Ladybugs

Lady beetles, popularly known as ladybugs, are a beloved and diverse group of insects found in many backyard gardens.  Oval to round in shape with a head that is partially covered by the pronotum, the plate covering the thorax, they come in a variety of colors, with or without spots.  Identification is made based on spot shapes and patterns.  There are about 500 species living in the U.S., most of which are predatory, which makes gardeners love them.  Many species have long, slender larvae with dark, spiny bodies that are also predators of garden pests.

Female ladybugs produce upwards of 1000 eggs laid in batches, several times over a period in late spring and early summer.  Eggs hatch in five to eight days, and larvae pupate to adulthood in three to seven weeks.  Their one-year life span takes them through winter hibernation under logs, buildings, and snow drifts, and in many houses.  Gathering in large groups of several hundred to several million, ladybugs can survive up to nine months of cold temperatures,  living off fat reserves.  They over-winter near their food sources and wake in spring when temperatures reach above 55˚F/13˚C. 

Ladybugs live in a variety of habitats, wherever aphids can be found, including forest, meadow, marsh, prairie and backyard gardens.  Feeding on soft-bodied insects, they provide natural pest control, especially in our gardens.  Both adults and larvae can consume several dozen insects daily.  Primary prey include aphids, spider mites, thrips, scale, insect eggs, and small insect larvae.  Ladybugs are also considered important for pest control in agricultural areas.  About 3,000 ladybugs can protect an acre of fruit trees or other crops.

Several non-native species can be found throughout the U.S.  Most have been brought here as part of a  biological control effort, but they can negatively affect native populations by outcompeting them for  food.  Several of these introduced species are now considered to be serious pests,  especially when inadvertently collected along with grapes for wine production, giving the finished product a sour flavor.

In early spring, before aphids hatch, several ladybug species located in the northern U.S. depend on pollen for up to half of their diet.  Providing early-flowering species containing a high pollen load can be very beneficial.  Several plants can be added to your garden that will help fulfill this need for ladybugs and other local pollinators including heather, red-flowering currant, grape hyacinth, and dandelion. 

Ladybugs are considered omens of good luck all over the world.  Four of them were carried into space on one of the shuttle missions to test the effects of zero gravity on insects.  Results indicate they have no trouble capturing their prey without gravity.  They are the official state insect in Delaware, Massachusetts, New Hampshire, Ohio and Tennessee.  Check out your backyard or nearby gardens to see these tiny natural wonders in action.