Ichthyoplankton of the Azores seamounts

Species composition and quantitative distribution of ichthyoplankton in the region of the oceanic seamounts of the Azores complex from 2000 to 2004 are considered. The spawning biomass of the main fishery item of this region—Atlantic jack Trachurus picturatus—is calculated. The ichthyoplankton of the Azores seamounts in the period under consideration included eggs and larvae of 60 fish species from 26 families. In the summer, 20 species of eggs and larvae from 11 families and, in winter, 57 species from 24 families were recorded. Larval Myctophidae and Gonastomatidae have the most mass in the plankton in both seasons. The eggs and larvae of commercial fish species (T. picturatus and Pacific mackerel Scomber japonicus) were recorded mainly in the cold period. The species and quantitative composition of ichthyoplankton of the South Azores seamounts is far more numerous than in the North Azores seamounts. The region of the seamounts of the South Azores complex, judging from the estimation of biomass of commercial fish with different methods, can be regarded as a reserve for the fishery of Russian vessels in the central eastern Atlantic.     

How Nemo finds home: the neuroecology of dispersal and of population connectivity in larvae of marine fishes

Nearly all demersal teleost marine fishes have pelagic larval stages lasting from several days to several weeks, during which time they are subject to dispersal. Fish larvae have considerable swimming abilities, and swim in an oriented manner in the sea. Thus, they can influence their dispersal and thereby, the connectivity of their populations. However, the sensory cues marine fish larvae use for orientation in the pelagic environment remain unclear. We review current understanding of these cues and how sensory abilities of larvae develop and are used to achieve orientation with particular emphasis on coral-reef fishes. The use of sound is best understood; it travels well underwater with little attenuation, and is current-independent but location-dependent, so species that primarily utilize sound for orientation will have location-dependent orientation. Larvae of many species and families can hear over a range of ~100-1000 Hz, and can distinguish among sounds. They can localize sources of sounds, but the means by which they do so is unclear. Larvae can hear during much of their pelagic larval phase, and ontogenetically, hearing sensitivity, and frequency range improve dramatically. Species differ in sensitivity to sound and in the rate of improvement in hearing during ontogeny. Due to large differences among-species within families, no significant differences in hearing sensitivity among families have been identified. Thus, distances over which larvae can detect a given sound vary among species and greatly increase ontogenetically. Olfactory cues are current-dependent and location-dependent, so species that primarily utilize olfactory cues will have location-dependent orientation, but must be able to swim upstream to locate sources of odor. Larvae can detect odors (e.g., predators, conspecifics), during most of their pelagic phase, and at least on small scales, can localize sources of odors in shallow water, although whether they can do this in pelagic environments is unknown. Little is known of the ontogeny of olfactory ability or the range over which larvae can localize sources of odors. Imprinting on an odor has been shown in one species of reef-fish. Celestial cues are current- and location-independent, so species that primarily utilize them will have location-independent orientation that can apply over broad scales. Use of sun compass or polarized light for orientation by fish larvae is implied by some behaviors, but has not been proven. Use of neither magnetic fields nor direction of waves for orientation has been shown in marine fish larvae. We highlight research priorities in this area.     

上海地区最常见嗜尸性蝇类三龄幼虫图解检索表

本文提供上海地区最常见嗜尸性蝇类三龄幼虫图解检索表,共4科11种.该检索表可用于案发现场法医昆虫的分类鉴定,进而推断尸体的死亡时间,也可用于重要有瓣蝇类幼虫的孽生地调查.     

龙眼荔枝卷叶蛾类寄主植物种类的初步研究

对广西龙眼荔枝卷叶蛾类寄主植物种类的初步考查结果表明,目前所采到的卷叶蛾种类中,它们的寄主范围不尽相同。柑桔褐带卷蛾Adoxophyes cyrtosema达15科31种;柑桔长卷蛾Homona coffearia和棉褐带卷蛾A.orana的寄主分别有14科21种和13科20种;后黄卷蛾Cacoecia asiatica和柑桔黄卷蛾Archips seminubibis的寄主有10科14种和8科13种;三角新小卷蛾Olethreutes leucaspis、圆角卷蛾Ebodocellerigera和斜斑小卷蛾Andrioplecta oxystaura,目前仅发现危害龙眼及荔枝。新发现柑桔长卷蛾可危害翠蜜枣、指天椒和皱果苋,柑桔黄卷蛾危害粪箕笃、苦丁茶、指天椒,柑桔褐带卷蛾可危害黑面神(Breyniafruticosa)。     

Morphology of the antennal sensory cone in insect larvae from various orders

This article describes the morphology of antennae in larvae of three species of beetles from the families Cerambycidae and Chrysomelidae; one species of the caddis fly from the family Limnephilidae; and four species of dipterans from the families Culicidae, Chironomidae, and Muscidae. In all investigated species, the antenna has a sensory cone on it. Larvae of the caddis fly, longhorn beetles, and leaf beetles have on their antenna solitary sensillae and the sensory cone. This proves the advanced evolution of these species. Despite reduction of the head capsule, the antennal sensory cone in ±9/58 larvae of higher dipterans has become the dominant sensory structure.     

Types of parasitism by larvae of water mites (Acari: Hydrachnellae)

The larvae of Hydrachnellae can be divided into three types, based on the habits of the parasitic (larval) stage in the life cycle. (1) The larvae do not leave the water. Parasitizing aquatic insects, they are permanently submerged and wet. Only some species of the family Hydrachnidae belong to this type. (2) The larvae leave the water. The parasitic phase occurs either on insects living on the water surface, or in the air stores of aquatic insects. In both cases the larvae are not in direct contact with water during the parasitic phase. The Limnocharidae, Eylaidae and some species of the Hydrachnidae belong to this type. (3) The larvae parasitize insects which live in the air and which can leave the direct proximity to water; therefore it may be difficult for the mite larva to return to water. Except for the Hydrachnidae, Limnocharidae and Eylaidae, all families of the Hydrachnellae belong to this type.     

Phylogeny of the Neuropterida (Insecta: Holometabola)

The Neuropterida, with about 6500 known species — living fossils in a way — at the base of the Holometabola (as a sister group of the Coleoptera), comprise Raphidioptera (about 210 species, two families), Megaloptera (about 300 species, two families) and Neuroptera (6000 species, 17 families). Megaloptera + Neuroptera is argued vs. the traditional Raphidioptera + Megaloptera. Raphidioptera are undisputedly monophyletic. Monophyly of Megaloptera is the operational hypothesis, although occasionally questioned. Sucking tubes of the larvae are the most spectacular autapomorphy of Neuroptera. The construction of larval head capsules indicates three evolutionary lines: Nevrorthiformia, and Myrmeleontiformia + Hemerobiiformia. Traditional Myrmeleontiformia is Psychopsidae + (Nemopteridae + (Nymphidae + (Myrmeleontidae + Ascalaphidae))), the present approach is (Psychopsidae + Nemopteridae) + all other Myrmeleontiformia. Hemerobiiformia are based on the ‘maxillary head’ concept. The ithonid clade Ithonidae/Rapismatidae + Polystoechothidae and the dilarid clade Dilaridae + (Mantispidae + (Rhachiberothidae + Berothidae)) are based on robust criteria. Other relationships remain unclear: Hemerobiidae + Chrysopidae (on similarity) and the ‘early offshoot’ concept of coniopterygidae (on autapomorphies) should not be perpetuated. Chysopidae + Osmylidae and (Hemerobiidae + (Coniopterygidae + Sisyridae)) + dilarid clade are discussed. Aquatic larvae, regarded as independent apomorphies of megaloptera and neuropteran Nevrorthidae and Sisyridae for a long time, are re‐interpreted as a synapomorphy of Megaloptera + Neuroptera and thus plesiomorphic within these groups. Terrestrial larvae (with cryptonephry to solve osmotic problems) are consequently apomorphic. Aquatic Sisyridae with cryptonephry of a single malpighian tubule, is conflicting, but larvae may have become secondarily aquatic, after a terrestrial intermezzo.     

State of the Ichthyoplankton Community along the Crimean Peninsula in August 2011

Data on species composition, spatial distribution of ichthyoplankton, and feeding of fish larvae in August 2011 are presented for the shelf and the open waters along the Crimean Peninsula from Kerch Strait to Karkinit Bay. In the ichthyoplankton, fish eggs and larvae represented 19 species from 16 families. The average egg abundance was 111 egg/m² and larvae abundance was 22 ind./m². The elimination ratio of the European anchovy Engraulis encrasicolus, which dominates in the plankton from the final stages of development to the prelarvae in 2011, was similar to that observed in 1957. The high number of larvae of the older age group in the western halistatic zone is explained by the peculiarities of the hydrological regime. Decrease in the pressure of predatory jelly macroplankton and an fodder zooplankton (zooplankton abundance) contribute to the survival of the fish larvae.     

跳甲属昆虫的食性及其生物学意义

跳甲属昆虫广布全世界,已知300多种,体色近似,外形差异不大,分类鉴定十分困难。但其中许多种类具特殊的食性特征,其寄主植物常是分类鉴定的向导和重要参考。作者分析了已知有寄主记录的59种跳甲的寄主,并根据其寄主范围划分为5种类型:取食多科、2科、1科多属、1科2属及1科1属,而以1科1属型为最多,占67.8%。至目前所知,其寄主范围限于双子叶植物,跳甲和寄主植物之间的对应关系是跳甲的“种”对植物的“属”。值得特别关注的是寄主植物的“种”与跳甲“亚种”之间的分化关系。成虫的取食范围大于幼虫,幼虫保持原始的取食特征。跳甲的同域物种分化可能通过食性转化而进行,食性转化可能先从成虫开始。成幼食性观察是研究寄主转移的关键。     

Distribution of Iron-Containing Granules in Lampreys,with Particular Reference to the Southern Hemisphere Species Geotria australis Gray

Perl's Prussian blue and bathophenanthroline have been used to investigate the sites where iron-containing granules are found within representatives of each of the three extant families of lampreys. Amongst the larvae, granules were present in the columnar cells of the posterior intestine in small amounts in some but not all northern hemisphere species (Petromyzonidae), and in moderate and very large amounts in the southern hemisphere families Geotriidae and Mordaciidae respectively. Granules were only found in large numbers elsewhere in the body of larvae of the Geotriidae, in which they were predominant in the adipose tissue of the nephric fold and fat column. It is suggested that these large iron deposits reflect the intake of an unusually large amount of iron, a feature which in turn could be related to the relatively high plasma iron levels and haemotocrit found in larvae of the Geotriidae. During metamorphosis, iron deposits accumulate in the liver of all species as haemoglobin is broken down.     

PARASITISM OF MYTHIMNA CONVECTA (WALKER) (LEPIDOPTERA: NOCTUIDAE) LARVAE IN SOUTH EAST QUEENSLAND

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Nineteen collections of Mythimna convecta (Walker) larvae, made during an extensive outbreak of this species in winter barley in 1978, revealed a total of 8 parasite species, belonging to the families Tachinidae, Ichneumonidae and Braconidae. Mean percentage parasitism of M. convecta larvae by all parasites was 18.2%, and highest parasitism in any collection was 52.3%. Apanteles ruficrus Haliday was the dominant parasite.     

Articulated coralline algae of the genus Amphiroa are highly effective natural inducers of settlement in the tropical abalone Haliotis asinina

The initiation of metamorphosis in marine invertebrates is strongly linked to the environment. Planktonic larvae typically are induced to settle and metamorphose by external cues such as coralline algae (Corallinaceae, Rhodophyta). Although coralline algae are globally abundant, invertebrate larvae of many taxa settle in response to a very limited suite of species. This specificity impacts population structure, as only locations with the appropriate coralline species can attract new recruits. Abalone (Gastropoda, Haliotidae) are among those taxa in which closely related species are known to respond to different coralline algae. Here we identify highly inductive natural cues of the tropical abalone Haliotis asinina. In contrast to reports for other abalone, the greatest proportion of H. asinina larvae are induced to settle and metamorphose (92.8% to 100% metamorphosis by 48 h postinduction) by articulated corallines of the genus Amphiroa. Comparison with field distribution data for different corallines suggests larvae are likely to be settling on the seaward side of the reef crest. We then compare the response of six different H. asinina larval families to five different coralline species to demonstrate that induction by the best inductive cue (Amphiroa spp.) effectively extinguishes substantial intraspecific variation in the timing of settlement.     

Loss of larval parasitism in parasitengonine mites

Larval Parasitengona are typically parasites, yet at least 29 species of water mites and one species of Trombidiidae forgo larval feeding and any association with a host. Species with non-feeding larvae are isolated cases within species groups or genera where the remaining species have parasitic larvae. Species without larval parasitism occur in at least 14 genera, eight families and four superfamilies of water mites; the loss of larval parasitism is presumably polyphyletic, having occurred at least 21 times. Lineages of water mites with non-feeding larvae frequently exist in parallel with almost identical populations or species that have parasitic larvae. Thus, there is tremendous potential for studies comparing the relative merits of the two life history strategies. Comparisons indicate that adults from lineages with non-parasitic larvae produce smaller numbers of larger eggs; the extra nutrition included in larger eggs permits the larvae to forgo feeding. Non-feeding larvae frequently have wider dorsal plates but reduced leg length, setal length and sclerotization when compared to parasitic larvae from sister lineages. The adults of lineages with non-feeding larvae are frequently smaller in comparison to adults of sister lineages with parasitic larvae. There is no apparent pattern in relation to habitat: lineages lacking larval parasitism occur in streams, temporary ponds and the littoral and planktonic regions of permanent lakes. © Rapid Science Ltd. 1998     

Winter spatial distribution of fish larvae assemblages relative to the hydrography of the waters surrounding Taiwan

The aim of this study was to investigate the species composition and distribution of fish larvae in relation to hydrographic conditions in the waters surrounding Taiwan Island (TI) in February 2003. In total, 242 kinds of fish larvae belonging to 127 genera and 75 families were recognized. Among these, 109 taxa were identified to the family or genus level, others to the species level. The 12 predominant types, which constituted 71% of the total fish larvae, were Engraulis japonica, Scomber sp., Diaphus spp., Benthosema pterotum, Carangoides ferdau, Embolichthys mitsukurii, Maurolicus sp., unidentified Myctophidae, Gonostoma gracile, Trichiurus lepturus, unidentified Gobiidae, and Myctophum asperum. The distribution of fish larvae showed a clear association with water masses around TI, with higher abundances and lower species richness northwest of TI where the China Coastal Current prevails, and lower abundances and higher species diversity east of TI where the Kuroshio Current dominates. Cluster analysis distinguished three station groups and four species groups, and the distribution patterns of fish larvae also corresponded to hydrographic conditions. The total abundances of fish larvae and eight of the 12 predominant taxa showed significant and positive correlations with zooplankton abundance, which suggests that food source might be a key factor determining the abundance and distribution of fish larvae during the winter.     

Host specificity of microsporidia pathogenic to the gypsy moth, Lymantria dispar (L.): Field studies in Slovakia

Several species of microsporidia are important chronic pathogens of Lymantria dispar in Europe but have never been recovered from North American gypsy moth populations. The major issue for their introduction into North American L. dispar populations is concern about their safety to native non-target insects. In this study, we evaluated the susceptibility of sympatric non-target Lepidoptera to two species of microsporidia, Nosema lymantriae and Vairimorpha disparis, isolated from European populations of L. dispar and applied in field plots in Slovakia. Application of ultra low volume sprays of the microsporidia maximized coverage of infective spores in a complex natural environment and, thus, exposure of non-target species to the pathogens. Of 653 non-target larvae collected from plots treated with V. disparis in 2002, 18 individual larvae representing nine species in four families were infected. These plots were monitored for two subsequent seasons and V. disparis was not recovered from non-target species. Of 2571 non-target larvae collected in N. lymantriae-treated sites, one larva was found to be infected. Both species of microsporidia, particularly N. lymantriae, appear to have a very narrow host range in the field, even when an inundative technique is used for their introduction. V. disparis infections in L. dispar exceeded 40% of recovered larvae in the treated study sites; infection rates were lower in sites sprayed with N. lymantriae. Several naturally-occurring pathogens were recorded from the non-target species. The most common pathogen, isolated from 21 species in eight families, was a microsporidium in the genus Cystosporogenes.     

Influence of hydrographic features on larval fish distribution during the south‐westerly monsoon in the waters of Taiwan,western North Pacific Ocean

The spatial distribution patterns of fish larvae and the relationships with hydrographic conditions in the waters surrounding Taiwan were studied in August 2004 when the south‐westerly monsoon prevailed. A total of 6566 fish larvae were identified, belonging to 80 families, 129 genera and 230 species. Cluster analysis revealed two station groups, one associated with the South China Sea Surface Current (SCSSC) and the other with the Kuroshio Current (KC). The SCSSC group was characterized by mostly coastal and neritic species, and the KC group was predominated by oceanic species. Larger fish larvae were generally more abundant in the neritic waters west of Taiwan where the SCSSC prevails than in the waters east of Taiwan where the KC prevails. The combination of chlorophyll a, zooplankton and nitrite best explained the relationship of larval fish distribution and environmental variables, implying that the distribution of fish larvae in summer was closely linked to the food source. The changing of monsoons potentially affects the succession of water masses and the transport and assemblage of fish larvae in this study area.     

Phytophagous British insects and mites and their food-plant families: total numbers and polyphagy

The Phytophagous Insects Data Base (PIDB) was used to summarize information about 6933 species of British insects/mites and their food-plant families. Total species in 183 insect families on 127 vascular plant families were correlated with numbers of plant species in each family in Britain and Europe, accounting for 41.8% of the variation. Families with trees had more insects, while ferns and aquatic, uncommon and ephemeral plants, particularly orchids, had fewer. Seven individual insect families were analysed separately: Aphididae were more closely correlated with plant species numbers than were the more polyphagous Geometridae. Agromyzidae were uncommon on families with trees. Of insect species 75.8% fed on only one plant family and 10.1% were recorded on two families. Species feeding on three families or more were considered to be polyphagous. In the 30 largest insect families, eight had species feeding on only one plant family, while 12 had more than 20% of their species polyphagous. Proportions of family-restricted insects were high on Pinaceae, Gramineae and Compositae, but low on Corylaceae, Primulaceae and Tiliaceae. More pest species were polyphagous. Polyphagy was related to large larvae, larvae overwintering, wood-feeding, ephemeral food sources, poor dispersal abilities and omnivory. Some polyphagous species might be actively evolving in exploitation of vacant niches, leading to later progressive specialization to food-plants.     

Replenishment of fish populations in the enclosed lagoon of Taiaro Atoll: (Tuamotu Archipelago, French Polynesia) evidence from eggs and larvae

 Taiaro Atoll Lagoon is normally isolated from the ocean, but at least 125 marine fish species of 31 families are present there. We sampled fish larvae in Taiaro Lagoon and the nearby ocean in February 1994 with plankton net, neuston net and light trap to investigate which taxa were completing their life cycles in the lagoon. Concentrations of fish eggs and larvae were very high in the lagoon indicating intense spawning, but larvae of only 18 taxa of 10 families were present. Only six, a callionymid, gobiids, a hemiramphid, a microdesmid, and two pomacentrids, were present across a full range of pelagic sizes, and were clearly completing their pelagic stage in the lagoon. Four other taxa, an apogonid, two labrids and a scarid, were common, but the largest individuals were small (<5 mm) postflexion larvae. These may have been completing their pelagic stage in the lagoon. The remaining lagoonal larvae (eight taxa) were rare and at the preflexion stage, so we could only conclude that they hatched from eggs spawned in the lagoon. Nineteen taxa of 15 families found as adults in the lagoon were present outside the lagoon as larvae, but not inside, suggesting that they may not normally complete their life cycles in the lagoon. Horizontal distributions of larvae in the lagoon are apparently due to the interaction of larval vertical distribution behaviour with a wind-driven countercurrent system. Accepted: 16 October 1996     

A survey of hymenopteran parasitoids of forest macrolepidoptera in the central Appalachians

In 1995 and 1996, we conducted a study of the hymenopteran parasitoids of macrolepidopteran larvae in the George Washington National Forest (GWNF), Augusta County, Virginia, and the Monongahela National Forest (MNF), Pocahontas County, West Virginia. Macrolepidopteran larvae were collected from canopy foliage and from under canvas bands placed around tree boles. A total of 115 macrolepidopteran species and 5,235 individual larvae were reared. Forty-two percent (2,221) of the larvae were gypsy moth, Lymantria dispar (L.) (Lymantriidae). A total of 43 primary and secondary (hyperparasitoid) hymenopteran parasitoid species were reared from 46 macrolepidopteran species. Hymenopteran families represented included Ichneumonidae (23 species), Braconidae (19), Eulophidae (6), Perilampidae (1), and Trigonalidae (1). We reared 41 and 28 parasitoid species from the GWNF and the MNF, respectively, with 19 species reared from both forests. Many parasitoid species were collected infrequently, suggesting that they are relatively rare on the sampled hosts. The introduced species Cotesia melanoscela (Ratzeburg) (Braconidae), and Euplectrus bicolor (Swederus) (Eulophidae) were among the most commonly reared parasitoids, the latter reared from native hosts. The four most commonly reared native parasitoids were Meteorus hyphantriae, Riley (Braconidae), Microplitis near hyphantriae (Ashmead) (Braconidae), Aleiodes preclarus Marsh & Shaw, and Euplectrus maculiventris (Westwood) (Eulophidae). A total of 53 new hymenopteran parasitoid-macrolepidopteran host records were documented. Results from this study will be used to evaluate long-term treatment effects of regional applications of Bacillus thuringiensis kurstaki, and the gypsy moth fungus Entomophaga maimaiga Humber, Shimazu & Soper on hymenopteran parasitoids of macrolepidopteran larvae.     

Opposed ciliary bands in the feeding larvae of sabellariid annelids

The larvae of marine annelids capture food using an unusual diversity of suspension-feeding mechanisms. Many of the feeding mechanisms of larval annelids are poorly known despite the abundance and ecological significance of both larvae and adults of some annelid taxa. Here we show that larvae of two species of sabellariid annelids, Sabellaria cementarium and Phragmatopoma californica, bear prototrochal and metatrochal cilia that beat in opposition to each other. For larvae of S. cementarium, we provide evidence that these opposed bands of cilia are used to capture suspended particles. In video recordings, captured particles were overtaken by a prototrochal cilium and then moved with the cilium to the food groove, a band of cilia between the prototroch and metatroch. They were then transported by cilia of the food groove to the mouth. Lengths of the prototrochal cilia, lengths of the prototrochal ciliary band, size range of the particles captured, and estimated rates of clearance increased with larval age and body size. Confirmation of the presence of opposed bands in larvae of sabellariids extends their known occurrence in the annelids to members of 10 families. Opposed bands in these different taxa differ in the arrangements and spacing of prototrochal and metatrochal cilia, and in whether they are used in combination with other feeding mechanisms. Opposed bands appear to be particularly widespread among the larvae of sabellidan annelids (a clade that includes sabellariids, sabellids, and serpulids), even in some species whose larvae do not feed. A parsimony analysis suggests that opposed bands are ancestral in this clade of annelids.