Yesterday Leonard and I walked the Wildflower Trail at Ash Creek Wildlife Area near Lookout CA (Modoc County). Our spring is very late this year, so wildflowers were not blooming in profusion. But aggregations of striped ladybugs (Paranaemia vittigera) were prolific on the grasses. Ladybugs often gather in large groups after emerging from pupation as adults. Soon though, they disperse over a large area.
There are over 4,300 species of ladybugs in the Family Coccinellidae, of which over 400 live in the United States. The longitudinal stripes on the elytra (wing covers) of striped ladybugs give them their common name. Other common names for P vittigera are striped ladybird and striped lady beetle.
When ladybugs are startled or disturbed, foul-smelling hemolymph seeps from their leg joints, leaving yellow stains on the surface beneath them. I vividly remember these stains from when, as a child, I collected and played with ladybugs as “pets”. They can also ooze vile-smelling alkaloids from their abdomen. Their aposematic coloration serves as a warning to predators of their unappetizing taste or toxicity.
Ladybugs are predators of scale insects, mites, whiteflies, aphids and the larvae and adults of other insects comprising their diet. When food is scarce, ladybugs will cannibalize the eggs, pupae, recently molted larvae and newly emerged adults of their own species.
Additional information on the ladybug life cycle and diet is included in my previous ladybug post – “Convergent Ladybug” on 11-14-2016.