- Author: Kathy Keatley Garvey
It's Arachtober and that means celebrating arachnids for the entire month of October.
Well, we ought to celebrate them year around, but October is THEIR month.
Let's especially applaud crab spiders when they prey on such agricultural pests as the lygus bug, also known as the "western tarnished plant bug." It's a member of the genus Lygus in the family Miridae and feeds on plants by piercing the plant tissues.
The lygus bug is easily distinguished by the triangular mark on its back.
The western tarnished plant bug (Lygus hesperus) is known as a very serious pest of cotton, strawberries and seed crops such as alfalfa, entomologists tell us. In California alone, the bug causes $30 million in damage to cotton plants each year, "and at least $40 million in losses to the state's strawberry industry," according to Wikipedia.
"Lygus bugs are one of the causes of irregularly shaped, cat-faced strawberries; another cause may be poor pollination, which results in small undeveloped seeds," says UC Statewide Integrated Pest Management Program (UC IPM) in its Pest Management Guidelines. "Lygus bugs damage fruit by puncturing individual seeds; this, in turn, stops development of the berry in the area surrounding the feeding site. Straw-colored seeds that are large and hollow are a good indication of lygus bug damage. Lygus bug damage is more of a problem in strawberry-growing areas where continuous fruit production occurs.
"Adults are about 0.25 inch (6 mm) long, oval, and rather flattened," UC IPM points out. "They are greenish or brownish and have reddish-brown markings on their wings."
So what happens when a crab spider nails a lygus bug?
The cheering section is loud.
- Author: Kathy Keatley Garvey
(Continued from the July 13th Bug Squad)
Our resident crab spider, family Thomisidae, appears to be an extremely poor hunter. She waits, camouflaged in the lavender patch, as bees buzz around her. They dart away when she lunges at them.
So here I am, a crab spider, as hungry as can be
Does anyone out there feel sorry for me?
"Yes," say the arachnologists. The apiculturists say "no."
Well, I'll just hang out in the lavender and keep lying low.
Hey, looky there! I'm going to fast-track that bee.
Sorry, I am who I am, and I gotta be me.
The next day, success. Or, as they say, it was "a good day for the spider and a bad day for the bee."
It was also a good day for a freeloader fly (family Milichiidae, probably genus Desmometopa). These flies always seem to appear seconds after a spider (or praying mantis) nails its prey. No dinner reservations required.
Other bees mark themselves "safe" from the crab spider. For now.
And life goes on. For the crab spider. For the freeloader flies.
- Author: Kathy Keatley Garvey
A crab spider, family Thomisidae, lies motionless in a patch of lavender, waiting to ambush a honey bee.
So here I am, a crab spider, as hungry as can be
Does anyone out there feel sorry for me?
"Yes," say the arachnologists. The apiculturists say "no."
Well, I'll just hang out in the lavender and keep lying low.
Hey, looky there! I'm going to fast-track that bee.
Sorry, I am who I am, and I gotta be me.
(Was the spider successful? Or did it experience food insecurity? To be continued)
- Author: Kathy Keatley Garvey
So here's this crab spider stalking a katydid nymph foraging on a Mexican sunflower, Tithonia rotundifola.
Dinner awaits!
Suddenly a native bee, Melissodes agilis, lands next to the katydid and begins to sip some nectar.
Decisions, decisions! Do I want a juice katydid nymph or a tasty long-horned bee? Do I have a choice in the matter or does it matter if I have a choice?
A moment in time. Time in a moment. The bee, unaware of danger, continues to forage. Then, abruptly, the bee takes flight.
One menu choice remains.
It was a good day for the crab spider.
It was not a good day for the katydid.
- Author: Kathy Keatley Garvey
It was a tough day for a Tettigoniid on a Tithonia.
When a katydid (Tettigoniid) encountered a crab spider on a Mexican sunflower, Tithonia rotundifola, in our garden, the katydid didn't last long. The spider administered a venomous bite and it was all over. The small, aggressive predator dragged its large prey beneath the Mexican sunflower to consume its meal. The cycle of life...
Do you know how katydids got their nickname?
The males have stridulating organs on their forewings and produce a shrill sound interpreted as “Katy-did, Katy-didn't."
Well, in this case the crab spider did (survive to live another day) and the katydid didn't.