Adalia bipunctatatwospotted lady beetle

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Geographic Range

Native to North America (Marshall 2000).

Habitat

Lady beetles will live in nearly any vegetation, as long as there are aphids or other small insects to eat.

Physical Description

Adult two-spotted lady beetles are 4-5mm long, and ovoid in shape. The head and thorax is black with yellow markings. Their undersides are black to reddish-brown; Their elytra (wing covers) are orange with one black spot on each side. The larvae are elongate, with soft bodies, and are black with yellow and white spots (they look a little like tiny alligators) (Marshall 2000, Milne & Milne 2000).

  • Range mass
    0 to 0 kg
    0.00 to 0.00 lb

Reproduction

Females deposit bright yellow eggs on the underside of leaves and other locations near potential food sources for the larvae. Pupae are black with yellow dots and are found hanging from leaf surfaces. Adults in the North live through the winter; there can be more than one generation in a year.

Behavior

Adults overwinter in large groups under logs, leaves, and bark. They occasionally enter buildings by accident, looking for a sheltered place to hibernate. If they get into a heated house they may be doomed, as the warmth keeps their metabolism going, and they may use up their fat and water reserves before spring.

Food Habits

Lady beetles feed on aphids and other small insects, insect eggs, and mites.

Economic Importance for Humans: Positive

This species helps control populations of aphids that are agricultural and horticultural pests.

Economic Importance for Humans: Negative

Can be a nuisance if large numbers get inside houses (Klaas 1998, Fleming 2000).

Conservation Status

Non-native lady beetle species have been introduced into North America for additional aphid control, and there is some concern that these species are displacing native species like the Two-Spot. (Marshall 2000)

Other Comments

These insects were given their name in the Middle Ages when they were dedicated to "Our Lady" in gratitude for their ridding crops of harmful insect pests.

Some people find it a nuisance when lady beetles come into their houses in large numbers to hibernate. The best course of action is to sweep or vacuum them up gently, and seal cracks to prevent them from gaining entry (Klaas 1998).

Ladybugs are more properly known as lady beetles, because "bug" applies most accurately only to insects in the order Hemiptera.

Contributors

Robin Street (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

native range

the area in which the animal is naturally found, the region in which it is endemic.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

References

Fleming, R. 2000. "Lady Beetles" (On-line). Accessed 03 March 2001 at http://insects.ummz.lsa.umich.edu/MES/notes/entnotes6.html.

Klaas, C. 1998. "Lady Beetles In Homes, Cornell Cooperative Extension Fact Sheet" (On-line). Accessed March 21, 2000 at http://www.cce.cornell.edu/factsheets/home/pests/lady-beetle.html.

Marshall, S. 2000. "Lady Beetles of Ontario" (On-line). Accessed 03 March 2001 at http://www.uoguelph.ca/~samarsha/lady-beetles.htm.

Milne, L., M. Milne. 1980. Field Guide to North American Insects and Spiders. New York: Knopf.