Bizarre Insects: Dinocampus Coccinellae

An unsuspecting ladybug.

One of a number of parasitoid wasps -- Dinocampus coccinellae -- stands out amongst other parasitic wasps because they parasitize the cutest bugs -- maybe the only cute bugs -- on the planet. Dinocampus coccinellae parasitize ladybugs. I know; it is not pleasant. Apparently, ladybugs with seven spots are the favorite of these ladybug killers. Those with two or ten spots are the safest. In fact, Dinocampus coccinellae never infest them.

The monstrous demise of ladybugs at the hands -- figuratively -- of Dinocampus coccinellae begins with the insertion of a single egg into the bug. The wasp larva hatches within the bug and begins to destroy any other larvae or eggs in its way. Next, it steals the nutrients the bug has until finally it eats the fat cells and reproductive organs of the ladybug.

While the wasp is graduating from one living feast to the next, it is going through several stages of its life cycle. There are four stages in this carnival of horrors before it gets worse. Eighteen to twenty-seven days after the egg is deposited in the ladybug, the resulting larva destroys the nerves that control the ladybug's legs, rendering it paralyzed. It then digs a tunnel out of the bug and makes its cocoon under it and betwixt its legs. The body of the still living victimized bug is now protection for the larva while it undergoes the next stage of transformation.

After roughly one week, the wasp emerges ready to propagate its species. Most of these wasps are females, but that does nothing to hinder their reproductive prowess. In fact, it makes them more efficient as these wasps reproduce asexually. They can insert eggs into 100 or more ladybugs in their lifetime without ever encountering a male Dinocampus coccinellae. They are perfect, deadly breeding machines.

Source

Bruce, Anne, The Wasp Life Cycle, retrieved 9/24/11, microscopy-uk.org.uk/mag/indexmag.html?