Ninth Segment Research Articles

Insights into the Eucyclops graeteri species complex (Copepoda, Cyclopidae) — the case of sulphidic groundwaters of Mangalia (Southern Dobrogea, Romania)

Members of the Eucyclops graeteri species complex are widely distributed in European groundwaters and share some morphocharacters such as: a long aesthetasc on the ninth segment of female antennula, short or very reduced spinule row ("serra") on furcal rami, lateral hairiness of 5th thoracic somite strongly reduced, and few or no hairs on the distal margin of the intercoxal sclerite of 4th legs pair. a long aesthetasc on the ninth segment of female antennula, short or very reduced spinule row ("serra") on furcal rami, lateral hairiness of 5th thoracic somite strongly reduced, and few or no hairs on the distal margin of the intercoxal sclerite of 4th legs pair. All these characters are subject to strong selective pressure in the underground environment; therefore, the study of molecular markers is needed to better define the taxonomy and phylogeny of this species group. The Southern Dobrogea region in Romania conceals dark, isolated, and sulfide-rich aquifers, accessible through artificial wells, springs, and the Movile Cave. The chemoautotrophically-based Movile Cave hosts a member of the E. graeteri complex, described several years ago as a subspecies (E. graeteri scythicus Plesa, 1989). The morphological and molecular analyses performed on specimens of this species complex collected from Southern Dobrogea revealed new records for E. graeteri scythicus both in sulfidic and non-sulfidic artificial wells dug near the cave as well as a species putatively new to science collected in three sulfidic wells from Mangalia. Mitochondrial markers allocated the Movile Cave population in a distinct clade within the genus Eucyclops, Eucyclops serrulatus s.l. being the closest taxon. The putative new species belongs to a different clade within the subfamily Eucyclopinae, raising doubts on the monophyly of this species complex. Furthermore, our investigations revealed the occurrence of ectosymbiont sulfur-oxidizing Thiothrix bacteria associated with E. graeteri scythicus suggesting that this putative symbiosis could allow this taxon to better cope with sulphidic-rich environments. These unique sulfidic groundwater environments therefore provide an interesting model system in which to study the taxonomy of copepods and their adaptation to very harsh environmental conditions.

Morphological and molecular identification of Xylocoris flavipes (Hemiptera: Anthocoridae) in southern China

Abstract During the investigation of natural enemy insects in grain depots, we've found an Anthocoridae insect accounted for a high proportion of natural enemy insects. We identify the enemy insects from morphology and molecular biology, so as to realize more accurate and effective control of storage pests by using the enemy insect. The images of the insects under the ultra-depth microscope (VHX-5000) showed that the insect adults were black brown in colour; the antennas of both the female and male had four segments, which increase in length sequentially from the base to the end, and had a length of 756.2 μm for the female and 741.1 μm for the male. The rostrums of both the female and the male insects were composed of three segments, the male's rostrum (596.8 μm) were shorter than the female's (734.6 μm), and the former two segments of the female's rostrum were significantly longer than the male's. The abdomen of the insect was bilaterally symmetrical, the female's abdomen was wider than the male, and the male insect had a dent between its eighth and ninth segments of the left abdomen, in which its male genitalia was located. In addition, the nymphs as a whole were tangerine in colour, and the eggs were elliptic with creamy white gloss and gridding patterns on the surface. The cytochrome C oxidase I (COI) gene sequences of the insects were identified by DNA barcoding technique, and the determined COI sequences were then submitted to the Genbank database for Blast alignment, and the results showed that the COI gene sequences had a high degree of similarity (99%) with X. flavipes records in the Genbank database. Therefore, we could determine that the insect was X. flavipes. In addition, the neighbor joining (NJ) was used to construct the evolutionary tree, and 1,000 repeated tests were conducted on the confidence levels of each branch. Based on the phylogenetic tree, we've found that X. flavipes belongs to Xylocoris genus. Based on morphology and COI sequence identification, we confidentiy determined that the collected natural enemy insect was X. flavipes. This is the first time that the identification of X. flavipes is being investigated from morphology and molecular biology. The research results are helpful to identify and distinguish the species of flower bugs, and beneficial for the better application of X. flavipes in biological control.

Interval uncertain optimization for damping fluctuation of a segmented electromagnetic buffer under intensive impact load

Aiming at the problems of demagnetization effect of electromagnetic buffer (EMB) caused by high velocity under intensive impact load and the difficulty and error of machining composite thin-walled long tube, a segmented EMB is proposed. The inner tube and air-gap are divided into initial segments and the traversing segments. Through theoretical analysis, impact test and simulation, it can be found that the RRF curve has two peaks. Firstly, in order to reduce the resultant resistance force (RRF) peaks, the sensitivity analysis based on optimal Latin hypercube design (OLHD) and polynomial regression was performed. The results show that the smallest contribution ratio to the dynamic response is the seventh and ninth segments of the inner tube, which are less than 1%. Then, fully considering the uncertain factors, important parameters are selected for uncertain optimization after sensitivity analysis. The interval order and interval probability degree methods are used to establish interval uncertain optimization model of the RRF considering robustness. The model was solved using an interval nested optimization method based on radial basis function (RBF) neural network. Finally, the Pareto front is obtained and numerical simulation is performed to verify the optimal value. It indicates that the two kinds of RRF peak is obviously reduced, and the optimization object and strategy are effective.

Contribution to the knowledge of male and female eremochaetid flies in the late Cretaceous amber of Burma (Diptera, Brachycera, Eremochaetidae)

A new and a previously known species of the genus Zhenia Q. Zhang, 2016 (Eremochaetidae) are illustrated and described based on two males and a female in amber: Zheniaburmensissp. nov. and Z.xiai Q. Zhang, 2016. The male Z.xiai is the first male of this species recorded. The relationships of Archisargoidea (including Eremochaetidae, Zhenia) are reassessed based on male genitalia. The superfamily is more likely related to the Stratiomyomorpha than to the Muscomorpha (including Nemestrinoidea). The components and structures of the ovipositor are re-illustrated. The results of our comparative study demonstrate that the ovipositor of Zhenia is similar in shape and detail to that of Rhagoletispomonella (Walsh, 1867) (Tephritidae). This study concludes that the ovipositor of Zhenia is most likely formed from abdominal eighth and ninth segments instead of the cerci, as a previous study found.

A general theory of genital homologies for the Hexapoda (Pancrustacea) derived from skeletomuscular correspondences, with emphasis on the Endopterygota

No consensus exists for the homology and terminology of the male genitalia of the Hexapoda despite over a century of debate. Based on dissections and the literature, genital skeletomusculature was compared across the Hexapoda and contrasted with the Remipedia, the closest pancrustacean outgroup. The pattern of origin and insertion for extrinsic and intrinsic genitalic musculature was found to be consistent among the Ectognatha, Protura, and the Remipedia, allowing for the inference of homologies given recent phylogenomic studies. The penis of the Hexapoda is inferred to be derived from medially-fused primary gonopods (gonopore-bearing limbs), while the genitalia of the Ectognatha are inferred to include both the tenth-segmental penis and the ninth-segmental secondary gonopods, similar to the genitalia of female insects which comprise gonopods of the eighth and ninth segments. A new nomenclatural system for hexapodan genitalic musculature is presented and applied, and a general list of anatomical concepts is provided. Novel and refined homologies are proposed for all hexapodan orders, and a series of groundplans are postulated. Emphasis is placed on the Endopterygota, for which fine-grained transition series are hypothesized given observed skeletomuscular correspondences.

PRIMEIRO ENCONTRO DE RHODNIUS DOMESTICUS NEIVA & PINTO, 1923 (HEMIPTERA: REDUVIDAE) NO MUNICÍPIO DE AÇUCENA, MINAS GERAIS, BRASIL

Triatomineos are vector insects from Tripanosoma cruzi, the main insect in causing Chagas’s Disease. In August 2013, professional from the Regional Health Superintendence of Coronel Fabriciano, Minas Gerais, registered the arrival of a Triatomine female identified as Rhodnius prolixus. The insect originated from a domestic residence of the people from Caeté, Açucena municipality. In order to confirm its identity, the insect was sent to the Research Center René Rachou (CPqRR/FIOCRUZ). In the identification of the triatominae, they used taxonomic keys and external morphology of the female genitals, allowing the insect to be identified as Rhodnius domesticus. The differentiating features in relation to other species were: the size of 15.5 mm, the brownish-yellow colour with chestnut brown in parts, absence of the spotted or speckled aspect, short head and non-curled feet. As well as this, the female genitals, in dorsal view, presented a moon shaped line dividing the ninth and tenth segment, and in ventral perspective presented the ninth segment finishing slightly below the tenth. The sample was stored in the collection of Chagas’s disease vectors (Fiocruz- COLVEC) do CPqRR/FIOCRUZ. It was the first time that this species was earmarked in the region. It’s important that entomology vigilance service is aware of the presence of the rare triatomines and process their identification correctly. In this way, entomologic collections and reference services have an important role, ensuring a quality service in identification.

Prospecting in Hückel‐space: From Hinokitiol to Non‐benzenoid Organic Electronics

Note from the Editor:Science is about connections. Some of these are connections between dreams and reality. Surely, dreams are the source of energy necessary to produce great science. In chemistry, the most obvious connections are the bonds: bonds between atoms, bonds between people. It was this metaphor that inspired the title “Bonding Beyond Borders” for the Nozoe Autograph Book publication project.In the following essay accompanying the publication of the ninth segment of the Nozoe Autograph Books, J. D. Tovar of Johns Hopkins University illustrates many connections. He connects some of the signatory's dreams, in the form of their real or projected novel compounds written decades ago, to today's state‐of‐the‐art. He connects theory with experiment. He connects structure with novel optoelectronic or electrical properties. He broadly and firmly connects his own research program with that of the greater novel aromatics community, a remarkable demonstration of progress given that he is barely a decade from receipt of his Ph.D. degree.We are pleased to have this splendid contribution to the Nozoe Autograph Books project.— Jeffrey I. Seeman Guest EditorUniversity of RichmondRichmond, Virginia 23173, USAE‐mail: jseeman@richmond.edu

Histological studies of the pheromone-producing gland in female of Spodoptera littoralis (Lepidoptera: Noctuidae)

Sex pheromone gland in female Spodoptera littoralis was studied histologically. The scent gland is located in the body cavity beneath the 7th and 8th abdominal tergites and ventrally around the ninth segments. The gland lies in the body cavity has an eversible sac forming a ring shaped structure. The eversible sac lined with cuticular layer that has spines pointing toward the lumen of the sac. The gland composed of two distinct regions secretory and storing. Cells of each region are composed of a single layer of flattened, columnar or cuboidal epithelial cells containing large circular or oval basal located nuclei and a layer of cuticle covering the epithelial cells with distinct spines. PAS-positive substances were demonstrated intracellular for both regions. In addition, the leuminal contents within the storing region are intensely PAS stained. Transmission electron microscopy of the ventral surface of the 9th segment showed the presence of electron opaque spherical bodies in the epithelial cells.

Morphological evidence for possible sites of Production of the female sex pheromone of Spodoptera littoralis (Lepidoptera: Noctuidae).

The morphology of the female sex pheromone gland of S. littoralis was studied using scanning electron and light microscopy. This gland is situated ventrally in the intersegmental membrane just in front of the last abdominal segments , the cuticula of the intersegmental membrane between eighth and ninth segments is thickened and slightly raised, bears furrows the rim of which just in front of the ninth is covered with cuticular hairs. The second structure involved in pheromone production is a gland lies in the body cavity situated beneath the eighth and seventh abdominal tergites, as an invagination of the ventral intersegmental membrane between eighth and ninth segments. This gland leads to a duct with an eversible sac. Examination of the tissue with scanning electron microscopy showed the presence of excreted droplets at the tips of cuticular hairs in the glandular area during the period of pheromone production.

A Nine-Segment Influenza A Virus Carrying Subtype H1 and H3 Hemagglutinins

Influenza virus genomic RNAs possess segment-specific packaging signals that include both noncoding regions (NCRs) and adjacent terminal coding region sequences. Using reverse genetics, an A/Puerto Rico/8/34 (A/PR/8/34) virus was rescued that contained a modified PB1 gene such that the PB1 packaging sequences were exchanged for those of the neuraminidase (NA) gene segment. To accomplish this, the PB1 open reading frame, in which the terminal packaging signals were inactivated by serial synonymous mutations, was flanked by the NA segment-specific packaging sequences including the NCRs and the coding region packaging signals. Next, the ATGs located on the 3' end of the NA packaging sequences of the resulting PB1 chimeric segment were mutated to allow for correct translation of the full-length PB1 protein. The virus containing this chimeric PB1 segment was viable and able to stably carry a ninth, green fluorescent protein (GFP), segment flanked by PB1 packaging signals. Utilizing this method, we successfully generated an influenza virus that contained the genes coding for both the H1 hemagglutinin (HA) from A/PR/8/34 and the H3 HA from A/Hong Kong/1/68 (A/HK/1/68); both subtypes of HA protein were also incorporated into the viral envelope. Immunization of mice with this recombinant virus conferred complete protection from lethal challenge with recombinant A/PR/8/34 virus and with X31 virus that expresses the A/HK/1/68 HA and NA. Using the described methodology, we show that a ninth segment can also be incorporated by manipulation of the PB2 or PA segment-specific packaging signals. This approach offers a means of generating a bivalent influenza virus vaccine.

Hedyselmis opis: Description of the larva and its phylogenetic relation to Graphelmis (Coleoptera: Elmidae: Elminae)

The riffle beetle genus Hedyselmis Hinton, 1976 includes two species from the Malay Peninsula, with adults with a highly deviating morphology. Its phylogenetic relationships are unclear, although it has been hypothesized to be related to Graphelmis Deleve, 1968, a large genus widely distributed in the Oriental and East Palaearctic regions. In this paper the larva of H. opis Hinton, 1976 is described based on material collected in the Cameron Highlands (Malaysia) and the conspecificity with co-existing adults tested using sequences of one nuclear (5' end of 18S rRNA) and three mitochondrial gene fragments (5' end of the large ribosomal unit + tRNAleu + 5' end of the NADH dehydrogenase subunit 1; 5' end of cytochrome c oxidase subunit I; and a fragment of cyto- chrome b) with a total of ca. 2,600 bp. This is the first example of the use of molecular data to match different life stages within the family Elmidae. The larva of H. opis has a subcylindrical body typical of many other elmid genera; abdominal segments 1-7 with preserved pleura; and ninth segment with oval operculum. The last instar larvae have clearly visible prominent spiracles on meso- thorax and abdominal segments 1-8. The phylogenetic position of Hedyselmis in relation to Graphelmis was investigated using molecular data for three species of Graphelmis plus a selection of other Elmidae genera. Hedyselmis opis is nested within Graphel- mis, confirming their close relationship and suggesting that their status requires taxonomic revision.

Structure of female genitalia of glassy-winged sharpshooter, Homalodisca coagulata (Say) (Hemiptera: Cicadellidae)

The functional reproductive morphology of the female glassy-winged sharpshooter, Homalodisca coagulata (Say), is described at both light microscopy and scanning electron microscopy levels. The female has nine abdominal segments; the seventh to the ninth abdominal segments are modified for reproduction; the eighth tergite is reduced to two segments, with the ovipositor partially exposed from the modified ninth segment—the pygofer. The pygofer, covered with trichoid and coeloconic sensilla, almost completely encloses the ovipositor, which consists of three pairs of valvulae and two pairs of valvifers. The first and second valvulae function together for oviposition. The first valvulae are located exterior to the second valvulae, both of which bear many trichoid, campaniform, and coeloconic sensilla. The third valvulae, possessing many coeloconic sensilla, envelope the first and second valvulae. Seven major muscles are found to be associated with the ovipositor and the pygofer. The oviposition process is described with respect to the activity of the valvulae and their associated musculature. The female morphology follows the general pattern of cicadellids as a group.

Expression Patterns of Anterior Hox Genes in the Polychaete Chaetopterus: Correlation with Morphological Boundaries

Expression patterns for five Hox genes were examined by whole-mount in situ hybridization in larvae of Chaetopterus, a polychaete annelid with a tagmatized axial body plan. Phylogenetic analysis demonstrates that these genes are orthologs of the Drosophila genes labial, proboscipedia, zen, Deformed, and Sex combs reduced and are termed CH-Hox1, CH-Hox2, CH-Hox3, CH-Hox4, and CH-Hox5, respectively. Expression studies reveal a biphasic expression pattern. In early larval stages, well before any indications of segmental organization exist, a novel pattern of expression in bilateral posterior proliferating cell populations, corresponding to the teloblasts, was detected for each of the genes, with CH-Hox1 and CH-Hox2 expressed before the remaining three. In middle larval stages, all five genes are expressed in bilateral strips along the ventral midline, corresponding with the developing ventral nerve cord. In addition, CH-Hox1 and CH-Hox2 show strong expression at the foregut-midgut boundary. By late larval stages the expression is generally confined to the ventral CNS and ectoderm of the anterior parapodia. Anterior boundaries of expression are “colinear,” at later larval stages, with CH-Hox2 expressed most rostrally, in the first segment, and anterior expression boundaries for CH-Hox1, CH-Hox3, CH-Hox4, and CH-Hox5 in segments 2, 3, 4, and 5, respectively. Like vertebrates and spiders, but unlike insects, CH-Hox3 participates in this colinear axial expression pattern. CH-Hox1 and CH-Hox2 have distinct posterior boundaries of expression in the ninth segment, which corresponds to a major morphological boundary, and may reflect a reorganization of Hox gene regulation related to the evolutionary reorganization of the Chaetopterus body plan.

Efferent neurons and specialization of abdominal segments in grasshoppers.

A specialized behavior, oviposition, is produced by the eighth and ninth abdominal segments of female grasshoppers. To begin to understand how these segments produce the behavior, which is not displayed by males or pregenital regions of the abdomen in females, the structure and function of efferent neurons in abdominal ganglia of both sexes were examined. In females, the eighth and ninth segments are specialized differently for oviposition: 20 ovipositor motor neurons were found in the eighth segment, and 26 were found in the ninth segment. Males had fewer motor neurons in their eighth segment, but the same number in the ninth segment, which is the only genital segment in males. However, the axons of several of the ninth segmental male motor neurons traveled to the periphery in the genital nerve, which is only found in males. In both sexes, pregenital ganglia had the most motor neurons, but these neurons, for the most part, had morphologies that strongly resembled those of genital segments. Efferent modulatory neuron numbers were not sexually dimorphic in the segments examined, except that males had a greater number in their ninth segment. Experimental methods that activate oviposition were found to also activate a rhythmical motor pattern in pregenital abdominal segments of both sexes. In females, the pattern was phase-coupled to oviposition, but persisted after the connections with the terminal abdominal ganglion were severed. The preponderance of similarities among efferent neurons and elicited motor activity suggests a common pattern of neural circuitry in the behaviorally diverse abdominal segments of grasshoppers.

Synaptic differentiation of single descending fibers studied by triple intracellular recording in the frog spinal cord.

Evoked excitatory postsynaptic potentials (EPSPs) were simultaneously intracellularly recorded in two lumbar motoneurons located in spinal segments 8-10 in response to intraaxonal stimulation of a descending fiber. Their mean amplitudes, paired-pulse facilitation, and short- and long-term posttetanic potentiation were compared to reveal possible functional differences among synapses formed by one axon on different postsynaptic targets. The mean amplitudes of EPSPs recorded in two motoneurons were significantly different in most experiments. This amplitude difference was related to the location of motoneurons in that it was twofold larger in motoneurons separated by >1 mm than in motoneurons located within 200 micron m of one another and also that the amplitude of EPSPs recorded in motoneurons located in the tenth segment was regularly smaller than the amplitude recorded in the ninth segment. The estimation of binomial model parameters suggests that the difference in mean EPSP amplitude was due mostly to differences in the maximal number of quanta prepared for release (binomial parameter N) and in mean release probability rather than to differences in quantal size. The ability of connections formed by a single axon on different motoneurons to undergo use-dependent synaptic modulations was different on scales of milliseconds, seconds, and tens of minutes as revealed by the measurements of effects of paired-pulse and tetanic stimulation. The difference in magnitude of short-term posttetanic potentiation in connections formed by a single descending axon was significantly correlated with the difference in mean probability of release in these connections. Thus our data revealed a functional nonuniformity of synapses formed by individual descending fibers on widely separated motoneurons, most likely innervating different muscles. This process can be one of the mechanisms by which a fine descending control of recruitment of motoneuronal populations is achieved.

Descriptions and distributional records of American Mecoptera. 4

Kalobittacus ramosus, new species Description based on one male specimen originally preserved dried but now in alcohol. Head: Eyes black, separated in front by about two thirds width of rostrum at base; vertex and occiput yellowish brown with a blackish area around ocelli; rostrum amber colored; antennal bases yellowish brown (flagella missing in holotype). Thorax: Pleura pale yellowish brown, dorsum slightly darker; small blackened areas at ventral apices of mesepisternum and mesothoracic meron and along postero-dorsal margins of mesoand metathoracic mera; pronotum without conspicuous bristles; scattered hairs sparsely distributed on all sclerites, abundant only on coxae. Femora yellowish, those of the hind legs slightly incrassate (fig. 2); tibiae yellowish, narrowly darkened distally; tarsi dark on front and middle legs, first tarsal segment of hind legs yel lowish, the others darkened. Membrane of wings {?g. 1) faintly tinged with yellow; stigmata very dark brown; front wings with an irregular apical brown spot extending from about the tip of vein R3 through all of cell 3rd R4 to near the tip of vein Mi, also with spots over first fork of Rs, subcostal cross-vein, fork of R, and branching of M from Cui (see fig. 1); hind wing with similar spots, the apical spot somewhat more extensive, with paler areas in cells 3rd Ra and 2nd R5, and with spots over subcostal cross-vein and branching of R fused. Vein 1A in front wing extending only as far as branching of M from Cui; 2A about two thirds as long as 1A. Vein 1A in hind wing co alescing with Cu2 for most of its length, crossing to posterior margin of wing near level of branching of M from Cui; 2A sinuate, about one third as long as 1A; 3A apparently absent. No costal cross-vein. Abdomen: Tergites and sternites yellowish brown, the membranous parts paler; tergites 2-6 bearing one or more long stout setae on lateral margins. Ninth segment greatly enlarged, the dorsal appendages of ninth tergite about twice the length of basistyles (fig. 4) sparsely covered with long hairs; tenth (anal) segment mostly membranous, its dorsal tip reach ing the upper margins of the dorsal appendages. Dorsal appendages con spicuously branched, each with one elongate, somewhat flattened projec tion extending caudad, one similar projection curving ventrad, and two shorter, thicker projections, one of these roughly conical in shape, directed

Calling Behavior of Manduca sexta (L.) (Lepidoptera: Sphingidae) with Notes on the Morphology of the Female Sex Pheromone Gland

The calling behavior of the female tobacco hornworm moth, Manduca sexta (L.), is described and correlated with pheromone release. The distribution of calling times over the first seven evenings after eclosion is reported; the females tended to start calling earlier and for a longer period the older they were. During observations over 96 h of continuous darkness, four regularly spaced periods of calling were seen with a mean interval of 25.4 h—a finding consistent with the existence of a circadian rhythm. Electroantennogram bioassays of parts of the female abdominal tip confirm the location of the female sex pheromone gland. The highest pheromonal activity was found in the region of the ventral membrane of the ninth segment, an area previously identified on histological evidence. The gland was examined with light and scanning electron microscopy. It is a modification of the ventral membrane of the ninth abdominal segment and consists of a monolayer of cuboid to columnar cells lining the cuticle. The surface of the intersegmental membrane is covered by small spines, some of which appear to have droplets at their tips. A second area of glandular appearance also was found underlying the anal papillae of the ninth segment.

Morphology of excretory organs inBranchiobdella pentodonta(Clitellata, Branchiobdellida)

Abstract The nephridium of Branchiobdella pentodonta is composed of a richly ciliated nephrostome, a lacunar capsule whose cells are phagocytic, a long nephridial tubule and excretory canal both concerned with reabsorption, and a dorsally placed nephridial pore. In contrast to the nephridia of previously studied species of Oligochaeta and Hirudinea the nephridia of Branchiobdella are characterized by having only two pairs of nephridia: an anterior in the second, third and fourth segments of the trunk and a posterior in the eighth and ninth segments. Another characteristic of Branchiobdella pentodonta is that the excretory orgen has no vascular supply and therefore waste matter is excreted solely from the coelomic fluid.

Morphological observations on sensory structures on the ovipositor and tarsi of the female and on the head capsule of the larva of the sorghum shootfly, Atherigona soccata Rondani

Trichoid, basiconic and campaniform sensilla have been observed on the ovipositor and tarsi of the sorghum shootfly, Atherigona seccata Rondani. The ovipositor of A. seccata comprises abdominal segments 6–9, with most of the trichoid sensilla located on the ninth segment. Two olfactory pegs each are located on the paired leaflets of the ninth segment. Sensilla on the tarsi include long and short basiconic sensilla and campaniform sensilla located near the anterior margin of the last tarsal segment. The sensory organs on the head capsule of the larva were studied by light, scanning and transmission electron microscopes. Four types of sensory receptors were observed on the cephalic lobes. They consist of four knob-shaped sensilla, two styloconic sensilla, two campaniform sensilla, and eight basiconic sensilla

Squelette et musculature des regions genitales et postgenitales de la femelle de Thermobia domestica (packard). Comparaison avec la region genitale de Nicoletia sp. (Insecta: Apterygota: Lepismatida)

The lepismatids show clearly the modifications brought about by the presence of the female genitalia upon the arrangement of the segmental constitutents. These modifications follow an antero-posterior and a ventro-posterior gradient. The influence begins in the seventh segment and still exists in the tenth segment. The maximum is seen in the ninth segment where the tergite is also modified. The gonocoxites VIII of Thermobia domestica are comparable to the coxites VII of Nicoletia sp. The valves VIII go forward as far as the sternal areas (reduced but still recognizable). This penetration is less pronounced in Nicoletia. The valves IX are more forward relative to the position of the gonocoxites IX and the sternal areas are no longer recognizable as sclerites. The gonocoxites IX are much modified : the antero-dorsal angle separates itself from the primitive coxite and forms an individualized sclerite (gonangulum) which is articulated with the tergite ; also, in the Lepismatids, this sclerite has the characteristics of the second valvifer of the Pterygota. The rest of the coxite extends and partially surrounds the valve ; this modification may lead to the dorsal valve of the orthopteroid type. Nicoletia shows more primitive characters than Thermobia concerning the ventral pregenital areas and reminds those of the machilids ; we have shown that the “languette” which covers the base of the genital valves must be interpreted, not as a sternite VIII, but as the result of the development of a presternal area ; this “languette” appears to be the precursor of the subgenital plate of the Pterygota. The primitive structure of the eleventh segment in Thermobia with cerci and the coxosternal areas is interesting.