Vol. 37 (1) (December 2004) Abstracts
An illustrated key to the earthworms of the Samoan Archipelago (Oligochaeta: Glossoscolecidae, Megascolecidae, Moniligastridae)
Abstract. In order to facilitate the study of earthworms in the Samoan Archipelago, an identification key has been assembled. The key relies exclusively on external characters so that non-specialists may use it easily. In addition to previously reported species, four more were collected by the author or collaborators during the fieldwork leading to the preparation of the key: Amynthas rodericensis Grube 1879, Pheretima (Pheretima) sangirensis Michaelsen 1891 species group, Pithemera pacifica Beddard 1899, and Polypheretima elongata Perrier 1872. A short diagnostic description of each species is included to verify identifications. However, users should be aware that the key can give wrong results if attempting to identify species not included in the key. Although it may be applicable to the earthworms of other SW Pacific islands, misidentifications are possible. These problems arise because many of the species presently known from the Samoan Archipelago belong to very large and diverse genera, many species of which will key to the same point in this simple key based on external characters. The following species are covered in the key: Pontoscolex corethrurus Muller 1856, Drawida barwelli Beddard 1886, Dichogaster reinckei Michaelsen 1898, D. affinis Michaelsen 1891, D. bolaui Michaelsen 1890, Amynthas corticis Kinberg 1867, A. gracilis Kinberg 1867, A. minimus Horst 1893, A. rodericensis, A taitensis Grube 1866, Metaphire californica Kinberg 1867, Perionyx excavatus Perrier 1872, Pheretima (Pheretima) montana Kinberg 1867, Ph. sangirensis species group, Pithemera bicincta Perrier 1872, P. pacifica, P. godeffroyi Michaelsen 1899, and Polypheretima elongata.
Micronesica 37(1): pp. 1-13, 2004. Full text.
Allozyme differentiation correlated with host-plant use in the pantropical species,
K. L. LOFDAHL, C. YOUNG
Abstract—Populations of the pantropical species, Drosophila ananassae, were reared from a variety of temperate and tropical fruits on the island of Guam and genotyped at three allozyme loci [malate dehydrogenase (MDH-1), malic enzyme (ME), and isocitrate dehydrogenase (IDH)]. Significant differentiation was found in both MDH-1 and IDH allele frequencies between populations breeding on the fruit of the cucumber tree (Averrhoa bilimbi) versus all other fruits tested [including starfruit (Averrhoa carambola)]. Genotype frequencies for these two enzymes deviated strongly from Hardy-Weinberg frequencies. This suggests possible population subdivision along host-plant lines in sympatric populations of this widely-distributed Drosophila species.
Micronesica 37(1): pp. 15-20, 2004. Full text.
Host fruit of Mango Fly (Bactrocera frauenfeldi (Schiner)) (Diptera: Tephritidae) in
LUC LEBLANC, JONAH WILLIAM, ALLAN J. ALLWOOD
Abstract—Host records of mango fly (Bactrocera frauenfeldi (Schiner)) in the Federated States of Micronesia are reported. During two years of surveying (1994-1996), 1123 samples of commercial or edible fruit and wild fruit, covering 127 species in 95 plant genera in 52 families, were collected and incubated for the emergence of fruit flies (family Tephritidae) in a fruit-holding laboratory in Pohnpei. Twenty-six species of commercial/edible fruits and 9 species of wild fruit, belonging to 24 genera in 15 families, were noted as hosts of mango fly. The importance of each host is discussed with regards to infestation levels, expressed as percentage of infested fruit. Also reported are the mean and maximum number of fruit fly puparia recovered from individual fruit and the number of puparia recovered per kilogram of ripe fruit.
Micronesica 37(1): pp. 21-31, 2004. Full text.
Prey items of migratory peregrine falcon (Falco peregrinus) and Eurasian kestrel (Falco tinnunculus) on Guam.
DANIEL S. VICE, DIANE L. VICE
No abstract for this note.
Micronesica 37(1): pp. 33-36, 2004. Full text.
Developing insecticide management for Insnesia glabrascuta (Caldwell) (Homoptera: Psyllidae) on young Ifit trees on Guam
ROSS H. MILLER
Abstract—The effects of four pesticides on populations of the psyllid, Insnesia glabrascuta (Caldwell), were examined on ifit trees, Intsia bijuga (Colebr.) O. Kuntze. The pesticides tested were Cygon®, a commercial over-the-counter formulation of dimethoate; Avid®, a commercial formulation of avermectin; Actara®, a commercial formulation of thiamethoxam; and Conserve®, a commercial formulation of spinosad. All pesticides caused initial mortality to psyllids. However, psyllid populations rapidly rebounded to pre-treatment levels in the Cygon® spray and drench treatments, while densities remained below pre-treatment levels longest in the highest concentrations of Actara®, Conserve®, and Avid® spray treatments. Psyllid population suppression was probably linked to residual activity characteristic of the different compounds and to physiological changes in tree leaves induced by feeding psyllids. Implications for the use of these pesticides for psylla management on ifit trees in Guam’s tropical insular environment are discussed.
Micronesica 37(1): pp. 37-48, 2004. Full text.
The local names of Pacific Monitor Lizards (Sauria: Varanidae) of Oceania & Indo-Malaysia, excluding Australia
M. K. BAYLESS
No abstract for this paper. Full text.
Micronesica 37(1): pp. 49-55, 2004.
Field response of Guam populations of the New Guinea Sugarcane Weevil, Rhabdoscelus obscurus (Boisduval) (Coleoptera: Curculionidae), to aggregation pheromones and food volatiles
R. MUNIAPPAN, J. BAMBA, J. CRUZ, G.V.P. REDDY
Abstract—Lures of aggregation pheromones of the Australian and Hawaiian populations of New Guinea sugarcane weevil, Rhabdoscelus obscurus (Boisduval), with other semiochemicals were used to clarify the identity of the weevil population in Guam. In a field experiment at eight different locations (Dededo, Tumon, Yigo, Hagåtña, Mangilao, Yona, Agat and Malesso), plastic bucket traps baited with the lure of the Australian R. obscurus population in combination with a food volatile compound (ethyl acetate) and cut sugarcane captured significantly more weevils (total of 348) than traps baited with pheromone lure of the Hawaiian R. obscurus population in combination with food volatile and cut sugarcane which caught a total of 128 weevils. Traps baited with lure containing only the food volatile and cut sugarcane or only cut sugarcane captured significantly fewer weevils (total of 36 and 30, respectively) than those baited with pheromone compounds. Data from trap catches indicate that the Guam population of R. obscurus responded significantly more to the pheromone lure of the Australian population than to pheromone lure of the Hawaiian population indicating that the Guam R. obscurus population is related more closely to the Australian population. Trap catches at the Tumon and Dededo locations were greater than those in Yigo,Yona, Mangilao, Hagåtña, Agat, and Malesso. Rainfall had a low correlation with trap catches at all locations except at Yigo where it positively correlated to the Australian population lure treatment. Semiochemical based trapping in weevil management has potential either in mass trapping or as part of an IPM program. A future line of work is also proposed for the control of weevil borers based on these initial results.
Micronesica 37(1): pp. 57-68, 2004. Full text.
New and noteworthy bird records for Micronesia, 1986–2003
G. J. WILES, N. C. JOHNSON, J. B. DE CRUZ, G. DUTSON, V. A. CAMACHO, A. K. KEPLER,
D. S. VICE, K. L. GARRETT, C. C. KESSLER, H. D. PRATT
Abstract--This paper documents noteworthy records of 73 bird species for Micronesia from 1986–2003. We describe six new records for the region, three each for the Mariana and Marshall Islands, two for the Carolines, and 25 new island records. Additional reports are included for species that are either rare or poorly documented for particular islands. Of the 61 species that are not resident in Micronesia, 52 are probably Palearctic in their origin, three are from elsewhere in Oceania, two each are Oriental and Nearctic, and one each is Australasian and Antarctic.
Micronesica 37(1): pp. 69-96, 2004. Full text
Green Turtles and their marine habitats at Tinian and Aguijan, with projections on resident turtle demographics in the southern arc of the Commonwealth of the Northern Mariana Islands
S. P. KOLINSKI1, L. I. ILO, J. M. MANGLONA
Abstract—An estimated 351 individual green turtles were observed via 448 sightings in 27 surveys covering roughly 59% of the total shore and outer reef perimeter of Tinian, Commonwealth of the Northern Mariana Islands. Fourteen green turtles were observed during tow surveys covering 95% of Aguijan’s shore and reef perimeter. No other sea turtle species were sighted. Juvenile turtles of various sizes dominated in all surveyed environments, and observations of turtles with estimated straight carapace lengths below 45 cm suggested recent and continuing recruitment at both Tinian and Aguijan. Twenty-four species of algae noted as green turtle forage in other regions of the world were identified at Tinian in this and previous surveys. Projections of turtle densities and abundances based on data from recent surveys of all southern-arc islands in the Commonwealth of the Northern Mariana Islands suggest the small uninhabited islands of Farallon de Medinilla and Aguijan sustain tens of turtles, while turtle numbers around the larger inhabited islands of Rota, Saipan and Tinian range from the very low to high hundreds. The Commonwealth portion of the southern arc is estimated to support between 1000 and 2000 mainly immature resident green turtles. Turtle density and abundance appear highest at Tinian despite its smaller size relative to Saipan and its apparent paucity of potential seagrass forage.
Micronesica 37(1): pp. 97-118, 2004. Full text.
Genetic diversity in Hawaiian stream macroinvertebrates
M. H. BEBLER , D. W. FOLTZ
Abstract—The Hawaiian archipelago is the world’s most geographically isolated island chain, with a high proportion of endemic plant and animal species. We studied DNA sequence variation in all four native species of Hawaiian stream macroinvertebrates. These species all exhibit freshwater amphidromous development, in which eggs are spawned and hatched in freshwater, the resulting larvae disperse in marine waters, and post-larval juveniles return to freshwater streams and grow to sexual maturity. The four species studied here were two caridean shrimps (Atyoida bisulcata Randall and Macrobrachium grandimanus Randall) and two gastropod molluscs (Neritina granosa Sowerby and Neritina vespertina Sowerby). Approximately 350 bp of the mitochondrial cytochrome oxidase subunit I (COI) gene was sequenced for 7 – 28 individuals of each species sampled from two islands (Hawai‘i and Kaua‘i) located at the extreme ends of the high islands. Estimates of nucleotide site diversity among the four species (range, 0.30% – 0.58%) and estimates of FST (range, -0.028 to 0.172) were comparable to previous studies of Hawaiian freshwater amphidromous fish and macroinvertebrate species, and also comparable to nucleotide site diversity among nonamphidromous shrimp of the infraorder Caridea (mean, 0.62%, N=40 species). The most common sequence haplotype in each species was shared between the two islands. These results suggest that population sizes in these amphidromous species are large enough to maintain genetic diversity, and that larval dispersal is sufficient to prevent the development of island-specific clades.
Micronesica 37(1): pp. 119-128, 2004. Full text.
Morphological characteristics and species separation of Hawaiian postlarval amphidromous fishes
M. E. BENBOW, A. J. BURKY, C. M. WAY
Abstract—There are five Hawaiian amphidromous fishes (Gobiidae: Lentipes concolor, Awaous guamensis, Sicyopterus stimpsoni, Stenogobius hawaiiensis; Eleotridae: Eleotris sandwicensis). Amphidromous adults deposit eggs on the stream bottom. After hatching, larvae drift to the ocean for growth followed by postlarval migration back into the streams. Postlarvae were collected to construct a dichotomous identification key based on 12 morphological measures and ray counts from four fins. Overall, the presense of fused pelvic fins, standard length (SL), and fin ray numbers were the most useful in species separation. Gobies were separated from the eleotrid by the former having fused pelvic fins. Within the gobies, S. stimpsoni had the largest SL [mean (SD) = 20.5 (1.0) mm] with A. guamensis [15.8 (0.6)mm] smaller and L. concolor [13.7 (1.3) mm] and S. hawaiiensis [13.3 (1.0) mm] the smallest. Although SL alone could not separate L. concolor and S. hawaiiensis, the former had 5 first dorsal fin rays compared to 6 in all other gobies. Nineteen pectoral fin rays separated S. stimpsoni from A. guamensis, and SL along with anal and second dorsal fin ray number, separated A. guamensis from S. hawaiiensis. Canonical discriminate function analysis was used as an exploratory approach to confirm the dichotomous key. With all morphological features entered into the analysis, three significant discriminate functions were generated with the most highly correlated morphological variables within each function the same as those used in the dichotomous key. Additionally, regression models were generated for predicting SL from total length (TL) of three postlarval species. Measures of TL do not require excessive handling or killing specimens; however, SL is usually the preferred measure for body size. The ability to identify migrating postlarvae under a variety of conditions aids in data acquisition under circumstances where preservation may or may not be necessary for the research objectives.
Micronesica 37(1): pp. 129-144, 2004. Full text.
The Odonata of Pakin, Ant, Mokil, and Pingelap Atolls, Eastern Caroline Islands, Micronesia
D. W. BUDEN
Abstract—Seven species of Odonata are recorded from among Pakin, Ant, Mokil, and Pingelap atolls, Eastern Caroline Islands, Micronesia–one Zygoptera (damselfly), Ischnura aurora; and six Anisoptera (dragonflies), including Anax guttatus, Agrionoptera sanguinolenta, Diplacodes bipunctata, Pantala flavescens, Tholymis tillarga, and Tramea transmarina. None is endemic to the islands, but A. sanguinolenta is known to breed only in Chuuk and Pohnpei states, eastcentral Micronesia; the six others are widely distributed in Oceania and the Indo-Australian region, and in some cases well beyond. The largest number of species recorded on any one of the four atolls is five each on Mokil and Pingelap–six each if unconfirmed records of A. guttatus are accepted. Multiple surveys on Ant and Pingelap atolls reveal differences in species composition on the two atolls, but no marked seasonal variations. Evidence of breeding was obtained for all but the two least common species (I. aurora and D. bipunctata) and data suggest that breeding occurs year-round.
Micronesica 37(1): pp. 145-155, 2004. Full text.
Chemical limitations of Yoga root growth in an acid soil
THOMAS E. MARLER, JOHN H. LAWRENCE
Abstract—Subsoil from an acid soil series was amended with CaSO4, MgO, or Ca(OH)2 to identify chemical factors that may be limiting of root growth of Elaeocarpus joga (yoga) in these soils. New root length of yoga seedlings in the three amendment treatments was increased about 70% above that in the untreated substrate. New root length did not differ among the three amendment treatments. These amendments increased dry weight of new roots about 85% above dry weight of new roots in the untreated substrate. The results indicate that both Ca deficiency and Al toxicity limit yoga root growth in the acid soils of Guam. These chemical limitations may be the reasons this species occurs exclusively in alkaline soils in Guam and Rota.
Micronesica 37(1): pp. 157-161, 2004. Full text.
Fig. 1. Phenotype of new root growth following 16 days of growth into untreated Akina subsoil (left) or into this soil amended with Ca(OH)2.
A record of Perochirus cf. scutellatus (Squamata: Gekkonidae) from Ulithi Atoll, Caroline Islands
GARY J. WILES
Abstract—This paper documents the occurrence of the gecko Perochirus cf. scutellatus at Ulithi Atoll in the Caroline Islands, where it is possibly restricted to a single islet. This represents just the third known location for the species and extends its range by 975 km. Information gathered to date suggests the species was once more widespread and is perhaps sensitive to human-induced habitat change.
Micronesica 37(1): pp. 163-166, 2004.
Vol. 37 (2) (August 2005) Abstracts
Food Composition Data from the Federated States of Micronesia
LOIS ENGLBERGER, GEOFFREY C. MARKS, MAUREEN H. FITZGERALD and KIPIER LIPPWE
Abstract—Food composition data on locally grown and harvested foods are important for many reasons: assessing diets for dietary improvement, nutrition research, and promotion of local foods. Vitamin A deficiency, anemia, and chronic diseases, including diabetes, heart disease, and certain cancers, have been identified as problems in the Federated States of Micronesia (FSM), and nutrient-rich foods should be promoted to alleviate these problems. The purpose of this paper is to increase understanding of local FSM foods and to determine which FSM foods have been analyzed for what nutrients. An expert informant and literature search was used to gather information on food composition studies that had been carried out. Data were found for 16 breadfruit, 17 banana, 19 giant swamp taro, and 5 pandanus cultivars; coconut products; apuch, noni, false durian, lime, and tangerine fruits; cultivars of one common taro, cassava, and sweet potato; selected dark green leafy vegetables; and seafoods. Great differences in nutrient content were found in the estimates for the various foods and food cultivars, in particular, for provitamin Acarotenoids, and essential vitamins and minerals, including calcium, iron, and zinc. There are still many foods and food cultivars that have not yet been analyzed or the analyses have been incomplete. Also, there are few studies that investigate differences of nutritional content between foods grown on mountainous islands and those from atolls. Further studies are needed to fill these data gaps.
Micronesica 37(2): 195-213, 2005. Full text.
Shallow-water benthic foraminifers from Mecherchar Jellyfish Lake
(Ongerul Tketau Uet), Palau
SHUNGO KAWAGATA, MAKOTO YAMASAKI, RIEKO GENKA and RICHARD W. JORDAN
Abstract—A sediment core taken from Mecherchar Jellyfish Lake (officially called Ongerul Tketau Uet), a marine lake in the Republic of Palau, was initially investigated for siliceous microfossils, however, a carbonate layer (67–78 cm below the sediment surface) was found to contain moderately preserved benthic foraminifers. Ten species have been identified from these samples to date, and most are common in subtropical to tropical shallow marine environments. The assemblage is dominated by two species, Helenina cf. H. anderseni and Rosalina globularis, with the other species being less common to rare. The presence of this carbonate layer below siliceous muds and anoxic bottom waters is assumed to represent the drier, cooler climate of the Little Ice Age which ceased about 100 years ago.
Micronesica 37(2): 215-233, 2005. Full text.
Nitrogen and phosphorus concentrations in tropical Pacific insular
streams: historical data from Tutuila, American Samoa
GUY T. DIDONATO
Abstract—Tropical Pacific insular streams are relatively unexplored compared to streams in temperate or other tropical regions, and more stream studies are necessary because human population growth threatens these unique island ecosystems. The population of Tutuila, the largest island of American Samoa, has grown exponentially in recent years. This report presents historical water quality data [total nitrogen (TN), nitrate (NO3 –+NO2–), total phosphorus (TP)] for eleven perennial streams on Tutuila sampled between 1979 and 1996. Data from 1979 show that streams impacted by human activities exhibited a higher median TN concentration (520 ug/L) than reference streams (329 ug/L). A similar difference was observed for NO3 –+NO2–. There was no significant difference between impacted and reference stream TP (129 vs. 102 ug/L, respectively). Data from the entire period indicate that TN and NO3 –+NO2– demonstrated more between year variability (CV = 60.2% and 26.5%, respectively) than did TP (CV=19.9%). Overall, though, these data do not demonstrate any obvious trends towards increasing nutrients in these island streams. Data suggest that the baseline nutrient levels are ca. 200–300 ug TN/L and 50–100 ug TP/L for reference streams on this island. These numbers are supported by data collected in 1997 from Laufuti Stream, a stream located in an uninhabited watershed on the nearby island of Ta’u, American Samoa. Future monitoring must examine the full range of stream types to accurately assess these insular stream ecosystems.
Micronesica 37(2): 235-247, 2005. Full text.
Distribution and abundance of regular sea urchins on two coral reefs in Fiji
S. E. COPPARD AND A. C. CAMPBELL
Abstract—The distribution and abundance of thirteen species of regular sea urchin were assessed on Sosoikula and Nukubuco reefs, Fiji. Their morphology and behavior were contrasted relative to wave activity, water depth, substratum composition, food, and predation through all the reefs zones. Densities and relative densities of species in each zone were determined and their significance tested relative to the species distribution. Results indicated species associations with different reef areas, thus habitat preferences, which reflected species’ competitive abilities and resource partitioning. Echinometra mathaei was the most prolific and adaptable species, having the greatest densities in all zones. Peak mean densities occurred in the mid back reef area on the echinoderm flat (2.64 ind. m–2), comprising 93.6% of all echinoids found. Diadema savignyi and Diadema setosum were found at maximum densities in the boulder zone, utilizing the narrow elevated crevice space. Both these species of Diadema showed an increase in test diameters and spine lengths from the reef crest to the hard coral bommies, proportional to the increase in observed crevice size. Echinothrix diadema and Echinothrix calamaris (brown color morph) demonstrated a similar trend, but with continued growth-related migration to the Porites and soft coral zone. The white color morph of E. calamaris showed no apparent association between size distribution and crevice space. This was due to behavioral adaptations, where both juveniles and adults aggregated together in the few very large crevices found. Algal and seagrass species distributions appeared to have only a moderate influence on echinoid species distributions, as most species diets appeared broad within habitat. Predation pressure was assessed to be relatively low, with greatest predator densities on the fore reef (0.24 ind. m–2). Refuge quality and availability, moderated by predation, combined with different echinoid morphologies and behaviors, determined species distributions through the reefs varied habitats.
Micronesica 37(2): 249-269, 2005. Full text.
A Nitrogen Budget, Including the Occurrence and Activity of
nitrogen fixers in nitrogen-rich and nitrogen-poor habitats of Guam,
ERNEST A. MATSON, ANDREW S. E. QUENGA
Abstract—In order to augment earlier studies on external nitrogen flux to Guam’s reefs and to identify internal sources of fixed nitrogen for the nearshore marine communities, a broad survey of the occurrence and amount of nitrogen fixation (ethylene production) was done on two contrasting reef moats. Nitrogen fixation was ubiquitous; it was detected in all samples at both sites, including coarse and fine sand, epiphytes of macroalgae and common corals, rocks, rhizoids, fecal pellets, and sessile invertebrates, and was undetectable in dark controls. Paradoxically, while the leeward reef site is heavily enriched both with nitrate (up to ca. 20 uM final conc) it had nitrogen fixation rates 10–15 times greater than in the relatively nitrogen-poor windward reef moat. This windward site is dominated by oceanic tidal water (90% tidal prism), and, in contrast to the leeward site, its waters are enriched with aquifer nitrate only up to ca. 2 uM before they flood over the reef crest. Rates of fixation were a minor part of the nitrogen budget, were somewhat lower than at other tropical sites, and ranged from 0.02 to 60 hmol N g–1 d–1, with an average of 150 umol N m–2 d–1 at the N-rich site and 11 umol N m–2 d–1 at the nitrogen-poor site. Nitrogen fixation, which costs half that of assimilatory nitrate reduction, may be energetically favored in highly productive, relatively nitrogen-rich, euryoxic habitats.
Micronesica 37(2): 271-285, 2005. Full text.
Sea Turtle Abundance at Isolated Reefs of the Mariana Archipelago
S. P. KOLINSKI, R. K. HOEKE, S. R. HOLZWARTH AND P. S. VROOM
Abstract—Seven shallow-water banks, shoals and isolated reefs of the Mariana Archipelago were surveyed for sea turtles using surface and underwater survey techniques as part of efforts to ascertain turtle distributions and numbers throughout the Mariana region. Three green turtles (Chelonia mydas) were observed, one each at Supply Reef, Zealandia Bank and Arakane Reef. No other turtle species were seen. Twenty-six species of macroalgae were identified at six of the seven reefs, three (12%) of which are known to be utilized by green turtles. The limited number of turtles at isolated reef systems may be due to low recruitment rates, inadequate habitat range and resources, increased exposure to predation, and/or increased effort required to remain on location. Although sea turtles in some cases utilize shallow isolated reef systems, these systems do not appear to support large turtle numbers on a resident basis in the Mariana region.
Micronesica 37(2): 287-296, 2005. Full text.
Two Species of Mangrove Trees Previously Unrecorded in the
Marshall Islands Found in Jaluit Atoll
NANCY VANDER VELDE AND BRIAN VANDER VELDE
Abstract—Jaluit Atoll, in the Republic of the Marshall Islands, has long been noted for its extensive mangrove wetlands. It has generally been held that the tree species to be found in these wetlands were predominately Bruguiera gymnorrhiza and Pemphis acidula, with a lesser amount of Sonneratia alba and Lumnitzera littorea, and a limited number of Rhizophora mucronata. However, recently two additional mangrove tree species were found, Xylocarpus cf. rumphii and Rhizophora apiculata, well established in the wetlands of Jaluit Atoll. The aboriginal inhabitants of the Marshall Islands were skilled sailors who traveled throughout Micronesia. Many plant species were introduced prehistorically from other areas and these had an impact on the terrestrial flora. Linguistic similarities with other regions, and related anthropological evidence may give evidence as to whether these recently documented mangrove species were introduced through human activity.
Micronesica 37(2): 297-308, 2005. Full text.