Thursday, August 17, 2017  

Ladybugs: Good Luck for the Garden


Who doesn’t love a ladybug? Cheerful and colorful, the ladybug is beloved by children, the subject of songs and nursery rhymes, and considered in many cultures to be a symbol of good luck.
    Ladybug, ladybug, fly away home... If home is in your garden, then good luck favors you. An adult ladybug can consume 50 to 60 aphids per day, but will also eat a variety of other insects and larvae including scales, mealy bugs, leaf hoppers, mites and other soft-bodied insects. During its two- to five-year lifespan, a single ladybug may consume as many as 5,000 aphids; but it won’t bite humans, damage plants, or harm structures. That cute little insect can lay up to 1,000 eggs in its lifetime and when those larvae hatch they begin feeding immediately. Many gardeners and farmers use them instead of chemicals for effective organic pest control.
Ladybugs aren’t really bugs at all. They’re beetles. Entomologically speaking, the term bugs applies to insects of the order Hemiptera. Ladybugs belong to the order Coleoptera, or beetles. (Insecta: Coleoptera: Coccinellidae, to be exact.) There are more than 4,000 species found worldwide and more than 350 species in North America. Europeans have called these dome-backed beetles by the name ladybirds, or ladybird beetles, for more than 500 years. In America, the name ladybird was replaced by ladybug. Scientists usually prefer the common name lady beetles.

Farmers’ Little Helpers

Ladybugs have been valued since medieval times as farmers’ helpers. Some believed that the tiny beetle was divinely sent to rid crops of insect pests. One legend from the Middle Ages tells a story of great crop failures due to swarms of predatory insects. The people prayed for help and soon the lady beetles flew to the rescue and devoured the pests. A reputation for bringing good luck followed the ladybug across Europe. The Turkish name for the insect literally means “good luck bug.” In many countries, including Russia, Italy and Turkey, the sight of the lady beetle is either a call to make a wish or a sign that a wish will soon be granted. In Austria, people asked the ladybug for good weather. In Switzerland, people told their children that human babies were brought by ladybugs. People in Central Europe believed that if a girl caught a ladybug and it crawled across her hand, she would be married within a year. In northern Germany, folks counted spots on the backs of ladybugs. Fewer than seven meant a big harvest. A common myth, totally unfounded, is that the number of spots on the insect’s back indicates its age. In truth, the number of spots is determined by the species and genetics of the beetle.
Like many other insects, lady beetles use aposematic coloration to signal their toxicity to potential predators. Insect-eating birds, frogs, wasps, spiders and dragonflies learn to avoid meals that come in red and black, and are more likely to steer clear of a ladybug lunch. A further defense, known as reflex bleeding, happens when the little lady is startled or threatened. The ladybug excretes a noxious mix of alkaloids, both vile-smelling and toxic, which predators may find unappetizing.
Lady beetles experience metamorphosis in four stages: egg, larva, pupa and adult. The length of the life cycle varies depending upon temperature, humidity and food supply. Usually the transition from egg to adult requires about three to four weeks, or as many as six weeks during cooler months. In the spring, overwintering adults find food, then lay 50 to 300 eggs in a generation. Eggs hatch in three to five days, and larvae feed on aphids or other insects for two to three weeks, then pupate. Adults emerge in seven to ten days. There may be as many as six generations of ladybugs per year. In the autumn, adult ladybugs look for warmth and shelter in which to hibernate, sometimes swarming by the thousands, in plant refuse and cozy crevices. It’s important to note that ladybugs are not structure-damaging pests. They can leave small stains due to reflex bleeding, but they don’t enjoy meals of wood or fabric as do other insects.

Host a Lady Lunch

There are two ways to play host to beneficial ladybugs in the garden — attract them naturally over time to a lady-friendly environment, or buy a quantity of sleeping ladybugs from a garden center or by mail order. Both methods have pros and cons. A natural environment draws a native species and provides a home where the ladybugs are likely to remain, rather than flying away to a more suitable ecosystem. A ladybug purchase provides measurable numbers (2,000 ladybugs covers up to 1,000 square feet of garden space), but if the environment isn’t properly prepared, the ladies will fly away in search of a more inviting home.
To attract native lady beetles, grow nectar- and pollen-rich plants with umbrella- shaped flowers. Good examples are fennel, dill, cilantro, caraway, angelica, tansy, wild carrot and yarrow. Other ladybug-friendly plants include roses, cosmos, coreopsis, scented geraniums and even dandelions. Keep moisture levels high by sprinkling frequently and maintaining plants close together.
Releasing ladybugs bought from a commercial vendor can be tricky and requires some planning. In their native environment, hibernating ladybugs become active again as temperatures rise. When spring weather awakens them, the first thing they do is disperse to find food. Some catalogs sell “preconditioned” ladybugs, which means that the insects have been fed before shipping and are less likely to fly away upon release. Timing is important for releasing store-bought ladybugs. Early spring evenings are ideal — ladybugs will not fly at night. Give the garden a light misting and spread a portion of the beetles at dusk over the course of several days. Place them on and around plants which attract (or have attracted) aphids. To provide an early breakfast for the ladybugs, an insect food of sugar and other additives like yeast can be sprayed on plants, directly on the bugs, or applied as a paste to wooden stakes.
Bright, dainty and charming, the ladybug is noted by garden experts as the top pest-control insect for plants. (Aphids are named the biggest plant pests.) So it’s a good idea to host some hungry ladies for seasonal garden parties. It’s certain that good luck will bloom.