Halloween Lady Beetle

(This column was first published in the September 21, 2000 Buffalo News.)

    Halloween is one of those festivals that have both religious and profane overtones. The name is short for "hallowed evening," the night before All Saints Day, but that eve is mostly celebrated as a time of witches and goblins.

    And now we have imported Halloween lady beetles, insects with their own contradictory roles. They are highly beneficial predators on destructive garden and agricultural pests and the lady of their name is the Virgin Mary. But they can be highly undesirable houseguests, often arriving as they do in very large numbers.

    Halloween lady beetle is only one of this insect's names. Its official common name, assigned by the Entomological Society of America, is multicolored Asian lady beetle. It is also called Japanese lady beetle, designating the country from which specimens were first imported and released in the southeastern United States.

    Most readers will be familiar with lady beetles or ladybugs, that second name the one familiar to us from the rhyme that begins:

Ladybug, ladybug, fly away home,
Your house is on fire, your children will roam....

    Remarkably, there are almost 500 species of lady beetle native to North America. Most are small (1/6 to 1/3 inch long) and nearly round, their backs usually orange patterned with black dots.

    Before the introduction of the Halloween lady beetle, it was possible to identify some species by the number of these dots. For example, the nine-spotted lady beetle has -- you guessed it -- nine of them. I assign as an exercise the determination of the number of dots on the thirteen-spotted lady beetle. Unfortunately the color pattern of this Halloween lady beetle ranges from none to as many as twenty dots, thoroughly complicating identification by a simple count.

    Why go to the trouble of bringing in these alien insects when we have our own species? It seems that this insect fills a different habitat niche from its American relatives. Our ladybugs stay near the ground; the Asian lady beetle spends much of its time in taller bushes and trees.

And they are indeed beneficial. If you have maple, walnut or willow trees or rose bushes, you should appreciate these newcomers, and pecan orchards in the South are an even better success story. Adult beetles consume several hundred destructive aphids in a single day and their larvae eat an additional thousand or more while developing. (The larva is ugly, black with yellow sides and segmented. Its appearance is a little like the hellgrammite used as fish bait.)

    There are two good reasons for assigning the name Halloween to these insects. Their base color is pumpkin orange and they invade homes at this time of year. They do not feed or reproduce indoors, their infrequent bite is a mere pinch; and they don't carry disease. But they do smell and, when disturbed, they "bleed" from their knees an orange stain that is difficult to remove.

    Your best defense against home invasion is to locate and seal off entry avenues such as siding gaps, poorly-fitting doors and screens and utility openings. If they do get in, however, avoid using pesticides as most, even foggers, are of limited benefit. It is better either to vacuum them. If you wish to release them, you can place a handkerchief in the vacuum cleaner hose to collect them. Another alternative is simply to sweep them into a dust pan -- gently in order to avoid those stains.

    A ladybug defense tactic is to play dead, but if you dump them outside, they will soon come to life and retreat into the leaf litter.-- Gerry Rising