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

The Haleakala Argentine ant project: a synthesis of past research and prospects for the future

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.1. The Haleakala Argentine Ant Project is an ongoing effort to study the ecology of the invasive Argentine ant in the park, and if possible to develop a strategy to control this destructive species. 2. Past research has demonstrated that the Argentine ant causes very significant impacts on native arthropods where it invades, threatening a large portion of the park’s biodiversity in subalpine shrubland and alpine aeolian ecosystems. 3. Patterns of spread over the past 30+ years indicate that the invasion process is influenced to a substantial degree by abiotic factors such as elevation, rainfall and temperature, and that the ant has not reached its potential range. Predictions of total range in the park suggest that it has only invaded a small fraction of available suitable habitat, confirming that this species is one of most serious threats to the park’s natural resources. 4. Numerous experiments have been conducted since 1994 in an attempt to develop a method for eradicating the Argentine ant at Haleakala using pesticidal ant baits. Thirty baits have been screened for attractiveness to ants in the park, and ten of these were tested for effectiveness of control in field plots. While some of these baits have been very effective in reducing numbers of ants, none has been able to eliminate all nests in experimental plots. 5. Research into a secondary management goal of ant population containment was initiated in 1996. By treating only expanding margins of the park’s two ant populations with an ant pesticide, rates of outward spread were substantially reduced in some areas. While this strategy was implemented from 1997 to 2004, it was ultimately discontinued after 2004 because of the difficulty and insufficient effectiveness of the technique. 6. In order to achieve the types of results necessary for eradication, the project would probably need to explore the possibility of developing a specialized bait, rather than relying on a commercially produced bait. An alternative would be to pursue approval to use Xstinguish bait, a commercial bait manufactured in New Zealand and not registered for use in the US, which has yielded good results against Argentine ants. Either route would involve significant regulatory hurdles. Because the baits ultimately used would likely be liquid or paste in form, there would also be major logistical challenges in devising methods to successfully apply the baits across the two large ant populations at Haleakala.I would like to thank S.M. Joe for help in the field, and the Hawaii Invasive Species Council and Haleakala National Park for funding and logistical support. A. Bernard of Innovative Pest Control Products provided the Gourmet Liquid Ant Bait and made helpful comments on an earlier version of this report. Any use of trade, product, or firm names in this publication is for descriptive purposed only and does not imply endorsement by the U.S. Government

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

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

Plant Root Systems Preserved in the Permian Cedar Mesa Sandstone at Moki Dugway, Southeastern Utah

Rooted green plants represent the base of the food chain for most terrestrial ecosystems, but, compared to animal burrows, root systems are relatively rarely recognized in ancient sedimentary rocks. Plant roots that penetrate unconsolidated sand dunes, especially those containing not only quartz grains, but also abundant grains of calcite (CaCO3), are commonly replaced by fine crystals of calcite (Klappa, 1980). These structures (known by geologists as rhizoliths from the Greek for “root rock”) are one form of calcite cemented soil and sediment called caliche (figure 1). Caliche crystallizes well above the water table and its calcite crystals are tiny because of rapid evaporation of soil water. One source of the calcium (Ca) and carbonate (CO3) ions necessary for making the calcite of caliche is falling dust, and another source is the dissolution of calcite grains already in the soil. Caliche is widespread in semi-arid regions. In regions with abundant rainfall, available calcium and carbonate ions are rapidly flushed downward, out of the soil, preventing calcite crystals from growing in the root zone. In arid regions there is too little available soil water for crystal growth. Because plant roots in modern semi-arid settings are commonly preserved by caliche (figure 1), rhizoliths in ancient rocks are good indicators of semi-arid paleoclimates. The Early Permian (245-286 million year old) root systems preserved the Cedar Mesa Sandstone at Moki Dugway (figure 2) grew on low-relief land surfaces that formed when dune fields were flattened by wind erosion. A near-surface water table may have prevented further erosion of the Permian dune sand and allowed the land surface to be colonized by woody plants

Hexagonal Fracture Patterns On Navajo Sandstone Crossbeds At Yellow Knolls, Washington County

At this geosite, the main features of interest—remarkably uniform and beautiful fracture patterns dominantly composed of linked hexagons—are present on outcrops of the Jurassic Navajo Sandstone. The Navajo was deposited by large, southward-migrating desert dunes about 200 million years ago, but the fractures that define the hexagons here are just a surficial veneer less than 20 inches (half a meter) deep. The fractures are a weathering phenomenon that developed under climate conditions similar to today’s. Steep thermal gradients develop in the sandstone because it is exposed to solar radiation and changing air temperature. Polygonal fracturing is present in other Navajo exposures in southern Utah, but only in non-bedded (homogeneous) rock. The beautiful, bedding-parallel fracture pattern developed here is very rare; it developed because the bedding planes in the rock at Yellow Knolls are unusually wide-spaced

Plant Root Systems Preserved in the Permian Cedar Mesa Sandstone at Moki Dugway, Southeastern Utah

Rooted green plants represent the base of the food chain for most terrestrial ecosystems, but, compared to animal burrows, root systems are relatively rarely recognized in ancient sedimentary rocks. Plant roots that penetrate unconsolidated sand dunes, especially those containing not only quartz grains, but also abundant grains of calcite (CaCO) are commonly replaced by fine crystals of calcite (Klappa, 1980). These structures (known by geologists as rhizoliths from the Greek for “root rock”) are one form of calcite cemented soil and sediment called caliche. Caliche crystallizes well above the water table and its calcite crystals are tiny because of rapid evaporation of soil water. One source of the calcium (Ca) and carbonate (CO) ions necessary for making the calcite of caliche is falling dust, and another source is the dissolution of calcite grains already in the soil

Hexagonal Fracture Patterns On Navajo Sandstone Crossbeds At Yellow Knolls, Washington County

At this geosite, the main features of interest—remarkably uniform and beautiful fracture patterns dominantly composed of linked hexagons (fi gures 1 and 2)—are present on outcrops of the Jurassic Navajo Sandstone. Th e Navajo was deposited by large, southward- migrating desert dunes about 200 million years ago, but the fractures that defi ne the hexagons here are just a surfi cial veneer less than 20 inches (half a meter) deep. Th e fractures are a weathering phenomenon that developed under climate conditions similar to today’s. Steep thermal gradients develop in the sandstone because it is exposed to solar radiation and changing air temperature. Polygonal fracturing is present in other Navajo exposures in southern Utah, but only in non-bedded (homogeneous) rock. Th e beautiful, bedding-parallel fracture pattern developed here is very rare; it developed because the bedding planes in the rock at Yellow Knolls are unusually wide-spaced

Cut, Fill, Repeat: Slot Canyons of Dry Fork, Kane County

The slot canyons of southern Utah have become popular destinations for hikers, climbers, and photographers. For most of these canyons, the geology is simple: sediment carried by flowing water abrades a thick, homogeneous sandstone. As time passes, the rate of down- cutting is rapid compared to the rate of cliff retreat. End of story. The strange abundance and configuration of the slot canyons along Dry Fork Coyote (a tributary of Coyote Gulch and the Escalante River), however, have a convoluted geologic history that is climate-driven and involves canyon cutting, canyon filling, and more canyon cutting

Burrows Dug by Large Vertebrates into Rain-Moistened Middle Jurassic Sand Dunes: A Reply

Odier (2007) is concerned with two issues: (1) I did not cite his work on burrows in the Navajo Sandstones of southeastern Utah in my article (Loope 2006), and (2) he believes I amwrong in interpreting the structures preserved in the Entrada Sandstone as burrows. On the first issue, I failed to cite both his 2004 abstract and the newly published book that he sent me in October 2006. My article was accepted on June 12, 2006; I returned the proofs on August 23; and the issue was published online on October 4, 2006. The timing of these events makes it clear why I did not cite the book. I did not cite the abstract because that would have necessitated airing my reservations about his interpretations. Since the middle 1970s, I have been aware of abundant cylindrical structures of likely biogenic origin in the Navajo Sandstone, and at the 2004 Geological Society of America meeting, I learned that Odier was interpreting these structures as mammal burrows. In my view, his interpretation could be correct, but, because the preferentially cemented (concretionary) features weather out of structureless sandstone, very little detail is available for study. For instance, in any one cylinder, the diameter commonly varies widely. What was the original diameter of the burrow (or the plant root)? Because bedding planes are absent, this simple question cannot be answered. In the “Conclusions” section of my article on burrows within the Entrada Sandstone, I emphasize the importance of thinlaminated sandstone to the preservation and recognition of biogenic structures; disruptions of this lamination by either physical or biogenic processes provide abundant clues that are simply unavailable in structureless sandstones. On the second issue, Odier (2007) states that the structures in the Entrada Sandstone that I interpret as burrows cannot be burrows because of the crossbedding that is present inside several of them. Instead, he interprets them as “wells” formed by heavy rain falling on dune sand. Many sedimentologists have been interested in the effects of heavy rain on subaerially exposed sand. Clifton (1977) described rain-impact ripples with wavelengths of about 1 cm that form transverse to the wind direction. Rain-wetted blocks of cohesive sand sometimes move down steep lee faces of dunes (Bigarella et al. 1969; Hunter et al. 1983; Loope et al. 2001). I am not aware, however, of reports of rain events that excavate 3-m-long, 50- cm-wide cylindrical voids that are inclined 15°–20° to the horizontal and cut dune crossbeds at a high angle. Figure 8 in my article shows the origin of the internal crossbeds: wind-blown sand drifted into the open burrow throats. For high-resolution, color images of these structures, please see http://www.geosciences.unl.edu/∼dloope/