It is about one centimetre long with a rusty orange head, thorax and legs, a black abdomen and an iridescent blue or purple lustre to the dark coloured elytra.
[6] Because it specifically targets Colorado potato beetles and is native to North America, Lebia grandis shows promise as a biological control species in the United States.
[4] The historical records for Lebia grandis show that it was present in areas where Leptinotarsa decemlineata was not found.
[7] The original host plant of the Colorado potato beetle, Leptinotarsa decemlineata was the buffalo bur, Solanum rostratum, in Mexico.
Lebia grandis may have had a relationship prior to this with the false potato beetle, Leptinotarsa juncta which feeds on horsenettle, Solanum carolinense.
The Lebia grandis adults showed no significant difference in the number of larvae of each prey species they chose to eat, but they did differentiate between their eggs.
Successful development of Lebia grandis from first instar larva to adult occurred with each of the three species of Leptinotarsa.
[4] These studies would seem to support the view that Lebia grandis was originally exclusively a parasitoid of L. juncta, but that the opportunity afforded by its encounter with L. decemlineata less than 150 years ago enabled it to exploit this new and abundant food source.