It happened one evening high above the town of Hesperia in California: National Weather Service radar operators spotted a giant swarm of ladybugs measuring 130 by 130 km not far from Los Angeles and heading toward the coast.
The blob showing up on their monitors, the weather mavens tweeted on June 4, was “not precipitation, but actually a cloud of lady bugs termed a ‘bloom.’ ” They also posted a video of the radar image on Twitter showing a large, green, undulating mass.
For gardeners, the swarm of tiny black-spotted orange creatures was a cause for celebration because many species of ladybugs tend to feast on aphids, spider mites, and mealybugs intent on laying waste to well-tended plants. “Lady bugs are good luck!” opined one member of the twitterati. “Not if you’re an aphid!” another responded. “Better than locusts,” added a third.
Gardeners were indeed in luck, according to the University of California Statewide Integrated Pest Management Program. The Sierra Nevada straddling Nevada and California hosts scads of Hippodamia convergens, also known as the convergent lady beetle, which has a voracious appetite for aphids.
H. convergens and other Hippodamia species, many of which are aphid connoisseurs, tend to overwinter in the mountains and then head for greener pastures in the spring. When ready, they surf a ride on the nearest wind current and ultimately spread out among California’s valley and coastal areas.
Ladybugs who prefer a more genteel mode of travel can wait for entrepreneurs to scoop them up and sell them to gardeners eager to promote this form of environmentally acceptable pesticide.
Bedbugs on the prowl
Other insects tend to travel too, often with human assistance. Take bedbugs, for instance: the nasty little buggers that feast on blood and leave a bloom of red welts on their human victims. They are not nearly as cute as the black-spotted ladybugs, and they tend to travel in a more clandestine fashion.
Bedbugs are “master hitchhikers,” says entomologist Chelle Hartzer, who works for the pest control firm Orkin. Adult bedbugs, about 4–5 mm long, attach themselves to luggage, purses, backpacks, and other belongings, she notes.
Members of the genus Cimex, bedbugs show up all over, “from public transit to five-star resorts . . . and can be found everywhere humans are,” Hartzer points out. Let that be a caution to those of you in the Northern Hemisphere as you plan your summer vacation.
If you are heading for the urban jungle, then take extra precautions in places like Baltimore; Washington, DC; and Chicago, numbers 1, 2, and 3 on Orkin’s latest Top 50 Bed Bug Cities list, which came out earlier this year. The ranking includes US metropolitan areas where Orkin performed the most bedbug treatments in homes and businesses in 2018.
Marc Reisch wrote this week’s column. Please send comments and suggestions to email@example.com.