The ragweed leaf beetle is a tiny beetle native to North America that feeds mainly on common ragweed, the plant behind much late-summer hay fever. It has spread to East Asia and Europe, where scientists now study it as a natural way to keep invasive ragweed in check.
Appearance
- Appearance
- About 1/8 to 3/16 in (3.5–4.7 mm) long, with females slightly larger than males. Pale yellowish brown with dark lengthwise stripes on the wing covers and three dark spots on the shield behind the head. The antennae are dark.
Where it lives
- Typical habitats
- Roadsides
- Vacant lots
- Field edges
- Range
- Native to North America: Canada, the United States, and Mexico. It has been introduced to East Asia (including Japan, China, and South Korea) and, since about 2013, to southern Europe.
- Preferred conditions
- Found wherever its host plants, especially common ragweed, grow in patches.
Behavior
- Diet
- Leaves of plants in the , above all common ragweed. Sunflower and cocklebur are also eaten.
Life cycle
- Larva
- Eggs are laid in clusters on the undersides of young leaves and turn from yellow to orange. Larvae feed on the leaves, then spin a loose cocoon near a leaf tip; the pupal stage lasts one to two weeks.
- Caterpillar food plants
- Common ragweed is the preferred host; sunflower and cocklebur are also used.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
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