NOTES Halodule pinifolia in the Palau Islands (Belau) extensive stands of Enhalus. We examined the Nine species of seagrasses have been reported Enhalus-Thalassia stands on the north end of previously from the Micronesian region. Six Babelthaup at Konre. In the latter part of l 977, species, Halodule uninervis, Cymodocea rotunda/a, Basilius further explored the west coast of Enhalus acoroides , Thalassia hemprichii, Halophila Babelt haup where she found unreported stands of minor and Halophila ova/is had been reported by Cymodocea serrulata and Thalassodendron ciliatum various authors (Fosberg, 1955, 1961, 1976; Moul , as well as Syringodium isoetifo/ium (personal 1957; den Hartog , 1970; Stone, 1971; Sachet and communication , 1978). She recognized the narrow­ Fosberg , I 973) and three species, Syringodium leaved seagrass on the west coast of Babelthaup isoetifolium, Thalassodendron ci/iatum and as different from anything she had observed Cymodocea serrulata were reported for the first time previously in the Palau Islands and sent the by Tsuda et al., (1977). The addition of Halodule specimen to me for identification. pinifo/ia (Miki) den Hartog to the seagrass flora of The Palau specimen: the Palau Islands increases the total number of Ngetpang Bay, west coast of Babelthaup , very sea grasses reported in Micronesia to ten. scarce on muddy silt substrate , in estuarine At the time Tsuda et al. (I 977) evaluated the bay, growing together with Halodule uninervis distribution of seagrasses in Micronesia, H. pini­ and Ha/ophi/a ova/is, I December I 977, J.E. fo/ia had not been reported for any of the islands or Vann Basilius 115 , (TEX) , atolls. In 1978, Joyce Vann Basilius , a Peace Corps has narrow leaves 0.5- 0.6 mm wide, with rounded volunteer in the Office of the Chief Conservationist serrulate tips typical of H. pinifo/ia . The leaves are for the Trust Territory of the Pacific Islands, sent 12- 14cm long. The herbarium specimen has been me a narrow-leaved Halodule from the west coast of compared with living cultures of H. pinifoli a from Babelthaup (Babeldaop), the largest of the Palau Thursday Island , Queensland , Australia and from Islands. She reported that the seagrass was rare but Suva, Fiji and is well within the range of variation occurred with Halophi/a ova/is and Halodule uni­ for the species. We have found that the leaf tips of nervis in a shallow bay. She attempted to find H. pinifolia are variable in experimental cultures additional stands but her work with the Peace and that leaves on the same short-shoot can be Corps ended shortly after the initial collection was either tridentate or serrul ate (McMillan et al., in made . John and Nancy Ogden (personal com­ press). In contrast , the broad-leaved plants of munication , I 979) studied the seagrasses in Palau , Halodule uninervis from Palau have consistently primarily in the vicinity of Malakai Channel , in produced wide leaves during more than thr ee years June 1978 but did not find any narrow-leaved in experimental cultures under growth chamber Halodule. conditions. The Palau plants have continued to J. V. Basilius and I had collected seagrasses in produce leaves that are 2.5 - 3.5 mm wide and various parts of the Palau Islands in March 1977. tridentate leaf-tips with a rounded median tooth. We collected Halophi/a ova/is, Cymodocea rotun­ These wide-leaved plants from Palau and from da/a and Thalassia hemprichii at Kayangel Thursday Island , Queens land, have isozyme sys­ (Ngcheange l), an atoll north of Babelthaup and tems and secondary compounds that differ from Cymodocea serrulata , a first collection for Palau tho se of H. pinifolia from Queensland (McMillan et reported in Tsuda et al. (I 977), on the east side of al., in press). Insufficient material was available for Urukthapel (Ngeruktabel) with Halodule univervis H. pinifo/ia from Palau for culture or for chemical and Enhalus acoroides. We collected Halophi/a comparisons . ova/is, Halodule univervis , Thalassia hemprichii and The status of narrow- and wide- leaved forms of Enhalus acoroides in the vast seagrass beds of H. uninervis as treated by den Hartog (1970) is Malakai Channe l and in Iwayama Bay , Koror. We uncertain. Few flowers ha ve been observed and observed the seagrass beds along the west coast of tho se that den Hartog recorded were primari ly for Babelthaup ~bi le enroute to Kayangel and noted narrow-leaved plants. He stated that anthers for H. Micronesica 16(2): 357- 363. 1980 (December). 358 Micronesica Fig. I. Staminate flower of H. univervis from Iwayama Bay , Koror , Palau. Plants had been in experimental culture for nearly three years at the time of flowering. Pollen had been released before the flower was photographed. uninervis were 2-3 mm long and for H. pinifolia were 2.5- 3 mm long. The wide-leaved plants from Iwayama Bay , Koror , Palau , flowered after nearly three year s in experimental culture (Fig. I). The staminate flower had anthers that were 9. 7 mm long , greatly exceeding anything that had been recorded previously in Halodule. The wide-leaved plants of H. uninervis in Palau may be unusual , but until more flowering is observed in other popu­ lations of H. uninervis, their status will remain uncertain. The distribution of H. pinifolia is reported by den Hartog (1970) to be Western Pacific , ranging from Formosa , the Ryukyu Islands and the Philippines through Malesia to northeastern Australia , Fiji , Tonga , and New Caledonia. Johnstone (in press , personal communication , I 980) reports its occur­ rence in Papua New Guinea at Port Moresby, Daru , Manus Island and Gaile. The occurrence in the Palau Islands represents an eastward extension from the Philippines into Micronesia. Tsuda et al. (I 977) have shown the attenuation of seagrass distribution iri' Micronesia from west (Palau) to east (Marshalls). Palau , now with I 0 reported species , has the greatest number of seagrasses in Micronesia. Toward the east , Yap has 7, Truk has 5 (Kock and Tsuda , I 978) , Vol. 16. Decemb er 1980 359 grasses from the Indo-P acific a nd the Gulf of Guam. Thi s beetle is a nat ive of Palau I sland s in the Mexico-Caribbean. Aqua t. Bot. 8: 163- 172. Western Caro lines. It was first reco rd ed by Chujo - - , and S. C. Williams. 1980. Systematic (I 937) from Pal au. Det ailed m orph ological de­ implic ation s o f i sozymes in Halophi/a section scription of thi s insect ha s been reported by H agen Halophila. Aquat. Bot. 9: 21- 31. and Doutt (I 950) and Gressitt (1955) . - - , 0 . Zapata , and L. Escobar. 1980. B. palau ensis has been first not ed on Guam in Sulphated phenolic compound s in seagrasses. 1973 in Maile and Afam e Heights. Inquirie s in Aqua t. Bot. 8: 267- 278. Maite revealed that ther e used to be a group of --- , S. C. William s, L. Escobar, and 0. Z apa ta. people from palau who lived in that area a few in press. Isozymes, secon dary compounds and years prior t o this o bserva tion. The infestation in experim ental cultures of Au strali an seagrasses Afame Height s, abo ut a mile fr om Maite , took in Halophila, Halodule, Zos tera, Amphibolis and place prob ably by tran sferring inf ested coconut Posidonia. Aust. J. Bot. fronds from Mait e to the so lid waste dump in Moul , E.T. 1957. Prelim inary report on the Afame Heights. Sub sequentl y, the beetle ha s spread flora of Onotoa Atoll , Gilbert Island s. Atoll Res. all over the island in about two year s time. Th e Bull. 57: 1-48. spread of the beetle within a localized area was Sachet , M .-H. , and F. R. Fo sberg. 1 973. aided b y the wind. Ho wever, its distributi on t o Rem arks o n Halophi/a (Hydro char itaceae). various parts of the island h as been aided by the Taxon 22: 4:W- 443. accidental tran sfer of infested coconut frond s from Stone , B. C. 197 1. Th e flora of Guam. one area to th e ot her for socia l events. Th e biology, Micron esica 6: 1- 659. habits, and attempt s at biological contro l of B. Tsuda , R. T. , F . R. Fosberg , and M.-H . mariana in S aipan ha ve been reported by Lange Sachet. 19 77. Distribution of seagrasses in (1950). The biolog y and habit s o f B. palauensis are Micron esia. Micronesica 13(2): 191 - 198. similar to B. mariana. Th e adult beetle lays eggs in Tu yama, T. 1940. F ragmenta Flor ae the folded tend er leaves of t he coconut palm . Grubs Micronesiacae I. J. J ap. Bot. 16: 194-205. feed on the leaflets by scra ping o n the green tissue. Pupation tak es place inside the folded leaflet or in ­ between le aflets that are tightly packed in the tender CAL VI N McMILLAN, Department of Botany, terminal leaf . Adults feed on the leaflets similar t o University of Texas at Austin, Aus tin, Texas their gru bs. 78712. Biological Control: Th e ce nter of geographical distribution of the genus Brontispa is Austro­ Malayan region (Lange , 1950). A number of Biological Control of the Palau Coconut Beetle , indigenous para sites o f Brontispa are known to Brontispa palauen sis (Esaki and Chujo), on Guam ' occu r in thi s region ; ho wever, o nly t he larva l and There are three species of coco nut b eetles, i.e., pupal paras ite, Tetrastich us brontispa e (Fe rrier e), Brontispa mar iana Spaeth , Brontispa pa/auensis has been widely used for biological control of (Esaki and Chujo), and Brontispa c haly beipennis Brontispa spp.