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Quick
Facts
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Common Name:
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Lady Beetle
(“Official” common name approved by the
Entomological Society of America)
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Other Common Names: |
Lady Bug, Ladybug,
Lady Bird and Lady Bird Beetle |
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Genus / Species:
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450 native and introduced species in
North
America
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Size: |
0.63/16 to 6.30/16 inch (1mm to 10mm) |
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Type
of Beneficial:
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Insect predator
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Type of Metamorphosis:
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Immature stages appear
different from adults (i.e., complete
metamorphosis)
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Beneficial
Stage(s):
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Both adults and larvae (often times called aphid lions) are predators
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Prey:
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Wide range of prey including small caterpillars,
aphids, thrips and other soft-bodied insects
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Occurrence:
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Wide distribution
throughout Galveston-Houston area.
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Mounted
Specimen?
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Yes
(mounted specimens for viewing available in insect collection at County Extension
Office)
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What is it about the tiny Lady Beetle that makes people
like them? Is it their bright colors or domed shape? Or do we sense how much
good they’ve done us through the centuries? Whatever the attraction, it’s
gone on for a long time and is quite widespread.
Many European cultures had a high regard for this beetle
family as early as the Middle Ages, when they were dedicated to the Virgin
Mary. In fact, their very names in different countries reflect this
connection: “God’s Cow” in Russia and Ireland and “Mary’s Hen” in Denmark.
Across northern Europe, there’s a tradition that you’ll
have a wish granted if a Lady Beetle lands on you. In Italy, it’s good luck
when one flies into your bedroom. Our own children’s rhyme “Ladybug,
ladybug, fly away home…” echoes similar rhymes across Europe. Children in
Russia ask the beetle to “Fly to the sky and bring back bread.”
Although they’re also called Lady Bugs (as well as Lady
Birds and Lady Bird Beetles), the term "bug" is most properly used for the
group of insects that classified as the "true bugs" (Order: Hemiptera).
Common examples of the “true bugs” in the order Hemiptera include
leaf-footed bugs, stink bugs and boxelder bugs. Because “lady bugs” are
actually beetles (Order: Coleoptera), the term Lady Beetle is the
technically correct
reference and is actually recognized as the official common name by the Entomological
Society of America (http://www.entsoc.org/pubs/common_names/index.htm).
Lady Beetles belong to the family Coccinelladae and their
good reputation is well-earned. Most of the 450 native and introduced
North American species are voracious predators of destructive plant-eating
insects such as aphids and scales. In fact, their habitat is determined by
what they eat.
Lady Beetles can be found on any crop that is susceptible
to aphids: vegetables, grains, legumes, strawberries and tree crops.
Females even lay their eggs as close as possible to aphid colonies. Lady
Beetles will also consume mites, moth and beetle eggs, thrips, pollen and
nectar.
Various species of Coccinellidae share many
characteristics. Most are dome-shaped and quite small (1mm to 10mm or
0.63/16 to 6.30/16 inch). While color and patterns vary from species to
species, most tend to be variations of red, orange, or yellow with black.
Some are simply black.
The life cycles are quite similar, too. Most Lady Beetles
begin life as one of a small cluster of tiny (1mm or 0.63/16 inch)
spindle-shaped cream, yellow, or orange eggs laid in protected sites on
stems and leaves. In about a week, the eggs hatch into alligator-like larvae
with 3 pairs of prominent legs.
The larvae are often gray or black with yellow or orange
bands or spots. After 20-30 days, the larvae pupate, then emerge as adults
in another 3-12 days, depending on temperatures and species. Adults may live
only a few months to more than one year.
Just how effective are Lady Beetles with pest control?
The Convergent Lady Beetle eats its own weight in aphids as a larvae and
consumes up to 50 a day as an adult. Its cousin, the Seven-spotted Lady
Beetle adult dines on several hundred aphids daily, while the larval form
eat may 200-300 as it develops.
The importation of Australian Lady Beetles is one of the
first notable demonstrations of pest control by natural enemies in the
United States. This species was introduced to help control cottony-cushion
scale, another Australian immigrant that was threatening citrus orchards in
California. During the late 1970s and early 1980s, the USDA introduced the
Asian Multicolored Lady Beetle in the southern and eastern states. These
little guys have all but eliminated the pecan aphid in those regions.
As beneficial as Coccinellidae are, the family is not
quite perfect. Like most families, they have a couple of closet skeletons.
There are two species in the United States that are considered destructive
because the adults and larva feed on crop plants: the Mexican bean beetle (Epilachna
varivestis) and the squash beetle (Epilachna borealis). Both
species are yellowish-orange with black spots.
The other “flaw” of this family as far as biological
control is concerned is that Lady Beetles fly. When the food runs out, they
migrate to better pastures. Providing alternate food sources, such as nectar
and pollen producing plants, in the same area as the target plants may
encourage some species to stay put. The family is also attracted to high
humidity and to shelter during unfavorable weather and for overwintering.
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