Wedge-shaped Beetle
Macrosiagon
Photographed on flowers of Seep Baccharis (Baccharis salicifolia). White Canyon Wilderness, Pinal Co., Arizona, USA. 30 March 2013. The intricate, pectinate antennae identify this as a male.
Ripiphoridae -- Wedge-shaped Beetle Family
These curious-looking insects are indeed shaped like a fruit wedge and can tumble away if disturbed. The adults are found on flowers where they feed on petals and pollen. Eggs are laid on flowers where wasps and bees are visiting. The first stage larva out of the egg is a minute crawler that will attach itself to a wasp/bee and gain transport back to the nest! There it will attach itself to a larva (immature wasp/bee), parasitizing it. The wasp larva dies as a result and the wedge-shaped beetle larva will finally pupate and later emerge as a new beetle.