Recent sio_mbrd_rw items

A Curious Marine Insect, Hermatobates

Mon, 16 Mar 2026 00:00:00 +0000

A Curious Marine Insect, Hermatobates

The Malayan Pond-Skaters

Wed, 11 Mar 2026 00:00:00 +0000

The Malayan Pond-Skaters

Incorporation of Cadmium into Drosophila

Sat, 7 Feb 2026 00:00:00 +0000

The purpose of this study was to determine the toxicity tolerance of Drosophila to cadmium in order to obtain flies with a high Cd body burden. CdCl₂ was added in various concentrations to the larval rearing medium. Development was normal in media containing less than 10²ug/g Cd (wet wt). Adult flies reared on a medium with 31 ug/g Cd (dry wt) contained an average of 73 ug/g Cd (dry wt). Much of the Cd incorporated into the body of the adult fly was located in the soft tissues and the haemolymph; only negligible amounts were found in the cuticle.

A New Rheumatobates from Costa Rica (Hemiptera: Gerridae)

Fri, 30 Jan 2026 00:00:00 +0000

The water strider described here was found in a mangrove swamp. The name is published so that it will be available for a forthcoming work on marine insects.

(Rheumatobates ornatus, n. sp.)

A New species of Hermatobates (Hemiptera: Heteroptera)

Fri, 30 Jan 2026 00:00:00 +0000

Hermatobates is a genus of rarely collected and little known marine insects. The first species, H. haddoni Carpenter was described in 1892. Several additional species were described subsequently (Coutière and Martin, 1901a, 1901b; China, 1956, 1957; Herring, 1965) and they were all assigned to the Gerridae although Matsuda (1960), in his review of the World Gerridae, excluded Hermatobates from that family. The status of this genus is thus still debatable; it will be discussed elsewhere (Andersen, Cheng & Polhemus, in preparation). A review of the relevant literature, with a list of the known species, their distributions and their biology, was published by Cheng (1976).

A Simple emergence trap for small insects

Thu, 29 Jan 2026 00:00:00 +0000

A Simple emergence trap for small insects

Studies on the Biology of the Gerridae (Hem., Heteroptera) II. The Life History of Metrocoris Tenuicornis Esaki

Thu, 22 Jan 2026 00:00:00 +0000

Studies on the Biology of the Gerridae (Hem., Heteroptera) II. The Life History of Metrocoris Tenuicornis Esaki

Studies on the Biology of the Gerridae (Hem., Heteroptera) I. Observations on the Feeding of Limnogonus Fossarum (F.)

Thu, 22 Jan 2026 00:00:00 +0000

Studies on the Biology of the Gerridae (Hem., Heteroptera) I. Observations on the Feeding of Limnogonus Fossarum (F.)

Skaters of the Seas – comparative ecology of nearshore and pelagic Halobates species (Hemiptera: Gerridae), with special reference to Japanese species

Sat, 17 Jan 2026 00:00:00 +0000

Skaters of the Seas – comparative ecology of nearshore and pelagic Halobates species (Hemiptera: Gerridae), with special reference to Japanese species

HALOBATES (Heteroptera: Gerridae) from the Seas Around Nosy Be, Magalasy

Sat, 17 Jan 2026 00:00:00 +0000

Three species are noticed: H. flaviventris, collected in light-samples at night on the continental shelf and slope; H. micans, collected on the shelf around Nosy Be, and in the Indian Ocean between north-Madagascar and equator; H. germanus collected off Nosy Be, generally not far from the continental slope. Almost all are sampled in the wet season (mai to november). Developmental stages and sex are identified.

INSECTA - Hemiptera: Heteroptera Gerridae Genus Halobates

Fri, 16 Jan 2026 00:00:00 +0000

INSECTA - Hemiptera: Heteroptera Gerridae Genus Halobates

Cadmium and Other Heavy Metals in Sea-Skaters (Gerridae: Halobates, Rheumatobates)

Fri, 5 Dec 2025 00:00:00 +0000

Exceptionally high concentrations of Cd (100 to 200 ppm dry weight) were found in samples of Halobates collected off Baja California. In contrast, no detectable Cd was found in Rheumatobates collected from mangrove lagoons in the Gulf of California. Concentrations of five other heavy metals in the two marine insects are also presented.

Halobates from the Coastal Water of China

Wed, 19 Nov 2025 00:00:00 +0000

Article is in Chinese, Abstract in English is included below and at the end of the article.

Little is known about the Halobates around the coasts of China. This study is based on samples collected from Bohai Sea, East China Sea and South China Sea.

Three species of oceanic Halobates, H. micans, H. sericeus and H. germanus, were collected from the East China Sea, but H. germanus was found in the South China Sea samples. Samples from Bohai Sea consisted of land insects blown out to sea. Adults as well as nymphs of all three Halobates species were collected. The biology and adaptations of these unique oceanic insects are discussed.

Ocean Striders from Melanesia (Hemiptera: Gerridae, Halobates SPP.)

Thu, 13 Nov 2025 00:00:00 +0000

The Halobates samples collected during the cruises "Bora", "Saint Vincent" and "Cyclone" were identified to species, sex and developmental stage. A list of stations from which each species was collected is presented, together with a map of their localities. A brief discussion on the distribution and biology of each species is appended.

Complete Species Phylogeny of the Marine Midge Pontomyia (Diptera:Chironomidae) Reveals a Cosmopolitan Species and a New Synonym

Tue, 4 Nov 2025 00:00:00 +0000

Pontomyia (Diptera: Chironomidae) is an exclusively marine and flightless insect genus with four described species from the Indo-Pacific and one undescribed taxon known only by its larvae, pupal skins and females from the western Atlantic. A previous study of relationships among three of the Indo-Pacific species reported each of them to be monophyletic, with high genetic diversity within P. natans Edwards, the type species, and P. pacifica Tokunaga. The evolutionary affinities of the Australian endemic P. cottoni Womersley that resembles P. natans, as well as the putative Atlantic species are hitherto undetermined. A complete molecular phylogeny of the genus based on two nuclear and two mitochondrial DNA markers indicates that P. cottoni and a Puerto Rican (Atlantic) larval population are nested within the P. natans clade. Furthermore, P. natans and P. cottoni are inseparable in all morphological characters used previously to distinguish them. Therefore, we synonymize...

Life History and Biology of the Riffle Bug Rhagovelia obesa Uhler (Heteroptera: Veliidae) in Southern Ontario

Mon, 4 Aug 2025 00:00:00 +0000

The life history of Rhagovelia obesa (Heteroptera: Veliidae) was investigated using field collected and laboratory reared material. The nymphal instars and adults are described and figured. This is the first life-history study of Rhagovelia or its related genera Tetraripis and Trochopus. These genera together have almost a worldwide distribution and are characterized by a unique swimming plume beating underwater. Four nymphal instars occur instead of the usual five. The overwintering stage is the egg, another unusual feature for aquatic Hemiptera. The site(s) of egg laying have not been located. For the first time Rhagovelia has been raised in the laboratory from first instar to adult.

Link to article from publisher: https://cdnsciencepub.com/doi/10.1139/z71-067

Notes on Marine Water-Striders with Descriptions of New Species - Part I. Gerridae (Hemiptera)

Thu, 25 Aug 2022 00:00:00 +0000

Nomenclatural and distributional notes are given for 15 described species of marine Gerridae, 1 species of Asclepios and 14 species of Halobates. Two new species are described, Halobates herringi and Stenobates insularis.

An Interesting Marine Insect, Rheumatobates Aestaurius (Heteroptera : Gerridae), from Baja California, Mexico

Thu, 25 Aug 2022 00:00:00 +0000

A marine littoral insect, Rheumatobates aestuarius Polhemus, is recorded from mangrove lagoons along the coast of Baja California, Mexico, with a detailed description of various instars. The males are characterized by prominent "moustaches'' on the 6th and 7th abdominal ventrites.

High Levels of Cadmium in Atlantic Seabirds and Sea-Skaters

Mon, 22 Aug 2022 00:00:00 +0000

High Levels of Cadmium in Atlantic Seabirds and Sea-Skaters

Disjunct Distributions of Halobates (Hemiptera: Gerridae) in the Pacific Ocean

Mon, 22 Aug 2022 00:00:00 +0000

Five species of Halobates are specially adapted to a pelagic life. They all occur in the Pacific Ocean, each with a well-defined zoogeographical range. Only two species were caught in a series of samples collected between Hawai'i and Tahiti: H. sericeus Eschscholtz, with an amphitropical distribution, and H. micans Eschscholtz, occupying the equatorial zone separating the northern and southern populations of the former. This disjunct distribution pattern may be maintained by zonal equatorial current systems. Although mixing of the two species may occur during seasonal weakenings of the currents, the two populations of H. sericeus appear to be quite separate, with little or no possibilities of genetic exchange.

Flatworms Afloat

Mon, 22 Aug 2022 00:00:00 +0000

Flatworms Afloat

Polonium and Plutonium in an Intertidal Food Chain

Mon, 22 Aug 2022 00:00:00 +0000

Polonium and Plutonium in an Intertidal Food Chain

The Grooming Organs of Culicoides (Diptera: Ceratopogonidae)

Tue, 9 Aug 2022 00:00:00 +0000

The fore tibial and hind tibio-tarsal grooming apparatus of Culicoides melleus and C. furens is described. The hind organ is more complex. The fore organ consists of a single comb of closely spaced spines supplemented by a few adjacent thickened setae, the whole complex being situated at the innter tibial apex.

Halobates (Heteroptera: Gerridae) from Micronesia with Notes on a Laboratory Population of H. Mariannarum

Mon, 8 Aug 2022 00:00:00 +0000

Seven species of sea-skaters, marine insects of the genus Halobates, are reported from Micronesia. Nymphs of nearshore species (H. mariannarum, H. flaviventris, H. nereis, H. princeps) are generally found in sheltered waters among mangrove roots and branches, whereas adults are usually found in more open water. Specimens of open-ocean species (H. micans, H. sericeus, H. germanus) may be found washed to shore after storms. Under laboratory conditions, each nymphal stadium of H. mariannarum lasts 12- 14 days.

New Net for Sampling the Ocean Surface

Fri, 5 Aug 2022 00:00:00 +0000

The 'Manta Net', a new design capable of continuous-flow collection of organisms and flotsam at the sea surface, is described and compared to the Neuston Net. The Manta Net stays reliably at the surface during the entire sample period; its handling requires 2 persons.

Notes on the Ecology of the Oceanic Insect Halobates

Fri, 5 Aug 2022 00:00:00 +0000

Members of the genus Halobates (Heteroptera: Gerridae) are the only known insects found in the oceans, yet they are among the least studied marine organisms. Although these insects have been known to marine biologists and oceanographers since the early 1800's, nothing much was added to our knowledge of these unique insects until the last 20 years (Cheng, 1972). We now know that there are 39 described species found in the world's oceans, seas, and lagoons (Herring, 1961, 1964).

Importance of Marine Insects (Heteroptera: Gerridae, Halobates spp.) as Prey of Eastern Tropical Pacific Seabirds

Fri, 5 Aug 2022 00:00:00 +0000

We analyzed the foraging ecology of seabirds in the eastern tropical Pacific Ocean during 1983–1991 on a series of oceanographic cruises during spring and fall of each year. We report details about the consumption of sea skaters Halobates spp., marine insects that are small, can hide well within sea foam, and can be very fast moving. One abundant sea skater of the four species present in the study area, H. sobrinus, is not taken by sea birds, and the reason is unknown. Among the predators, it appears that frigate storm-petrels, White-faced Storm-Petrel Pelagodroma marina and White-bellied Storm-Petrel Fregetta grallaria (likely also White-throated Storm-Petrel Nesofregetta fuliginosa), make directed efforts to consume sea skaters, a fact that may explain their unique flight and foraging behavior: slow, with extensive “kicksplashing” against the sea surface, to incite movement in Halobates. The few other seabirds for which sea...

Can Halobates Dodge Nets? I. By Daylight?

Fri, 22 Jul 2022 00:00:00 +0000

The frequency of occurrence of the oceanstrider (Halobates spp.), taken in surface plankton samples during the EASTROPAC project, is lower in daytime than at night. The analyses indicate that these insects can see and often avoid the mouth of an approaching net.

UV Absorption by Gerrid Cuticles

Fri, 22 Jul 2022 00:00:00 +0000

Halobates is exposed to continuous insolation at the sea surface throughout its life. Although the UV-absorbance spectrum of its dorsal cuticle (260-450 nm) is similar to those of related species from inshore and freshwater habitats where shelter from sunlight is available, the UV absorbance of the cuticle in a direction perpendicular to its outer surface is much higher in Halobates than in a mangrove-dwelling Rheumatobates or a stream-dwelling Gerris.

Can Halobates Dodge Nets? II. By Moonlight?

Fri, 22 Jul 2022 00:00:00 +0000

Analyses of surface plankton samples collected at night during the EASTROPAC project suggest that Halobates (Heteroptera: Gerridae) may be able to see and avoid nets by the illumination provided by a full moon.

A Comparative Study of the Lipids of Water-Striders from Marine, Estuarine, and Freshwater Environments: Halobates, Rheumatobates, Gerris (Heteroptera: Gerridae)

Fri, 22 Jul 2022 00:00:00 +0000

The lipids of water-striders from three different aquatic environments (marine-Halobates germanus and Halobates sericeus; estuarine- Rheumatobates aestuarius; and freshwater- Gerris remigis) differ considerably in their fatty acid composition. The polyunsaturated 22:6 fatty acid, present only in Halobates, is presumably derived from its marine plankton food. The 20:5 acid is a major component of the lipids of Gerris and Rheumatobates, which feed on terrestrial insects known generally to lack long-chain (> C-18) polyunsaturated acids; it is presumably synthesized by chain elongation from C-18 precursors. Differences in food and habitat may account for some of the observed differences in fatty acid composition.

Neutral triglyceride lipids are stored in all three genera: in Halobates this fraction represents 74-92s of the total lipid, while in Rheumatobates and Gerris...

The Ocean-Strider HALOBATES (Heteroptera: Gerridae)

Wed, 20 Jul 2022 00:00:00 +0000

The genus Halobates, first described by Eschscholtz (1822) was monographed by Herring (1961), with notes on biology and known distribution of the 38 known species and a key for their separation. More recently Savilov (1967) provided additional information on the distribution of the Pacific species. Our knowledge on the biology and ecology of these unique oceanic insects is very scanty.

Our knowledge of the limits of distribution of oceanic Halobates is still very incomplete. From available data they seem to be largely determined by the climatic conditions of the water, and there is no doubt that wind as well as water current play an important role in their distribution. An understanding of the relative importance of these two dispersive factors may help us to understand the distributions not only of Halohates but also of other pleuston organisms.

Superhydrophobicity and size reduction enabled Halobates (Insecta: Heteroptera, Gerridae) to colonize the open ocean

Wed, 11 May 2022 00:00:00 +0000

Despite the remarkable evolutionary success of insects at colonizing every conceivable terrestrial and aquatic habitat, only five Halobates (Heteroptera: Gerridae) species (~0.0001% of all known insect species) have succeeded at colonizing the open ocean – the largest biome on Earth. This remarkable evolutionary achievement likely required unique adaptations for them to survive and thrive in the challenging oceanic environment. For the first time, we explore the morphology and behavior of an open-ocean Halobates germanus and a related coastal species H. hayanus to understand mechanisms of these adaptations. We provide direct experimental evidence based on high-speed videos which reveal that Halobates exploit their specialized and self-groomed body hair to achieve extreme water repellence, which facilitates rapid skating and plastron respiration under water. Moreover, the grooming behavior and presence of cuticular wax aids in the maintenance...

Discovery of the Flightless Marine Midge Pontomyia (Diptera: Chironomidae) at Christmas Island, Australia

Mon, 9 May 2022 00:00:00 +0000

We document the discovery of a unique flightless marine midge Pontomyia (Chironomidae) in the Indian Ocean, presenting descriptions and photographs of the insect and its environment at Christmas Island, Australia. The insect is identified as P. natans, with distinctive male genitalia and rudimentary claws on the hind legs. This species is widely distributed in the Pacific Ocean but the only previous record from the Indian Ocean was from the Maldives. It is highly likely that other populations are present along the continental coast of the latter ocean basin.

Guide to the Aquatic Heteroptera of Singapore and Peninsular Malaysia. I. GERRIDAE and HERMATOBATIDAE

Mon, 9 May 2022 00:00:00 +0000

This is the first guide to the aquatic Heteroptera of Singapore and Peninsular Malaysia to be published as a series in the Raffles Bulletin of Zoology. The families Gerridae and Hermatobatidae are included. Gerridae, with 22 genera and 54 recorded species, are probably the commonest aquatic bugs in our regions whereas Herrnatobatidae, a monotypic family, is represented by only 2 species. We have provided lists of known local species of Gerridae and their habitats, a key to genera as well as keys to species where applicable. We have also included illustrations of representative species of each genus, some of the key characters used, and notes on biology and habitat.

Guide to Aquatic Heteroptera of Singapore and Peninsular Malaysia. Introduction and Key to Families

Mon, 9 May 2022 00:00:00 +0000

This is the first of a series of publications planned as guides to aquatic Heteroptera of Singapore and Peninsular Malaysia to be published in the Raffles Bulletin of Zoology. A key to families and a list of known genera with number of described species for each genus are given.

The Endemic Sea-Skater HALOBATES ALLUAUDI BERGOTH, 1893 (HEMIPTERA: GERRIDAE) in the Seychelles

Mon, 11 Apr 2022 00:00:00 +0000

ABSTRACT - The sea-skater Halobates alluaudi Bergroth, 1893, endemic to the Seychelles, was collected from the islands of Mahe, Praslin, La Digue, and Curieuse, but not from Cousin, Ste. Anne or Cerf. Large flotillas, consisting of both nymphs and adults, were found only associated with mangroves or under overhanging coastal vegetation. Adult females were rare in all the samples and were completely absent from samples from Praslin.

Populations of HALOBATES (HEMIPTERA: GERRIDAE) Across Two Oceans

Mon, 11 Apr 2022 00:00:00 +0000

Specimens of the sea-skater Halobates (Gerridae) were collected in 63% of net tows taken during a 14-month expedition (October 1981 to December 1982) across the Atlantic and the Pacific Oceans between Plymouth, England and Sydney, Australia. Seven species were found including all five open-ocean species (H. micans, H. sobrinus, H. splendens, H. sericeus and H. germanus) and two coastal species (H. robustus and H. proavus). The occurrence and abundance of H. micans in the Atlantic Ocean were positively correlated with seawater temperatures. There was a remarkable similarity between the distribution and age structure of the Atlantic H. micans population in the present study and that of a 1978 expedition along the same cruise track, indicating a high degree of zoogeographical constancy. Although different Halobates species do co-occur, limits of distribution of the five Pacific species appeared to be well...

Chemical Composition and Behavioral Responses of the Marine Insect Halobates hawaiiensis (Heteroptera: Gerridae)

Tue, 18 Jan 2022 00:00:00 +0000

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 nymphalextracts 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...

Insects in marine environments

Thu, 18 Nov 2021 00:00:00 +0000

Insects in marine environments

Book Review: the Biology of Mangroves

Wed, 3 Nov 2021 00:00:00 +0000

Book Review: the Biology of Mangroves

Chromosomes of Five Species of Sea-Skater (Gerridae-Heteroptera)

Wed, 3 Nov 2021 00:00:00 +0000

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 2n~ = 31, the highest chromosome number so far determined for the Gerridae. In a proposed ancestral form, A. shiranui, 2n6' = 23. Males of all five species have an unpaired chromosome, assumed to be the X chromosome of an XO sex chromosome system.

Distribution and Abundance of Halobates Species (Insecta: Heteroptera) in the Eastern Tropical Pacific

Mon, 18 Oct 2021 00:00:00 +0000

Halobates specimens were sorted from 1,649 surface neuston samples collected from the eastern tropical Pacific Ocean. At least one specimen was captured in each of 498 samples. Only 34 samples contained more than one species of Halobates. Four species, H. micans, H. sobrinus, H. sericeus, and H. splendens, were found in the eastern tropical Pacific area. The abundance estimates (lower bounds) range from 400 to 10,000 per km² . Detailed zoogeographical distributions of the four species arepresented. Halobates micans is a warmwater cosmopolite found between lat. 20° N and 20° S; H. sericeus appears to be confined to the central watermasses of the North and South Pacific and does not occur in the zonal equatorial currents; H. sobrinus, the most abundant of the four, is confined to the equatorial upwelling regions off the west coast of Central America; and H. splendens, the rarest species, appears to be associated with the central South Pacific watermass or the South American...

Distribution of the Oceanic Insects Halobates (Hemiptera: Gerridae) off the South Coast of Japan

Fri, 13 Aug 2021 00:00:00 +0000

Specimens of ocean skaters Halobates were collected off the south coast of Japan in the East China Sea in 1995, and from the Kumano-nada Sea to the East China Sea in 1998 and 1999. Three species were identified: H. micans, H. germanus and H. sericeus. We found two species co-occurring in comparable densities in different years, a phenomenon not hitherto reported in other regions of the ocean. We discuss distributions of the three Halobates species with special reference to the influence of the Kuroshio Current, temporal variations of sea-surface temperature, and monsoonal winds.

New Distribution and Habitat Records of Biting Midges and Mangrove Flies from the Coasts of Southern Baja California, Mexico

Fri, 13 Aug 2021 00:00:00 +0000

ABSTRACT: Alegaselia minutior Borgmeier (Phoridae) is reported here for the first time for Baja California. At least in the spring months, Culicoides furens (Poey) (Ceratopogonidae) is the commonest biting midge around Isla San Jose', Bahi'a Balandra and neighboring sites. It was found breeding around the aerial roots of the mangrove Avicennia nitida in swamp mud and burrows of the crab Sesarnw sulcatum. Smittia sp. (Chironomidae) and an apparently undescribed species of Dasyhelea (Ceratopogonidae) were collected from the same habitat on Isla San Jose! We present also some quantitative results for C. furens from emergence traps and preliminary behavior experiments. Deinocerites mcdonaldi Belkin & Hogue (Culicidae) was found breeding in burrows of the crabs Cardisoma crassum and S. sulcatum at several sites north of La Paz: these records extend the known northern limit for its distribution.

Species Composition and Distribution of Ocean Skaters Halobates (Hemiptera: Gerridae) in the Western Pacific Ocean

Fri, 13 Aug 2021 00:00:00 +0000

Five species of ocean skaters Halobates are the only insects that have successfully colonized the ocean. In the western Pacific Ocean, three species of Halobates, H. micans, H. sericeus and H. germanus, are known to occur over a wide area. We investigated the spatio-temporal features of Halobates during the three cruises of R/V Hakuho Maru in the western Pacific in 1994, 1995 and 1998. During these cruises, the area between latitudes 7^o N - 22^o N and longitudes 125^o E - 150^oE was surveyed in all cruises, and in this area H. germanus was absent while H. micans and H. sericeus were caught every year. In 1994 and 1995, H. micans was found almost to the exclusion of H. sericeus and in 1998 H. sericeus was found almost to the exclusion of H. micans, suggesting that these two species rarely co-occur, while their...

The Magnitude of Global Marine Species Diversity

Fri, 7 May 2021 00:00:00 +0000

The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered.

HALOBATES in the Banda Sea (Indonesia): Monsoonal Differences in Abundance and Species Composition

Mon, 26 Apr 2021 00:00:00 +0000

The sea-skater Halobates was collected in eastern Indonesian waters during the SNELLIUS II Expedition in August 1984 (SE monsoon) and February/March 1985 (NW monsoon). About 200 specimens were caught in 18 tows at offshore sites in August, in the upwelling season, but more than 1,000 in 18 tows in February, when the mixed layer was nutrient depletedand chlorophyll-poor. The Indo-Pacific species H. germanus predominated in thecatches during both cruises, its density being inversely related to surface chlorophyll concentration. Reproductive activity of H. germanus was highest in oligotrophic conditions, the relative abundances of nymphs and of cast skins being much higher in February than inAugust. Shifts in the population structure in February suggested a development time of about 7 days or less per stadium at a surface seawater temperature of 29°C. The cosmopolitan H. micans and the coastal H. flaviventris and H. princeps were absent or rare in August but present in...

Are There Separate Populations of HALOBATES in the Gulf of Mexico?

Mon, 26 Apr 2021 00:00:00 +0000

Various developmental stages of the pelagic insect Halobates micans were sorted from four series of neuston samples collected in the Gulf of Mexico and the Caribbean Sea by different institutions during various expeditions. Studies on seasonal occurrences and comparisons of developmental stage compositions suggest that in the Gulf of Mexico there is probably an indigenous population which presumably overwinters as eggs and may complete two or three generations each year between March and November.

Increased Oceanic Microplastic Debris Enchances Oviposition in an Endemic Pelagic Insect

Wed, 14 Apr 2021 00:00:00 +0000

Plastic pollution in the form of small particles (diameter less than 5 mm)—termed ‘microplastic’— has been observed in many parts of the world ocean. They are known to interact with biota on the individual level, e.g. through ingestion, but their population-level impacts are largely unknown. One potential mechanism for microplastic-induced alteration of pelagic ecosystems is through the introduction of hard-substrate habitat to ecosystems where it is naturally rare. Here, we show that microplastic concentrations in the North Pacific Subtropical Gyre (NPSG) have increased by two orders of magnitude in the past four decades, and that this increase has released the pelagic insect Halobates sericeus from substrate limitation for oviposition. High concentrations of microplastic in the NPSG resulted in a positive correlation between H. sericeus and microplastic, and an overall increase in H. sericeus egg densities. Predation on H. sericeus eggs and recent hatchlings may facilitate the...

Marine Insects of the Genera Halobates and Hermatobates (Heteroptera) from Neuston Tows around Lizard Island, Great Barrier Reef

Fri, 19 Feb 2021 00:00:00 +0000

Two species of Halobates and one species of Hermatobates were found in neuston tows taken at seven locations around Lizard Island, Great Barrier Reef. The open-ocean Halobates sericeus Eschscholtz was much more abundant than the nearshore Halobatesprinceps White. Hermatobates weddi China was mainly found in one location, Watson's Bay, and was more frequently caught at night than during the day. Neither Halobates specles was caught in any of the tows taken at night.

Life on the High Seas - the Bug Darwin Never Saw

Wed, 2 Dec 2020 00:00:00 +0000

Among millions of insect species known in the world only five species of Halobates (Heteroptera: Gerridae) are able to live in the high seas. The general public is probably not aware that there are insects living on the open ocean and even most marine scientists have never seen a live or preserved specimen with their own eyes. The genus Halobates was first collected during a Russian oceanographic expedition around the world between 1815 and 1818.

Goose Barnacles (Cirripedia: Thoracica) on Flotsam Beached at La Jolla, California

Wed, 26 Aug 2020 00:00:00 +0000

A total of 1,913 specimens of Lepas (Dosima) fascicularis and 642 specimens of L. (Lepas) pacifica, many still alive, were collected on a 1,000-m stretch of beach at La Jolla between 5 and 9 July 1974. They were attached to various substrates which had enabled them to float at the sea surface before being cast ashore. The predominant substrates were feathers (90 pieces, bearing 657 Dosima, 221 Lepas), sea grass leaves (122 pieces: 835 Dosima, 75 Lepas), brown algae (39 pieces: 200 Dosima, 86 Lepas), and tar (57 pieces: 113 Dosima, 209 Lepas). Dosima is the predominant species on most of the substrates whereas tar lumps appeared to be preferentially settled by Lepas. The size distributions (Dosima, 1-22 mm; Lepas, 1-16 mm) provided no indications of generational discontinuities. The beaching of these normally pleustonic animals should be considered in relation to preceding...

Mitochondrial DNA sequence variation and phylogeography of oceanic insects (Hemiptera: Gerridae: Halobates spp.)

Wed, 26 Aug 2020 00:00:00 +0000

Relatively few insects have invaded the marine environment, and only five species of sea skaters, Halobates Eschscholtz (Hemiptera: Gerridae), have successfully colonized the surface of the open ocean. All five species occur in the Pacific Ocean, H. germanus White also occurs in the Indian Ocean, whereas H. micans Eschscholtz is the only species found in the Atlantic Ocean. We sequenced a 780 bp long region of the mitochondrial cytochrome oxidase subunit I gene (COI) for a total of 66 specimens of the five oceanic Halobates species. Our purpose was to investigate the genetic variation within species and estimate the amount of gene flow betweenpopulations. We defined 27 haplotypes for H. micans and found that haplotype lineages from each of the major oceans occupied by this species are significantly different, having sequences containing five to seven unique base substitutions. We conclude that gene flow between populations of H. micans inhabiting the Atlantic, Pacific, and Indian...

Sex Attractant in the Marine Insect Trochopus plumbeus (Heteroptera: Veliidae): a Preliminary Report

Wed, 26 Aug 2020 00:00:00 +0000

We present evidence of sex-attracting substances, produced by males of the marine insect Trochous plumbeus. This small veliid is widely distributed in the Caribbean. Large numbers were found in the mangrove areas of several islands in the Bahamas. Field assays using live insects and extracts demonstrated that females were highly attracted to males and male extracts, but not the opposite. Gas chromatography-mass spectrometry analyses of extracts from both males and females revealed the presence of a series of aldehydes and long-chain aliphatic acids that are insoluble in water, some of which could possibly act as surface-dispersible semiochemicals.

Biology of Halobates (Heteroptera: Gerridae)

Fri, 31 Jul 2020 00:00:00 +0000

Until about 10 years ago Halobates was probably known to only a handful of entomologists; outside this segment of the entomological world it was generally unknown. However, during the last 10 years there has been a great deal of research on various aspects of the biology of this unique insect genus. It has now become a well-known organism among marine biologists; ironically though, it is still not well-known among entomologists. Recent findings on this unique genus of insects are reviewed, with additional information from unpublished personal observations.

Occurrence and Density of Halobates micans (Hemiptera: Gerridae) in the Eastern South Indian Ocean

Wed, 29 Jul 2020 00:00:00 +0000

Two species of ocean skaters, Halobates germanus and Halobates micans, live in the tropical and subtropicalwaters of the Indian Ocean. From December 1992 to December 1993, Halobates was intensively sampledin 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 speciesin the eastern South Indian Ocean.

Halobates (Heteroptera: Gerridae) from Micronesia with Notes on a Laboratory Population of H. mariannarum

Wed, 29 Jul 2020 00:00:00 +0000

Seven species of sea-skates, marine insects of the genus Halobates, are reported from Micronesia. Nymphs of nearshore species (H. mariannarum, H. flaviventris, H. nereis, H. princeps) are generally found in sheltered waters among mangrove roots and branches, whereas adults are usally found in more open water. Speciments of open-ocean species (H. micans, H. sericeus, H. germanus) may be found washed to shore after storms. Under laboratory conditions, each nymphal stadium of H. mariannarum lasts 12-14 days.

Aquatic Heteroptera (Insecta: Gerromorpha and Nepomorpha) from Xishuangbanna, Yunnan, China

Wed, 29 Jul 2020 00:00:00 +0000

Eighty five species of aquatic and semi-aquatic Heteroptera belonging to 14 families are reported from Xishuangbanna and nearby counties in Yunnan. Collecting locations and habitats are given. Ten species (Hydrometra jaczewskii, H. longicapitis, H. orientalis, Amemboa (Amemboa) sexualis, A. (A.) lyra, Metrocoris ciliatus, Pleciobates pacholatkoi, Ptilomera burmana, Rhyacobates anderseni, Ventidus pulai) are new records for China. In addition, Nine new species (Timasius yunanensis, Ranatra lansburyi, R. sterea, Micronecta (Micronecta) erythra, M. (M.) janssoni, M. (M.) lobata, M. (M.) ornitheia, M. (Unguinecta) melanochroa, Anisops pseudostali) based on material collected during this study, have been described and published elsewhere.

Factors Limiting the Distribution of Halobates Species

Wed, 29 Jul 2020 00:00:00 +0000

The open ocean is almost devoid of insects, except for members of the genus Halobates, first described in 1822. The Challenger expedition produced the first review on the genus but the next major review was not published until 1961. Until the late 1970s marine biologists paid very little attention to these unique insects. We now recognize 45 species in the genus, five being pelagic, the rest distributed in tropical near-shore habitats, often endemic to island groups. Since many remote tropical islands have rarely or neer been visited by marine entomologists, it is likely that new species remain to be discovered.

The Marine Insect Halobates (Heteroptera: Gerridae): Biology, Adaptations, Distribution, and Phylogeny

Fri, 24 Jul 2020 00:00:00 +0000

Among the million or so insect species known, only a few thousand are found in marine habitats. The genus Halobatesis almost exclusively marine and is unique in having the only known species to live in the open ocean. Of the 46 Halobatesspecies described, only five are completelyoceanic in habitat, with the majority of species living in coastal areas associated with mangroves or other marine plants. This review presents a brief historical account of the genus and providesinformation on various aspects of its life history, ecology, special adaptations, distribution, and biogeography. Distribution maps of the five oceanic species as well as several of the more widely distributed coastal species have been updated. The phylogeny and evolution of Halobatesbased on morphology and recent molecular data are also discussed. A key to all known species of Halobatesand related genera and a checklist of all species and their distributions are included as appendices.

A Taxonomic Study of the Malayan Gerridae (Hemiptera: Heteroptera) with notes on their Biology and Distribution

Fri, 24 Jul 2020 00:00:00 +0000

The Malayan Gerridae are monographed based mainly on the collections made by the authors. Of the total of 41 species recorded from Malaya, 4 species are being described elsewhere and are designated here without specific names. All the species are described and figured except Stenobates biroi which we have not collected. Keys to the genera and species are included. Notes on biology and distribution are also given. The Malayan gerrid fauna is both rich and varied and includes 18 genera, representing all six subfamilies of the Gerridae.

Insecta: Hemiptera, Heteroptera

Fri, 24 Jul 2020 00:00:00 +0000

Insecta: Hemiptera, Heteroptera

Marine Insects of Guam: Heteroptera and Diptera

Wed, 22 Jul 2020 00:00:00 +0000

A list of marine Heteroptera and Diptera currently known from Guam is given. Some notes on biology and distribution are alsoincluded.

Fluidisation as a Feeding Mechanism in Beach Flies

Wed, 22 Jul 2020 00:00:00 +0000

Fluidisation as a Feeding Mechanism in Beach Flies

Marine and Freshwater Skaters: Differences in Surface Fine Structures

Wed, 22 Jul 2020 00:00:00 +0000

Marine and Freshwater Skaters: Differences in Surface Fine Structures

Marine Insects

Thu, 28 Sep 2006 00:00:00 +0000

Insects now comprise over 75% of all described animal species and exhibit not only a rich variety of form, color and shape, but also a range of ecological adaptations unexcelled by any other group. Nevertheless, they have generally failed to establish themselves in the world’s seas and oceans. Some speculations as to why insects are so rare in marine habitats have been based on a single postulated obstacle, such as the low concentrations of calcium in seawater. Others have been based on a complex combination of biological, physical and chemical factors. How such factors may have operated to exclude most of an otherwise highly successful group of animals from the most extensive biotope on earth is still not understood.

Actually, some insects are associated with the sea. Even on the open ocean, thousands of kilometres from land, we can find Halobates, which, however, spends all its life on the sea surface. As far as we know, no marine insects remain submerged throughout...