- Author: Kathy Keatley Garvey
His in-person and Zoom seminar, "Scoliid Wasp Evolution and Some Adventures with Posterior Predictive Simulation," will begin at 4:10 p.m. (Pacific Daylight Time) in 122 Briggs Hall. The Zoom link is https://ucdavis.zoom.us/j/99515291076
Khouri will deliver his seminar in two parts: "The Evolutionary History of Mammoth Wasps (Hymenoptera: Scoliidae)" and "Comparing the Power of Data-Based Phylogenetic Posterior Predictive Checks in the Context of Cucleotide and Amino Acid Data."
"Ziad's work on the mammoth wasps is unique," said host Kimsey, director of the Bohart Museum of Entomology and a distinguished professor of entomology. "This is a family of large bodied distinctive parasitoid wasps that have never had a modern systematic treatment, and the genus and species level taxonomy was a mess. He has brought together modern and classical techniques to bring taxonomic order to this family of wasps and discovered how they evolved."
Some 2300 mammoth wasp specimens, mostly from the Americas, Korea and South Africa, are housed in the Bohart Museum's global collection.
Khouri shares these abstracts from his seminar:
Part 1: "The Evolutionary History of Mammoth Wasps (Hymenoptera: Scoliidae)"
Scoliid wasps comprise a clade of aculeate insects whose larvae are parasitoids of scarabaeid beetle grubs. While scoliids have been studied and used as biological control agents, research into the group's evolution, as well as the stability of scoliid taxonomy, has been limited by a lack of reliable phylogenies. We use ultraconserved element (UCE) data under concatenation and the multispecies coalescent to infer a phylogeny of the Scoliidae. In order to mitigate potential issues arising from model misspecification, we perform data filtering experiments using posterior predictive checks and matched-pairs tests of symmetry. Our analyses confirm the position of Proscolia as sister to all other extant scoliids. We also find strong support for a sister group relationship between the campsomerine genus Colpa and the Scoliini, rendering the Campsomerini non-monophyletic. Campsomerini excluding Colpa (hereafter Campsomerini sensu stricto) is inferred to be monophyletic, with the Australasian genus Trisciloa recovered as sister to the remaining members of the group. Many sampled genera, including Campsomeriella, Dielis, Megascolia, and Scolia are inferred to be non-monophyletic. Analyses incorporating fossil data indicate an Early Cretaceous origin of the crown Scoliidae, with the split between Scoliini + Colpa and Campsomerini s.s. most probably occurring in the Late Cretaceous. Posterior means of Scoliini + Colpa and Campsomerini s.s. crown ages are estimated to be in the Paleogene, though age 95% HPD intervals extend slightly back past the K-Pg boundary, and analyses including fossils of less certain placement result in more posterior mass on older ages. Our estimates of the stem ages of Nearctic scoliid clades are consistent with dispersal across Beringia during the Oligocene or later Eocene. Our study provides a foundation for future research into scoliid wasp evolution and biogeography by being the first to leverage genome-scale data and model-based methods. However, the precision of our dating analyses is constrained by the paucity of well-preserved fossils reliably attributable to the scoliid crown group. Despite concluding that the higher-level taxonomy of the Scoliidae is in dire need of revision, we recommend that taxonomic changes be predicated on datasets that extend the geographic and taxonomic sampling of the current study.
Part II: "Comparing the Power of Data-Based Phylogenetic Posterior Predictive Checks in the Context of Cucleotide and Amino Acid Data"
When used for phylogenetic inference, exonic DNA sequences can be coded in multiple ways, including as nucleotides, amino acids, and codons. In empirical studies, the choice of data type and associated model is often predicated on which model is less expected to be violated in ways that lead to inaccurate inference. Posterior predictive checks are one method for assessing the adequacy of phylogenetic models and potentially providing an indication of inference reliability. We used a simulation-based approach to explore how our ability to detect model inadequacy using phylogenetic posterior prediction, as well as the associated inference errors, may vary with data coding. Specifically, we simulated data under multiple models, including codon models featuring process heterogeneity across lineages, selection heterogeneity across sites, and selection for codon usage. We then performed inference and posterior predictive checks under nucleotide and amino acid models from the GTR family. We found that some simulation conditions resulted in significant differences, between amino acid and nucleotide treatments, in our ability to detect model violation, even when the magnitude of error in an estimate of interest was similar. Moreover, we corroborate the results of other studies indicating that error in tree length estimation is not always correlated with error in topology reconstruction. Although the use of amino acid models generally resulted in more accurate topologies, we found tree length errors to often be greater than for nucleotide models when the data being analyzed were generated using branch-heterogeneous codon models. We show that the magnitude and direction of tree length estimation error can depend on both data coding and properties of the data-generating process. We conclude that if posterior predictive checks are to be used for purposes such as data filtering, practical effect size thresholds indicative of low inference reliability must be established separately for amino acid and nucleotide data. We also advise caution and recommend careful selection of models and data coding when performing analyses where accurate inference of tree length is important.
Khouri joined the UC Davis graduate program in 2012 and is pursuing his doctorate in entomology. His dissertation research involves the phylogenetics, evolution and taxonomy of Scolliidae (Hymenoptera) and phylogenetic posterior prediction.
He holds a bachelor's degree in biology (2012) from Notre Dame University - Louaize (NDU). He did undergraduate research on the identification of bee and other pollinator specimens at the American University of Beirut; assessed genetic diversity in Spartium junceum populations (known as Spanish broom, rush broom, or weaver's broom); and collected specimens for the establishment of an insect collection at NDU.
The Bohart Museum, located in Room 1124 of the Academic Surge Building on Crocker Lane, is currently closed to the public. It houses eight million insect specimens, as well as a live "petting zoo" (Madagascar hissing cockroaches, stick insects and tarantuias) and an insect-themed gift shop, now online.
Nematologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology, coordinates the seminars. For any Zoom technical issues, contact Siddique at ssiddique@ucdavis.edu. (See list of seminars)
- Author: Kathy Keatley Garvey
DAVIS--The UC Davis Linnaean Games Team, the reigning national and regional champions, won the 2016 games conducted Monday night, April 4 in Honolulu at the annual meeting of the Pacific Branch of the Entomological Society of America (PBESA)
The team, comprised of captain Ralph Washington Jr., and members Brendon Boudinot, Jessica Gillung and Ziad Khouri, defeated the University of Hawaii in the semi-finals and then went on to nail the championship with a victory over the UC Riverside team.
The Linnaean Games is a college-bowl type competition in which teams answer questions about insects and entomologists. The teams hold practice sessions throughout the year.
Washington is studying for his doctorate with major professors Steve Nadler and Brian Johnson, who respectively specialize in systematics and evolutionary biology of nematodes and the evolution, behavior, genetics, and health of honeybees; Boudinot with major professor Phil Ward, systematics and evolutionary biology of ants; and Jessica Gillung and Ziad Khouri with major professor Lynn Kimsey, who specializes in the biology and evolution of insects. Kimsey directs the Bohart Museum of Entomology.
The Pacific Branch of ESA encompasses 11 U.S. states (Alaska, Arizona, California, Hawaii, Idaho, Montana, Nevada, Oregon, Utah, Washington and Wyoming); several U.S. territories, including American Samoa, Guam and the Northern Mariana Islands; and parts of Canada and Mexico.
The national Linnaean Games will take place at the ESA's meeting, set Sept. 25-30 in Orlando, Fla. It is being held in conjunction with the International Congress of Entomology (ICE). More than 7000 entomologists from throughout the world are expected to attend. The ICE meeting is co-chaired by UC Davis chemical ecologist Walter Leal, professor, Department of Molecular and Cellular Biology, and research entomologist Alvin M. Simmons of the United States Department of Agriculture's Agricultural Research Service, Charleston, S.C.
- Question: According to the experiment performed at UCB in 1991, the fastest land insect in the world registered a record speed of 1.5 m/s or 3.36 mph, which was equal to 50 body lengths per second. Name the insect.
Answer: American Cockroach, Periplanetaamericana - Question: According to Alder and Willis (2003), in the history of arthropod borne disease in South Carolina, which insect vectored human disease is known by the names Aigue Fever, Bilious Fever, Country Fever, Intermittent Fever, Remittent Fever, and Tertian Fever?
Answer: Malaria - Question:What animal was imported to Mauritius from India in the 18th century to control the Red Locust, Nomadacris
semptemfasiciata?
Answer: The Mynah Bird - Question: What is the active ingredient in the insecticidal product known as NEEM?
Answer: Azadiracthin - Question: In systematics, what is the term for a group containing a common ancestor and some but not all of its descendants?
Answer: A paraphyletic group
Related Link:
UC Davis Wins National Championship
- Author: Kathy Keatley Garvey
DAVIS--They're the national champs!
The UC Davis Linnaean Games Team, comprised of four graduate students in the UC Davis Department of Entomology and Nematology, won the National Linnaean Games Championship at the 2015 Annual Meeting of the Entomological Association of America (ESA), held recently in Minneapolis. See YouTube video at https://youtu.be/_hA05K0NET4.
They did so by correctly answering such questions as:
“What is the smallest insect that is not a parasite or parasitoid?”
“Nicrophorus americanus is listed under what legislative act?” and
“What are the three primary conditions that define eusociality?”
The UC Davis team defeated powerhouse University of Florida 130 to 70 to win its first-ever national championship in the 32-year history of the ESA's Linnaean Team Games.
The Davis team is comprised of captain Ralph Washington Jr., and members Brendon Boudinot, Jessica Gillung and Ziad Khouri, and is advised by faculty members Larry Godfrey, Extension entomologist, and Elina Niño, Extension apiculturist.
The Linnaean Games is a college-bowl type competition in which teams answer questions about insects and entomologists. The teams hold practice sessions throughout the year.
The UC Davis Linnaean Games Team earlier won the regional competition hosted by the Pacific Branch of ESA. They defeated Washington State University in the finals. Both teams competed at the nationals.
Washington is studying for his doctorate with major professors Steve Nadler and Brian Johnson, who respectively specialize in systematics and evolutionary biology of nematodes and the evolution, behavior, genetics, and health of honeybees; Boudinot with major professor Phil Ward, systematics and evolutionary biology of ants; and Jessica Gillung and Ziad Khouri with major professor Lynn Kimsey, who specializes in the biology and evolution of insects. Kimsey directs the Bohart Museum of Entomology.
“They played well and obviously studied hard,” said Gamesmaster Deane Jorgenson, who chaired the event and asked the questions. She is a research scientist at Syngenta, Burnsville, Minn.
Toss-Up Question: What is the smallest insect that is not a parasite or parasitoid?
Answer: Beetles in the family Ptiliidae.
Bonus Question:Some species of mosquitoes lay eggs that can undergo diapause or aestivation. Give at least three cues that trigger the aquatic eggs to hatch.
Answer: Temperature, immersion in water, concentration of ions or dissolved solutes.
Toss-Up Question: Chikungunya is an emerging vector-borne disease in the Americas. Chikungunya is derived from the African Language Makonde. What means Chikungunya in Makonde?
Answer: Bending up.
Toss-Up Question: A Gilson's gland can be found in what insect order?
Answer: Trichoptera
Toss-Up Question: Certain Chrysomelid larvae carry their feces as a defensive shield. To what subfamily do these beetles belong?
Answer: Cassidinae.
Bonus Question: The first lepidopteran sex pheromone identified was bombykol. What was the first dipteran sex pheromone identified? Give the trade or chemical name.
Answer: Muscalure, Z-9-Tricosene. It is also one of the chemicals released by bees during the waggle dance.
Toss-Up Question: What famous recessive gene was the first sex-linked mutation demonstrated in Drosophila by T.H. Morgan?
Answer: White
Bonus Question: Cecidomyiidae are known as the gall flies. What is unique about the species Mayetiola destructor, and what is its common name?
Answer: Mayetiola destructor is the Hessian Fly, a tremendous pest of wheat. It does not form galls.
Toss-Up Question: Nicrophorus americanus is listed under what legislative act?
Answer: The Endangered Species Act
Toss-Up Question: In what insect order would you find hemelytra?
Answer: The order Hemiptera.
Toss-Up Question: The subimago stage is characteristic of what insect order?
Answer: The order Ephemeroptera
Bonus Question: A 2006 Science article by Glenner et al. on the origin of insects summarized evidence that Hexapods are nothing more than land-dwelling crustaceans, which is to say that the former group Crustacea is paraphyletic with respect to the Hexapoda. What hierarchical name has been used to refer to this clade?
Answer: Pancrustacea
Toss-Up Question: What are the three primary conditions that define eusociality?
Answer: Cooperative brood care, overlapping generations, and reproductive division of labor
A total of 10 teams competed in the 2015 Linnaean Games:
- Eastern Branch: Virginia Tech University and University of Maryland
- North Central Branch: Michigan State University and Purdue University
- Pacific Branch: UC Davis and Washington State University
- Southeastern Branch: University of Georgia and University of Florida
- Southwestern Branch: Oklahoma State University and Texas A&M
A YouTube video of the championship game will be posted soon. Last year North Carolina State University defeated the University of Florida to win the finals. The 2014 championship game is online at
https://www.youtube.com/watch?v=HA9TsFFmQBE&feature=youtu.be
Related Links:
National Championship on YouTube
Origin of Linnaean Games (Richard Levine in American Entomologist)
Previous Winners (Entomological Society of America)
