Insects and Their Relatives
Insects make up the largest group of animals on Earth, with over a million known species, and possibly up to 5.5 million species in total – most, of course, yet to be discovered – though estimates vary widely. Beetles alone are estimated to make up a quarter of all known animal species.
Insects and their relatives – including crustaceans, spiders, scorpions, mites, ticks, millipedes and centipedes – are arthropods, a diverse group of animals named for their “jointed legs.”
Like all arthropods, insects have an exoskeleton, and must molt (shed the external skeleton) in order to grow.
As insects develop, they go through a process called metamorphosis; the degree of change between immature and adult stages may be minimal; or it may be extreme and include a total reorganization of the body during the pupal stage (think caterpillar, chrysalis, butterfly).
Insects have six legs and the majority have two pairs of wings as adults; no other arthropods have developed wings.
Insects provide food for many other organisms, including a vast array of vertebrates and invertebrates; essential pollination services for most flowering plants; natural products (such as silk, honey, dyes); biological control of other insects; and recycling services.
Some insects damage crops or structures, spread pathogens and disease, and occasionally sting or bite – but the vast majority of insects are essential members of the ecosystems which they inhabit.
Insects of the RPBG
This garden is home to many insect species with a variety of ecological roles. Some you will see easily and often, such as butterflies or their caterpillars, our large bumble bees, flower-visiting hover flies or cucumber beetles, or winter aggregations of lady beetles.
Others might only present themselves indirectly by leaving “signs” such as stippled, chewed, or mined leaves; frass (insect poop); discarded exoskeletons (common in large aphid colonies), sticky honeydew (another form of poop); or galls (such as those made by aphids on manzanitas, or by wasps on oaks and willows). Wherever you look you will find insects or evidence of their presence.
This guide is meant to help you find and appreciate a few of the insects that make their homes here. They are arranged here by their natural evolutionary groupings, called orders. Some insects that you might encounter in the Garden include the following:
Butterflies and Moths (order Lepidoptera)
Bees, Wasps and Ants (order Hymenoptera)
Beetles (order Coleoptera)
Flies (order Diptera)
“True bugs” (order Hemiptera)
Dragonflies and Damselflies(order Odonata)
