Leaf Beetles - Family Chrysomelidae is 2nd largest among the phytophagous (plant-eating) beetles, taking a back seat only to the weevils (Family Curculionidae). There are as many as 35,000 described species and perhaps up to 60,000 total species. Presently, the Chrysomelidae are classified in 195 genera and approximately 1,720 valid species and subspecies (plus 149 Bruchinae species) accepted as occurring in North America north of Mexico. [1]

Leaf beetles feed strictly on plant materials. The adults usually consume leaves, stems, flowers, and pollen. Most larvae are subterranean in habit, feeding on roots and rootlets, but others will consume foliage as well. Many chrysomelids are very specific to particular host plants, but most are able to live on a variety of plants; e.g. the so-called dogbane leaf beetle, which feeds  on milkweed (Asclepias sp.) as well as the dogbane genus Apocynum. [2]

Habitat: Meadows and forest clearings, roadsides / Food: Dogbane and other members of the milkweed family / Life cycle: Yellow eggs are laid on the host plant or on the ground; larvae tunnel through soil to roots, feed, and pupate in soil.

References

1. JR, Ross H. Arnett et al., American Beetles, Volume II: Polyphaga: Scarabaeoidea
   through Curculionoidea, 1st ed. (CRC, 2002).
2. Jürgen Gross, On the Evolution of Host Plant Specialization in Leaf Beetles (Logos, 2001).

Order Coleoptera: Beetles are the dominant form of life on earth: one of every five living species is a beetle. Coleoptera is the largest order in the animal kingdom, containing a third of all insect species. There are about 400,000 known species worldwide, ~30,000 of which live in North America.  Beetles live in nearly every habitat, and for every kind of food, there's probably a beetle species that eats it.
Beetles first appeared during the lower Permian period, about 270 mya
Beetles Index | Longhorns | Leaf Beetles | Soldier | Blister | Lady | Scarab