For Insect Systematics and Biodiversity
We are interested in understanding relationships between different groups of organisms at the population, species levels, and above. Our focus is on insects, but the data and theoretical basis of our research applies to all of life.
Systematics is the study of the relationships between groups of any size, including species and populations. We use DNA sequence, morphological characters, and ecology to construct phylogenies for taxa of interest, and use the information to understand the processes of evolution. In addition to a better understanding of evolution, systematics is an essential tool for protecting agriculture, improving conservation, and has direct applications to medicine and the life sciences in general. By building DNA- and morphology-based phylogenies, we are able to identify new species and uncover hidden relationships and patterns between species. The current projects in our lab focus on the application of systematics to improving agriculture and conservation efforts in Hawai'i and elsewhere.
I am broadly interested in the evolution, ecology and conservation of insects. Projects in the lab often incorporate multiple themes pertaining to empirical research and to threatened species or the effective control of invasive species. By including theoretical and applied aspects in our research, we hope to increase the relevance of our work. Through the University of Hawaii Insect Museum (add link), I help maintain a broader resource available to a swath of researchers with applications to most entomological work in Hawaii. Mostly I enjoy being part of a group that is productive and has fun together in the lab and doing fieldwork!More Info
I have had a lifelong interest in the biodiversity of beetles worldwide, with special focus on their systematics, evolution, and conservation. My background is both one of research, including much high-throughput molecular study, and of curatorial work in some of the finest entomological collections on the planet. My passion is discovering and documenting beetles in the wild.More Info
Camiel is a Junior Researcher working on a group of ~ 1,000 fruit flies (Tephritidae: Dacini), which show intricate evolutionary patterns with relation to host use, morphological crypsis and pollination. Camiel also curates this part of the collection in the University of Hawaii Insect Museum, which has a rich history of research and now holds over 200 species of Dacini fruit flies. Using DNA sequencing, his research uses these resources to infer relationships between species and test hypothesis on why there are so many species, why their diets are different, if they evolved with their host plants and which species pose the largest risks to become pests.More Info
I am a Junior Researcher from the University of Hawaii at Manoa. My research interests focus on the systematics, population genetics, and evolution of native and invasive insects in Hawaii. For my research, I use molecular methods to study the economically damaging tribe Dacini (Diptera: Tephritidae) which includes many pest species such as the oriental fruit fly (Bactrocera dorsalis) and the melon fruit fly (Zeugodacus cucurbitae). I have several projects on phylogenetics of several moth genera; Hyles (Sphingidae), Manduca (Sphingidae) Syndemis (Tortricidae) and Hemileuca(Saturniidae). I analyze molecular data using a variety of methods to investigate how various forces (geography, drift, selection, dispersal, vicariance, life history, etc.) shape population structure, species boundaries, and evolutionary relationships.More Info
A life-long love of insect ecology and conservation emerged from my childhood spent traipsing through the diverse ecosystems of rural Florida. Five years spent researching ants at the USDA- ARS CMAVE further cemented my passion for entomology. As a Masters student at the University of Hawaiʻi Mānoa, supported by my husband and our two young sons, I have had the opportunity to study the population biology of Hawaiʻiʻs first federally listed endangered insect, Blackburnʻs sphinx moth, Manduca blackburni.More Info
I'm most interested in how evolution works on the population level, and how that percolates to deeper evolutionary patterns. Through biodiversity and population dynamics studies, I hope to aid the conservation of rare species, the control of economically and ecologically impactful pests, the study of evolution, and even raise public awareness of these issues.More Info
After completing my undergraduate education at Cornell University, where I received a degree in Ecology and Evolutionary Biology as well as a minor in Entomology, I came to the University of Hawaii. Having been interested in insects from a young age, my goal was to explore broader interests in ecology and conservation using insect systems. I began my research career at Hawaii studying the invasive origins and genetic diversity of the Coconut Rhinoceros Beetle (Oryctes rhinoceros), and am currently working on a dissertation project employing modern metabarcoding techniques to investigate diets and food webs of the arthropod community above the inversion layer on the Maunakea volcano.More Info
Molecular systematics and adaptive radiation of the Hawaiian endemic moth genus Hyposmocoma (Lepidoptera: Cosmopterigidae)
Threat assessment of the invasive leafhopper species introduced to Hawaii.
Phylogenetics of the Genus Omiodes (Lepidoptera: Crambidae)
Daniel Rubinoff in collaboration with Akito Y. Kawahara, Patrick Schmitz, and Will HainesInteractive key to Hawaiian Fancy-cased caterpillars and moths (Hyposmocoma)
Cone-cased aquatic larvae in Iao Valley stream of Maui
Picture of a newly discovered species of Hyposmocoma
Remote volcanic island archipelagos make incomparable natural laboratories for the study of patterns of diversification and species formation. In the Hawaiian Archipelago, an isolated island chain in the middle of the Pacific Ocean, the extreme isolation, topographical diversity, and chronological linear arrangement of islands provide an unparalleled natural experiment for observing processes of adaptive radiation, and the evolution of ecological and phenotypic diversity within a rapidly multiplying lineage. The endemic cosmopterigid moth genus Hyposmocoma is one of the greatest radiations in the Hawaiian Islands, and may rival or exceed Drosophila in endemic Hawaiian species diversity. The species of Hyposmocoma occupy an extraordinary diversity of native habitats and include at least a few aquatic species on each of the main islands. Another remarkable trait of Hyposmocoma is the spectacular diversity of cases carried through larval development as shelters. Hyposmocoma’s utility and importance is not simply due to the high number of species in the genus, but also it is the remarkable ecological diversity of the group, which even includes predatory species, and the evolutionary resource this exceptional model provides for understanding the mechanisms and patterns of diversification and species formation on islands, as well as across vastly different environments.
We propose to conduct a broad survey of the diversity of the microlepidoptera belonging to the speciose genus Hyposmocoma throughout the Hawaiian Archipelago. Newly acquired data will be integrated into an existing database. Specifically, we will employ a total evidence approach including molecular, morphological, and ecological characters to reconstruct phylogenetic relationships among species in the aquatic/terrestrial and related clades. This research project will provide insights into the evolution of ecological novelty and address fundamental questions about the relationship between ecological diversification and patterns of speciation because the factors that foster or limit ecological diversification may bear directly on rates of speciation. Island systems offer successful colonists unique opportunities to diversify into niches that might not be available in geologically older, less isolated and as a result, ecologically more complex continental ecosystems. Such opportunities reveal novel propensities to invade, colonize, and speciate into dissimilar niches as indicated by the shifts between aquatic and terrestrial species in Hyposmocoma. But specific understanding of the evolutionary processes leading to such dramatic life history shifts is often lacking. Hyposmocoma offers a unique opportunity to study a monophyletic, species rich, ecologically diverse, and conservation relevant island radiation.
Emergence of a cone-cased moth from Iao Valley of Maui
Burrito-cased larvae resting in the Garden of the Gods of Lanai
Kala'i, one of our high school volunteers, working on the Hyposmocoma project
New species of Hawaiian Hyposmocoma moths. Adult specimens are shown, all 18 species were reared under laboratory conditions at the Insect Systematics Lab of the University of Hawaii.
Diversity of case types found in the spectacular endemic Hawaiian Hyposmocoma moth radiation.
Jaco Le Roux and Daniel Rubinoff
Dr. Jaco Le Roux hopes to establish the number and identity of the leafhopper species introduced to Hawaii so he can assess the threat that it poses to our local flora and fauna. This research effort includes molecular systematics and phylogeography of invasive leafhoppers and those from putative source regions. These data could potentially also assist in identifying native range regions where productive biological control agents are likely to be found, should this prove a viable control option.
Macrosteles”, or 'aster leafhoppers' represent a newly introduced insect pest that has invaded O'ahu watercress crops. They transmit an aster yellow pythoplasma that has cost the watercress industry hundreds of thousands of dollars in damage due to crop losses. Of even greater concern is the possibility that the leafhoppers in Hawai'i will spread and negatively impact other agricultural crops. Understanding the invasion history, e.g. the country of origin, the route of introduction, etc., is the first step in initiating efforts to control or eradicate any invasive species. The taxonomy of the genus Macrosteles is problematic due to morphological conservatism across different species, making identification cumbersome at best.
Will Haines, Cynthia King and Daniel RubinoffTwo graduate students worked with this Hawaiian radiation of moths. Will Haines has been studying the systematics of the genus Omiodes. Cynthia King has quantified the non-target effects of introduced parasitoids on endemic moths in this genus.
My main focus is the evolutionary history of a radiation of moths in the genus Omiodes. The genus Omiodes contains about 80 species worldwide, in both the neotropics and paleotropics. Hawai‘i is home to 23 endemic species, all of which likely descended from a single ancestor that colonized the islands some millions of years ago.
The Hawaiian species show a range of host specificities, ranging from generalists whose larvae feed on many types of native and non-native grasses, to specialists which feed only on a single species of native plant such as Dianella sandwicensis (ukiuki) . There is also some variation in degree of geographic endemism; many species are widespread and found on all the main Hawaiian Islands, while others are restricted to a single island.
One of the oddest things about the evolutionary history of these moths, and what inspired me to work on them, is that five species of endemic Hawaiian Omiodes have apparently evolved to specialize on the leaves of Polynesian cultivars of banana, a plant that was introduced into Hawai‘i within the past 1,500 years. It has been presumed that the divergence of these species from a palm-feeding ancestor was triggered by the introduction of banana, implying a very rapid rate of speciation, and presenting a rare opportunity to examine speciation or host-race formation.
Unfortunately, partly due to the impacts of non-native predators and parasitoids, many species of Omiodes, including four of the banana-feeding species, have been listed as extinct, and Hawaiian cultivars of banana are themselves threatened. However, we have successfully rediscovered several species of Omiodes formerly thought to be extinct, and I am hopeful that extant populations of banana-feeding species exist.
At present my research focuses on assessing the non-target impacts of introduced parasitoids on endemic leaf-roller moths (Crambidae: Omiodes). The genus Omiodes contains 23 endemic Hawaiian moth species, and individuals in the group have adapted to a wide range of host plants (including grasses, sedges, lilies, palms and legumes). Many of the species have made recent host plant shifts, feeding on plants such as banana and coconut which were introduced by Polynesians approximately 1500 years ago, as well as sugarcane, which arrived in the islands closer to 150 years ago. Two species in this group O. accepta (sugarcane leafroller) and O. blackburnii (coconut leafroller) actually became pests of economic significance on sugarcane and coconut, defying the stereotype that native insects do not become pests. A variety of biocontrol agents were subsequently released for their suppression. At present two-thirds of the other species in the genus are listed as extinct, and the precipitous declines have been attributed to the non-target effects of introduced parasitoids. In the last two years however, five of the extinct species have been “rediscovered,” and with additional surveys it is very possible that more may be detected.
My research attempts to quantify the non-target parasitism rates in several Omiodes species. To accomplish this, Omiodes eggs and larvae are exposed to parasitism under varying conditions, then retrieved and reared until eclosion. Field trials were completed on Maui during summer 2006 at upcountry field sites (Makawao FR, Haleakala Ranch, UH Kula Agricultural Station) and lower elevation sugarcane field sites. Additional trials are underway on Oahu at HARC Maunawili, as well as at the UH Manoa Lyon Arboretum. In this manner I hope to understand the impact which parasitism by non-native parasitoids and the effects of predation has on these populations. Whether indicative of low or high impacts by introduced parasitoids, results will provide valuable information for future biological control efforts in Hawai'i. This research is made possible by a Tropical and Subtropical Agricultural Research Grant (TSTAR) from the Cooperative States Research Education and Extension Service (CSREES), US Department of Agriculture.
Study of Attraction of Nontarget Organisms to Fruit Fly Female Attractants and Male Lures in Hawaii.
Study of Wekiu bug population genetics and phylogenetics of the Hawaiian Nysius
Identification and study of Dacini fruit flies through DNA sequencing methods
Luc Leblanc, Daniel Rubinoff, and Mike San-Jose(Cooperative Agreement No. 58-5320-4-501 between USDA-ARS and the University of Hawaii at Manoa CTAHR-PEPS)
The main purpose of this project was to assess environmental risks of using fruit fly (Tephritidae) attractants for their control or eradication in the Hawaiian environment. More specific focus was on the use of male lures (cue-lure, methyl eugenol) and female synthetic food attractants (BioLure, torula yeast and solulys).
Traps baited with female attractants and male lures were setup in native, mixed native and non-native forests, farmlands, orchards and residential areas. Traps were maintained for 10-24 weeks and emptied weekly at 35 sites on Hawaii Island (2005) (Figure 1) and 46 sites on Maui (2006) (Figure 2). Trap catches were compared against catches from unbaited control traps. On Hawaii island, 9 sites formed a 20 km transect along the Stainback Highway (138-1,045 m above sea level), 15 sites were maintained in a 35 km transect along the Saddle Road (439-2,012 m), 6 sites were along the upper Hamakua Ditch Trail in wet native forest (North Kohala Forest Reserve) (906-1,019 m), and 5 sites were in the agricultural community of Waimea (744-872 m). On Maui, we maintained 14 sets of traps in 9 sites in the Kula agricultural community (517-1,138 m), primarily in persimmon and coffee orchards and their adjacent non-native forests, and 37 sites in mostly endemic forest on the northern slope of Haleakala Mountain (1,184-1,583 m) in the Makawao, Waikamoi and Koolau Forest reserves.
Fig 1: Trapping sites on Hawaii island
Fig 2: Trapping sites on Maui island
Male lures, combined with insecticides, are commonly used in traps to monitor male Bactrocera fruit fly populations and detect incursion of exotic species. They also constitute a powerful tool for fruit fly suppression and eradication through male annihilation. The large-scale use of male lures for control and eradication has raised concern of possible nontarget impacts on insects other than fruit flies, especially beneficial species and the numerous endemic Hawaiian insects.
Past attempts in Hawaii to characterize the range of nontargets attracted to male lures, by comparing captures in lure-baited traps with unbaited control traps, have resulted in an impressive list of 36 insect species, in 16 families of Diptera, Coleoptera, Hemiptera and Hymenoptera, assumed to be attracted to methyl eugenol. Among them were 11 species of endemic Hawaiian Drosophilidae (Figures 3 to 7), a very diverse group with 559 described species, of which 12 are recognized as endangered by the US Fish and Wildlife. However, at least 26 of these purportedly lure-attracted species are scavengers, and authors cautioned that some of them may have been actually secondarily attracted to decaying fruit flies that could not be excluded from entering male lure traps.
|Fig 3||Fig 4||Fig 5||Fig 6||Fig 7|
|Figures 3 to 7: Various representatives of endemic Hawaiian Drosophilidae|
Our study aimed to further investigate male lure nontarget effects by carefully discriminating between actual attraction to male lures and secondary attraction to decaying insects. Trapping was carried out across a broad range of environments, including intact native forest, mixed native/invasive forest, invasive forest, agricultural and residential areas.
Bucket traps made from drinking cups and baited with cue-lure or methyl eugenol (ME) (Scentry lure plugs) were maintained and emptied weekly at every trapping sites on Hawaii and Maui islands. To control for the possible attraction to dead insects, bucket traps artificially baited with decaying oriental fruit flies were maintained at all sites, except in the Maui endemic forest. Unbaited bucket traps were also maintained at all sites to control for the random entry of insects into traps. Vapor tape and a 20% solution of propylene glycol were included in all traps to kill and preserve trapped insects, respectively. In addition to the bucket traps, MultiLure traps charged with the 3-component BioLure food attractant and, in Maui forest, bucket traps baited with fermented mushroom, were maintained to ensure that the apparent lack of attraction to male lures is not due to the absence of potential nontarget species at trapping sites.
Traps with male lures and decaying flies captured 401 recognized arthropod species, in 17 orders and 93 families, dominated by Diptera (94.9% of all captures, 248 species), primarily in the families Drosophilidae, Phoridae and Milichiidae.
Cue-lure did not significantly attract any nontarget insects, and melon flies were usually not numerous enough in traps to cause secondary attract scavengers. These results are fully consistent with conclusions from previous studies.
Seven nontarget species in five insect orders were significantly attracted to ME-baited traps, regardless of the presence or absence of decaying fruit flies. Five of these are closely associated with flowers, feeding on pollen or nectar. Honeybees (Apis mellifera L.) (Apidae) and the flower fly Allograpta obliqua (Say) (Syrphidae) were attracted in rather small numbers (0.04-0.09 per trap per day). Honeybee attraction to ME in Hawaii was previously documented in literature, and orchid bees (Apidae: Euglossinae) are similarly drawn to ME in South America. Two endemic species of Crambid moths [Mestolobes minuscula (Butler) (Figure 8) and Orthomecyna exigua (Butler) (Figure 9)] were also attracted to ME in Kula (Maui) orchards. Although endemic, these two species are common on Maui in non-native habitats at lower altitude. The introduced sap beetle Carpophilus marginellus Motsch. (Nitidulidae), a common flower visitor that contributes to fruit tree pollination in Japan, is attracted to decaying fruit flies, but also to ME in traps. The attraction of flower insects is no surprise, since ME or some of its related compounds have been detected in the flower blossoms of a diversity of plant families.
Although our traps captured limited numbers of green lacewings (Chrysopidae), they were previously reported as attracted to ME in Hawaii, the Philippines, and Taiwan. Adult chrysopids, depending on species, feed either on live insects, or on flower pollen and nectar and honeydew from Hemiptera. At least of two of the three species attracted to ME are flower feeders, strongly suggesting an attraction to ME as emulation of floral compounds, further supported by the lacewing attraction to the natural flower fragrance compound eugenol in Malaysian rainforest.
The endemic plant bug Orthotylus coprosmae Polhemus (Hemiptera: Miridae) (Figure 10) is attracted to ME in Maui endemic forests, consistent with previous ME attraction records of three other endemic mirids on Kauai. At least one of these feeds on a host plant known to contain ME. A similar plant kairomone relationship may also explain published records of endemic anobiid beetles attraction to ME traps on Kauai.
Methyl eugenol attracts females of the endemic fungus gnat Bradysia setigera (Hardy) (Sciaridae) (Figure 11). Conspecific males and other common sciarids are not attracted. In this case it likely acts as a pheromone analogue rather than a kairomone.
|Fig 8||Fig 9||Fig 10||Fig 11|
|Figures 8 to 11: Endemic Hawaiian nontarget insects attracted to methyl eugenol|
At least 56 species in 21 families of Diptera, Hymenoptera and Coleoptera were significantly drawn to decaying fruit flies rather than male lure. They were abundant in traps with decaying flies, and were collected in ME traps only when enough dead trapped flies had accumulated. We demonstrated that 8 of the 36 species previously reported as attracted to ME are actually drawn to dead flies, and that most other species belonged to families attracted to decaying flies, rather than ME, most commonly the Drosophilidae, Phoridae, Chloropidae, Lonchaeidae, Milichiidae, Neriidae, Otitidae, Psychodidae, Sphaeroceridae, Calliphoridae, Muscidae, and Sarcophagidae. Most species in these families are indeed scavengers. Aside from the ME-attracted C. marginellus, other endemic and introduced Nitidulidae were attracted only to decaying flies.
Drosophilidae were the most numerous and diverse nontargets attracted to decaying flies at all sites. Our results confirm or strongly support that most or all of the 11 endemic and 5 introduced drosophilids reported in literature as ME-attracted were actually attracted to dead flies. Nearly half (143 of 306) of the drosophilids expected to occur at the trapping sites were collected using BioLure and mushroom bait traps, but not in male lure traps. Invaluable data was generated on drosophilid distribution in endemic and disturbed ecosystems in Hawaii. It is an unforeseen extra benefit from this research project that is the focus of a publication soon to be submitted to an invertebrate conservation-oriented journal. Fragrant leaves of Cheirodendron trigynum (Gaud.) Heller (Araliaceae), the most common larval host species for endemic drosophilids, were demonstrated through Solid Phase Microextraction (SPME) analysis not to contain ME.
A few species of predators and parasitoids were attracted to decaying flies. Almost all are associated with decaying matter (Staphylinidae) or parasitoids of houseflies (Encyrtidae, Braconidae, Pteromalidae).
Precautionary suggestions are provided to minimize the undesirable nontarget impact of the use of ME for control or eradication on flower-associated insects, endemic plant bugs and fungus gnats and scavenger insects. Flower insects were attracted in small numbers (0.03-0.15 per trap per day) in our study, consistent with previously published data, suggesting that attraction is likely to be short-ranged, and can be further minimized if a ME trap or dispenser is hung to a tree past its flowering stage. This was confirmed by the much lower honeybee and moth captures in non-flowering persimmon trees that in adjacent flowering coffee trees in Kula. A comparison of captures of endemic saprophagous insects in decaying fly and BioLure traps in orchards and backyards, native forest and ecotone forest adjacent (< 100 m) to native forest shows that very small numbers of a few endemic species are captured in non-native sites.
|Fig 12: Endemic Hawaiian viviparous blowflies (Dyscritomyia)|
This is not the case in endemic forest and its adjacent ecotones, where a broad diversity of endemic drosophilids and calliphorids (the larviparous Dyscritomyia) (Figure 12) are trapped. Based on studies of range of dispersal of 14 common North American Drosophilid species by Donald McInnis (USDA-ARS), who estimated their maximal dispersal distance to be 300 meters at most, we concluded that using traps at least 300 meters from native forest will minimize possible nontarget effects, if dead target flies accumulate inside traps.
The dry food lure BioLure in the MultiLure trap (Figure 13) was developed as an alternative to the traditionally used liquid protein lures in glass McPhail traps (Figure 14) by identifying and using the individual volatiles from the bacterial breakdown of protein hydrolysate that were most attractive to fruit flies. The 3-component BioLure, used in our study, is composed of ammonium acetate, trimethylamine hydrochloride and putrescine. Although originally developed as a monitoring tool, BioLure has become a common tool to control the Mediterranean fruit fly [Ceratitis capitata (Wiedemann)], through mass-trapping, in fruit tree orchards in Spain and Israel. In Hawaii it is used, in combination with protein bait sprays, to suppress C. capitata in Maui orchards.
|Fig 13||Fig 14|
Nontarget attraction to BioLure, mainly saprophagous Diptera, has been reported in literature, but not studied systematically in a diversity of habitats. We have therefore investigated nontarget attraction to BioLure across a range of endemic and agricultural habitats in Hawaii, compared nontarget attraction of the individual BioLure components, and determined whether the omission of the putrescine ingredient results in decreased nontarget catches without reducing captures of target C. capitata.
MultiLure traps baited with 3-component BioLure, as well as unbaited controls, were maintained continuously, or intermittently in endemic forest, at every trapping site on Hawaii and Maui islands. A solution of 20% propylene glycol was added to each trap to preserve and facilitate identification of captured insects. Trap contents was emptied weekly. These traps served the dual purpose of characterizing nontarget attraction to BioLure and confirming the presence of nontargets that may potentially be attracted to the male lure traps also present at each site. Additionally, three sites were selected, one in endemic forest and two in orchards, to study fruit fly and nontarget attraction to the separated individual components of BioLure. A third trap, with only two components, was also maintained at each site in Kula (Maui), to determine if the omission of the putrescine ingredient results in a decrease in nontarget captures without compromising captures of C. capitata.
Captures in BioLure traps were numerically dominated by Diptera (94.3%). The endemic forest site samples were dominated by endemic and introduced Drosophilidae and endemic Calliphoridae, while most of the captured nontargets in the nonnative sites were of introduced species. The majority of nontarget species belonged to families whose larvae are scavengers on decaying plant or animal matter (Drosophilidae, Chloropidae, Lonchaeidae, Neriidae, Otitidae, Phoridae, Anthomyiidae, Calliphoridae, Muscidae, Sarcophagidae and Nitidulidae). These same families and species of were also strongly attracted to the bucket traps baited with decaying fruit flies.
BioLure attracted few beneficial predators or parasitoids, except for a few parasitoids of house flies and moderate numbers of tachinids flies. Pollinators were not attracted to BioLure. Although it attracted very few green lacewings (Chrysopidae), there is literature evidence that protein hydrolysate and BioLure can attract the pollen and nectar-feeding species.
A comparison of attraction to the components in separate traps and the three components together inside a trap in a randomized block design has shown that ammonium acetate or, to a lesser extent, putrescine, are the main components attractive to nontargets, depending on the species. It was also demonstrated, as is the case for target fruit flies, that the three components act in synergy, attracting larger numbers of nontargets together in a trap than in three traps baited with the separate components.
The elimination of the putrescine ingredient from BioLure traps resulted in significant capture reduction for five nontarget species and an overall 20% reduction in the number of nontargets attracted, with no reduction in target C. capitata captures. I can therefore be omitted from BioLure when used for Mediterranean fruit fly monitoring or control in Hawaii.
Leblanc, L., Rubinoff, D., and R.I. Vargas. 2009. Attraction of nontarget species to fruit fly (Diptera: Tephritidae) male lures and decaying fruit flies in Hawaii. Environ. Entomol. 38: 1446-1461.
Leblanc, L., O’Grady, P.M., Rubinoff, D., and S.L. Montgomery. 2009. New immigrant Drosophilidae in Hawaii, and a checklist of the established immigrant species. Proceedings of the Hawaiian Entomological Society. 41: 121-127.
Leblanc, L., Vargas, R.I., and D. Rubinoff. 2010. Attraction of Ceratitis capitata (Diptera: Tephritidae) and endemic and introduced nontarget insects to BioLure bait and its individual components in Hawaii. Environ. Entomol. IN PRESS.
Leblanc, L., Vargas, R.I., and D. Rubinoff. 2010. A comparison of nontarget attraction to BioLure and liquid protein food lures in Hawaii. IN PREPARATION.
Vargas, R.I., Shelly, T.E., Leblanc, L. and J.C. Piñero. 2010. Recent advances in methyl eugenol and cue-lure technologies for fruit fly detection, monitoring, and control. Vitamins and Hormones. Section: Pheromones, vol. 83. Academic Press. SUBMITTED.
are four species of pest fruit flies (Tephritidae)
in Hawai'i. All are invasive, and most of them are from tropical
For more information on fruit fly diversity and management, consult the Pacific Fruit Fly Website and the Hawaii Area-Wide Fruit Fly Pest management Program site.
Melon Fly (Bactrocera cucurbitae) was the first pest fruit fly detected in Hawai'i in 1895. Its larvae breed on cultivated and wild Cucurbitaceae, as well as papaya.
Mediterranean Fruit Fly (Ceratitis capitata) has been the dominant polyphagous fruit pest since from its discovery in 1907, until the introduction of Oriental fruit fly.
Oriental Fruit Fly (Bactrocera dorsalis) was detected in Hawai'i in 1945, and has become the main fruit pest of edible and wild fruits in Hawai'i. Following its introduction, it has displaced the Mediterranean fly to become the dominant species, limiting the Mediterranean fly to attack coffee and fruit at higher elevations.
Malaysian fruit fly (Bactrocera latifrons) is the most recent migrant, known in Hawai'i since 1983. Its host range is restricted to cultivated and wild solanaceous plants. It is not a serious crop pest.
Photos are courtesy of Jari Sugano (University of Hawai'i at Manoa)
Jesse A. Eiben and Daniel Rubinoff
Male Wekiu Bug
Female Wekiu Bug
Jesse Eiben and Jaco Le Roux atop Mauna Kea.
View of the summit of Mauna Kea from the northeast
Male Wekiu Bug in the Wild
Wekiu Bug size progression from nymph to adult
Nysius species diversity
Jesse Eiben is studying the life history and population genetics of the wekiu bug (Nysius wekiuicola). This unique Hawaiian flightless bug lives only on the inactive volcanic mountain of Mauna Kea. Very little about the life of this rare bug has been described since its formal discovery in the early 1980s.
The alpine habitat on Mauna Kea represents one of the most extreme environments in the Hawaiian Islands. Daily temperature fluctuations between 108ºF and 25ºF, winter snow pack, and virtually no plant life suggests lifelessness. However, there is a specialized endemic fauna.
One of the best known Hawaiian endemic insects to have evolved on the volcano summit is the wekiu bug. The wekiu bug is an insect predator-scavenger that tolerates very cold temperatures and preys exclusively on low-elevation insects deposited near the summit and immobilized by wind and cold. This micropterous seed bug is restricted to the cinder cones of Mauna Kea above 11,700 ft, and exhibits the most extreme specializations of morphological and behavioral characters in the genus Nysius.
The wekiu bug, and other Mauna Kea endemic species, may be threatened by habitat loss due to astronomy development or global warming factors stressing this fragile ecosystem. The wekiu bug is a candidate for listing under the endangered species act. Through cinder composition studies, transects, and live-trap sampling, the range of suitable habitat for the wekiu bug has recently been expanded, including two new cinder cone populations found in April 2006 (Porter and Englund, 2006).
We are for the first time maintaining wekiu bugs in captivity in temperature and environmental controlled conditions. This research addresses the unknown life history of the wekiu bug and will be used to create robust and scientifically valid life table to be used for the conservation and management decisions concerning the wekiu bug. We are investigating the genetic structure of the wekiu bug populations to determine population isolation as it relates to these conservation efforts.
We are investigating the molecular phylogeny of the endemic Hawaiian radiation of Nysius seed bugs, including the unique and anomalous wekiu bug, Nysius wekiuicola (Ashlock and Gagné). The Hawaiian Nysius contain a quarter of the world's species in the genus, with the wekiu bug (and its sister species the Mauna Loa bug, N. aa) showing the most extreme deviation from the standard Nysius character set. The Hawaiian Nysius seed bugs are widely distributed in drier environments on all of the Hawaiian Islands, from Midway to the Island of Hawaii.
While all other Nysius are seed-feeders typical of the family Lygaeidae, N. wekiuicola and N. aa are both flightless, micropterous, cold tolerant, scavenger-predators of moribund insects on the 13,790 ft volcanoes of Mauna Kea and Mauna Loa on the island of Hawaii. The wekiu bug is a candidate for listing under the Endangered Species Act, due to its decreasing numbers, limited range, specialized habitat requirements, isolated populations, and habitat destruction. Low levels of mtDNA variation suggest that the wekiu bug and Mauna Loa bug are very recently diverged. In addition, they are closely related to other Hawaiian Nysius indicating a rapid adaptive shift from the standard morphology and feeding of the rest of the Hawaiian seed bugs.
Wekiu Bug Life History: We have established lab protocols to successfully keep wekiu bugs in captivity. The wekiu bug colony is being used to describe the bug’s life cycle, nymphal description and development, fecundity and natality, and to create a temperature dependent growth curve of the insect. This baseline data is being used to advise the conservation community concerned with the potential factors having led to the apparent decline in wekiu bug numbers on Mauna Kea.
Wekiu Bug Population Genetics: With a robust sampling of wekiu bugs from all cinder cone populations on Mauna Kea, we have a rough picture of the genetic variation seen between potential disparate populations of the bugs. So far, using mitochondrial DNA and nuclear DNA, there are a very limited number of DNA haplotypes of wekiu bugs on Mauna Kea.
Phylogenetics of the Hawaiian Nysius: Since many Nysius are considered agricultural pests and Hawaii’s status of the invasive species capital of the world, it is important to have up-to-date taxonomic information available for the entomological community in research and agriculture. Collections of Hawaiian Nysius from all major islands and many of the Northwest Hawaiian Islands have provided a robust sample of the extant Hawaiian Nysius. Phylogenetic analyses indicate the endemic Hawaiian Nysius seed bugs are not a monophyletic group. The NWHI Nysius are quite distinct from the Main Hawaiian Islands, and these two lineages in Hawaii indicate a very rare occurrence of separate introductions and species radiations within the same genus. We are using our recent collections of endemic and introduced Nysius to re-write the Dichotomous key and create an interactive Lucid key of Nysius found in Hawaii which has been updated only occasionally since it’s major revision in 1942 by Dr. Usinger.
Eiben, J. E. and D. Rubinoff. 2014. Application of agriculture-developed demographic analysis for the conservation of the Hawaiian alpine wekiu bug. Conservation Biology. 28:1077-88 doi: 10.1111/cobi.12315.
Pu'u Makanaka and glacial erosion from 16,000 years ago
Larvae of the globally represented fruit fly family Tephritidae feed on fruit or flowers and around 250 of the ca. 5,000 species have developed into pests, of which some have greatly expanded their distribution ranges in human history.
As many fruit flies are similar in appearance, being able to distinguish established species from exotic species, and pests from non-pests is an important part of a robust biosecurity system. In the case of a suspected incursion, rapid diagnosis is particularly important and would assist in containing and eradicating the populations before they establish. Invasive species disrupt ecological systems, cause homogenization of biota, significantly damage crops and even drive native species to extinction
There is a range of applied, ecological and evolutionary questions surrounding these flies that we focus on to come to a deeper understanding of the group as well as the evolutionary processes involved. How did so many species come to look so similar? Which characters can be used to identify them? Why are they attracted to plant-produced synomones? When did they switch between different host plants? Why are some species highly host specific, while others attack almost any fruit?
Dacini fruit flies can be found in tropical and subtropical regions of the Old World. The genera Zeugodacus and Bactrocera have their highest diversity in South-East Asia, where most of our field work is focussed. Recent trips have been to Thailand, Vietnam, Taiwan, Bangladesh, Malaysia and more.
The University of Hawaii Insect Museum holds historical collections from one of the most productive fly taxonomists: the late Dr. Elmo Hardy. His specimens along with the collections from more recent field work by our group have resulted in one of the most complete Dacini collections in the world, with over 100,000 flies stored either frozen in ethanol or dried and pinned, which are managed in a digital database. These collections form the primary basis for all our research.
We use DNA data in conjunction with morphology in order to provide a practical way to identify the species and study their population structure and evolution. Using Sanger sequenced markers, GBS, ddRAD, Pac-Bio and other new sequencing methods, we reconstruct phylogenies and use these to answer evolutionary questions. We also use COI barcoding and SNP essays to develop reliable methods for molecular species identification.
Researchers involved in this project:
Camiel Doorenweerd - Junior Researcher
Michael San Jose - PhD candidate
Julian Dupuis - Junior Researcher
Daniel Rubinoff - PI
Dan's YouTube fieldwork videosView
Fieldwork in Sabah, BorneoView
Fieldwork with Forest and Kim StarrView
Conrad's Gillett's fieldwork photo collectionView
Fieldwork in VietnamView
Akito Kawahara on a field trip with researchers and assistants from Limahuli Gardens Natural Preserve, one of the most pristine valleys on Kauai.View
Will Haines photographs Hyposmocoma near the ocean.View
Will Haines explores Molokai for Omiodes species.View
PhD students Will Haines and Jesse Eiben went insect hunting on Maui.View
PI Dan Rubinoff, graduate student Will Haines and undergraduates Clinton Pong and Jane Winhall-Rice survey the insects found on Kamakou Preserve, Molokai.View
A trip by Jaco and Dan to Haleakala.View
PI Dan Rubinoff takes a trip to the island of Hawaii.View
A collection of pictures of Hawaii by Dan during the course of his insect surveys.View
A collection of pictures of Maui by Dan during the course of his insect surveys.View
Hyposmocoma Field Trip, September 2003View
Two color forms of Manduca BlackburniView
When going on field work, Dan enjoys finding interesting snacks and chips. He holds chip tastings to rank the best and worst of the flavors. Check out the rankings below!
|Spain and Canada|
|Chili & Lemon||2||3||1|
|Cheesy Corn Nuts||/||/||/|
|Mac. Nut Brittle||4||2||4|
|Thailand and Sri Lanka|
|Brown Rice Cheese Bacon||1||1||0|
|Brown Rice BBQ||2||1||1|
|Turkey and Taiwan|
|Taiwan Mystery Candy||5||1||2|
|Rings Pizza (Bobi)||2||2||0|
|Olive & Feta||4||3||3|
|Malaysia and Canada|
|Sour Cream & Carm. Onion||2||2||0|
|Roast Chicken Dance||0||0||2|
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Check out the Insect Museum for more extensive native insect collections, identification, and research!