Thursday, December 15, 2011

Ten Ugly Little Animals Who Belong in the Garden

[This one really should have been published on Yahoo, but my online time was very limited...somehow it got lost in the stack of manuscripts.]

“Green” is the hottest advertising term these days. Everybody seems to want to “green up” their home and garden. However, a recent request for suggestions on “Green” ways to kill honeybees shows that not all of us are familiar with the fundamentals of Green gardening.

You don’t want to kill honeybees. Not ever. Our North American ecology is hopelessly dependent on them. Besides, their social, intelligent habits makes it easy to move honeybees wherever you want them to go. Bees are our friends. They have no place on this Top Ten list of small animals that may look ugly, but are worth having in your garden:

Ugly Animal Friend #1: Spiders. In North America only two species, neither of which is common anywhere and neither of which hangs out in gardens, are venomous enough that their bite is anything to worry about. Our other spiders may or may not nip harmlessly if threatened. They eat insects.If they crawl on you or move into your home, they’re probably trying to protect you. Flip them off your clothes or carry them out of your house, saying “Thank you.”

Ugly Animal Friend #2: Cicadas. The cicada family is divided into two main groups: annual cicadas, which live about a year, emerge in late summer, and are bigger than tree frogs; and periodical cicadas, which may spend as many as seventeen years underground before emerging in early summer, and are almost as big as tree frogs. Adult cicadas live just long enough to make baby cicadas, or grubs. They don’t bite, and do only slight, superficial, cosmetic damage to shrubs and trees. Greenies put them out of houses and offices, because they’re messy when crushed.

Probably depending on the local population density, some Greenies enjoy listening to the loud rasping sounds male cicadas make to advertise themselves to female cicadas, and others enjoy reflecting on the fact that few cicadas live even seven days after emerging from the ground. If you have a dense population of periodical cicadas, you might also want to advance the cause of science by noticing differences in their noises and preferred mating positions. In Virginia and Maryland, home of the infamous “Brood X” of seventeen-year cicadas, scientists now think there are three separate species that happen to share the same habitat and life cycle.

Despite the folklore that cicadas advertise themselves as being the biblical plague of locusts from Egypt when one call “Egypt, Egypt” and another kind call “Pharaoh, Pharaoh,” the “locusts” that devour every green thing in an area are common grasshoppers whose look and habit have changed due to overcrowding.

Ugly Animal Friend #3: Ichneumon wasps (also called ichneumon flies). These look like overgrown paper wasps, except for having “tails” that are longer than the insect itself. The tails are not stingers. They are ovipositors, or egg-placers. They are sharp, and can place eggs deep inside rotten wood, but the wasps prefer to puncture bagworm bags and parasitize other hard-shelled insects that have few other predators. Ichneumon wasps are solitary and non-aggressive.

Ugly Animal Friend #4. Silk moth caterpillars. Native silk moths, as distinct from Asian silkworm moths, are large, showy, mostly night-flying insects characterized by either having no mouths or having only vestigial mouth parts; they don’t eat, but live on the fat stored up in their chunky, furry little bodies. As moths they usually live only one night, but some species can potentially survive up to a week. If luckier than most of their kind, the moths will have time to mate once before they die. Although they seem to make the most of this short pleasure (Paul Villard reported that, if not disturbed, silk moth couples may cuddle all day), each pair produces relatively few eggs, which the mother usually disperses as widely as possible.

Typically the eggs hatch into caterpillars in spring, and the caterpillars spend part or all of the summer growing big, fat, and ugly. Many silk moth caterpillars will eventually be three inches long and so fat they roll from side to side when they walk. Most silk moth caterpillars have green or brown skin with an assortment of warts, horns, and bristles that allow scientists to identify the species.

Although most silk moth caterpillars don’t eat the annual plants in the vegetable garden, most do eat the leaves of ornamental shrubs and trees. However, some ornmental plants actually bloom better next year after being partly stripped by caterpillars.

Two kinds of silk moth caterpillars are truly obnoxious: Io moth larvae, which are green and live on ailanthus trees, and buck moth larvae (also known as stinging worms), which come in a wide range of colors, start their lives in oak trees, and may eat fruit tree leaves in the last week or so of their lives as caterpillars. Their bristles are actually poison tubes. Every bristle on every caterpillar is about as toxic as a bee or wasp sting, so if you inadvertently touch these pests, you can expect to feel about as bad as you would after being stung by a whole colony of bees or wasps.

Some other silk moth caterpillars look even nastier than these two, but that’s only camouflage to discourage predators. The bristles don’t contain venom. North America’s biggest example (in more ways than one) is the massive Regal Silk Moth, Citheronia regalis. Its larvae are commonly known as Hickory Horned Devils. They usually grow five inches long, sometimes six, before turning into moths. You’d definitely feel a pinch if one nipped you with its jaws, and Villard claimed that the stiff, spiky bristles gave him a rash, but most people who’ve handled these creatures say they’re harmless. In addition to hickory leaves they have been known to nibble on some crops, notably cotton plants. Nevertheless, the big, showy, fragile moths don’t overpopulate their living area, so as a species they’re harmless.

Ugly Animal Friend #5: Monarch butterfly caterpillars. Based on descriptions of “large, hairless caterpillars with black, green, and yellow stripes, and horns” people have confused these creatures with swallowtail butterfly caterpillars, which can become a pest on carrot, dill, and anise plants. Baby monarch butterflies aren’t pretty, but they eat only milkweed and can never become pests. They don’t bite or sting. Avoid crushing them, which might be messy, and they’ll give you no trouble at all.

Ugly Animal Friend #6: Junebugs, a.k.a. June beetles or May beetles. (British “May bugs” are a different insect.) These small, brown, hard-shelled insects fly at night, are attracted to light, and may buzz around porch lights or windows. They’re not much to look at, but neither do they do any particular harm.

Ugly Animal Friend #7: Mantids. I personally think mantids are attractive, as insects go. As insects go, they’re also intelligent; people have kept them as pets and trained them to walk about on leashes and take bits of ground meat from spoons. They’re on this list because some people think they look “scary” rather than pretty.

Mantids’ habits are not exactly appealing. They grab and eat any other insect that moves within range. Many female mantids literally bite their mates’ heads off, while mating, but this is pardonable; male mantids can mate just as effectively without their heads, and wouldn’t live long afterward anyway. Both male and female mantids also hatch out of egg clusters in ravenous little swarms, in which the stronger siblings eat as many of the slower-moving siblings as they can catch, which is less pardonable. Apart from that, however, their gluttony makes mantids very useful in a garden. Mantids don’t bite warm-blooded animals, but devour pest and nuisance insects.

Ugly Animal Friend #8: Earthworms. There are different species and even different genera of earthworms. All of them are basically tubes of muscle that take in soil at one end and cast it out the other, aerating and improving the soil as they go. You don’t have to build a bin for indoor earthworms to help turn vegetable scraps into compost (the worms won’t actually eat the vegetable scraps until they are compost), to be “Green,” but you can; the worms want to stay in the soil and, if they do get out, can’t bite or sting or even scratch. Large fish and almost all birds will happily control the population density, if you choose to raise earthworms.

Ugly Animal Friend #9: Woodlice, a.k.a. pill bugs (some can roll up in a ball, some can’t). These little parts of nature’s recycling process are often found on the undersides of damp, rotting wood. If the wood happens to be part of your house, shed, or garden furniture, or if you plan to use it to build something, you will want to discourage woodlice by taking steps to reduce the dampness and decay. There’s no need to do anything about the woodlice themselves. They have their place in the world, and stick to it. It’s the damp and mold that damage wood; woodlice can only eat what’s already damaged beyond repair.

Ugly Animal Friend #10: Bumblebees. These small, fat, ground-nesting bees have very little direct impact on human lives, good or bad, but they pollinate many useful wild plants. Some bumblebees have stings that humans can feel; most of the bumblebees who could sting humans never do.

Bumblebees are not to be confused with carpenter bees, which are similar in shape and color, but much larger. Carpenter bees are basically solitary, although several individuals may use the same tree or building. They eat and nest in unfinished wood. They seldom really damage buildings, but may invite further damage by antsand termites; so, although they pollinate wildflowers,they’re also a nuisance. Male carpenter bees don’t sting. Females do. Both sexes will bite in self-defense. “Greenies” are more concerned about painting and varnishing wood to discourage carpenter bees than we are about killing carpenter bees, although many “Greenies” will crush a carpenter bee when the opportunity appears.