Comparison of Postembryonic Organization of the Genital Segments in Trichoceridae, Tipulidae, and Anisopodidae (Diptera, Nematocera)

The number of abdominal segments in Tipulomorpha and Bibionomorpha larvae and aduts is discussed. For Nematocera, the most primitive number of abdominal segments in both male and female larvae is nine. Reduction of the IX abdominal segment and its subsequent fusion with the VIII segment occurs in different phyletic lines in Nematocera and might have evolved several times. In Trichocera spp. nine abdominal segments are present. In the genital segments the main interrelationships in the position of the anus and some main innervation areas, especially the ventral lobes, and the derivatives of the genital primordia were followed during postembryonic reorganization by studying variously stained serial sections from all developmental stages from the first larval instar to the adult stage. Homologies between male and female derivatives of the IX segment genital primordium were established for Trichoceridae. The trichoceroid male claspers and female ovipositor were found to be of sternal origin and highly specialized structures. They appear to be unique features of the Tipulomorpha. Postembryonic development in Limonia nubeculosa Meigen, 1804 and Sylvicola cinctu (Fab-ricius, 1787) was studied in the same way. In Limonia males the trichoceroid functional system for grasping is present. In Anisopodidae ( Sylvicola ), another functional system for grasping has been evolved by the male, which only includes primordial derivatives. In the adults, fusion of the VIII and IX segments prevents development of outer clasping organs or special structures for egg guidance.     

A new species of Acentrella Bengtsson (Ephemeroptera: Baetidae) from Great Smoky Mountains National Park,USA

Acentrella barbarae sp. n. is described from eggs, larvae, and imagines collected from Great Smoky Mountains National Park, North Carolina and Tennessee, USA. Larvae were collected from cobble-pebble substrate in stream rapids. Life stages were associated by rearing. Eggs have longitudinal chorionic ridges with small, longitudinal furrows. Larvae are distinguished by having segment 3 of the labial palp apically rounded, abdominal terga with posteromedian projections, and tibiae and tarsi with relatively short setae on the outer margins. Imagines are distinguished by the colouration and posterior elevation of abdominal terga. Other Acentrella larvae occur in the same streams as the new species, including A. parvula, which we report from Tennessee for the first time. We provide an updated key to the larvae of North American Acentrella species.     

Discovery of swimming larvae in Elmidae (Coleoptera: Byrrhoidea)

The aquatic larvae of the family Elmidae (Coleoptera) have been considered unable to swim because they lack swimming setae on their body and legs. We discovered that riffle beetle larvae (Leptelmis gracilis Sharp) are in fact able to swim. After opening the tuft‐like gills on the last abdominal segment they swim by repeatedly bending the abdomen into a U‐shape very quickly and in a wavy manner, while their head and thorax move anteriorly, resulting in a sigmoidal body shape. The flat bodies of L. gracilis larvae could be advantageous for swimming compared to the cylindrical or semicylindrical bodies of larvae in related genera.     

Larva and pupa of Cyphopisthes descarpentriesi Paulian (Coleoptera: Scarabaeoidea: Ceratocanthidae) and their phylogenetic implications

Abstract Pupae and mature larvae of the Australian ceratocanthid beetle, Cyphopisthes descarpentriesi Paulian 1977, are described and extensively illustrated. This is the sixth species of the family for which immature stages are known and the first from the Australian region. Unlike other ceratocanthid larvae described before, those of Cyphopisthes Gestro lack stridulatory teeth on the middle and hind legs and any trace of a frontoclypeal suture on the cranium. Reduced one-segmented labial palpi in Cyphopisthes are unique in Scarabaeoidea. Monophyly of the family is not corroborated by larval characters. Absence of spiracular closing apparatus in larvae is reported in the family for the first time. Like pupae of Ceratocanthus White and Germarostes Paulian, those of Cyphopisthes have thoracic projections, but their shape and location are different. Spiracles are found on abdominal segments 2−4 of pupa; that on segment 2 differs in colour and location from the others.     

Discovered in our backyard: a new genus and species of a new family from the Rocky Mountains of North America (Diptera, Tabanomorpha)

Abstract. A new genus of the Tabanomorpha, Oreoleptis, gen.n. , assigned to the monotypic family Oreoleptidae, fam.n. , is described from the Rocky Mountains of North America. The male, female, larva and pupa of Oreoleptis torrenticola, sp.n. are described and illustrated. Adults were reared from larvae collected from torrential streams and rivers, and from pupae collected from riverbanks. No adults have been collected yet in the field. The larvae have two pairs of very long, ventrolateral, crocheted prolegs on abdominal segments 2–7, and a short, dorsal pair on segments 6–7. The larval head and mouthparts resemble those of athericids and tabanids. The mandibular hook has an internal canal, the basal mandibular sclerite is compressed with both condyles coming together and articulating on the tentorial phragma; the mandibular brush is located on a vertical rod; and the salivary pump is greatly enlarged. The adult male genitalia have aedeagal tines similar to athericids, tabanids and Bolbomyia Loew, the hypandrium is fused with the gonocoxites, the epandrium is subrectangular, lying flat on the gonocoxites, and tergite 10 is present (a mixture of advanced and primitive features). The endoaedeagal process is reduced (as in athericids), and the gonocoxal apodemes are long and slender, an advanced condition shared by athericids and tabanids. The female has a long, extrusible postabdomen and ovipositor, two-segmented cerci, and the basal cercal segment has a prominent posteroventral lobe, typical of rhagionids and pelecorhynchids. Cladistic analysis assigns the genus Oreoleptis to sister group status of the Athericidae + Tabanidae. However, wing venation, simple, unmodified female abdomen, undivided first tergite, and two-segmented female cercus, excludes this taxon from the Athericidae and Tabanidae. The relationships of the new family are discussed and the phylogeny of the higher Tabanomorpha reassessed.     

The life cycle of Pteronarcys scotti (Plecoptera: Pteronarcyidae) from the Southern appalachians,U.S.A.

Larval and adult Pteronarcys scotti Ricker were collected from a mountain stream in northwestern South Carolina, USA. The pattern of larval growth indicated a semivoltine life cycle. Emergence occurred in April and early May, and small larvae first appeared in May. Sexual dimorphism in adult size was apparent; males were 0.8 as large as females in head capsule width.

Female larvae possess a midventral notch on the eighth abdominal segment that can be used to sex larvae as small as 2.5 mm in head width. Female larvae as small as 1 mm in head width have a midventral break in the posterior setal row of segment 8. These characters are illustrated.     

The larvae of the burrowing mayfly genus Tortopus (Ephemeroptera: Polymitarcyidae)

The larval stage of Tortopus is redescribed based on three species: T. puella from North America, the only species of the genus previously known from larva, and the larvae of T. obscuripennis and T. sarae from South America described here. Generic characters of the larva include: relatively large finger-like gill near base of maxilla, inner margin of mandibular tusks with a subdistal tubercle, straight or weakly convex frontal ridge present between antennae, reduced unilamellated gill on abdominal segment I. Additionally the male imagines of both Neotropical species are described for the first time, and T. obscuripennis is recorded from Bolivia. Diagnoses, SEM photographs, and illustrations are given for the new stages described and for the identification of the three Tortopus species known as larvae.     

Nucleotide substitutions at the -6 position in the promoter region of the factor IX gene result in different severity of hemophilia B Leyden: consequences for genetic counseling

Mutations in the promoter region of the factor IX gene result in hemophilia B Leyden, which is characterized by considerable improvement in the disease after puberty. We have found that distinct nucleotide substitutions at the -6 position in the Leyden-specific (LS) region are associated with a different severity of hemophilia B. The proband (aged 2) from one family is a severe hemophiliac with factor IX activity (F.IXC) and antigen (F.IXAg) levels less than 1.0U/dl. F.IXC and F.IXAg levels in two affected uncles are approximately 30% of normal levels. The LS region was targeted for analysis because the phenotypes suggested the inheritance of a factor IX Leyden gene. An abnormal TaqI digestion pattern was found in amplified DNA from the proband, and sequencing showed a G (-6) to C transversion that was linked to the disease in the family. In another family, two brothers (aged 8 and 9) suffer from mild hemophilia with F.IXC ranging from 7 to 10 U/dl and F.IXAg from 3 to 4 U/dl. They are the only documented members of the family with a bleeding tendency. Denaturing gradient gel electrophoresis on amplified fragments from one of the patient's genomic DNA corresponding to the 8 exons and flanking sequences of the factor IX gene suggested a defect only in a segment from the 5 region. This segment showed an altered TaqI digestion pattern, and sequencing demonstrated a G(-6) to A transition that was traced to the patients's mother and a grandmother. The different phenotypes associated with the G (-6) to A purine nucleotide transition compared with a G(-6) to C transversion provide evidence that this area is directly involved in the regulation of the human factor IX gene expression in vivo by binding of regulatory factors. The ability to predict that the conditions of a hemophilia B patient will improve with age has important implications for genetic counseling of the family. Therefore, the LS region should always be included when scanning the factor IX gene for mutations.     

Larval morphology of Agabus clypealis (Thomson, 1867) and A. pseudoclypealis Scholz, 1933 and notes on their distribution (Coleoptera: Dytiscidae)

The third instar larvae of Agabus clypealis (Thomson, 1867) and A. pseudoclypealis Scholz, 1933 are described. Important morphological structures (head, legs, and abdominal segment 8 with urogomphi) are illustrated. Both species share a completely sclerotized abdominal segment 6 with A. setulosus (J. Sahlberg, 1895). Morphological characters and species phenology are discussed in relation to the A. confinis-species group. All available literature records and some new and additional data on distribution of the two species are provided. Agabus clypealis is recorded for the first time from Estonia, and there is no reason to doubt the records of A. pseudoclypealis from Kazakhstan.     

<Emphasis Type="Italic">Prodajus curviabdominalis</Emphasis> n. sp. (Isopoda: Epicaridea: Dajidae), an ectoparasite of mysids,with notes on morphological changes,behaviour and life-cycle

Adults and larvae of a new ectoparasitic isopod, Prodajus curviabdominalis n. sp., are described from the mysid Siriella okadai Ii collected from the Seto Inland Sea, western Japan. The adult female is found within the host marsupium with the cephalon directed posteriorly, whereas the dwarf adult male attaches to the ventral surface of the female pleon. The cryptoniscid larva usually attaches to the second or third abdominal somite of the host, using an oral sucker. Mature adults of the new species are distinguished from all other congeners by: pleon of ovigerous female strongly curved dorsally, with large swellings on ventral side; pereon of ovigerous female narrow; exopods on male uropods present; male pleon short and thick. This is the third record of a member of the Dajidae from Japan. The behaviour of the cryptoniscid larvae of the new species on the host mysid was also observed using a video camera. Larvae moved from the first attachment site, usually the second or third abdominal somite of the host mysid, into the marsupium. When host oostegites were not fully developed, larvae entered beneath the host carapace until her marsupium was fully formed. The host infected by a female P. curviabdominalis moved the oostegites rhythmically, an action which may aid the respiration of the parasite.     

The probable significance of tracheal tufts in the 8th abdominal segment of Heliothis virescens (F.) on the development of its parasitoid, Toxoneuron nigriceps (Viereck)

The 8th abdominal segment of Heliothis virescens (Fabricius) larvae contains aerating trachea and tracheole tufts that end in the hemocoel of the 8th segment, unlike the tracheae that invade tissues in other segments. These tracheal tufts from the 8th abdominal segment extend to the tokus region, which along with the telson cavity is known to act as a “lung” for hemocytes in Calpodes ethlius and a few other lepidopteran larvae. The goal of this research was to study the effects of these tracheal tufts in the 8th abdominal segment on parasitoid development inside the host larvae, H. virescens. The first objective was to determine if the eggs of the parasitoid, Toxoneuron nigriceps, are predominantly located among the tracheal tufts of the 8th abdominal segment compared to other body cavity regions irrespective of their oviposition site or the position of the host larvae. The results showed that several hours after oviposition most of the eggs are found in the 8th abdominal segment irrespective of the oviposition site or the position of the host larvae. The second objective was to study the effect of varying oxygen concentrations in vitro on various developmental stages of the egg. The results showed that decreasing oxygen concentrations adversely affects the parasitoid egg development in vitro. A third objective was to determine the oxygen concentration in 8th abdominal segment of the host larvae and compare it to other regions of the body using an oxygen sensor placed in vivo. The results suggested relatively high concentration of oxygen in the 8th abdominal segment compared to other regions of the host, thus supporting our hypothesis that the increased oxygen level in the 8th abdominal segment is important to the development of the parasitoid eggs.     

Distinguishing features of immature stages of Panchaetothripinae (Thysanoptera: Thripidae) known in New Zealand

Diagnostic morphological characters of the juvenile Panchaetothripinae in New Zealand are illustrated. Keys developed enable colonies with only immature stages to be identified without needing to rear adults. Live larvae or larvae in ethanol are distinguished by the presence of expanded tips of body setae (Parthenothrips dracaenae), the absence of setae at the abdomen tip (Hercinothrips bicinctus), setae at abdomen tip not longer than abdominal tip width (Heliothrips haemorrhoidalis) and abdominal tip setae longer than abdominal tip width (Sigmothrips aotearoana, endemic species). The presence or absence of spine-like setae on abdominal segments 9 and 10, and the number and length of setae on the wing buds, enable identification of pupae. Abdominal spine-like setae were on the prepupa and pupa of H. bicinctus and S. aotearoana, species that pupate off the plant, and are probably defensive structures. This is the first record of spine-like setae on segment 10 of terebrantian pupae.     

The abdomen of a free-living female of Strepsiptera and the evolution of the birth organs

Mengenillidae is a small, basal family of Strepsiptera, mainly characterized by free-living females in contrast to the endoparasitic females of Stylopidia. Here, we describe external and internal structures of the female abdomen of Eoxenos laboulbenei (Mengenillidae). The external morphology was examined and documented using microphotography. Internal structures were reconstructed three-dimensionally using a μCT-data set. The morphologically simplified abdomen comprises 10 segments. The integument is weakly sclerotized and flexible. Spiracles are present dorsolaterally on segments I–VII. Segment VII bears the posteroventral birth opening and the small abdominal segment X carries the anus at its apex. Numerous eggs float freely in the hemolymph. The musculature of segments I–IV is composed of ventral and dorsal longitudinal muscle bundles, strongly developed paramedial dorsoventral muscles and a complex meshwork of small pleural muscles, with minimal differences between the segments. Segments V–X contain more than 50 individual muscles, even though the musculature as a whole is weakly developed. Even though it is not involved in processing food, the digestive tract is well-developed. Its postabdominal section comprises a part of the midgut and the short hindgut. The midgut fills a large part of the postabdominal lumen. The lumina of the midgut and hindgut are not connected. Five or six nodular Malpighian tubules open into the digestive tract at the border region between the midgut and hindgut. The birth organ below the midgut releases the primary larvae after hatching via the birth opening at segment VII. It is likely derived from primary female genital ducts. The presence of six additional birth organs of segments I–VI are de novo formations and a groundplan apomorphy of Stylopidia, the large strepsipteran subgroup with endoparasitic females. The loss of the primary birth organ of segment VII is an apomorphy of Stylopiformia (Stylopidia excl. Corioxenidae).     

长蝎蛉幼期形态附生物学记述

【目的】蝎蛉科(Panorpidae)是长翅目(Mecoptera)最大的科,是重要的生态指示昆虫。然而,由于对环境条件要求苛刻,饲养困难,其幼期研究很不充分。【方法】本研究通过人工饲养成虫获得了长蝎蛉Panorpa macrostyla Hua的卵、幼虫和蛹等全部虫态,运用光学显微镜和扫描电子显微技术观察了其超微形态,并简要记载了其生物学特性。【结果】长蝎蛉每年发生1代,成虫发生于6月末至8月初。卵椭球形,卵壳表面覆盖一层隆起的网状结构。幼虫蠋型,具3对分4节的胸足和8对不分节的腹足;头壳高度骨化,具1对由26个小眼组成的复眼和1对3节的触角,口器咀嚼式;腹部第1-9节背面具有成对的背毛突,第10节仅有1根背毛突,腹部末端具有一个可伸缩的吸盘;呼吸系统为周气门式,具1对前胸气门和8对腹气门。幼虫共4个龄期,以预蛹期在土室内越冬。蛹为强颚离蛹,外形接近成虫,雄蛹腹部末端膨大。【结论】基于幼虫形态特征,长蝎蛉明显区别于新蝎蛉属Neopanorpa、华蝎蛉属Sinopanorpa、双角蝎蛉属Dicerapanorpa以及单角蝎蛉属Cerapanorpa幼虫。然而,长蝎蛉幼虫头部刚毛L2和SO2,腹部末节刚毛D2,SD1和SD2端部均膨大呈棒状,与蝎蛉属Panorpa其他种类区别明显,表明长蝎蛉的属级地位需要进一步研究。     

A gross study of the compartmentalized stomach of two new-world camelids, the llama and guanaco

The origin of supernumerary gonapophyses in a polymorphic variant of Aedes stimulans has been determined histologically. Genotypic males (Mm) will develop gonapophyses on abdominal segment 8 when primordia on the larvae are subjected to a high-to-low thermal regimen. The gonapophyses develop from the normally evanescent podal buds of the eighth imaginal disc. Their course of development is similar to that of the normal gonapophyses that arise from the podal buds of the ninth imaginal disc.     

Modern thrips families Thripidae and Phlaeothripidae in Early Cretaceous amber (Insecta: Thysanoptera)

Two specimens of Thysanoptera with forked sensilla on third and fourth antennal segments were described from the Lebanese Neocomian and the Spanish Albian ambers, and attributed to the new genus Tethysthrips n. gen. in the family Thripidae Stevens 1829. One specimen with a tubular tenth abdominal segment was also discovered in the Lebanese Neocomian amber, and attributed to the new genus Rohrthrips n. gen. belonging to the family Phlaeothripidae Uzel 1895. Thripidae and Phlaeothripidae are nowadays the most species-rich families of Thysanoptera. The present discoveries of Early Cretaceous fossils show how diversified these families and thrips already were at that time. Moreover, this tubuliferan Rohrthrips specimen has plesiomorphies no longer present in the recent genera, in particular on the wings. Therefore it brings new insight in the evolution of Tubulifera.     

A new record of monogeneric family Vietnamellidae (Insecta: Ephemeroptera) from India

A new record of monogeneric family Vietnamellidae (Insecta: Ephemeroptera) is established for India with Vietnamella sp. A described based on the larvae from Arunachal Pradesh, India. This species can be distinguished from other known species of this genus in the larval stage by the following combination of characters: (i) outer pair of projections in head large and stout, triangular, cone-shaped with serrated spines; (ii) posterolateral angles of abdominal terga 2–9 extended into sharp projections; (iii) caudal filaments pale yellowish brown with dense lateral setae on inner and outer margins of middle part; (iv) femora of mid- and hind-legs broader; and (v) second segment of the maxillary palpi shorter than first segment.     

Precursor structures and evolution of tympanal organs in Lepidoptera (Insecta, Pterygota)

 The patterns of scolopal organs and their innervation were studied by the methylene blue method in larvae, pupae and adults of an Yponomeuta species (Yponomeutidae) and of tympanate adult representatives of the Noctuoidea, Geometridae, Drepanidae and Pyraloidea. The studies were focused mainly on the mesothorax, the metathorax and some anterior abdominal segments. In the abdominal tympanal organs of Geometridae, Drepanidae and Pyraloidea, the auditory scolopidia are homologous with the lateral scolopal organs of the first abdominal segment; however, the hearing organs as such evolved independently in the three taxa. The studies confirm that the tympanal organ in the Noctuoidea is derived from the caudal dorsolateral region of the metathorax including its dorsal scolopal organ and the B-cell. The adult scolopal organs are present already in the larvae and are maintained nearly unchanged during metamorphosis to the adult. Only in the Noctuoidea are the three sensory cells of the larval scolopal organs, which become part of the tympanal organs, reduced to one (in Notodontidae) or two (in other Noctuoidea) during metamorphosis. A hypothetical scenario of the evolution of the tympanal organs is outlined. Accepted: 12 March 1997