MASTER’S STUDENTS
University of Hawaii at Mānoa, Department of Plant and Environmental Protection Sciences (PEPS)
Influence of urbanization on the abundance of Aedes albopictus (Diptera: Culicidae) in the Nu’uanu Valley on Oahu, Hawaii
Establishment of Aedes albopictus (Skuse) (Diptera: Culicidae) on the Hawaiian Islands has led to endemic Dengue virus transmission and potential for future arbovirus outbreaks. Urbanization in and around Honolulu has provided optimal habitat for Ae. albopictus leading to increased human biting and disease risk. We explored how urbanization influences the abundance of Ae. albopictus in the Nu’uanu Valley, Oahu. Three sites with varying urbanization levels were selected and located in an urban-industrial district, a residential area, and a forest preserve. At each site, we placed 15 ovipositional traps and monitored them weekly for four weeks to evaluate the abundance of Ae. albopictus. A potential larvae habitat survey was conducted at each ovitrap and urbanization was quantified by site using a building footprint map. We created generalized linear mixed models to examine the number of Ae. albopictus eggs laid. Drivers of mosquito populations evaluated included potential larval habitats, abiotic environmental factors, and four urbanization measurements. Our final model contained the fixed effects of potential natural habitat density, elevation, and average building size with site as a random effect. The results indicate Ae. albopictus are most prevalent in areas containing high amounts of natural breeding sites, at low elevation, and around high densities of small buildings. Areas of predominately single-family homes had the highest presence of mosquito eggs. This study highlights the patterns observed in Ae. albopictus abundance in the Nu’uanu Valley, Honolulu. By utilizing trends elucidated, public health agencies can provide targeted messaging upon the next arbovirus outbreak in Hawaii.
Ali Miarkiani
UH Mānoa, PEPS
Can hacking solve the mosquito problem?
Mosquitoes sing a love song to each other before they mate. I have hacked an existing, inexpensive, mass-produced, bug zapper using a small readily available microcontroller used by DIY enthusiasts in order to produce different pure notes. Mixing the pure notes together I hope to create a song that will attract mosquitoes into the bug zapper. Every time the bug zapper zaps a mosquito the microcontroller will record what note was playing at the time allowing me to use a method called A B testing in order to find the most irresistible song for mosquitoes. I chose this method because it is the same method used by companies in the commercial industry to find the most enticing commercials.
Elizabeth Conlon
UH Mānoa, Department of Botany
Hawaiian yellow-faced bee foraging ecology and floral resource use in coastal strand habitats, Oʻahu
Nearly 90% of the world’s flowering plants are pollinated by animals, and bees comprise the most dominant pollinator group (Ollerton 2017). All 63 species of bees native to Hawai‘i radiated from a single colonization event by one genus, Hylaeus (Daly & Magnacca 2003). Threatened by disturbance, invasive insects, and habitat loss, endemic Hylaeus are rapidly declining in diversity and abundance across the islands. Hylaeus anthracinus, the most common native species of yellow-faced bees found on the coastline of O‘ahu, was federally listed as endangered in 2016 along with 6 other Hawaiian Hylaeus species (USFWS 2016). Despite the population decline of Hylaeus, little is known about their specific habitat or foraging requirements (Magnacca 2005). This project focuses on identifying the plant communities and flower characteristics that support the species H. anthracinus, with the goal of understanding H. anthracinus floral resource use. To investigate the foraging ecology and range of flowering species visited by H. anthracinus, I observed bees along the coastline at James Campbell National Wildlife Refuge and Ka Iwi State Scenic Shoreline on the island of Oʻahu over the course of a year. In this presentation, I will share preliminary results about the rate of H. anthracinus visitation to different native and alien coastal plants, as well as insight into flower preferences determined by the frequency of bee visits.
PhD STUDENTS
Yumary Vasquez
University of California, Merced, Quantitative and Systems Biology Program
Comparative genomics of endosymbionts across endemic Hawaiian
Nutritional endosymbionts are a vital part of a sap-feeding insect's survival. Endemic Hawaiian leafhoppers (Hemiptera: Cicadellidae: Nesophrosyne) are obligate phloem and xylem feeders, a diet that cannot nutritionally sustain animal life. Nesophrosyne relies on the bacteria, Candidatus Sulcia muelleri (hereafter known as Sulcia) and Candidatus Nasuia deltocephalinicola (hereafter known as Nasuia), that have been co-evolving for over 300 million years. This association is vital to the host by assisting in the production of 10 essential amino acids that are limited in their depauperate diet. These symbionts are intracellular and vertically inherited; therefore, they are prone to strong genetic drift with subsequent loss of essential free-living genes. Genome reduction varies widely throughout lineages causing variation among symbiont genomes, even if they are the same bacterial species. As genomic capabilities degenerate in beneficial symbionts, hosts must compensate using their own mechanisms. However, it remains unclear how this symbiosis has evolved in closely related species that have undergone an adaptive radiation. To answer this question, we investigated the genome evolution of Sulcia (190kb) and Nasuia (112kb) across 20 leafhopper species that span five Hawaiian Islands and eight host plant groups. Sulcia and Nasuia genomes exhibit gene loss across varying degrees in leafhopper species of the same genus. Additionally, Sulcia genomes are experiencing lower rates of molecular evolution compared to the co-symbiont, Nasuia. Collectively, these results indicate an ongoing symbiotic genome reduction among Hawaiian leafhopper lineages and distinct patterns of evolutionary rate in each bacterial partner.
Michelle Au
UH Mānoa, PEPS
The biology and impacts of the Ramie moth, Arcte coerula (Lepidoptera: Noctuidae) on endemic nettles (Urticaceae) in Hawaiʻi
In November 2018, the state of Hawaiʻi discovered the ramie moth, Arcte coerula (Lepidoptera: Noctuidae), on Maui defoliating māmaki trees, Pipturus albidus (Urticaceae). It is the first record of the ramie moth in Hawaiʻi and the United States. As of November 2020, this new pest has spread to Hawaiʻi island. Native Hawaiian māmaki has cultural, ecological, and agricultural importance to Hawaiʻi as a medicinal plant in traditional lāʻau lapaʻau practices, an essential food source for endemic insects, and a newly emerging tea crop, respectively. Field and laboratory observations suggest that high populations of the ramie moth could potentially devastate these trees. This project assessed the ramie moth’s threat to Hawaiʻi through studies looking at its biological impact on the state’s natural and agricultural systems. We determined the current geographic distribution of the ramie moth in Hawaiʻi, identified its impacts on māmaki and other potential host plants, and analyzed possible control efforts to manage the ramie moth’s population in Hawaiʻi. Outcomes from this project will provide the state with crucial information to contain the spread of this new pest in Hawaiʻi, thus saving our important native forests, preserving the state’s emerging māmaki tea industry, and reducing millions in long-term management costs.
Mason Russo
UH Mānoa, PEPS
Efficacies of systemic insecticides against the coconut rhinoceros beetle, Oryctes rhinoceros, on Oahu Hawai’i.
The coconut rhinoceros beetle, Oryctes rhinoceros, is a highly damaging invasive insect that feeds on coconut palms and other palm species. This pest had spread across the Pacific during World War Two but was controlled successfully with the release of specimens infected with a Oryctes nudivirus (OrnV). However, beetles resilient to OrnV were found in Guam, where they later became widespread after a typhoon created numerous breeding sites. Since then, O. rhinoceros was found on the Hawaiian Island of Oahu in 2013 and is the same resilient biotype found on Guam. This triggered an extensive eradication program using mass trapping, detector dogs, green waste sanitation, breeding site surveys, public outreach, and insecticidal treatments. These studies evaluated the efficacy of systemic insecticides in laboratory and field settings as a potential addition to the integrated pest management program. The laboratory assays tested the efficacy of Imidacloprid, Acephate, Dinotefuran, and Abamectin at 25 and 250 parts per million (ppm) on adult rhinoceros beetles reared in the University of Hawaii’s Arthropod Containment Facility (UH-ACL). This was followed by two concurrent field trials evaluation preventative and curative treatments injecting these systemic insecticides into coconut palms. Efficacy of treatments was determined using two surveyors taking visual observations of O. rhinoceros feeding damage on coconut palm trees every month. The results of the laboratory trial indicated that all the chemicals were effective at both 25 and 250ppm. The field trial results indicated that imidacloprid injections reduced the total amount of new feeding damage.
Heather Stever
University of California Merced, Quantitative and Systems Biology Program; UH Hilo
Hawaiian Seed Bugs and Their Microbes: A Story of Evolution & Adaptation
Seed-feeding Nysius insects (Hemiptera: Lygaeidae) have a symbiotic association with distinct intracellular bacteria, “Candidatus Schneideria nysicola” (Gammaproteobacteria). While many other hemipteran insect groups generally rely on bacterial symbionts that synthesize all ten essential amino acids lacking in their plant sap diets, the nutritional role of Schneideria in Nysius hosts that specialize on a more nutritionally complete seed-based diet has remained unknown. To determine the nutritional and functional capabilities of Schneideria, we sequenced the complete Schneideria genomes from three distantly related endemic Hawaiian Nysius seed bug species. The predicted nutritional contribution of Schneideria includes four B-vitamins and five of the ten essential amino acids that likely match its hosts’ seed-based diet. Disrupted and degraded genes in Schneideria suggests that Hawaiian lineages are undergoing continued gene losses observed in the smaller genomes of the other more ancient hemipteran symbionts. Furthermore, our analysis of Schneideria in seed-feeding Hawaiian Nysius has set the stage for our current investigation into the role of microbial symbionts in the evolution and remarkable adaptations of the only two carnivorous scavenger species among Hawaiian Nysius seed bugs: the wēkiu bug and the a‘a bug.
Kylle Roy
Purdue University Forestry and Natural Resources Department; and USGS-PIERC
The in vitro and in vivo volatile organic compounds associated with Rapid ʻŌhiʻa Death and the response of Xyleborini ambrosia beetles to those compounds
Rapid ʻŌhiʻa Death (ROD), a fungal disease associated with ambrosia beetles (Coleoptera: Curculionidae) is devastating the keystone tree species of Hawaiʻi, ʻōhiʻa lehua (Metrosideros polymorpha). Our previous reseach has found ambrosia beetles in the tribe Xyleborini to be highly invovled with the spread of the ROD pathogens, Ceratocystis lukuohia and Ceratocystis huliohia, both indirectly through contaminated frass and directly through potential vectoring. In order to further understand the semiochemical relationship among Xyleborni beetles, ʻōhiʻa, and the Ceratocystis fungi, we indentified the volatile organic compounds (VOCs) of the pathosystem both in vitro and in vivo, then tested the response of these beetles to the compounds using olfactometer assays.
Chasen Griffin
UH Mānoa; School of Life Sciences; Zoology; Pacific Biosciences Research Center
Impacts on Development and Survival of the Tiger Mosquito, Aedes albopictus (Diptera: Culicidae), in Response to Altered Larval Habitat Microbiota
The Tiger Mosquito, Aedes albopictus, is considered among the most invasive mosquito species. It is a known vector of several medically important human pathogens including chikungunya virus, dengue virus, and Zika virus. Aedes albopictus’s ability to invade new territories is a significant public health concern because these invasions will expand the capacity for transmission of novel pathogens in populations of largely naïve human hosts. The need to understand the components facilitating both the ability to invade new environments and to vector disease is imperative. Once such component—the microbiome—plays a significant role in many biological processes of mosquitoes and has received substantial attention in the past decade. The microbiome is acquired from environmental sources, which directly links the environment to mosquito biology. Manipulation of the larval habitat microbiota using different filtration regimens results in varying developmental and survival outcomes in A. albopictus larvae. Adults that emerge from larvae reared in manipulated larval habitats also have varying survival outcomes when fed different carbohydrate diets. Additionally, microbiome compositions are altered in adult A. albopictus reared in manipulated larval habitats, likely impacting other aspects of host physiology. The results indicate that targeting the microbiome, environmentally and in the mosquito host, presents as a possible tool in combatting Aedes albopictus both as a pest and vector of disease.
Kyhl Austin
UH Mānoa; PEPS
Extinct or not? Recent rediscoveries of native Hawaiian moths
The Hawaiian Islands are often called "the extinction capital of the world.” Native animals and plants such as tree snails, honeycreepers, and lobelioids are famous not only for their extreme diversity in Hawaii but also because of their extremely high rates of extinction over the past two centuries. Having a baseline estimate for what species are extant versus extinct is crucial is developing conservation plans. Through museum visits, literature reviews, and personal field work, I have created a database for all described species of Hawaiian Lepidoptera and have cataloged the year each species was last reliably seen or collected. I will showcase some of the rediscoveries I have made and highlight groups of moths that I consider "high priority" -- likely extant but not recorded in over a century.
Zhening Zhang
UH Mānoa; PEPS
The impact of supplemental feeding of honeybee colonies in Hawaii
The mild tropical climate and the absence of Africanized bees makes Hawaii a unique place for year-round beekeeping. The lush vegetation superficially suggests an abundance of food resources for the local bees throughout the year, consequently, providing supplemental food to colonies during winter seems unnecessary in Hawaii compared to temperate areas. However, the winter months in Hawaii are slightly cooler, often rainier, shorter daylight hours and a noticeable colony population decline. Whether providing supplemental food during this season could improve the overall health conditions of honeybees in Hawaii was unclear. In this study, sugar syrup and pollen protein patties were used to feed honeybee colonies in Waimanalo, Oahu. Feeding was started in January and stopped when the nectar flow commenced. Colonies were monitored for a total of nine months to examine short and long-term impact of feeding. The results showed that fed colonies began to grow larger by the end of feeding period, and most interestingly, the feeding benefit carried over to post-feeding period. Control colonies showed a higher deformed wing virus level than the fed group. Fed colonies produced nearly twice as much honey compared to the control group at the end. This result shows the importance of feeding bees in Hawaii but identified differences from temperate areas. The colony growth data contributes to understanding of honeybee phenology of Hawaii and in other tropical and subtropical areas with similar climate and food sources in a way to improve bee management skills and increase economic benefit.
POSTDOCTORAL RESEARCHERS
Kristin Bowers
Department of Entomology, Plant Pathology & Weed Science, New Mexico State University, Las Cruces, NM.
Evaluating the field host range of the brazilian peppertree thrips, Pseudophilothrips ichini, a biological control agent for chinaberry, Schinus terebinthifolia.
Christmasberry, (Schinus terebinthifolia) is one of the most problematic upland invasive weeds in Hawai’i. The biological control agent Pseudophilothrips ichini has a narrow host range and was approved for release in 2019 against S. terebinthifolia in the southeastern US. Fundamental host range testing in outdoor plots indicated that P. ichini preferred the target weed S. terebinthifolia but can develop poorly on closely related non-target trees under no-choice conditions. We evaluated the likelihood of the non-target host plant use and spillover of P. ichini on non-target trees, including native Hawaiian plants, under field conditions in Florida. We examined residence time, larval development, and movement of P. ichini. The results indicated that P. ichini has a narrow fundamental host range, like that found during quarantine testing, and poses minimal risk to non-target species in Florida and Hawaii.
Daniel Paulo
University of Hawaii at Manoa, PEPS; USDA-ARS Hilo, Tropical Crop and Commodity Protection Research Unit (TPCCPRU)
How to make a mutant fruit fly: Using modern functional genomics to recreate classical mutant phenotypes in non-model tephritids of high agricultural relevance
Tephritid fruit flies are among the most invasive and destructive agricultural pests worldwide. Over recent years, the family has been in the center of genome manipulation studies using the CRISPR/Cas9 system aiming at developing of new strains engineered to facilitate their management and control. However, few comprehensive protocols have been described for efficient delivery of CRISPR/Cas9 components in tephritids, limiting the technology to a few most thoroughly studied species within the family. Here, we revisited 5 years of CRISPR research in Tephritidae and propose a simple, reliable, and easy-to-transfer CRISPR/Cas9 gene knockout protocol for in vivo functional analysis of candidate loci in tephritid fruit flies. We demonstrated the efficiency of our protocol by disrupting the white eye (we) gene in the melon fly, Zeugodacus cucurbitae (Coquillett). High rates of somatic mosaicism were induced by microinjecting pre-assembled Cas9-sgRNA complexes into non-dechorionated embryos during early embryogenesis. Mosaic flies efficiently transmitted modified alleles to the subsequent generation, allowing the rapid development of stable mutant lines. We achieved similar results when targeting the orthologue in the Oriental fruit fly, Bactrocera dorsalis (Hendel), illustrating the reproducibility of our methods. Finally, we introduced new mutations in the recently discovered white pupae (wp) loci in the melon fly, recreating the classical White puparium phenotype successfully used in suppression programs of this species. To our knowledge, this is the first demonstration of CRISPR-based genome-editing in the genus Zeugodacus, and we anticipate that the procedures described here will contribute to advancing genome-editing in other non-model tephritid fruit flies.
David Molik
USDA-ARS Hilo, TPCCPRU
Phylogenomics and Related Transposons of Caffeine Response Genes in Some Insects
The Adaptive Horizontal Gene Transfer of HhMAN1 in Hypothenemus hampei (common name: Coffee Berry Borer Beatle) is part of a larger evolved caffeine response of insects of which little is known about. Known protein coding genes of other insects implicated in caffeine response are Ac78c, Cyp6a2, Cyp6a8, jnj, Gr66a, and Gr93a. By looking at the transposon activity on top of and around HhMAN1 and the several other known caffeine response genes across insect species, while also looking at the phylogenomics of the several caffeine response genes themselves, we can build a picture of the evolution of caffeine response. Understanding the evolution of this response is useful in the understanding of how insecticide resistance evolves and understanding through Historical Contingency which insects might easily evolve resistance to which insecticides. To complete this analysis, we use 46 HiFi/HiC genomes which are then annotated for orthologs and transposons, separately, orthologs for the genes of interest are found via blast alignment. Gene trees, Phylogeny, and molecular tests for selection are all used in understanding the evolution of caffeine response.
Kelsey Coffman
USDA-ARS Hilo, TPCCPRU
Parasitoid wasps, viruses, and prospects for biocontrol
Parasitoid wasps are insects that survive as obligate parasites that feed from and eventually kill their insect hosts. One of the most spectacular biological innovations that has repeatedly arisen in parasitoid wasp lineages is the evolution of heritable associations with viruses. Parasitoid wasps use these viruses as biological weapons that they introduce into host insects to subdue host defenses and alter host physiology, thereby promoting successful parasitism. To gain a more comprehensive understanding of beneficial virus evolution, we aim to functionally and genetically characterize novel viruses, including those inherited by the wasps Fopius arisanus and Diachasmimorpha longicaudata, which are important biological control agents for many tropical fruit fly pests. Study of an endogenous nudivirus produced by F. arisanus wasps is still in an early stage, although the poxvirus carried by D. longicaudata offers a transformative example of viral symbiosis that expands upon current notions of microbial symbiont evolution and challenges existing ideas regarding the evolutionary processes that govern mutualistic viruses. Additionally, this research can be applied to future innovations in fruit fly biological control. F. arisanus and D. longicaudata are two of the most successful biological control agents used for fruit fly suppression in Hawaii, and they both produce heritable viruses that are pathogenic to a wide range of important fruit fly pest species. Identification of the molecular processes used by these viruses to exploit fruit fly physiology could lead to novel control strategies that leverage naturally occurring virulence tactics against pest populations.
Carlos Congrains Castillo
UH Manoa, PEPS; USDA-ARS Hilo, TPCCPRU
Phylogenomics provides insights into Neotropical true fruit flies (Anastrepha: Tephritidae)
Evolution
Insect pests cause loses of crop production affecting worldwide agriculture. Species identification
is a challenging and crucial task to apply adequate measures of pest control. Anastrepha genus
comprises more than 300 true fruit fly species, which are widely distributed in tropical and
subtropical regions of the Americas. This genus is classified in species groups, being fraterculus
group one of the most import from an economic and biological points of view, because it includes
cryptic and closely related polyphagous species that probably diverged under gene flow such as
the Anastrepha fraterculus complex. Despite their importance, the evolutionary mechanisms
involved in the rapid diversification of this group is unclear as well as their phylogenic
relationships. Here we performed a phylogenomic approach using thousands of genes to unravel
the evolutionary relationships of A. fraterculus group and six other Anastrepha species groups.
Gene trees showed strong phylogenetic incongruence due to incomplete lineage sorting and
introgression among fraterculus group lineages. Although this gene tree discordance, we
developed a strategy based on topology comparison that allowed us to find phylogenetically
informative genes. Our findings provide insights regarding the intricate patterns of evolution of A.
fraterculus and support hypothesis of being an assemblage of closely related cryptic lineages that
evolved under interspecific gene flow. Notably, we found a set of genes that retained high genetic
variation, which are promising for developing tools to identify these species.
… … … … … … … … … … … … … … … … … … … … … … … … … … … … …
2021-2022 HES OFFICERS
President | Nicholas Manoukis - Research Leader, Tropical Crop and Commodity Protection Research Unit, Daniel K. Inouye Pacific Basin Agricultural Research Station, USDA-ARS, Hilo, Hawaii.
Treasurer | Darcy Oishi - Biological Control Section Chief, Hawaii State Department of Agriculture (HDOA), Plant Pest Control Branch, Honolulu, Hawaii.
Secretary | Cynthia King - Hawaii State Department of Agriculture (HDOA), Plant Pest Control Branch, Honolulu, Hawaii.
HES Editor | Mark Wright - Professor of Entomology and Extension Specialist, Department of Plant and Environmental Protection Sciences (PEPS), University of Hawaii at Mānoa.
Advisor | Paul Krushelnycky – Associate Research Scientist, Department of Plant and Environmental Protection Sciences (PEPS), University of Hawaii at Mānoa.
2022 SYMPOSIUM ORGANIZERS
Dara Stockton – Research Entomologist, Tropical Crop and Commodity Protection Research Unit, Daniel K. Inouye Pacific Basin Agricultural Research Station, USDA-ARS, Hilo, Hawaii.
Ikkei Shikano – Assistant Professor of Entomology, Department of Plant and Environmental Protection Sciences (PEPS), University of Hawaii at Mānoa. Dr. Shikano is also the incoming president-elect for HES during the 2022-2023 term.
KEYNOTE SPEAKER
Mark Wright – Professor of Entomology and Extension Specialist, UH Mānoa. Mark works on IPM of pests of tropical fruit and nut crops, concentrating on biological control. He has also worked on biocontrol of invasive species attacking native plant species in Hawaii. He has published papers addressing augmentative and classical biological control, development of pest sampling methods, the role diversified cropping systems in conservation biocontrol, and even the effect of bee alarm pheromones as deterrents of African elephants. Mark is currently an associate editor of Biocontrol Science and Technology, an editor of Proceedings of the Hawaiian Entomological Society, and serves on the editorial board of Biological Control.
COMPETITON JUDGES
Angel Acebes-Doria - Research Biologist, TCCRPU, USDA-ARS, Hilo, Hawaii
Peter Follett - Research Entomologist, TCCRPU, USDA-ARS, Hilo, Hawaii
Roshan Manandhar – Assistant Extension Agent, UH Kauai Extension Office
Charles Mason - Research Biologist, TCCRPU, USDA-ARS, Hilo, Hawaii
Ikkei Shikano – Assistant Professor of Entomology, UH Mānoa
Jia Wei-Tay– Assistant Professor of Urban Entomology, UH Mānoa