Posts Tagged: spotted cucumber beetle
You usually see them crawling around, but never about to fly.
The Western spotted cucumber beetles (Diabrotica undecimpunctata) is one of California's most common insects. And though quite attractive in coloring, it's a major agricultural pest.
"Come in, my pretty," is probably what a witch would say during the Halloween season.
Retired UC Berkeley entomologist Jerry Powell, in his book, California Insects (co-authored by Charles Hogue), describes the adult as "bright green with six variable black spots on each wing cover and variable amounts of black on (the) legs and underside."
"They eat leaves and flowers of all kinds except conifers; (they're) particularly abundant on plants of the squash family."
They're found throughout California, except at the highest elevations, he says.
But have you ever seen this insect take flight?
We recently watched a spotted cucumber beetle crawl beneath a tangerine leaf and vanish. Suddenly, like a submarine periscope, its antennae appeared, twitchy rapidly. Then its head popped up.
That huge dark object (camera!) startled it, though. It took flight, landing a few feet away on the sidewalk.
With its wing covers open, it looked very much like a polka-dotted airplane on a runway.
Spotted cucumber beetles crawls along a tangerine leaf. (Photo by Kathy Keatley Garvey)
Antennae twitching rapidly, the spotted cucumber beetle looks around. (Photo by Kathy Keatley Garvey)
Spotted cucumber beetle lands, and then opens its wing covers preparing for flight. (Photo by Kathy Keatley Garvey)
It wasn't much of a fight.
The assassin bug scored a TKO.
Here's what happened: an assassin bug ambushed a spotted cucumber beetle in the Häagen-Dazs Honey Bee Haven at the Harry H. Laidlaw Jr. Honey Bee Research Faciility on Bee Biology Road, UC Davis.
It was "good guy vs. bad guy."
It was "beneficial insect vs. major agricultural pest."
The assassin bug (Zelus renardii) is a force to be reckoned with, especially when it comes to a spotted cucumber beetle (Diabrotica undecimpunctata).
The assassin bug wears no white hat but it should. A cunning predator, it lies in wait and stabs an unsuspecting prey with a lethal toxin powerful enough to paralyze and dissolve tissue.
Then it's all over but the feeding.
The assassin bug sort of looks like a cartoon character, with its beady eyes, long beak (proboscis) and its long, slender antennae.
The spotted cucumber beetle looks a little like a ladybug (aka lady beetle) except for its coloration. It's a 12-spotted greenish-yellow insect. And a pest. Diabrotica dines on young, tender plants like cucumbers, squash, pumpkins and melons (cucurbits). It also transmits a virus.
So it was the good guy vs. the bad guy. Zelus vs. Diabrotica.
This time the good guy won.
That loud cheering sound you hear is from all the melon growers out there.
Predator and the prey: Assassin bug (left) corners a pest, a spotted cucumber beetle. (Photo by Kathy Keatley Garvey)
Assassin bug stabs the spotted cucumber beetle. (Photo by Kathy Keatley Garvey)
Assassin bug wins. (Photo by Kathy Keatley Garvey)
Assassin bug dining on spotted cucumber beetle. (Photo by Kathy Keatley Garvey)
You don't have to travel to Africa to go on safari.
You can go on a "bug" safari in your own backyard.
And you can stay as little or as long as you like without incurring such costs as air travel, hotel stays, and food expenses.
Of particular interest now in our backyard are the pink African daisies. Now that autumn has surfaced, the salvia, catmint and lavender are scaling back and it's time for the insects to favor the pink African daisies.
Yesterday we saw scores of pollinators "in the pink." They included honey bees, hover or flower flies, sweat bees, white cabbage butterflies and fiery skipper butterflies.
One honey bee was so heavily dusted with pollen that she could barely fly.
A fiery skipper skipped along, sipped some nectar, and then fluttered away.
Meanwhile, a pest, a spotted cucumber beetle, appeared. It was not on the desirable guest list, but it touched down anyway.
However, something about the proximity of the macro lens startled the uninvited guest and off it flew.
Final Score: Pollinators, 5. Pests, 0.
Pollen-laden honey bee foraging on a pink African daisy. (Photo by Kathy Keatley Garvey)
Fiery skipper sips nectar from a pink African daisy. (Photo by Kathy Keatley Garvey)
Spotted cucumber beetle senses danger and is about to fly. (Photo by Kathy Keatley Garvey)
Two's company, three's a crowd?
Yes, when a spotted cucumber beetle tries to share a sunflower with two honey bees.
That was the scene Sunday in a sunflower field along Pedrick Road, Dixon, Solano County.
The spotted cucumber beetle is a pest. Honey bees are beneficial.
It was a bucolic scene: blue skies, golden sunflowers, scores of honey bees....and a few pests.
Spotted cucumber beetle sharing a sunflower with two honey bees. (Photo by Kathy Keatley Garvey)
Honey bee packing a heavy load. (Photo by Kathy Keatley Garvey)
Bucolic scene--bee hives straddling a sunflower field. (Photo by Kathy Keatley Garvey)
The spotted cucumber beetle (Diabrotica) is a major agricultural pest. You'll see it on cucumbers, squash, corn, beans, watermelons, musk melons, cotton, tomatoes and other crops. You'll see it on ornamentals, too, including roses, dahlias, agapanthus and zinnias.
In its larval form, it's known as the southern corn rootworm. The larvae feed on roots and stems, and the adults, on foliage, pollen and flowers. The adults burrow into the corn ear tips and chew on the corn silks.
At first glance, the spotted cucumber beetle, about one-fourth inch long, resembles a ladybug or lady beetle that's changed its colors. Instead of reddish beetle with large black spots, however, these beetles are yellowish-green with large black spots.
When hiking last week in the cliffs above Timber Cove, Sonoma County, we spotted scores of spotted cucumber beetles. They were foraging on dandelions, seaside daisies and the California state flower, the golden poppy.
Seemed like every other flower harbored a spotted cucumber beetle. Or two.
Its predators, including tachnid flies, soldier beetles, lacewings and ladybugs, were no where in sight.
Spotted Cucumber Beetle
Two on a Poppy