Females can become highly cannibalistic in the presence of other females.
Doctoral candidate Yao Hua Law (right), who studies with major professor Jay Rosenheim, UC Davis Department of Entomology, will speak on "My Neighbors Drive Me Cannibalistic: Mechanisms of Density-Dependent Cannibalistic Behavior and its Effects on Population Dynamics" at a seminar from 12:10 to 1 p.m., Wednesday, Oct. 6 in 122 Briggs Hall.
The lecture, which will be his exit seminar, will focus on the egg cannibalism behavior expressed in the generalist predator, Geocoris pallens.
It's also known as the "big-eyed bug."
G. pallens females are weakly cannibalistic when alone, but become highly cannibalistic in the presence of other females, he said. "I will discuss the possible mechanisms of this behavior, as well as the implications of this behavior for the arthropod community that G. pallens interact with," said Law, who will be introduced by Rosenheim.
Law’s lecture will be webcast live (http://uc-d.na4.acrobat.com/ucsn1/) and then archived on the UC Davis Department of Entomology website. The seminars are chaired by assistant professors Neal Williams and Louie Yang.
The fall seminars began Sept. 29 and will continue through Dec. 3. Most are held from 12:10 to 1 p.m. on Wednesdays. See schedule.
Sivakoff (right), a doctoral candidate in the UC Davis Department of Entomology, won a 2010 Robert and Peggy van den Bosch Memorial Scholarship for her work on the regional movement of the pest.
The lygus bug (Lygus hesperus) is a serious pest of such crops as alfalfa, strawberries and cotton.
Her research? "Understanding the Relative Dispersal Ability of Lygus hesperus and Its Predators Using a Novel Large-Scale Mark-Capture Technique."
“In California’s Central Valley, Lygus hesperus is under poor biological control despite a suite of known predators,” said Sivakoff, who studies with major professor Jay Rosenheim. “One possible explanation for this poor performance in the field is a discrepancy in the dispersal ability of the pest and its predators. To examine this directly, we performed a large-scale mark-capture experiment where we marked L. hesperus and its predators in an alfalfa field using protein markers.”
Following the marking procedure, the grower harvested the alfalfa field, and this prompted a dispersal event. At several times following the harvest, Sivakoff and colleagues sampled surrounding cotton fields for L. hesperus and its predators, including big-eyed bugs (Geocoris spp.), damsel bugs (Nabis spp.), green lacewings (Chrysopa and Chrysoperla spp.), and convergent lady beetles (Hippodamia convergens).Another UC Davis entomology doctoral candidate, Alex Van Dam (left) received a Robert and Peggy van den Bosch Memorial Scholarship for his research on a scale insect.
His project: “Investigating Host-associated Lineage Splitting within Dactylopius Using Molecular Phylogenetics.”
Van Dam studies with major professor Bernie May of the UC Davis Department of Animal Science.
Sivakoff and Van Dam were among eight University of California doctoral candidates sharing a total of $95,000 as recipients of the scholarships.
The recipients are all involved in biological control, said coordinators Kent Daane and Nicholas Mills, co-directors of the Center for Biological Control, UC Berkeley. Eligible to apply for the annual scholarships are doctoral candidates from UC Davis, UC Berkeley and UC Riverside. Selection is by a panel of biocontrol faculty representing the three schools.
The other recipients of 2010 van den Bosch scholarships:
Albie Miles, UC Berkeley, for "Evaluating the Influence of Floral Resource Provisioning on Biological Control of Leafhoppers and Mealybugs in California Vineyards." Major professor: Miguel Altieri.
Steve Bayes, UC Berkeley, for "Determining the Population Structure of Navel Orangeworm (Amyelois transitella): an Invasive Agricultural Pest in California." Major professor: Steve Welter.
Jason Mottern, UC Riverside, for his work on molecular relationships within the parasitic wasp family, Aphelinidae. Major professor: John Heraty.
Jamie Gonzalez, UC Riverside, "Genetic Effects of Prolonged Mass Rearing on Trichogramma pretiosum Fitness: Inbreeding Depression and Selection for Adaptation the Mass Rearing Conditions." Major professor: Richard Stouthamer.
Casey D. Butler, UC Riverside, "Assessment of the Potential for Biological Control for Management of Bactericera cockerelli (Hemiptera: Triozidae)." Major professor: John Trumble.
Jennifer Henke, UC Riverside, for his work dealing with t secondary impacts on fish. Major professor: William Walton.
Congratulations to them all!
Skippers and sedum. Sedum and skippers.
A perfect match. The flower, sedum (family Crassulaceae), and the fiery skipper butterfly (Hylephila phyleus, family Hesperlidae) make a stunning autumn photo.
When late afternoon sun strikes its fighter-jet wings, it glows brilliantly. Move closer and you'll see the skipper sipping nectaring. Move a little more closer and...it's gone.
It does keeps its distance.
Butterfly expert Art Shapiro, professor of evolution and ecology at UC Davis, provides comprehensive information on fiery skippers and other butterflies on his website, Art's Butterfly World.
He calls the fiery skipper "California's most urban butterfly, almost limited to places where people mow lawns. Its range extends to Argentina and Chile and it belongs to a large genus which is otherwise entirely Andean. Its North American range may be quite recent. Here in California, the oldest Bay Area record is only from 1937."
Only 1937? A newcomer, but what a beauty.
You gotta love the Joe-Pye Weed.
It's a shady character and a late bloomer. That is, it loves the shade and blooms in the late summer and early fall.
Better yet, bees and butterflies love it.
Once you hear the distinctive name, Joe-Pye Weed (Eupatorium purpureum) you'll never forget it.
We're told that Joe Pye was a Native American Indian herbalist who used the perennial to treat an outbreak of typhus among the colonists of Massachusetts Bay. The grateful colonists immortalized him by naming the plant for him.
Sometimes it's called "Queen of the Meadow." Sometimes it's called "gravel root." And sometimes "snakeroot."
No matter what you call this four-foot-high plant, the name that really sticks is "Joe-Pye Weed."
Insects can get Pye in their eye.
There's a whole lot of crunchin' going on.
The redhumped caterpillar has discovered our redbud tree, which it considers an "all-you-can" buffet.
Now this is a voracious eater on the same scale of a fellow named Joey "Jaws" Chestnut.
Seconds? Yes, please.
Thirds? Of course.
Well, say "when!"
Distinguished by a bright red head and an equally bright red hump behind its head (Joey has neither, by the way), the caterpillar is yellow with red and white stripes. It's about an inch and a half long and can defoliate or skeletonize a leaf faster than you can say "The redhumped caterpillar is a Schizura concinna in the family Notodontidae." (Or “Joey Chestnut ate 54 dogs and buns on July 4, 2010 and took home the Mustard Belt.”)
The redhumped caterpillar is quite fond of redbud leaves but it also takes a liking to liquidambar, walnut and plum leaves, to mention a few.
Noted butterfly expert Arthur Shapiro, professor of evolution and ecology at UC Davis and the person behind "Art's Butterfly World," took one look at my trio of happy campers...er...caterpillars and commented:
"As you can see, they are gregarious and warningly colored. The red hump contains a defensive formic acid gland. They hold their anal prolegs, which are not useful for walking, in the air and thrash their rear ends in unison when disturbed. This is the ONLY defoliator of redbud around here, and is very common."
Shapiro says it also "attacks walnut and a variety of other chemically distinctive trees that other things don't eat, as a rule. The damage is minor, and I strongly advise against spraying; hand-picking can be used if control is deemed necessary, but they feed so late in the season that there is no actual harm to the tree."
No, no harm. Just some skeletonized leaves and leaf stubs.
What's the adult look like?
"The moth is very nondescript," he says. "It holds its wings wrapped around the body cylindrically and looks remarkably like a cigarette butt, though it is probably 'imitating' a broken-off twig. Despite authoritative commentary to the contrary, they have two broods a year here but are usually seen in fall. The species is native on both coasts and oddly absent in most of the mid-continent."
It will be awhile before we see the adults, which are grayish-brownish.
Shapiro says the insects "pupate in litter or slightly below the soil surface and won't hatch until June or so, if true to form."
Meanwhile, it's OTL, followed by OTD and OTB (out-to-lunch, dinner and breakfast).
It's already won the Redbud Belt.