SEPTEMBER 17- 23, 2021 | PAJARO VALLEY MAGAZINE
GARDENING
6
TRICKY INSECT Cuckoo wasps pollinate certain flowers, making them beneficial to gardens.
Cuckoo wasps Secretive pests take over other insects’ burrows By KATE RUSSELL
T
hese murderers and thieves probably don’t look the way you expect them to, and you might even like them. These tiny criminals are not after your electronics or your bank account. Instead, they are trying to sneak into the burrows of ground-dwelling solitary bees, wasps, sawflies, silk moths and stick bugs.
Introducing the cuckoo wasp. There are more than 3,000 different cuckoo wasps in the world and 166 species in California. They are also known as emerald wasps, jewel wasps, ruby wasps and gold wasps, depending on the color. These wasps don’t look anything like the yellow jackets or paper wasps that most of us see each summer. They look more like harmless beetles. There is debate
about whether or not these insects can sting, so be forewarned. Cuckoo wasps get their name because they lay their eggs in the nests of other solitary bees and wasps, much the way cuckoo birds leave their eggs to be raised by unsuspecting host birds. Some cuckoo wasps are parasites. Parasitic cuckoos eat the offspring of their hosts. Other cuckoo wasps are kleptomaniacs, stealing the food left for the host’s offspring. In either case, it doesn’t end well for the host’s offspring. Laying eggs in a bee’s burrow is no mean trick. Female cuckoo wasps watch as dutiful parents drag paralyzed spiders and other insects into their burrows, stocking up a larder for their offspring. The female cuckoo waits until the host flies off before sneaking inside to lay her eggs. Research has shown that cuckoo wasps are able to mimic the smell of their hosts, rendering them invisible within the darkness of a burrow. Particularly brazen cuckoo wasps will catch a ride on the paralyzed prey, carefully staying out of sight. This is dangerous business. Luckily for the cuckoo, if she is spotted, her brightly colored, heavily pitted exoskeleton is able to protect her from bites and stings. She is also able to curl up into a ball the same way a sowbug or an armadillo might. If she curls up inside an angry host’s burrow, the host has no choice but to throw it outside unharmed. If you happen to spot one curled up, it may simply be taking a nap. Adults may be found feeding on nectar from flowers the carrot family, sunflower family, and spurge family. As they collect nectar, they pollinate those flowers, which makes them beneficial. They also reduce populations of sawflies, which is good news for your garden. Cuckoo wasps are secretive and they move very quickly. If you watch for them, you might catch a glimpse of their jeweled bodies moving through your landscape. Kate Russell is a UCCE Master Gardener.
