Good Bug/ Bad Bug

While researching last week's blogs on "good bugs," the kind that eat destructive bugs in our yards and communities, I was struck by the claim on one website that "If all the good bugs were taken from the earth, mankind could only live for a few weeks." Of course, we depend on good bugs for pollination and balance in the insect world. But in light of this claim, I was interested to read in our Sunday newspaper supplement that the world would be no worse off without mosquitos. They do not fall into the "good bug" category.  According to Parade Magazine's Marilyn Vos Savant, if all the mosquitos on earth disappeared other bugs would take their place in the food chain and we would be safer from the diseases spread by these noxious insects. As mentioned previously here, mosquitos are carriers of malaria, encephalitis, yellow fever, dengue fever, meningitis, and - more significantly here in Southern California, West Nile virus.

So how do we maintain a healthy yard, keeping bad bugs at bay while encouraging the good ones? Several approaches can be helpful. First, take precautions in your yard to diminish the favorable habitats of bad bugs like mosquitos. Empty any containers that may have filled with water from the recent rains. Keep pools chemically balanced and keep water off pool covers. Consider obtaining Gambusia fish, for decorative ponds. These "mosquitofish" are often available at no cost through the San Diego County Department of Environmental Health: 858-694-2888. Other ways to safeguard your home against mosquitos: change water in bird baths at least once a week; keep litter and garden debris out of rain gutters; do not over water your yard; fill holes in landscaping left by tree removal; make an inspection of your yard to assure that you do not have standing water anywhere. 

Another aspect of maintaining a healthy balance between good bugs and bad bugs is to avoid broadcast spraying, or trying to kill every bug in sight. Customers occasionally call who do not want to see bugs of any kind. Rather than specify an insect which is causing concern, such as cockroaches or fleas, they want us to just "kill everything!" Hopefully last week's series on good bugs will cause homeowners to think twice about those hard-working bugs that keep the planet buzzing. We are not sure about the idea that mankind would only survive a few weeks without good bugs, but we would rather not find out. Help us maintain a good balance by identifying targeting only the harmful bugs. For a list of good bugs in California, click here.

Quiz Answers: Good Bugs

This week we have been featuring some of the good bugs that inhabit our yards and neighborhoods. What constitutes a good bug? One that helps pollinate plants or eats the destructive bugs that eat your garden. Monday's blog gave information on ground beetles, one of the unsung heros of the bug world. Today we have answers to yesterday's quiz on good bugs. How did you do?

1. (a) The praying mantis is one of the classic good bugs that works to kill bad bugs in your yard. In fact, they are so good for plantings that you can buy praying mantis egg cases online as a natural garden helper. Known as the "dragons of the insect world," praying mantis have excellent eyesight, heads that can rotate 180 degrees, and quick reflexes - making them formidable predators. They eat moths, crickets, flies, and in the case of females, their own mates. 

2. As you may have learned in Monday's blog, ground beetles are good bugs because they (c) eat slugs, among other pests. 

3. An average ladybug eats around (c) 5,000 harmful bugs in its lifetime. Technically called lady beetles or ladybird beetles, these colorful garden helpers can also be purchased for release in the yard, either at a local garden center or online. And they are among the cutest of bugs. Definitely good guys!

4. Beneficial nematodes are (a) microscopic parasites. They live in the soil and prey onground-dwelling insects like fleas, ants, termites, and grubs. If you choose to buy beneficial nematodes for your yard, be sure you buy from a reputable supplier. Ask your local garden center what kind of nematode might be most beneficial in your area.

5. Earthworms thrive in (c) moist soil. As for their importance, Charles Darwin noted, "... it may be doubted if there are any other animals which have played such an important part in the history of the world as these lowly organized creatures." They not only aerate the soil by plowing tunnels through which air and water can more easily flow, but leave nitrogen-rich "castings" in their wake, enriching the soil.

6. Of the plants listed, (a) parsley and sage are the most attractive to good bugs. Other attractive plants include clover, foxglove, cosmos, marigolds, and sunflowers.

7. Wasps are helpful because they (b) lay eggs on caterpillars, which hatch to larvae that then eat their host. This colorful process is the featured photo in yesterday's blog. The Braconid wasp is especially good to have in your tomato patch - they are a major predator of tomato horn worms.

Tuesday's Quiz: Good Bugs

Today's quiz tests your knowledge of insects that can be beneficial around the garden. Some are more familiar than others. The hope is that we'll all take a second look at some of the "good bugs" out there and give them a chance to help the ecological balance in our yards.

1. Which of these is considered a "good bug" - they kind that eats more destructive bugs?

a. Gypsy moth

b. praying mantis

c. aphids

d. mosquitos

2. Ground beetles are "good bugs" because they:

a. aerate the soil

b. pollinate flowers and fruit trees

c. eat slugs

d. help clean stagnant water

3. How many unhelpful bugs does an average ladybug eat in its lifetime?

a. 1,000

b. 3,000

c. 5,000

d. 10,000

4. Beneficial nematodes are what kind of bug?

a. microscopic parasites

b. tiny larvae that eat harmful insects

c. small flying insects that cross-pollinate

d. aquatic insects that filter water

5. Earthworms are some of nature's most efficient composters. In what kind of soil do they thrive?

a. Sandy soil

b. Heavy clay

c. Moist soil

d. Alkaline soil

6. Which of the following are plants that attract good bugs?

a. parsley and sage

b. rosemary and thyme

c. hostas and agapanthas

d. roses and gardenias

7. How do wasps help destroy destructive bugs?

a. They sting grasshoppers and locust.

b. They lay eggs on caterpillars, and the larvae then eat the caterpillars.

c. They build nests near water, then feed on mosquito larvae.

d. They emit an odor that is offensive to slugs.

Good Bugs

As a follow-up to last week's focus on spiders, this week we'll look at other "good bugs" - those beneficial to gardens. The term "good bug" may seem like an oxymoron until we mention a few by name: lady bug, praying mantis, honey bee, ground beetle. These are bugs you WANT in your yard - bugs that either help plants or eat the bugs that eat plants. Let's start with the most unlikely on the list: Ground beetles.

Ground beetles are from the family Carabidae. Although sometimes confused with cockroaches at first sight, these common beetles seldom invade homes and can be useful in the garden. There are about 2,500 known species of ground beetles in North America. Adults, referred to as "Carabids," can be anywhere from 1/16 to 1-3/8 inches long, flat and elongated with a narrow head and hard wing covers. They are generally nocturnal, running quickly at night and feeing on potentially harmful insects. Usually found under rocks, logs or boards, they love to chow down on slugs, snails, cutworms and root maggots, and the larvae of many harmful insects. The worst thing we can say about ground beetles is that some varieties can produce an offensive odor - garnering them the moniker "stink bug" or "stink beetle."

Pictured above is the ground beetle and larva of the genus Calosoma in the family Carabidae. These beetles are often called "caterpillar hunters." During April of 2005, when there was an abundance of painted lady butterflies in the Anza-Borrego Desert, these beetles were very abundant - feeding off the pupae. For more information and some great pictures of other types of local beetles, see the website here.

If you have an over-abundance of ground beetles, eliminate any debris or rubbish outside where they may hide. Weather strip or seal off openings and crevices in outer walls in order to exclude them from the home. Also, it may be helpful to reduce exposed night lights, as these night-active bugs are often attracted to lights. Try to remember, even though they may not be the most attractive bugs around, they are not harmful. If you find you have more than you can handle, call a pest professional.