Evolution probing for semiochemicals based on secondary metabolites in the cuticles of three species of Halobates (Heteroptera: Gerridae)

We developed methods for characterizing semiochemicals in the cuticles of the sea-skater Halobates (Gerridae). Such substances may be involved in chemical communication at the sea surface and have been shown to act as sexual pheromones for a related marine insect Trochopus plumbeus (Veliidae). We identified 86 volatile compounds in extracts from three Halobates species ( H. micans Eschscholtz, H. hawaiiensis Usinger and H. sobrinus White) and used them to reconstruct the phylogeny of the clade. Sixty-seven of the compounds were found to be parsimony-informative. Suspected semiochemicals appear to be specific autapomorphies in the phylogram, and our results indicated that chemical profiles may be used to predict the phylogenetic history of Halobates . Moreover, the phylogenetic tree derived from our data is congruent with a previously published one based on morphology and mitochondrial DNA sequence (780 bp in the COI gene). The potential role of each compound to be used for chemical communication was also reviewed. At appropriate concentrations, some of the cuticular compounds, being partly hydrophobic and partly hydrophilic, could disperse on the sea surface and thereby play an energetically efficient role in chemical communication, e.g. mate location. Less dispersible components might act as 'sun-screens' and provide protection from UV-irradiation during daylight hours.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 671–688.     

A fossil Halobates from the Mediterranean and the origin of sea skaters (Hemiptera, Gerridae)

Five species of sea skaters, genus Halobates Eschscholtz, are the only insects to have successfully colonized the open ocean. In addition, 38 species are found in sheltered coastal waters throughout tropical Indo-Pacific. The taxonomy of the genus is relatively well known, and the phylogeneuc relationships between extant species have recently been analysed (using cladistic methods). In the present paper, we describe the first fossil species of sea skaters, Halobates ruffoi sp. no v. from the Eocene deposit 'Pesciara di Bolca', in the province of Verona, northeastern Italy (geological age about 45 Myr). The significance of this fossil in setting the time scale for the reconstructed phylogeny and anagenesis of adaptive features of sea skaters, and in understanding the evolution and historical zoogeography of these marine insects is discussed.     

Ten new species of Haliotrema (Monogenoidea: Dactylogyridae) from Australian fish and a revision of the genus

Ten new species of Haliotrema from Australian fish are described and figured: H. cteno-chaeti sp. n. from Ctenochaetus strigosus; H. falcanalis sp. n. from Triacanthus falcanalis; H. lineate sp. n. from Acanthurus lineatus; H. chrysotaeniae sp. n. from Lutjanuschrysotaenia; H. cromileptis sp. n. from Cromileptis altivelis; H. epinepheli sp. n. from Epinephelus merra and E. fasciatus; H. holocentri sp. n. from Holocentrus ruber; Haliotrema chrysostomi sp. n. from Lethrinus chrysostomus and Plectorhinchus pictus; H. fleti sp. n. n. from L. fletus and L. chrysostomus; H. scari sp. N. from Scarus fasciatus.
H. dempsteri (Mizelle & Price, 1964) comb. n. from Acanthrus mata, A. dussumieri and A. xanthopterus: H. johnii (Tripathi, 1959) comb. n. from Lutjanus johni and L. fulviflamma: H. parahaliotrema (Mizelle & Price, 1964) comb. n. from Zebrasoma veliferum and A. grammoptilus: and H. obesa (Caballero, Bravo Hollis & Grocott, 1955) comb. n. from Tetraodon hispidus are redescribed and transferred from the genera Parahaliotrema Mizelle & Price, 1964, Ancyrocephalus Creplin, 1839, Parahaliotrema , and Tetrancistrum Goto & Kikuchi, 1917 respectively.
H. brevis (Mizelle & Price, 1964) comb, n. , H. canescens (Mizelle & Price, 1964) comb. n. and H. zanclus (Mizelle & Price, 1964) comb. n. are transferred from Pseudohaliotrema Yamaguti, 1953; H. eilatica (Paperna, 1965) comb. n. , H. teuthis (MacCallum, 1915) comb. n. , H. triacantha (Tripathi, 1959) comb. n. and H. lethrini (Yamaguti, 1937) comb. n. are transferred from Ancyrocephalus Creplin, 1839.
The generic diagnosis is emended to include the above-mentioned species and the taxonomy of the genus is discussed and the formation of six species groups is proposed.     

The ecology and behaviour of a marine insect, Halobates fijiensis (Hemiptera: Gerridae)

Observations were made in Fiji on the adaptive strategies of a marine gerrid, Halobates fijiensis , a species of the only genus of insects to have successfully colonized the open sea. The immature stages spend most of their time in flotillas on sheltered water close to mangroves, whereas adults usually occur singly and on both sheltered and open water behind the protecting reef systems. Wind has a decisive influence on the distribution of H. fijiensis: in strong onshore winds, all stages, including adults, remain close to the shelter of mangroves, but in calm conditions, older immatures venture considerable distances from the mangroves. Halobates fijiensis feed on floating, dead insects. Adults of the chironomid fly Tanytarsus halophilae , whose larvae live on intertidal sea-grasses, accounted for over 60% of the prey items recorded. Halobates fijiensis feeds at around the time of high water, either as individuals or in small, well-dispersed groups. Eggs are laid on intertidal turtle grass (Syringodium) , green coralline algae (Halimeda) or occasionally coral rubble, at or shortly after the point of low water on days of extreme low spring tides. Halobates fijiensis is preyed upon by the robber-fly Clinopogon scalaris (Diptera: Asilidae). Field observations showed that there is a clear effect of group size on the distance at which an approaching predator model is detected.     

New species of mites (Acari: Astigmata: Heterocoptidae) from the Australian and Oriental regions,with a description of the female of <Emphasis Type="Italic">Uvallicoptes peeteri</Emphasis> Haitlinger, 1999

Heterocoptes lombokensis sp. n. from Lombok, Bali and Java (Indonesia), H. sumatrensis sp. n. from Sumatra (Indonesia), H. samueli sp. n. from Australia, H. barbarae sp. n. from New Britain Islands (Papua New Guinea), H. marcellae sp. n. from Sulawesi (Indonesia) and Nolaecoptes tanahloticus sp. n. from Bali (Indonesia) are described. The female of Uvallicoptes peeteri Haitlinger, 1999 is described and new records for this species are given. Males and females of the genus Heterocoptes are keyed.     

Occurrence and density of Halobates micans (Hemiptera: Gerridae) in the eastern South Indian Ocean

Two species of ocean skaters, Halobates germanus and Halobates micans, live in the tropical and subtropical waters of the Indian Ocean. From December 1992 to December 1993, Halobates was intensively sampled in the easternmost region of the South Indian Ocean (13–18.5°S, 114–121E°), from which there have been a small number of records of Halobates. No H. germanus was caught, but a total of 1190 H. micans were collected, with densities estimated at 13 900–28 100 individuals/km². This suggests that H. micans lives in the study area at high densities comparable to those in the Atlantic and the Pacific Oceans. We also discuss the possible effects of ocean currents and winds on the geographic distributions of the two Halobates species in the eastern South Indian Ocean.     

Chromosomes of five species of sea-skater (Gerridae-Heteroptera)

We report here the first chromosome numbers for sea-skaters. Meiotic metaphase figures were obtained from the testes of three littoral species: Asclepios shiranui, Halobates flaviventris and H. robustus and two pelagic species: H. germanus and H. micans. In the four species of Halobates 2nd♂=31, the highest chromosome number so far determined for the Gerridae. In a proposed ancestral form, A. shiranui, 2n♂=23. Males of all five species have an unpaired chromosome, assumed to be the X chromosome of an XO sex chromosome system.     

Taxonomic Revision of the Marine Genus Heterodrilus Pierantoni (Oligochaeta,Tubificidae)1

Marine tubificids possessing trifid anterior setae are morphologically and taxonomically reviewed, on the basis of material from the Atlantic and Pacific Oceans. Heterodrilus Pierantoni, 1902 is revised to include thirteen species, H. arenicolus Pierantoni, 1902, H. minisetosus sp.n.H. ascensionensis sp.n. H. queenslandicus (Jamieson, 1977), H. lacertosus sp.n. H. scitus sp.n. H. keenani sp.n. H. claviatriatus sp.n. H. subtilis (Pierantoni, 1917), H. jamiesoni sp.n. H. occidentalis sp.n. H. pentcheffi sp.n. and H. bulbiporus sp.n. The genus is briefly defined: marine tubificids with trifid setae in preclitellar segments (with H. subtilis as the only exception); paired spermathecae located in segment X; vasa deferentia entering apical, ental ends of slender, ciliated atria, which bear broadly attached masses of prostate glands; paired male pores, and generally with penial setae arranged in bisetal bundles. Heterodriloides gen.n. is established for H. quadrithecatus sp.n. distinguished from Heterodrilus by two main features: its spermathecae are located in XII, with a supplementary pair generally located in XI; and its vasa enter the ectal part of the atria. Giereidrilus gen.n. a third genus with trifid setae, is established to include Phallodrilus ersei Giere, 1979 and G. inermis sp.n. Both species have unpaired spermathecal and male pores, and their atria are not ciliated. Heterodrilus, Heterodriloides and Giereidrilus are placed in the subfamily Rhyacodrilinae Hrabě, 1963.     

Halobates collected during the circumnavigational expedition 'Operation Drake'

Samples of marine pleuston were collected from the sea-surface along considerable sections of the track of Eye of the Wind during its 2-year circumnavigational expedition 'Operation Drake' from November 1978 to October 1980. One hundred and eleven of the tow samples contained insects of the genus Halobates . They were assigned to four oceanic species: H. micans, H. sericeus, H. germanus and H. splendens; two coastal species: H. maculatus, H. princeps, and one undescribed species. Various development stages of the oceanic species were found. The locations, time of collection and surface temperatures where sea-skaters were collected are tabulated. Distributional boundaries and population densities of the oceanic species collected are discussed.     

New species of Leaf-beetles (Coleoptera,Chrysomelidae) from China: XI

New species of the subfamilies Megalopodinae (Temnaspis humerosa sp. n.), Chrysomelinae [Chrysolina furialis sp. n., Ch. oxanae sp. n., Ch. pingchuana sp. n., Oreomelina (Oreomelina) obtusa sp. n., O. (Oreomelina) splendens sp. n. from Sichuan], and Galerucinae (Liroëtis obliquevirgata sp. n. from Sichuan, Hyphaenia lutescens sp. n. from Chongqing, H. potanini sp. n. from Sichuan, and H. kabaki sp. n. from Shaangxi) are described.     

Eight new species ofHamatopeduncularia Yamaguti, 1953 (Monogenea: Ancyrocephalidae) from Ariidae of Peninsular Malaysia

Eleven species of Hamatopeduncularia Yamaguti, 1953 were found on six species of ariids caught off the west coast of Peninsular Malaysia. They are: H. arii Yamaguti, 1953 from Arius maculatus; H. thalassini Bychowsky & Nagibina, 1969 from A. thalassinus; H. simplex Bychowsky & Nagibina, 1969 from Osteogeneiosus militaris; H. isosimplex n. sp. from A. venosus, A. maculatus and A. sagor; H. malayanus n. sp. from A. caelatus; H. manjungi n. sp. from A. thalassinus; H. papernai n. sp. from A. maculatus; H. elongatum n. sp. from A. thalassinus; H. longicopulatrix n. sp. from A. venosus; H. venosus n. sp. from A. venosus; and H. malaccensis n. sp. from O. militaris and A. maculatus.     

Hydromermis contorta (Kohn) and Hydromermis pseudocontorta n. sp. from chironomids of Lake Itasca and Long Lake, Minnesota

Hydromermis contorta (Kohn) and Hydromermis pseudocontorta n. sp. are described from chironomids in Lake Itasca and Long Lake, Minnesota, respectively. The former was recovered from adult females of Glyptotendipes paripes (Edwards) and the latter from fourth-instar larvae of Chironomus sp. Hydromermis pseudocontorta n. sp. resembles H. contorta in cephalic structures, overall size, and the presence of a restricted trophosome in the female. The terminal mouth, long uterine and vulvar limbs of the vagina, and the strongly chitinized brownish spicule of H. contorta contrast with the subventral mouth, short vaginal limbs, and the light yellow spicule of H. pseudocontorta n. sp. Both nematode species emerge from the host as sexually mature adults and both species give evidence of mating while in the host. The H. contorta described by Welch is designated as a new species, Hydromermis albionis n. sp.     

Chemical composition and behavioral responses of the marine insect Halobates hawaiiensis (Heteroptera: Gerridae)

Halobates is the only insect genus with representatives in the open ocean. How adults find one another at sea has long been an intriguing issue. Since chemical communications have been demonstrated in a related marine veliid Trochopus, and laboratory bioassays indicated behavioral differences between males and females when insect extracts were presented, we carried out similar studies on Halobates. Analyses of surface lipid constituents of female and male Halobates hawaiiensis revealed marked differences. Palmitic and oleic acid, major constituents in the male extracts, were absent in the female extract, whereas nonacosenol, dominating the female extracts, was not detected in the male extracts. Analyses of nymphal extracts indicated an intermediate chemical profile. Surface waxes of all insect stages investigated showed nonacosanol and isononacosanol to be main components. "Headspace" analyses of airborne chemicals showed high levels of 4-hydroxy-4-methyl-2-pentanone and benzaldehyde from the male, whereas benzyl alcohol was the main component in the female mixture.     

Description of four new species of Haemaphysalis Koch, 1844 (Acari: Ixodidae) from the H. (Rhipistoma) spinulosa subgroup,parasites of carnivores and rodents in Africa

Systematic Parasitology - Haemaphysalis (Rhipistoma) bochkovi n. sp., H. (R.) burkinae n. sp., H. (R.) horaki n. sp. and H. (R.) walkerae n. sp. (Acari: Ixodidae), are described based on males and...     

A new Huffmanela species (Nematoda: Trichosomoididae) parasitizing atherinid fishes in north Patagonian Gulfs, Argentina

Huffmanela moraveci n. sp. (Nematode: Trichosomoididae) is described from the skin of fins and gills of the silversides Odontesthes smitti Lahille, 1949, and Odontesthes nigricans Richardson, 1848 (Pisces: Atheriniformes), from southwestern Atlantic coast, on the basis of the morphology of adults and eggs found in the host tissues. Huffmanela moraveci n. sp. can be distinguished from Huffmanela carcharini, H. banningi, H. japonica, H. mexicana, H. paronai, H. schouteni, H. shikokuensis, H. branchialis, H. filamentosa, H. ossicola, and H. lata by the size and shape of the eggs. The adult stage of H. moraveci n. sp. can be differentiated from H. hufmani and H. canadensis by the position of the nerve ring and by the total esophagus length/body length ratio. Huffmanela moraveci n. sp. also differs from H. huffmani by the presence of bacillary bands and by the body length. This is the first report of a species of Huffmanela in South America, the first report of a species of Huffmanela with Odontesthes spp. as host, and the third known adult form in the genus.     

The marine Tubificidae (Oligochaeta) of the barrier reef ecosystems at Carrie Bow Cay, Belize, and other parts of the Caribbean Sea, with descriptions of twenty-seven new species and revision of Heterodrilus, Thalassodrilides and Smithsonidrilus

Fifty-nine species of Tubifieidae are recorded from Belize on the Caribbean side of Central America. Twenty-five are new to science: Ainudrilus geminus sp.n., Heronidrilus gravidus sp.n., Heterodrilus flexuosus sp.n., H. ranus sp.n., H. modestus sp.n., Coralliodrilus rugosus sp.n., C. randyi sp.n., Phallodrilus compactus sp. n., P. singularis sp.n., P. vicinus sp.n., P. nasutus sp.n., P. bipartitus sp.n., Inanidrilus reginae sp.n., Olavius finitimus sp.n., O. vacuus sp.n., O. (Olavius) pravus sp.n., Bathydrilus vetustus sp.n., B. egenus sp.n., Thalassodrilides bruneti sp.n., Limnodriloides anxius sp.n., L. major sp.n., L. sacculus sp.n., L. adversus sp.n., Smithsonidrilus appositus sp.n., S. involutus sp.n. Phylogenetic analyses indicate that Heterodrilus Pierantoni, 1902, Thalassodrilides Brinkhurst & Baker, 1979, and Marcusaedrilus Righi & Kanner, 1979, are paraphyletic taxa as previously defined. They are therefore revised to include also apomorphic species earlier attributed to separate genera; in so doing, Marcusaedrilus becomes a junior synonym of Smithsonidrilus Brinkhurst, 1966. Smithsonidrilus pauper sp.n. (Peru), and S. multiglandularis sp.n. (Florida and Puerto Rico) are also described, and Limnodriloides claviger Erséus, 1982 is regarded as a synonym of L. pierantonii (Hrabě, 1971).     

Four New Species of the Genus Hemicriconemoides (Nematoda:Criconematidae)

Four new species of the genus Hemicriconemoides (H. californianus n.sp., H. taiwanensis n.sp., H. annulatus n. sp., and H. nitida n.sp.) are described. The range of total length of H. mangiferae is increased on the basis of specimens collected in Israel, Observations on H. mangiferae and H. litchi support the validity of H. litchi as distinct from H. mangiferae.     

Description of Two New Neotropical Helicopsyche (Trichoptera: Helicopsychidae)

Helicopsyche flinti sp.n. and Helicopsyche cochleara sp.n. are described from Brazil and Ecuador. H. cochleara sp.n. has certain affinities with H. planorboides Machado from eastern Brazil. H. flinti sp.n. is related with other Neotropical Helicopsyche.