Survey for ants on the island of Maui, Hawaii, with emphasis on the little fire ant (Wasmannia auropunctata)

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.The little fire ant (LFA), Wasmannia auropunctata, is an aggressive pest ant with a painful sting that has spread to many parts of the world through human commerce. In the State of Hawaii, LFA had been intercepted previously as early as 1930, but only recently, in 1999, were established populations found in the Puna District, on the island of Hawaii (Big Island), occupying residential and agricultural sites, such as fruit orchards and plant nurseries. A single population was found on Kauai in 1999, but it has been contained and nearly eradicated. However, on Hawaii island, LFA is now well established in the Puna/Hilo area, with at least 50 sites covering at least several hundred acres. Even though nursery shipments leaving Hilo are checked for LFA by inspectors of the Hawaii Department of Agriculture, it is likely that LFA-infested shipments have reached Maui. This study surveyed portions of the island of Maui for ants, with a main goal of finding populations of LFA. Since much of the nursery material sent from Hawaii to Maui is promptly planted in new developments, searches were focused on newly developed/landscaped areas. During the survey, over 18,000 ants were collected on 4,300 peanut butter baited chopsticks at 360 sites, resulting in 823 locations with 23 ant species but no LFA. The big-headed ant (Pheidole megacephala) was by far the most abundant ant encountered in the survey and present at 55% of the sampling sites. However, since not all ant species are equally attracted to the peanut butter bait used in this survey, the relative abundance of ant species encountered may be biased, and 12 species of ants previously recorded for Maui were not collected in the survey.Primary funding for the study was from the U.S. Fish and Wildlife Service. Funding was also received from the US Geological Survey, Invasive Species Program

Climatology of Haleakalā

The steep mountain slopes of Haleakalā Volcano (Maui, HI) support some of the most spatially diverse environments on the planet. Microclimates found across vertical gradients on the mountain slopes can change over relatively short differences in slope exposure and elevation and are strongly influenced by a persistent temperature inversion and northeast trade winds that are characteristic of this region. Eleven climate stations, which comprise the HaleNet climate network, have been monitoring climatic conditions along a 2030-m leeward (960 to 2990 m) and a 810-m windward (1650 to 2460 m) elevational transect, beginning as early as June of 1988. Hourly measurements of solar radiation, net radiation, relative humidity, wind speed, temperature, precipitation and soil moisture, and derived variables including potential evapotranspiration, vapor pressure deficit, soil heat flux, and daytime cloud attenuation of sunlight are analyzed in this study. This report documents the annual, diurnal and elevational characteri tics of these climatic variables as well as their behavior over the period-of-record (~1988 to 2013) in both the 6-month dry (May – October) and wet (November to April) seasons. Results show that the climate gradients along both leeward and windward elevation transects are highly influenced by the trade wind inversion in both dry and wet seasons. Period-of-record trends in the dry-season, show increases in energy and decrease in moisture at high elevations (>2000 m). Significant dry season changes include: decreases in precipitation (5 to 8% decade-1), relative humidity (3 to 5% decade-1) and cloud attenuation of sunlight (-2 to -5% decade-1) and increase in solar radiation (2 to 4% decade-1), vapor pressure deficit (9 to 10 % decade-1), zero precipitation days (4 to 5% decade-1) and potential evapotranspiration (3 to 7% decade -1). For the wet season, an opposite signal of change was observed at high elevation although trends were not as robust as the dry season trends. Reported dry season trends are potenti lly explained by a 4% significant increase in TWI frequency identified over a similar observation period (1991-2013). In addition to a climate variable analysis, this report also highlights other past and ongoing research projects that have taken place on the mountain and provides a summary of the history of the HaleNet climate network, the people and organizations that have contributed to its operation, and a list of publications that have made use of HaleNet climate data. It is the authors’ hope that this information will aid resource managers in protecting the ecosystems and other natural resources, and provide insight into ongoing and future climate changes on Haleakalā.The data analysis presented here and the preparation of this report were supported by the acific Island Climate Science Center (PICSC) and the Pacific Island Climate Change Cooperative (PICCC) and the Pacific Island Ecosystem Research Center (PIERC). We also thank Paul Krushelnycky, Shelley Crausbay, Abby Frazier, Henry Diaz, Erica von Allmen, Thomas Schroeder and Ross Sutherland for their contributions to this report. In conducting fieldwork on Maui, the authors were given support, encouragement, and assistance by numerous ndividuals. We extend our gratitude especially to Jotoku and Doris Asato, Dennis Nullet, Bill Minyard, Ryan Mudd, Dave Penn, Ron Nagata, Ted Rodrigues, Timmy Bailey, Matt Brown, Pamela Waiolena, Chuck Chimera, Kathy Wakely, Philip Thomas, and Sabine Jessel. We thank Haleakalā National Park and PIERC, and the USGS, for their long support of the HaleNet system. We owe a special debt of gratitude to Gordon Tribble of PIERC for his unwavering commitment to sustaining HaleNet. We would also like to thank Jeff Burgett of PICCC, Deborah Solis of the U.S. Army Corps of Engineers and Neil Fujii and Jeremy Kimura of the Commission on Water Resource Management. Over the years, HaleNet research has also been supported with funding from the University of Hawai‘i Research Council, the Water Resources Institute Program of the U.S. Geological Survey, the Cooperative National Parks Resources Study Unit, NSF EPSCoR (under award 0903833), and PICCC

Non-Indigenous Bamboo along Headwater Streams of the Luquillo Mountains, Puerto Rico: Leaf Fall, Aquatic Leaf Decay and Patterns of Invasion

The introduction of bamboo to montane rain forests of the Luquillo Mountains, Puerto Rico in the 1930s and 1940s has led to present-day bamboo monocultures in numerous riparian areas. When a non-native species invades a riparian ecosystem, in-stream detritivores can be affected. Bamboo dynamics expected to influence stream communities in the Luquillo Experimental Forest (LEF) were examined. Based on current distributions, bamboo has spread downstream at a rate of 8 m y -1 . Mean growth rate of bamboo culms was 15.3 cm d -1 . Leaf fall from bamboo stands exceeded that of native mixed-species forest by c. 30(k = -0.021), and leaves from another abundant riparian exotic, Syzygium jambos (Myrtaceae) (k = -0.018), decayed at relatively slow rates when submerged in streams in fine-mesh bags which excluded macro-invertebrate leaf processors. In a second study, with leaf processors present, bamboo decay rates remained unchanged (k = -0.021), while decay rates of S. jambos increased (k = -0.037). Elemental losses from bamboo leaves in streams were rapid, further suggesting a change in riparian zone/stream dynamics following bamboo invasion. As non-indigenous bamboos spread along Puerto Rico streams, they are likely to alter aquatic communities dependent on leaf input

Food Habits of Introduced Rodents in High-Elevation Shrubland of Haleakala National Park, Maui, Hawai'i

Mus musculus and Rattus rattus are ubiquitous consumers in the high-elevation shrubland of Haleakala National Park. Food habits of these two rodent species were determined from stomach samples obtained by snap-trapping along transects located at four different elevations during November 1984 and February, May, and August 1985. Mus musculus fed primarily on fruits, grass seeds, and arthropods. Rattus rattus ate various fruits, dicot leaves, and arthropods. Arthropods, many of which are endemic, were taken frequently by Mus musculus throughout the year at the highest elevation where plant food resources were scarce. Araneida, Lepidoptera (primarily larvae), Coleoptera, and Homoptera were the main arthropod taxa taken. These rodents, particularly Mus musculus, exert strong predation pressure on populations of arthropod species, including locally endemic species on upper Haleakala Volcano

Status of the silversword in Haleakala National Park: past and present

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.The Haleakala silversword, Arhyroxiphium sandwicense DC. ssp. macrocephalum (Gray) Meyrat, declined markedly in the late 1800's and early 1900's due to browsing by goats and cattle and to vandalism by humans. During the 1930's, after protection was provided by the national park, much concern arose over the high level of seed predation by native insects. Nevertheless, following protection, silversword numbers have increased and now total about 50,000 individuals. Although total crater-wide numbers remained stable between censuses in 1971 and 1982, large fluctuations have occurred on individual cinder cones. Plots for long-term study of silversword population dynamics have been established, with data taken annually. Preliminary results after three years suggest that many seedlings establish in some years, few or none in others; that substantial natural mortality occurs in some years; and that wide population fluctuations from year to year are occurring. The greatest threats to the Haleakala silversword today are thought to be the Argentine ant (Iridomyrmex humilis) and the western yellow-jacket (Vespula pensylvanica), aggressive alien predators (of insects) which could disrupt ecosystem processes, especially pollination. Park managers now recognize the need for preservation of the entire complex of organisms belonging to the silversword ecosystem.National Park Servic

Current and potential ant impacts in the Pacific Region

Worldwide, ants are a powerful ecological force, and they appear to be dominant components of animal communities of many tropical an temperate ecosystems in terms of biomass and numbers of individuals. However, the biotas of many Pacific islands evolved without ants. Relatively few ant species have been successful invaders of native communities on continents, and these include most of the species that pose the greatest problems for Pacific islands. They generally have multiple queens per colony, are unicolonial (lacking internest aggression), quickly recruit to food items, thrive in a variety of habitats including disturbed areas, and can be highly aggressive to other any species. Virtually nothing has been published on effects of non-native ants on native arthropod fauna on Pacific islands with the exception of Hawaii, the Galapagos archipelago, and New Caledonia. In addition, many ant species in the Pacific have long been a nuisance for humans, and significant agricultural impacts have occurred from ants tending hemipteran insects of crop plants

Learning from quarantine successes.

Among U.S. states, Hawaii stands out for it's very high rate of colonization by non-indigenous species. Hawaii's need for prevention and management of invasive species are arguably greater than for the rest of the United States because both tourism and agriculture require a relatively pest-free environment to flourish. In addition, Hawaii's highly endemic biodiversity, several spectacular national parks, and about one-third of all federally listed endangered species are also at risk and threatened primarily by current and future invasions. This paper examines Hawaii's federal and state quarantine entities and procedures. Comparisons are made to quarantine developments in Australia and New Zealand