The Structure and Phenology of Non-Native Scolytine Beetle Communities in Coffee Plantations on Kaua'i.

Populations and communities are known to respond to abiotic conditions, but the forces determining the distribution of particular insect pests are sometimes overlooked in the process of developing control methods. Bark and ambrosia beetles (Curculionidae: Scolytinae) are important pests of crops, forestry, and ecosystems worldwide, yet the factors that influence their success are unknown for many species. The Hawaiian archipelago is host to over three dozen invasive scolytines, many of which occur on Kaua'i and are pests of agriculture. We analyzed scolytine community dynamics at two coffee estates: a hand-harvested site in a tropical wet forest and a mechanically harvested site in a tropical dry savanna. Our regression analyses show overall scolytine abundance was negatively correlated with rainfall, as were four species: the tropical nut borer (Hypothenemus obscurus), H. brunneus, Cryphalus longipilus, and Xyleborinus andrewesi. These relationships contributed to the compositions of the communities being markedly dissimilar despite having the same species richness. Multivariate analysis found no influence from temperature or harvest method on community dynamics. This information can be valuable for the timing of pest control methods, for predicting the success of possible new scolytine arrivals on Kaua'i, and for forecasting how these species may spread with climate change.

The Native Hawaiian Insect Microbiome Initiative: A Critical Perspective for Hawaiian Insect Evolution.

Insects associate with a diversity of microbes that can shape host ecology and diversity by providing essential biological and adaptive services. For most insect groups, the evolutionary implications of host-microbe interactions remain poorly understood. Geographically discrete areas with high biodiversity offer powerful, simplified model systems to better understand insect-microbe interactions. Hawaii boasts a diverse endemic insect fauna (~6000 species) characterized by spectacular adaptive radiations. Despite this, little is known about the role of bacteria in shaping this diversity. To address this knowledge gap, we inaugurate the Native Hawaiian Insect Microbiome Initiative (NHIMI). The NHIMI is an effort intended to develop a framework for informing evolutionary and biological studies in Hawaii. To initiate this effort, we have sequenced the bacterial microbiomes of thirteen species representing iconic, endemic Hawaiian insect groups. Our results show that native Hawaiian insects associate with a diversity of bacteria that exhibit a wide phylogenetic breadth. Several groups show predictable associations with obligate microbes that permit diet specialization. Others exhibit unique ecological transitions that are correlated with shifts in their microbiomes (e.g., transition to carrion feeding from plant-feeding in Nysius wekiuicola). Finally, some groups, such as the Hawaiian Drosophila, have relatively diverse microbiomes with a conserved core of bacterial taxa across multiple species and islands.

Metschnikowia orientalis sp. nov., an Australasian yeast from nitidulid beetles.

A novel species, Metschnikowia orientalis sp. nov., is described for haploid, heterothallic yeasts isolated from nitidulid beetles sampled in flowers in Rarotonga in the Cook Islands, and the Cameron Highlands of Malaysia. As evidenced by analysis of D1/D2 large subunit rDNA sequences, the species is related to Candida hawaiiana, to which it is similar in growth responses. Cylindrical, conjugated asci and acicular ascospores of moderate size are formed. Rudimentary mating reactions were observed with Metschnikowia aberdeeniae and Metschnikowia continentalis, but not with C. hawaiiana. The type strain of M. orientalis is UWOPS 99-745.6(T) (h(+)) (=CBS 10331(T)=NRRL Y-27991(T)) and the designated allotype is UWOPS 05-269.1 (h(-)) (=CBS 10330=NRRL Y-27992).

Metschnikowia hamakuensis sp. nov., Metschnikowia kamakouana sp. nov. and Metschnikowia mauinuiana sp. nov., three endemic yeasts from Hawaiian nitidulid beetles.

Three heterothallic, haplontic yeast species, Metschnikowia hamakuensis, Metschnikowia kamakouana and Metschnikowia mauinuiana, are described from isolates associated with endemic nitidulid beetles living on various endemic plants on three Hawaiian islands. As morphospecies, they are similar to Metschnikowia hawaiiensis, but based on mating compatibility and ascospore formation, they can be assigned clearly to distinct biological species. Analysis of ITS/5.8S and D1/D2 large subunit rDNA sequences shows that, with M. hawaiiensis and two other isolates, these species form a distinct subclade within the large-spored Metschnikowia species, indicating that they are Hawaiian endemics. Type cultures are: M. hamakuensis, UWOPS 04-207.1(T) = CBS 10056(T) = NRRL Y-27834(T) (type, h(+)) and UWOPS 04-204.1 = CBS 10055 = NRRL Y-27833 (allotype, h(-)); M. kamakouana, UWOPS 04-112.5(T) = CBS 10058(T) = NRRL Y-27836(T) (type, h(+)) and UWOPS 04-109.1 = CBS 10057 = NRRL Y-27835 (allotype, h(-)); and M. mauinuiana, UWOPS 04-190.1(T) = CBS 10060(T) = NRRL Y-27838(T) (type, h(+)) and UWOPS 04-110.4 = CBS 10059 = NRRL Y-27837 (allotype, h(-)).