the sap they sucked from the plant – more on this in a moment) when stroked by the ants’ antennae, and the ants then tote these droplets home for dinner, but in exchange for this the ants protect the colony from all intruders. Go ahead and stick your finger among the aphids and see what happens. Quickly your finger will be attacked by the nearest ants. So the clever costumes used by the lacewing and butterfly larvae do a pretty good job of tricking the ants. If you don’t believe it, consider this: some researchers introduced undisguised larvae to an aphid colony and the ants patrols effectively removed them from the scene.

The aphids get an additional benefit from the “milking” process mentioned above. As we all know, a steady diet of sugars isn’t nutritionally balanced; even aphids need some protein, especially when it comes time to reproduce. In order to acquire the necessary nutrition (nitrogen), the aphids consume more sugary sap than they need. Their systems then separate out the minute traces of nitrogen and excrete the excess sugars (honeydew). The nitrogen is then utilized in making the necessary proteins for reproduction.

And this brings us to the life cycle of the woolly alder aphid. When you gaze upon a colony of aphids coating the twigs and branches of your alders, you are looking naught but females. There won’t be a male in sight. This is because these insects reproduce asexually, via a process known as parthenogenesis. This system of reproduction is actually a lot more common than you’d think. Unlike many insects, the virgin female aphid gives birth to live young (no time and energy wasted in making eggs), all of which are daughters. In almost no time at all, the daughters are squeezing out girls of their own. This reproductive strategy has the advantage of producing individuals perfectly adapted for the host plant and its immediate environment. Some researcher with nothing better to do once calculated that one female aphid could give rise to over 600 BILLION clones of herself over the course of a single season! Thank goodness for predators, parasites, diseases and limited numbers of host plants, eh?

But, even this sort of perfection has its limits, and towards the end of the summer, the host plant may be weakening, or the colony just needs to move on (perhaps the host is getting too crowded). Things become stressful and suddenly a generation is produced that has males. You will know this has happened when the formerly stationary insects have produced models with wings. The resources are now available for sexual reproduction, which results in the mixing up of genetic material. This in turn produces offspring that may be better able to survive conditions in other locations, so off they go. Natural selection will then determine which ones will survive.

What an amazing world we live in. Every time you turn around there is something new to discover. Who knew that white fuzz on a shrub could turn out to be so strange and exotic! I love science fiction, but part of me really believes that we don’t need to travel the expanses of the universe to find bizarre lifeforms: they are already here and living among us. So go forth, ye citizens of Earth, and see what fantastic lives you can uncover right in your own back yard!


Sunday, June 14, 2009

Fighting Colorado Potato Beetles in the Adirondacks

Last year it seems my yard was the staging ground for every potato beetle in Newcomb. No other gardeners I’ve spoken with seem to have had any, yet my potatoes were covered and defoliated faster than my patrols could keep up. This spring I resolved that I would not fall victim to these insects. I ordered an organic-certified insecticide, and read that by planting my ‘taters later (say, mid-June), I could avoid an infestation.

Well, I went out in the garden the other day (after planting my potatoes…I just couldn’t wait another week), and found a Colorado Potato Beetle on a potato plant that had just emerged, a sprout from an overlooked potato from 2008. I crushed it beneath my boot. Then I found another…and another. A couple days ago I went back out and found that not only did I have adult beetles grazing on these resurrected plants (they are sprouting up all over the place – I must work on my potato digging skills), but they were mating and laying eggs. I smooshed several clusters of the brilliant orange eggs before I went inside and mixed up a batch of spray. Thus armed, I commenced my attack. Then it rained. » Continue Reading.


Sunday, June 7, 2009

Gardening for Butterflies and Moths

Most of us are familiar with monarch butterflies, those stunning Hallowe’en-colored insects that make phenomenal migration flights from the northern parts of North American to the hidden forests in Mexico. But if you mention painted ladies, people are more likely to think of old Victorian houses with bright new paint jobs, or women with questionable reputations, than they are butterflies. Likewise, thanks to ads for a popular sleeping remedy, luna moths are easily recognized by much of the American population, while Isabella moths remain mostly unknown (woolly bear caterpillars turn into Isabella moths). » Continue Reading.


Monday, May 25, 2009

Must-do Nature Events for Summer 2009

Summer. The word conjures up images of the outdoors: sunshine, trees, beaches, birds, flowers. It is THE time to go beyond your door and explore the natural world. There are so many options that, as Calvin noted in the Calvin and Hobbes comic strip, “The days are just packed.” Here are three summer activities on my “to-do” list this year.

1. Orchid Hunting. Orchids are wonderfully strange wildflowers that hide out in many Adirondack wetlands. Some are in bogs (Ferd’s Bog, near Inlet, is famous for its white-fringed orchids), some are in roadside ditches (like the smaller purple fringed orchids I found last year near home and the green wood orchid I tracked down along the road to Tahawus). But I’ve also found ladies tresses on a dry roadside bank! The best time to go orchid hunting (and this is visual “hunting” – orchids are all protected by law, so do not collect or pick them) is mid-July through early August. Visit a wetland or roadside ditch near you, or go for a drive to a public wetland, like the Boreal Life Trail at the Paul Smiths VIC (white fringed orchids, rose pogonia, and grass pinks await you there, although the latter two are at their best late June into early July). I recommend taking along Newcomb’s Wildflower Guide to help you identify your discoveries. » Continue Reading.


Saturday, May 16, 2009

The Lost Ladybug Project – Perfect for Families

“Ladybug, Ladybug, fly away home
Your house is on fire and your children are gone.”

I never really understood that little ditty when I was a kid. I mean, why would you tell this specifically to a ladybug, as opposed to a bumblebee or a dragonfly?

As it turns out, there is a reason. A quick search on the Web turned up a neat little website on nursery rhymes: http://www.rhymes.org.uk/ladybug_ladybug.htm. It seems that in merry ol’ England it was traditional to burn the fields after the fall harvest to cut down on potential future insect infestations. The farmers knew that this beetle, which they call a ladybird, was the farmer’s friend (they are ravenous aphid-eaters), so this was essentially a courtesy call made to tell the insects to leave the fields before they set them on fire.

Today we find ladybugs mostly in our houses in the winter and spring. This is because these insects seek out good hidey-holes for hibernation (cracks along the outside of the house), and when they detect the warmth and light inside, they move on in. Ladybugs are totally harmless, but they can exude a foul-smelling orange goo from their legs if they are pestered. This is a defense mechanism meant to drive away predators, but to them a broom is just as aggressive as a bluejay, so if you try to sweep them away, they may leave this exudate on your walls and curtains. The majority of the ladybugs that turn up in your house are probably non-natives, the Halloween ladybug being the most common perpetrator. This species is orange and black, and often shows up in the fall.

Despite this apparent evidence to the contrary, many native ladybug species are in rapid decline. Back in 1986, when the nine-spotted ladybug was proposed as New York’s state insect, it was common, but by 1988 its population was in a tailspin. One hasn’t been seen in New York now since the late ‘80s. Only one specimen has been found since then in all of the eastern US, and that was discovered by two children in Virginia.

What can YOU do? Cornell University, home to many a citizen science project, has started the Lost Ladybug Project (www.lostladybug.org). This is a great hands-on project for kids, families, or adults. All you do is go out, look for ladybugs, take their pictures, and send the photos in to Cornell, along with the particulars of where you found the ladybug, when you found it, etc. There are three species they are especially interested in finding: nine-spotted, two-spotted, and transverse ladybugs. If you go to their website, they have lots if photos and color print-outs that can help you succeed in this mission.

I know that I’m going to add ladybug hunting to my list of outdoor activities this summer. I have a patch of tansy that in the past has been loaded with ladybugs, both adults and their larvae (which are strange-looking beasts). Chances are most of these will be introduced species, but you never know…lurking among the immigrants there just might be a native or two.


Tuesday, December 16, 2008

DEC Seeks Comments on Firewood Measures

The New York State Department of Environmental Conservation (DEC) today announced it has proposed making permanent a regulation to restrict the import, sale and transport of untreated firewood to aid in the fight against the spread of tree-killing pests and diseases. A public-comment period on DEC’s proposal runs through Feb. 9, 2009. DEC encourages interested parties to weigh in on the proposal – which can be viewed on the DEC website — at two public hearings or through written comments. » Continue Reading.


Wednesday, October 29, 2008

Keep An Eye Out for Emerald Ash Borer

The arrival of the shiny, emerald green beetle, about 1/2 inch long and 1/8 inch wide, in the U.S. may be as serious a threat to white, green, and black ash trees as Dutch elm disease was to the American elm.

Ash trees are a common species; green and black ash grow in wet swampy areas and along streams and rivers; white ash is common in drier, upland soils. Many species of wildlife, including some waterfowl and game birds, feed on ash seeds. Ash is used as a source for hardwood timber, firewood, and for the manufacturing of baseball bats and hockey sticks. The New York State Department of Agriculture and Markets estimates the total economic value of New York’s white ash to be $1.9 billion dollars. » Continue Reading.


Saturday, September 27, 2008

DEC Grants Available for Invasive Species

New York State Department of Environmental Conservation (DEC) Commissioner Pete Grannis announced today that grant applications are now being accepted for projects proposing to eradicate terrestrial invasive species. Terrestrial invasive species is defined as a plant or animal that lives or grows predominately on land. Applications will be accepted until October 31, 2008

DEC is making up to $1 million in state grants available to municipalities and not-for-profit organizations for projects to eradicate and/or permanently remove infestations of terrestrial invasive species throughout the state. The funding for these grants was secured in the 2008-09 enacted state budget, through the Environmental Protection Fund. State funds can be used to pay for up to one-half of the cost of selected projects. Individual grants for terrestrial eradication proposals will be awarded for projects that range from $2,500, up to $100,000. » Continue Reading.


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