The elm leaf beetles and their larvae don't want to hold your hand--unless perhaps you're holding a elm leaf that they can eat.
A recent walk down the 200 block of Buck Avenue, Vacaville, California, revealed the damage this pest does. The stately canopied elms don't look so stately, what with the dry skeletonized leaves, the browning and the dieback.
And if you look closer, you'll see the leaves--the feeding site--dropping prematurely, and beetles and their larvae falling with them.
Infestations of these beetles can defoliate large elm trees, according to the UC Integrated Statewide Management Program's Pest Note on this pest, Xanthogaleruca (=Pyrrhalta) luteola.
Have you ever seen them? They're about 1/4 inch long, yellow to olive-green with a black stripe on each side and four black spots near the head. They are an invasive species from southern Europe, introduced here in the 1800s, and considered the most serious elm defoliator in the United States.
"Females lay yellowish eggs in double rows of about 5 to 25 on the underside of leaves," according to UC IPM. "Eggs become grayish before hatching. Larvae resemble caterpillars and are black when newly hatched and shortly after molting (shedding the old skin). After feeding, larvae become yellowish to green with rows of tiny dark tubercles (projections). Third-instar larvae grow up to 1/3 inch long and have dense rows of dark tubercles down their sides that resemble two black stripes. Pupae are orange to bright yellow."
We observed some natural enemies on site: lady beetles, aka ladybugs, and their larvae munching on the larvae of the elm leaf beetles. Yes, beetle larvae eating beetle larvae. Lady beetles and their larvae target soft-bodied insects, and not just aphids.
UC IPM says:
"The elm leaf beetle develops through four life stages: egg, larva, pupa, and adult. Adults commonly overwinter in bark crevices and woodpiles or in buildings. In spring they fly to elm foliage and chew leaves, and females lay eggs. Eggs hatch into larvae that develop through three instars (growth stages) over a period of several weeks while chewing on foliage and then crawl down the tree trunk. Mature larvae become curled and inactive (a stage referred to as prepupae), then pupate, sometimes in large numbers, around the tree base. After about 10 days as pupae, adults emerge and fly to the canopy to feed and, during spring and summer, lay eggs. The elm leaf beetle has at least one generation a year in northern California and two to three generations in central and southern California."
Elm trees with massive defoliation can weaken the tree and pave the way for diseases and damage from other pests.
If you have elm trees, especially European elm species, and you have these little buggers all over them, you might want to access the UC IPM Pest Notes to see how to manage them.
These beetles mean business./span>
"Sweat bees have earned their common name from the tendency, especially of the smaller species,to alight on one's skin and lap up perspiration for both its moisture and salt content."
So write University of California scientists in their award-winning book, California Bees and Blooms, a Guide for Gardeners and Naturalists.
California has some 1600 species of undomesticated or wild bees, point out the authors (Gordon Frankie, Robbin Thorp, Rollin Coville and Barbara Ertter).
And one of them is the sweat bee, Halictus ligatus, a member of the family Halictidae. It's a medium-sized, ground-nesting bee with a striped abdomen.
This week one of these species (as identified by research scientist John Ascher) looked especially striking on a Black-Eyed Susan, Rudbeckia hirta, a member of the Aster (Asteraceae) family. Both the plant and the bee are natives.
Several years ago we managed to photograph a flameskimmer dragonfly, Libellula saturata, munching on one of these sweat bees. Not a good day for that little gal!
No dragonflies were around, however, when we watched this one foraging on a Black-Eyed Susan.
Did you know that the Black-Eyed Susan is the designated state flower of Maryland? And that it was the inspiration for the University of Southern Mississippi's school colors (black and gold)? And that it's a larval host to butterflies such as the bordered batch, gorgone checkerspot and silvery checkerspot?
Who knew? If you plant it, though, be aware that it is toxic (when ingested) to cats.
A reader asked: "A friend was just telling me that butterflies and moths land differently. She couldn't remember if it was a moth that landed with its wings up or down. It looks like they land with their wings down. Am I right?"
We asked three experts affiliated with the University of California, Davis, for their responses.
Art Shapiro, UC Davis distinguished professor of evolution and ecology, commented: "There are moths that hold the wings erect over the back like butterflies, and butterflies that hold them out at the sides like moths. Life can be confusing."
Entomologist Jeff Smith, who curates the Lepidoptera collection at the Bohart Museum of Entomology, UC Davis, said: "It depends on the kind of moth or butterfly. Some species/genera of moths will rest with wings folded vertically over them and some rest with wings folded flat over the abdomen. Same with butterflies, and some of this may depend on which surface they want to expose to dangers around them. For example, anglewing butterflies (Polygonia) have great bark-like colors on the ventral surface and they rest with wings over the body so they blend in with the bark of trees that they choose to land on. Buckeye butterflies most often expose the upper surfaces which have the large eyespots that may deter predators. So, not a good rule of thumb."
Bohart Museum associate Greg Kareofelas commented: "Some moths land flat against the substrate, but others can land with their wings closed over their back, depends on the situation sometimes. Some butterflies land with their wings closed, then open them, etc., etc. I think every possibility is possible."
The Bohart Museum, located in Room 1124 of the Academic Surge Building on Crocker Lane, is temporarily closed due to COVID-19 pandemic precautions. However, it is usually open to the public four days a week and it traditionally hosts open houses throughout the year, including a Moth Night that features moth displays and blacklighting. John "Moth Man" De Benedictus, senior museum scientist Steve Heydon and colleagues set up a blacklighting system, comprised of a UC-lit white sheet, in the UC Davis Arboretum and Public Garden.
Home of nearly eight million insects, the Bohart Museum also includes a year-around gift shop (now online) and a live "petting zoo," comprised of Madagascar hissing cockroaches, stick insects and tarantulas. UC Davis distinguished entomology professor Lynn Kimsey serves as the director.
(Editor's Note: Check out the moth and other videos on the Bohart Museum website)
Sometimes you can't see the trees for the forest.
And sometimes you can't see the spider at all in a purple forest.
Such was the case this week when a tiny white crab spider cunningly figured out the best place to prey was in a flowering artichoke.
At first the spider crawled on top of the thistle, as honey bees dived in and out, threading through the petals, foraging for nectar and pollen. Did the bees spot the predator? If they did, they paid no attention. They were acting like kids jumping into a pool on a triple-digit temperature day on the first day of summer.
Then the spider slipped over to the edge of the purple forest and hid in the shadows. There it reigned supreme, Purple Reign. Unseen, and out of the heat.
Crab Spider: 3
Honey Bees: 0
Three sisters became breakfast, lunch and dinner.
Hunger in a purple forest.
If Cinderella were a moth, what species would she be? Maybe this tiny, shimmering one.
When we spotted this visitor during National Moth Week on a Mexican sunflower, Tithonia rotundifola, in our pollinator garden, we asked our Bohart Museum of Entomology associates for identification.
John "Moth Man" De Benedictis and Greg Kareofelas said it appears to be a Cadra figulilella, the raisin moth, family Pyralidae.
How did the raisin moth get its name? Most likely because it was first identified on Muscat raisins in Fresno County in 1928, according to Wikipedia. It's a pest in its larval stage, feeding on such dried fruits as raisins and dates. "The larvae in particular are herbivorous and prefer to feed on dry fruits on the ground or still on the plant. In particular they feed on fallen figs, ripe carob pods, grapes, cottonseed cake, cacao beans, prunes, peaches, apricots, pears, and more." This species is found throughout much of the world, including California, Florida, the Eastern Mediterranean region, and some parts of Australia, South America, and Africa.
Remember the Cinderella story? After her father died, Cinderella lived with her cruel stepmother, Lady Tremaine, and two evil stepsisters, Anastasia and Drizella, who forced her to work as their maid. When Cinderella received Prince Charming's ball invitation, she wanted to wear her deceased mother's party dress but her jealous stepsisters destroyed it. Like magic, her Fairy Godmother appeared and gifted her with a a silver shimmering gown and tiny glass slippers. Bottom line, Cinderella loses a slipper at the ball, when the Fairy Godmother's magic vanishes. Prince Charming learns it belongs to Cinderella, and they marry and live happily ever after.
Not sure if this moth lived happily ever after, but poof, it vanished shortly after I took this image.
Happy National Moth Week...