I never thought much about ladybugs until I was hiking in Redwood Regional Park and stumbled across thousands of them decorating fallen logs, sign posts and plants! There are many species of ladybugs but the type I encountered was the convergent lady beetle. I became fascinated and curious, wondering why they were all gathered together and what they were doing. It turns out they come every year for the late fall and winter to the same spot. Although ladybugs only live for about a year, they are able to find the same places where their previous generations spent their winters by sensing pheromones left behind. When it starts getting cold it becomes difficult for ladybugs to move around so they hibernate in moist spots, clumped together to stay warm and avoid drying out. Then when spring arrives it is easy for them to find a mate before migrating away.
All insects play an important role in their ecosystem, but some insects are particularly popular with humans. Ladybugs are one of them, as their diet of soft-bodied aphids is very useful in agriculture and in the garden. Since aphids tend to feed on crops like potatoes, cabbage, fruits and corn, the presence of ladybugs can minimize the damage done by these pests. A single ladybug can eat about 5,000 aphids before it dies!
If you’d like to see the ladybugs yourself and you live in the Bay Area they appear in Redwood Regional Park in the Oakland hills between October and February, and are most abundant on the Stream Trail near the Prince Trail and the Tres Sendes Trail.
And if you’re curious to learn a little more about the ladybugs in the Bay Area, here is a quick KQED video about it!