Beetles

Estimates of the number of kinds of beetles vary, but it is generally agreed that beetles are the largest and most diverse group of insects, and make up 75% of all described animal species! In California alone there are about 10,000 species, occupying a variety of habitats.

One of their most distinguishing characteristics is the hardened or leathery pair of front wings (called elytra) that usually meet in a line down the middle of the back. They must unfold their second pair of membranous wings (usually tucked away under the elytra) to fly. Allow a lady beetle, for example, to crawl to the top of your finger, and watch it unfurl its hidden membranous wings and take flight.

As larvae and adults, beetles are chewers, with a large range of habits and diets. They are scavengers and detritivores, and predators of other invertebrates. Many are herbivores, feeding on every possible plant part: seeds, wood, roots, flowers, and everything in between. Beetles were probably among the earliest pollinators, and today pollinate some of the Garden plants that belong to the oldest flowering plant lineages, such as magnolias (Magnolia spp.) and spicebush (Calycanthus occidentals).

In the Garden you are most likely to encounter adult beetles, rather than larvae or pupae, though these other stages are worth looking for. Lady beetles (Coccinellidae) (also called ladybugs) – often seen crawling about plants looking for insect prey such as aphids – are probably the most familiar insects in California and the Garden.

Adults of one species, the convergent lady beetle (Hippodamia convergens), migrate annually between breeding sites and overwintering sites. Adults spend the winter in large sluggish aggregations in scattered lower elevation sites – including in the Garden! You are likely to see them near the Canyon section in a bunch of California fescue (Festuca californica), shown below.