DAVIS--Paramjit Kaur of India who was a visiting scholar in the Frank Zalom lab last summer and fall, won “Best Poster Presentation” at the fourth International Conference on Insect Science, held in Bangalore, India.
She titled her poster--research co-authored by Zalom--“Prey Preference of the Predatory Mite, Neoseiulus californicus McGregor for Tetranychus urticae Koch and Eotetranychus lewisi (McGregor) on Strawberry at Different Temperatures.”
Kaur is an assistant professor of acarology at Punjab Agricultural University in Ludhiana, India. The Indian Society for the Advancement of Insect Science sponsored the conference.
The two-spotted mite, Tetranychus urticae, is a key pest of strawberries in California. The Lewis mite, Eotetranychus lewisi, is an emerging problem in southern California strawberry production, Kaur wrote.
In a note to integrated pest management specialist Zalom, professor of entomology, Kaur credited him for his support and guidance. She wrote: “I am so happy for this valuable achievement. This all happened due to your support and guidance. I am really thankful to you for providing me best opportunity to work with you. Again, I am thankful to you for providing me space in your lab. The time spent in Davis was the best time in my life. Thanks a lot.”
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Feb. 20, 2013
Assistant professor Joanna Chiu will host the seminar, which is scheduled to be recorded for later viewing on UCTV.
About her research and her upcoming seminar, Dahanukar says: "We are interested in the molecular neurobiology of feeding behavior. Insects use highly diverse groups of gustatory receptors (Grs) to taste the chemical world and determine the palatability of potential food sources. In Drosophila melanogaster, the 68 receptors of this family are expressed in complex combinatorial patterns in taste neurons. In previous studies we and others identified a highly conserved clade of eight Gr genes that encode sugar receptors. Although some of these have been linked to detection of sweet compounds by genetic analysis, their precise functions are still poorly understood. Little is also known about how stimuli that are typically not rich in sugars trigger highly attractive gustatory responses in Drosophila."
"We have also obtained functional expression of a taste receptor from the mosquito Anopheles gambiae in Drosophila. We are now poised to further investigate taste detection and Gr function in Drosophila and other insects."
Among her honors, Dahanukar received a National Science Foundation Career Award in 2012; the Whitehall Foundation Award in 2011; the 2000 Ruth L. Kirschstein National Research Service Award. She was awarded a Government of India National Merit Scholarship in 1990.
She holds a bachelor of science degree in life sciences in 1990 from the Bombay University, India; a master's degree in environmental management from Duke University; and a doctorate in genetics in 1999 from Duke University, where she studied patterning along the anterior-posterior axis in Drosophila embryos. In 1999, she joined the laboratory of John Carlson at Yale University to pursue post-doctoral training in the molecular neurobiology of insect chemosensory systems. Dahanukar joined the faculty of the UC Riverside Department of Entomology in 2009.
Among her latest publications:
2011
Wisotsky, Z., Medina, A., Freeman, E. & Dahanukar, A. Evolutionary
differences in food preferences rely on Gr64e, a receptor for glycerol. Nat
Neurosci 14(12): 1534-1541.
Kwon, J.Y., Dahanukar, A., Weiss, L.A. & Carlson, J.R. Molecular and cellular
organization of the taste system in the Drosophila larva. J Neurosci 31(43):
15300-15309.
Weiss, L.A., Dahanukar, A., Kwon, J.Y., Banerjee, D. & Carlson, J.R. The
molecular and cellular basis of bitter taste in Drosophila. Neuron 69(2): 258-
272.
Dahanukar, A. & Ray, A. Courtship, aggression and avoidance: Pheromones,
receptors and neurons for social behaviors in Drosophila. Fly 5(1): 58-63.
2010
Benton, R. and Dahanukar, A. Chemosensory coding in single sensilla. In
“Drosophila neurobiology methods: A companion to the Cold Spring Harbor
Neurobiology of Drosophila course,” Scott Waddell, Bing Zhang and Marc
Freeman (ed.), CSHL press. pp.247-276.
2007
Dahanukar, A., Lei, Y-T., Kwon, J. Y. and Carlson, J.R. Two Gr genes
underlie sugar reception in Drosophila. Neuron 56(3):503-516.
Kwon, J.Y., Dahanukar, A., Weiss, L.A. & Carlson, J.R. The molecular basis
of CO2 reception in Drosophila. Proc Natl Acad Sci U S A 104(9):3574-3578.
2006 Hallem, E. A., Dahanukar, A., and Carlson, J. R. Insect odor and taste
receptors. Annu Rev Entomol 51: 113-135.
2005
Coelho, C. M., Kolevski, B., Bunn, C., Walker, C., Dahanukar, A., and
Leevers, S. J. Growth and cell survival are unevenly impaired in pixie mutant
wing discs. Development 132(24): 5411-5424.
Dahanukar, A., Hallem, E. A., and Carlson, J. R. Insect chemoreception. Curr
Opin Neurobiol 15(4): 423-430.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Feb. 20, 2013
They previously filed a petition to save Franklin's bumble bee, a bumble bee known to inhabit a small area of southern Oregon and northern California. Thorp has been monitoring Franklin's bumble bee (Bombus franklini) since 1998 but hasn't seen it since August 2006 when he detected one at Mt. Ashland.
In a recent press release, the Xerces Society related that the rusty-patched bumble bee, (Bombus affinis), "has disappeared from 87 percent of its historic range (which once included 25 states). Where it is still found, this bee is much less abundant than it was in the past."
“The charismatic and once common rusty patched bumble bee has suffered severe and widespread declines throughout its range in the eastern U.S. since 1997," Thorp said. "The few scattered recent sightings thanks to intensive searches are encouraging, but the species is in critical need of federal protection.”
Researchers at the University of Illinois recently found "higher levels of a fungal pathogen and lower levels of genetic diversity," wrote Sarina Jepsen, the Xerces Society's endangered species program director, in a press release. "Notably, the rusty-patched bumble bee was too scarce in the landscape to be included in these analyses."
"The leading hypothesis suggests that this fungal pathogen was introduced from Europe by the commercial bumble bee industry in the early 1990s, and then spread to wild pollinators," Jepson noted. "Although it has not been proven, the hypothesis is supported by the timing, speed and severity of the decline—a crash in laboratory populations of bumble bees occurred shortly before researchers noticed a number of species of formerly common bumble bees disappearing from the wild."
The Xerces Society, an international organization founded in 1971 and headquartered in Portland, Ore., is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat and is at the forefront of invertebrate protection worldwide, harnessing the knowledge of scientists and the enthusiasm of citizens to implement conservation programs.
Related links:
Rusty-patched bumble bee, Xerces Society website
Declining bumble bee population, UC Davis Entomology website
Franklin's bumble bee, UC Davis Entomology website
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Feb. 14, 2013
Mills is a professor of insect population ecology in the Department of Environmental Science, Policy and Management at UC Berkeley and a curator at the Essig Museum of Entomology.
"There have been many accidental introductions of phytophagous insect pests into new geographic regions and in the absence of biotic resistance from entomophagous insects some have become invasive and notorious as pests of natural and managed ecosystems," Mills says. "In contrast, there are very few examples of biotic resistance to insect invasions by entomophagous insects. Since its discovery in California in 2006, the light brown apple moth has accumulated a rich set of resident parasitoid species comparable to that seen in its native Australia. However, in contrast to the low levels of parasitism that invasive hosts typically experience from resident parasitoids, parasitism levels for light brown apple moth are very high."
Mills will discuss the importance of resident parasitoids as barriers to the invasions of light brown apple moth (Epiphyas postvittana) in California. In 2009 he was appointed a member of Light Brown Apple Moth Review Committee, National Research Council of the National Academies. His research interests include invasive species, biological control, and ecology of natural enemies.
Native to Australia, LBAM has been found in a dozen counties since retired UC Berkeley entomologist Jerry Powell, a moth taxonomist, first detected the pest in his Berkeley backyard on July 19, 2006.
As a caterpillar, the moth eats just about everything from A to Z: apple, apricot, beans, caneberries (blackberry, blueberry, boysenberry, raspberry), cabbage, camellia, chrysanthemum, citrus, clover, cole crops, eucalyptus, jasmine, kiwifruit, peach, pear, persimmon, plantain, pumpkin, strawberry, tomato, rose and zea mays (corn).
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
Feb. 13, 2013
If you're not closely related, communication won't be as effective.
Newly published research in today's Proceedings of the Royal Society B: Biological Sciences shows that kin have distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors,” says lead researcher and ecologist Richard Karban, a professor in the UC Davis Department of Entomology.
For example, fire ants can recognize kin. “Ants will destroy queens that are not relatives but protect those who are,” Karban said.
That ability is less well studied for plants, until now.
“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.”
The research, “Kin Recognition Affects Plant Communication and Defense,” is co-authored by two scientists from Japan and two from UC Davis: Kaori Shiojiri of the Hakubi Center for Advanced Research, Kyoto University, and Satomi Ishizaki of the Graduate School of Science and Technology, Niigata University; and William Wetzel of the UC Davis Center for Population Biology, and Richard Evans of the UC Davis Department of Plant Science.
To simulate predator damage, the researchers “wounded” the plants by clipping them and then studied the responses to the volatile cues. They found that the plants that received cues from experimentally clipped close relatives experienced less leaf damage over the growing season that those that received cues from clipped neighbors that were more distantly related.
“More effective defense adds to a growing list of favorable consequences of kin recognition for plants,” they wrote.
The researchers performed their field work on sagebrush (Artemisia tridentata) at Taylor Meadow, UC Sagehen Creek Field Station, near Truckee. They conducted four field experiments over three years “that compared the proportion of leaves that were damaged by herbivores over the growing season when plants were provided with volatile cues clipped from a close relative versus cues from a distant relative,” the scientists wrote.
For closely related kin, they snipped stem cuttings (clones), potted them, and then returned the pots to the field. They determined relatedness “by using microsatellites that varied among individual sagebrush clones.”
The result: “Plants responded more effectively to volatile cues from close relatives than from distant relatives in all four experiments and communication reduced levels of leaf damage experienced over the three growing seasons,” they wrote. “This result was unlikely to be caused by volatiles repelling or poisoning insect herbivores.”
Karban, who has studied plant communication among the sagebrush at the site since 1999, likened the plant communication to neighbors “eavesdropping.” They “hear” the volatile cues of their neighbors as predators damage them.
Plants do communicate, Karban said. A basic form of plant communication occurs when it is being shaded and it responds by moving away.
“Some definitions of communication require that both the sender and receiver benefit by engaging in the behavior,” the researchers wrote. “Sagebrush is a long-lived perennial, making estimates of the costs and benefits of communication difficult although plants that responded to volatile cues from damaged neighbors experienced greater survival at the seedling stage and greater production of new branches and inflorescences over 12 years.”
Karban said that the volatiles released by “experimentally damaged plants are highly variable among individuals.”
“In the future we plan to examine this chemical variability to determine which chemicals are active as signals and why they exhibit so much variability,” Karban said. “Ultimately, we would like to be able to understand the chemical nature of the volatile cues, how plants use them to communicate, and whether as agriculturalists, we can control host plant resistance to herbivores.”
The work was supported by grants from the Japan Society for the Promotion of Science (JSPS) and the U.S. Department of Agriculture.
Related Link
Rick Karban's Lab Research