Search

Background Visual opsins are expressed in the compound eyes and ocelli of insects and enable light detection. Three distinct phylogenetic groups of visual opsins are found in insects, named long (LW), short (SW) and ultraviolet (UV) wavelength sensitive opsins. Recently, the LW group was found to be duplicated into the LW2b and the LW2a opsins. The expression of LW2b opsins is ocelli specific in some insects (e.g., bees, cricket, scorpion flies), but the gene was not found in other orders possessing three or less ocelli (e.g., dragonflies, beetles, moths, bugs). In flies, two LW2b homologs have been characterised, with one expressed in the ocelli and the other in the compound eyes. To date, it remains unclear which evolutionary forces have driven gains and losses of LW opsins in insects. Here we take advantage of the recent rapid increase in available sequence data (i.e., from insect genomes, targeted PCR amplification, RNAseq) to characterize the phylogenetic relationships of 1000 opsin sequences in 18 orders of Insects. The resulting phylogeny discriminates between four main groups of opsins, and onto this phylogeny we mapped relevant morphological and life history traits. Results Our results demonstrate a conserved LW2b opsin only present in insects with three ocelli. Only two groups (Brachycera and Odonata) possess more than one LW2b opsin, likely linked to their life history. In flies, we hypothesize that the duplication of the LW2b opsin occurred after the transition from aquatic to terrestrial larvae. During this transition, higher flies (Brachycera) lost a copy of the LW2a opsin, still expressed and duplicated in the compound eyes of lower flies (Nematocera). In higher flies, the LW2b opsin has been duplicated and expressed in the compound eyes while the ocelli and the LW2b opsin were lost in lower flies. In dragonflies, specialisation of flight capabilities likely drove the diversification of the LW2b visual opsins. Conclusion The presence of the LW2b opsin in insects possessing three ocelli suggests a role in specific flight capabilities (e.g., stationary flight). This study provides the most complete view of the evolution of visual opsin genes in insects yet, and provides new insight into the influence of ocelli and life history traits on opsin evolution in insects.

Platystethynium (Platypatasson) earlyi Huber, sp. n. (Hymenoptera: Mymaridae), is described from both sexes reared from an egg of Rhaphidophoridae (Orthoptera) found in an old mining tunnel in New Zealand. The male is micropterous and has lateral ocelli but no median ocellus, a unique feature in Mymaridae found so far only in males of Platystethynium Ogloblin species. The remaining described Eastern Hemisphere species of Platystethynium are discussed and Platystethynium glabrum Jin & Li, syn. n., is placed in synonymy under P. onomarchicidum Ogloblin. A key to females, and males where known, of the described Eastern Hemisphere species of Platystethynium is given.

Background The re-evolution of complex characters is generally considered impossible, yet, studies of recent years have provided several examples of phenotypic reversals shown to violate Dollo’s law. Along these lines, the regain of wings in stick and leaf insects (Phasmatodea) was hypothesised to have occurred several times independently after an ancestral loss, a scenario controversially discussed among evolutionary biologists due to overestimation of the potential for trait reacquisition as well as to the lack of taxonomic data. Results We revisited the recovery of wings by reconstructing a phylogeny based on a comprehensive taxon sample of over 500 representative phasmatodean species to infer the evolutionary history of wings. We additionally explored the presence of ocelli, the photoreceptive organs used for flight stabilisation in winged insects, which might provide further information for interpreting flight evolution. Our findings support an ancestral loss of wings and that the ancestors of most major lineages were wingless. While the evolution of ocelli was estimated to be dependent on the presence of (fully-developed) wings, ocelli are nevertheless absent in the majority of all examined winged species and only appear in the members of few subordinate clades, albeit winged and volant taxa are found in every euphasmatodean lineage. Conclusion In this study, we explored the evolutionary history of wings in Phasmatodea and demonstrate that the disjunct distribution of ocelli substantiates the hypothesis on their regain and thus on trait reacquisition in general. Evidence from the fossil record as well as future studies focussing on the underlying genetic mechanisms are needed to validate our findings and to further assess the evolutionary process of phenotypic reversals.

We described a new species of cockroach, Periplaneta gajajimana sp. nov., which was collected in Gajajima, Kagoshima-gun Toshimamura, Kagoshima Prefecture, Japan, on November 2012. The new species is characterized by its reddish brown to blackish brown body, smooth surface pronotum, well developed compound eyes, dark brown head apex, dark reddish brown front face and small white ocelli connected to the antennal sockets. In male, the tegmen tip reach the abdomen end or are slightly shorter, while in the female, it does not reach the abdominal end and exposes the abdomen beyond the 7th abdominal plate. We confirmed the validity of this new species by breeding the specimens in our laboratory to demonstrate that the features of the progeny were maintained for several generations. For comparison and easy identification of this new species, the key to species identification of the genus Periplaneta that had been reported in Japan to date are also presented.

Millerichthys robustus is the only annual killifish distributed in America with phenotypic color variations, not yet described. Accordingly, we first describe the color pattern in both sexes to define its phenotypical variations. We then analyze the frequency of these phenotypes on a geographical scale, in four localities that represent opposite points of Millerichthys’s distribution in the Mexican southeast. Color analysis based on the RGB system allowed us to define five-color phenotypes in males continuously distributed in various perceptual units between two extreme colors (yellow-red): yellow, moderate orange, dark orange, strong orange and red. These color patterns found in M. robustus could be attributed to melanin, carotenoid, and pteridine pigments. The orange phenotypes was present in all localities studied. The yellow phenotype was present only in northeastern and northwestern locations, and the red phenotype was present only in northern populations. Female color variations were observed in the number of ocelli (from 1 to 15) at the base of the caudal peduncle and dorsal region. Ocelli have been associated with anti-predator functions because they resemble the eyes of vertebrates, thus shifting the target of predator attacks to less vital body parts. Females with 3 ocelli were the most frequent phenotype, and females with 13–15 ocelli occurred only in the northern populations. We concluded that male and female of M. robustus are not randomly distributed along their distribution range, which suggest that color phenotypes may react differently to biotic and abiotic factors that probably determine their distribution and frequency within the studied population.

A new free-living marine nematode species of the genus Belbolla Andrassy, 1973 belonging to the family Enchelidiidae is described based on specimens collected from the sediment of a subtidal benthic environmental habitat in the East Sea, Korea. Belbolla wonkimi sp. nov. differs from its congeners by the combination of the following characteristics: a relatively long body (3263-3396 μm), the absence of ocelli, nine oesophageal bulbs in the posterior pharynx, well-developed two winged precloacal supplements, longer spicule length (115-130 μm, 1.6-1.8 anal body diameter long), and a triangle-shaped shorter gubernacular apophysis (17-18 μm). Comparative tables on the biogeographical and morphological characteristics of Belbolla species are presented. A DIC (differential interference contrast) photomicrograph of the new species is also provided. This is the first taxonomic report on the genus Belbolla from Korean waters.

The Johnston's organ (JO) in the insect antenna is a multisensory organ involved in several navigational tasks including wind-compass orientation, flight control, graviception, and, possibly, magnetoreception. Here we investigate the three dimensional anatomy of the JO and its neuronal projections into the brain of the desert ant Cataglyphis, a marvelous long-distance navigator. The JO of C. nodus workers consists of 40 scolopidia comprising three sensory neurons each. The numbers of scolopidia slightly vary between different sexes (female/male) and castes (worker/queen). Individual scolopidia attach to the intersegmental membrane between pedicel and flagellum of the antenna and line up in a ring-like organization. Three JO nerves project along the two antennal nerve branches into the brain. Anterograde double staining of the antennal afferents revealed that JO receptor neurons project to several distinct neuropils in the central brain. The T5 tract projects into the antennal mechanosensory and motor center (AMMC), while the T6 tract bypasses the AMMC via the saddle and forms collaterals terminating in the posterior slope (PS) (T6I), the ventral complex (T6II), and the ventrolateral protocerebrum (T6III). Double labeling of JO and ocellar afferents revealed that input from the JO and visual information from the ocelli converge in tight apposition in the PS. The general JO anatomy and its central projection patterns resemble situations in honeybees and Drosophila. The multisensory nature of the JO together with its projections to multisensory neuropils in the ant brain likely serves synchronization and calibration of different sensory modalities during the ontogeny of navigation in Cataglyphis. This article is protected by copyright. All rights reserved.

Ceratolejeunea panamensis is described from Chiriquí province, Panama. The new species is distinguished from other species of the genus Ceratolejeunea by its numerous, scattered ocelli (6-20) in the leaf lobes and the very shortly bifid, reniform underleaves.

The Aleiodes bakeri (Brues) species subgroup of the A. seriatus species group is defined based on two previously described species, A. bakeri and A. nigristemmaticum (Enderlein), and is greatly expanded in this paper with an identification key, descriptions, and illustrations of 18 new species from the Neotropical Region: A. andinus Shaw & Shimbori, sp. nov.; angustus Shimbori & Shaw, sp. nov.; asenjoi Shimbori & Shaw, sp. nov.; bahiensis Shimbori & Shaw, sp. nov.; barrosi Shimbori & Shaw, sp. nov.; brevicarina Shimbori & Shaw, sp. nov.; coariensis Shimbori & Shaw, sp. nov.; goiasensis Shimbori & Shaw, sp. nov.; gonodontivorus Shaw & Shimbori, sp. nov.; hyalinus Shimbori & Shaw, sp. nov.; inga Shimbori & Shaw, sp. nov.; joaquimi Shimbori & Shaw, sp. nov.; lidiae Shimbori & Shaw, sp. nov.; mabelae Shimbori & Shaw, sp. nov.; maculosus Shimbori & Shaw, sp. nov.; ovatus Shimbori & Shaw, sp. nov.; santarosensis Shaw & Shimbori, sp. nov.; and taurus Shimbori & Penteado-Dias, sp. nov. It is hypothesized that the A. bakeri species subgroup is a monophyletic lineage within the larger and probably artificial A. seriatus species group (those Aleiodes with a comb of flat setae at the apex of the hind tibia), and can be distinguished from other members of the seriatus group by having the hind wing vein r present, although weakly indicated; the hind wing marginal cell suddenly widened at junction of veins RS and r; the subbasal cell of the fore wing mostly glabrous but often with two rows of short setae subapically; glabrous regions of the wings also commonly found in the first subdiscal, discal, and basal cells of the fore wing, and the basal cell of hind wing; ocelli quite large, with the width of a lateral ocellus being distinctly larger than the ocellar-ocular distance; and being relatively large Aleiodes species with body almost entirely brownish yellow or reddish brown. In addition, a new replacement name, Aleiodes buntikae Shimbori & Shaw, nom. nov., is proposed for the species formerly called Aleiodes (Hemigyroneuron) bakeri Butcher & Quicke, 2011.

Based on molecular phylogenetic analyses and morphological characters, a new species from Bangladesh, northern Vietnam, and southwestern China, Leptolejeunea nigra, is described. It is mostly similar to L. balansae but remarkable for having brownish black ocelli in its leaf lobes. In the molecular phylogeny, the samples of L. nigra are not nested within any clade and form an independent lineage. In particular, the molecular dating suggested that the divergence of L. nigra happened in time span of the formation of the Himalayas.

The paper deals with the description of a new species Soligorskopterus shpinevi, which was found in Upper Devonian deposits cropped out in the Mikhailovsky quarry (the City of Zheleznogorsk, Kursk region, Russia). The new species is based on the single although practically complete specimen visible from its abdominal side. The new species is characterized by following features: (1) widest part of the body is disposed in area of second/third sternites, the L/W ratio of prosoma is about 0.7; (2) compound eyes are crescentic, with rounded ends; (3) the ocelli are small, of ovoid shape, orientated along the prosoma, diverge towards anterior direction; (4) the ocellar area anteriory two-lobed, heart-like; (5) the metastoma of prolonged shape, with parallel lateral margins, straight posterior margin and round anterior margin; (6) the length of sternites is more or less equal; (7) the basal part of the telson is broad subtriangular. The upper Devonian deposits of the studied area show a distinctly regressive trend, which ended in complete change of the shallow water lagoon deposits by interruption of sedimentation up to the Jurassic time. This trend corresponds well to the “terrestrialisation” of the late Devonian environments, which could be also reflected in developing of “walking” of some of the Devonian eurypterids in contrast to less evolutionary advanced representatives of this group.

Light is the most important Zeitgeber for entraining animal activity rhythms to the 24-h day. In all animals, the eyes are the main visual organs that are not only responsible for motion and colour (image) vision, but also transfer light information to the circadian clock in the brain. The way in which light entrains the circadian clock appears, however, variable in different species. As do vertebrates, insects possess extraretinal photoreceptors in addition to their eyes (and ocelli) that are sometimes located close to (underneath) the eyes, but sometimes even in the central brain. These extraretinal photoreceptors contribute to entrainment of their circadian clocks to different degrees. The fruit flyDrosophila melanogasteris special, because it expresses the blue light-sensitive cryptochrome (CRY) directly in its circadian clock neurons, and CRY is usually regarded as the fly’s main circadian photoreceptor. Nevertheless, recent studies show that the retinal and extraretinal eyes transfer light information to almost every clock neuron and that the eyes are similarly important for entraining the fly’s activity rhythm as in other insects, or more generally spoken in other animals. Here, I compare the light input pathways between selected insect species with a focus onDrosophila’sspecial case.

A new species of Hypogastrura from the Romanian Carpathians is described and illustrated. The new species is characterised by unique combination of morphological characters: presence of seven ocelli, the antennal segment IV with 4 thin, cylindrical sensilla, the presence of 5 setae on ventral tube, the short anal spines situated on high papillae and distinct chaetotaxy. The species is not easy to classify in the present system of the generic subdivision. Considering the presence of only 7+7 ocelli, the new species can be compared only with H. pyrenaica (Cassagnau, 1959), while in other morphological features it is similar to H. aterrima Yosii, 1972 and H. tethyca Ellis, 1976. The similarity between these species and systematic position of the new species are discussed.

For several decades, Troglotayosicus Lourenco, 1981, remained an enigmatic, monotypic scorpion genus believed to be troglobitic. The discovery and description in recent years of several endogean species of the genus, inhabiting the leaf litter of tropical rainforests in Colombia and Ecuador, advanced knowledge about these scorpions. The known distribution of Troglotayosicus was considerably expanded along the Andes, and it was demonstrated that, despite the absence of median ocelli, the genus is composed primarily of species that inhabit leaf litter. In the present study, Troglotayosicus ballvei, sp. nov., is described from Sacha Huagra Lodge, adjacent to Archidona Municipality, in Napo Province, Ecuador, raising the number of Troglotayosicus species to six, three each in Colombia and Ecuador. An updated map of the known distribution of the genus is presented.

The eyes of insects display an incredible diversity of adaptations to enhance vision across the gamut of light levels that they experience. One commonly studied contrast is the difference in eye structure between nocturnal and diurnal species, with nocturnal species typically having features that enhance eye sensitivity such as larger eyes, larger eye facets, and larger ocelli. In this study, we compared eye structure between workers of closely related nocturnal and diurnal above ground foraging ant species (Hymenoptera: Formicidae) in four genera (Myrmecocystus, Aphaenogaster, Temnothorax, Veromessor). In all four genera, nocturnal species tend to have little cuticular pigment (pale), while diurnal species are heavily pigmented (dark), hence we could use cuticle coloration as a surrogate for activity pattern. Across three genera (Myrmecocystus, Aphaenogaster, Temnothorax), pale species, as expected for nocturnally active animals, had larger eyes, larger facet diameters, and larger visual spans compared to their dark, more day active congeners. This same pattern occurred for one pale species of Veromessor, but not the other. There were no consistent differences between nocturnal and diurnal species in interommatidial angles and eye parameters both within and among genera. Hence, the evolution of eye features that enhance sensitivity in low light levels do not appear to have consistent correlated effects on features related to visual acuity. A survey across several additional ant genera found numerous other pale species with enlarged eyes, suggesting these traits evolved multiple times within and across genera. We also compared the size of the anterior ocellus in workers of pale versus dark species of Myrmecocystus. In species with larger workers, the anterior ocellus was smaller in pale than in dark species, but this difference mostly disappeared for species with smaller workers. Presence of the anterior ocellus also was size-dependent in the two largest pale species.

Cockroach specimens of the genus, Squamoptera were collected from the Iriomote island of Okinawa prefecture, Japan. The morphological features of the specimens were characterized as having a white band on the dorsal surface of its thorax, its tegmen reduced into a tiny scale-like structure and the hindwing was absent. Ocelli was also absent and the small compound eyes not extending to apex of the head nor to the frontal face but extend further lower than the base of the antennae. When the specimens were reared in the laboratory, besides the short wing form, the long wing form began to appear in the rearing colony. In our reproductive biological study, we observed that hatching of the ootheca from the short wing female takes about 30 days, with an average of 6.6 nymphs being hatched from one ootheca. The male to female ratio of the offspring was 36:30. However, the frequency appearance of the offspring from the ootheca of the short wing female was 98.5% short wing and 1.5% long wing form. Our specimens occasionally show body polymorphism in the form of individuals having long wings instead of the usual short one. The long wing form does not show the white band on the dorsal surface of its thorax.

Visual perception of the environment is mediated by specialized photoreceptor (PR) neurons of the eye. Each PR expresses photosensitive opsins, which are activated by a particular wavelength of light. In most insects, the visual system comprises a pair of compound eyes that are mainly associated with motion, color or polarized light detection, and a triplet of ocelli that are thought to be critical during flight to detect horizon and movements. It is widely believed that the evolutionary diversification of compound eye and ocelli in insects occurred from an ancestral visual organ around 500 million years ago. Concurrently, opsin genes were also duplicated to provide distinct spectral sensitivities to different PRs of compound eye and ocelli. In the fruit fly Drosophila melanogaster, Rhodopsin1 (Rh1) and Rh2 are closely related opsins that originated from the duplication of a single ancestral gene. However, in the visual organs, Rh2 is uniquely expressed in ocelli whereas Rh1 is uniquely expressed in outer PRs of the compound eye. It is currently unknown how this differential expression of Rh1 and Rh2 in the two visual organs is controlled to provide unique spectral sensitivities to ocelli and compound eyes. Here, we show that Homothorax (Hth) is expressed in ocelli and confers proper rhodopsin expression. We find that Hth controls a binary Rhodopsin switch in ocelli to promote Rh2 expression and repress Rh1 expression. Genetic and molecular analysis of rh1 and rh2 supports that Hth acts through their promoters to regulate Rhodopsin expression in the ocelli. Finally, we also show that when ectopically expressed in the retina, hth is sufficient to induce Rh2 expression only at the outer PRs in a cell autonomous manner. We therefore propose that the diversification of rhodpsins in the ocelli and retinal outer PRs occurred by duplication of an ancestral gene, which is under the control of Homothorax., Author summary Sensory perception of light is mediated by specialized photoreceptor neurons of the eye. Each photoreceptor expresses unique photopigments called opsins and they are sensitive to particular wavelengths of light. In insects, ocelli and compound eyes are the main photosensory organs and they express different opsins. It is believed that opsins were duplicated during evolution to provide specificity to ocelli and the compound eye and this is corelated with their distinct functions. We show that Homothorax acts to control a binary Rhodopsin switch in the fruit fly Drosophila melanogaster to promote Rhodopsin 2 expression and represses Rhodopsin 1 expression in the ocelli. Genetic and molecular analysis showed that Homothorax acts through the promoters of rhosopsin 1 and rhosopsin 2 and controls their expression in the ocelli. We also show that Hth binding sites in the promoter region of rhodopsin 1 and rhodopsin 2 are conserved between different Drosophila species. We therefore proposed that Hth may have acted as a critical determinant during evolution which was required to provide specificity to the ocelli and compound eye by regulating a binary Rhodopsin switch in the ocelli.

International audience; Specimens of Teissiera polypofera Xu, Huang & Chen, 1991 were found in waters off the northeast Brazilian coast between 8.858 degrees S, 34.809 degrees W and 9.005 degrees S, 34.805 degrees W and 56 to 717 m depth. The genus can be distinguished from other anthomedusae by the two opposite tentacles with cnidophores and four exumbrellar cnidocyst pouches with ocelli. Specimens were assigned to Teissiera polypofera due to the long and narrow manubrium transposing bell opening and polyp buds with medusoid buds on it, issuing from the base of manubrium. This study represents the first record of the genus in the Atlantic Ocean.

Two species of the genus Diaparsis Förster, D. phobos sp. nov. and D. deimos sp. nov., are described from Madagascar. The genus Diaparsis, as well as the subfamily Tersilochinae, is recorded from Madagascar for the first time. Both new species possess unuque morphological features previously unknown in the subfamily Tersilochinae: D. deimos sp. nov. has a remarkable slightly decurved ovipositor, and D. phobos sp. nov. possesses deep impressions on outer sides of ocelli.

In addition to the compound eyes insects possess simple eyes known as ocelli. Input from the ocelli modulates optomotor responses, flight-time initiation and phototactic responses, behaviours that are predominantly mediated by the compound eyes. In this study, using pattern electroretinography (pERG), we investigated the contribution of the compound eyes to ocellar spatial vision in the diurnal Australian bull ant, Myrmecia tarsata by measuring the contrast sensitivity and spatial resolving power of the ocellar second-order neurons under various occlusion conditions. Furthermore, in four species of Myrmecia ants active at different times of the day and in European honeybee, Apis mellifera, we characterized the ocellar visual properties when both visual systems were available. Among the ants, we found that the time of activity had no significant effect on ocellar spatial vision. Comparing day-active ants and the honeybee we did not find any significant effect of locomotion on ocellar spatial vision. In M. tarsata, when the compound eyes were occluded, the amplitude of the pERG signal from the ocelli reduced by three times compared to conditions when the compound eyes were available. The signals from the compound eyes maintained the maximum contrast sensitivity of the ocelli as 13 (7.7%), and the spatial resolving power as 0.29 cpd. We conclude that ocellar spatial vison improves significantly with input from the compound eyes, with a noticeably larger improvement in contrast sensitivity than in spatial resolving power.

We describe the new liverwort species Lejeunea ryszardii from montane rainforest in the Central Cordillera of Colombia (Dept. Quindío) and Rectolejeunea halinae from submontane rainforest in the Western Cordillera (Dept. Risaralda). Both species stand out by copious vegetative reproduction via caducous leaves. Lejeunea ryszardii resembles the Caribbean L. paucidentata in the leaf lobes with toothed margins and a narrow base but strikingly differs from the latter species in: 1) leaf margins with mamillose cells, which are sometimes crowned by a small papilla, and with scattered rhizoids with or without a tooth-like base; 2) lobules with narrowly elongate, curved, sharp tooth; 3) stem epidermis brownish and somewhat thick-walled; 4) copious production of caducous leaf lobes. Moreover, L. ryszardii is dark green to brown in color and probably dioicous while L. paucidentata is light green and autoicous. Rectolejeunea halinae resembles the neotropical R. flagelliformis in having ciliate caducous leaves but clearly differs from the latter in the pointed leaf tips, the presence of ocelli in underleaves, and the flagelliform shoots with flat, entire-margined underleaves. The discovery of these new species adds two further endemic taxa to the rich bryophyte flora of the Colombian Andes.

Two new bristletail species of the family Machilidae are described: Allopsontus tyrnyauzi sp. n. from the Caucasus and A. zinchenkoi sp. n. from the Pamir-Alai Mountain system. The former species belongs to the subgenus Kaplinilis Mendes, 1990. Among the species described within this subgenus, numerous short, pigmented, appressed setulae on the underside of the 5-7th maxillary palpomeres and the 3rd labial palpomere in males are found only in A. tyrnyauzi sp. n. and A. bifarius (Wygodzinsky, 1970), the latter known from western Mongolia and Tuva. Allopsontus tyrnyauzi sp. n. differs from A. bifarius in the relatively short eye contact line, more dilated paired ocelli, urosternites with a right apical angle, the narrower sensory fields on the fore femora in males, and fewer paramere segments. Allopsontus zinchenkoi sp. n. belongs to the subgenus Anisopsontus Mendes, 1990 and differs from the other consubgeners in the color of the compound eyes, the width to length ratio of the paired ocelli, longer abdominal styli, larger sensory fields on the fore femora in males, and the relatively short ovipositor.

Lithobius (Ezembius) polyommatus sp. n. and Lithobius (Ezembius) dulanensis sp. n. discovered from Qinghai-Tibet Plateau, China, are described. The two new species are morphologically similar, but could be distinguished by having mostly 12 ocelli other than 14 ocelli, anterior accessory spur absent versus present on legs 14, dorsal sulci on male 14th legs absent versus present and dorsal lateral setae short, only the largest as stout as the general setae instead of only long setae on the second article of the female gonopod. A key to the Chinese species of Ezembius is presented.

Jumping spiders have four pairs of eyes (ocelli) of which only the principal eyes (PEs) are used to detect features of objects. Photoreceptors in the retina of the PEs form four layers (PL1-4) and terminate in the first optic ganglion (FOG). Here, we focus on Hasarius adansoni because it has unique depth vision besides color vision and its FOG appears to contribute to the initial processing of these visual modalities. We first investigated the neuroanatomical organization of the FOG. The three-dimensional structure of the FOG revealed by synapsin immunostaining is horseshoe-shaped and consists of four terminal zones (TZ1-4). Then, we traced single photoreceptors through serial sections and found that green-sensitive receptors of PL1 and 2 terminate in TZ1 and 2, respectively, by keeping retinotopic organization. In contrast to TZ1 and 2, TZ3 receives terminals of ultraviolet-sensitive receptors from lateral regions of both PL3 and 4, while photoreceptors of the medial region of PL3 and 4 terminate in TZ4. We further studied details of photoreceptor terminals and the branching pattern of interneurons in the FOG in Golgi stained preparations. Photoreceptors have long lateral processes in each terminal zone. Some photoreceptors terminating in TZ3 have branches innervating TZ1, indicating that TZ1 receives different spectral information. A type of interneuron connects TZ1 and 2, while others have branches within a single terminal zone or in the entire FOG. These results suggest that TZ1 and 2 contribute to color, shape, and depth vision, while TZ3 and 4 have specific roles for UV vision.

Australobius polyspinipes sp. n. (Lithobiomorpha: Lithobiidae) was recently discovered from Tianheshan Mountain, Hebei Province, China, and it is described here. Morphologically the new species is similar to A. nodulus Ma, Song &Zhu, 2008 and A. magnus (Trozina, 1894), both recorded from China. The new species can be easily distinguished from those by having 7+7–8+8 coxosternal teeth, 10–12 ocelli on each side of the cephalic plate, 5+5 spurs on the first article of the female gonopods and differences in plectrotaxy of legs. The main morphological characters and a key to the known Chinese species of genus Australobius based on adult specimens is presented.

An undescribed species of the frogfish genus Histiophryne, of the teleost order Lophiiformes, family Antennariidae, is described on the basis of 60 specimens collected from shallow inshore waters of Western and South Australia. Previously confused with its morphologically similar congener H. cryptacanthus, it differs from the latter and from all other members of the genus in having the following combination of features: illicium tiny but easily discernible without aid of a microscope; esca present, a small tuft of filaments, easily distinguished from illicium; skin covered with tiny dermal spinules, especially on head, cutaneous filaments and appendages absent; dorsal-fin rays 15–16; pectoral-fin rays 9 (rarely 8); vertebrae 22–23; head, body, and fins typically off white, sometimes peppered with numerous small, close-set ocelli. Genetic divergence from its congeners in the nuclear recombination activation gene-2 (RAG2) and cytochrome oxidase-I (COI) genes is at least 8.9%. The new species is diagnosed, d...

A new monstrilloid copepod species, Cymbasoma cheni sp. nov., from Meizhou Bay (an embayment in Fujian Province, southeastern China) is described and illustrated. The diagnostic character of the new species is the structure and armature of the fifth leg, which is represented by a single lobe armed with three naked setae subequal in length. The new species closely resembles Cymbasoma bowmani Suarez-Morales and Gasca, 1998 in the structure of the fifth legs, and the body proportions, including total body length, and relative lengths of the cephalothorax and the genital double somite. However, Cymbasoma cheni sp. nov. is distinguished by lack of cuticular ornamentation on the cephalothorax, the position of the oral papilla, and the structure of the fifth leg with three naked setae. Although the structure of the fifth legs is similar in Cymbasoma cheni sp. nov. and Cymbasoma quintanarooense (Suarez-Morales, 1994), the new species can be easily distinguished from Cymbasoma quintanarooense by the relative length of the antennule, differences in the genital double-somite and the ovigerous spines, and the shape of ocelli. This is the sixth record of this genus from China seas.

The samarid flatfish Plagiopsetta biocellata sp. nov. is described from Egypt, Gulf of Aqaba, southern Red Sea, based on a specimen collected in the coral-reef lagoon at a depth of 0-1 metres. The new species is characterised within the genus Plagiopsetta by 61 dorsal-fin rays, anal-fin rays 53, pectoral-fin rays on ocular side 8, caudal-fin rays 14; lateral-line scales on ocular side 74; lateral line on blind side incomplete, with 14 scales; gill rakers on ocular side 2 + 4; abdominal vertebrae 11; caudal vertebrae 31; a pair of large ocelli present on posterior body on ocular side; pectoral fin pale, with a distal black blotch. A key to the species of the genus Plagiopsetta is presented.

Buestanmyia gen. nov., is described from Pichincha Province, Ecuador with one included species, with B. chiriboga sp. nov. It is characterized by very short and scarce ommatrichia, frons wide and slightly divergent below, basal callus subquadrate with median dorsal projection reaching half the height of the frons, ocellar triangle and ocelli absent, scape 3.5x the length of the pedicel, scape and pedicel with strong and erect hairs, proboscis less than the length of the head, basicosta bare, wings slightly smoky, with clouds on the cells costal and subcostal, vein R4 with a short appendix; cell cup with short appendix.

The forewings and hindwings of butterflies and moths (Lepidoptera) are differentiated from each other, with segment-specific morphologies and color patterns that mediate a wide range of functions in flight, signaling, and protection. The Hox geneUltrabithorax(Ubx) is a master selector gene that differentiates metathoracic from mesothoracic identities across winged insects, and previous work has shown this role extends to at least some of the color patterns from the butterfly hindwing. Here we used CRISPR targeted mutagenesis to generateUbxloss-of-function somatic mutations in two nymphalid butterflies (Junonia coenia,Vanessa cardui) and a pyralid moth (Plodia interpunctella). The resulting mosaic clones yielded hindwing-to-forewing transformations, showingUbxis necessary for specifying many aspects of hindwing-specific identities, including scale morphologies, color patterns, and wing venation and structure. These homeotic phenotypes showed cell-autonomous, sharp transitions between mutant and non-mutant scales, except for clones that encroached into the border ocelli (eyespots) and resulted in composite and non-autonomous effects on eyespot ring determination. In the pyralid moth, homeotic clones converted the folding and depigmented hindwing into rigid and pigmented composites, affected the wing-coupling frenulum, and induced ectopic scent-scales in male androconia. These data confirmUbxis a master selector of lepidopteran hindwing identity and suggest it acts on many gene regulatory networks involved in wing development and patterning.

A precondition for colour vision is the presence of at least two spectral types of photoreceptors in the eye. The order Hymenoptera is traditionally divided into the Apocrita (ants, bees, wasps) and the Symphyta (sawflies, woodwasps, horntails). Most apocritan species possess three different photoreceptor types. In contrast, physiological studies in the Symphyta have reported one to four photoreceptor types. To better understand the evolution of photoreceptor diversity in the Hymenoptera, we studied the Symphyta Sirex noctilio, which belongs to the superfamily Siricoidea, a closely related group of the Apocrita suborder. Our aim was to (i) identify the photoreceptor types of the compound eye by electroretinography (ERG), (ii) characterise the visual opsin genes of S. noctilio by genomic comparisons and phylogenetic analyses and (iii) analyse opsin mRNA expression. ERG measurements revealed two photoreceptor types in the compound eye, maximally sensitive to 527 and 364 nm. In addition, we identified three opsins in the genome, homologous to the hymenopteran green or long-wavelength sensitive (LW) LW1, LW2 and ultra-violet sensitive (UV) opsin genes. The LW1 and UV opsins were found to be expressed in the compound eyes, and LW2 and UV opsins in the ocelli. The lack of a blue or short-wavelength sensitive (SW) homologous opsin gene and a corresponding receptor suggests that S. noctilio is a UV-green dichromate.

Upon discovery that the Boquila trifoliolata is capable of flexible leaf mimicry, the question of the mechanism behind this ability has been unanswered. Here, we demonstrate that plant vision possibly via plant-specific ocelli is a plausible hypothesis. A simple experiment by placing an artificial vine model above the living plants has shown that these will attempt to mimic the artificial leaves. The experiment has been carried out with multiple plants, and each plant has shown attempts at mimicry. It was observed that mimic leaves showed altered leaf areas, perimeters, lengths, and widths compared to non-mimic leaves. We have calculated four morphometrical features and observed that mimic leaves showed higher aspect ratio and lower rectangularity and form factor compared to non-mimic leaves. In addition, we have observed differences in the leaf venation patterns, with the mimic leaves having less dense vascular networks, thinner vascular strands, and lower numbers of free-ending veinlets.

Two new species of bristletails of the family Machilidae are described from caves in the Western Caucasus (troglophile Coryphophthalmus troglophilus sp. nov.) and in the Eastern Carpathians (trogloxene Trigoniophthalmus ukrainensis sp. nov.). The main morphological adaptations of C. troglophilus sp. nov. to life in caves include green eye color; weak body pigmentation; well-developed arolium and claws; relatively long cerci, tarsae and tibiae of the hind legs; long apical needles of the urostyli; large sublateral spines on urocoxites IX. C. troglophilus sp. nov. resembles C. abchasicus (Kaplin, 2017), but they are distinguishable in color of eyes, ratio of eye contact to length, length of cerci, structures of the labial palps, legs, urocoxites IX, ovipositor, and parameres. Trigoniophthalmus ukrainensis sp. nov. has no recognized morphological adaptations to life in caves. This species resembles T. alternatus (Silvestri, 1910), but they are easily distinguished in the number of annuli in distal chains of flagellum, ratio of width to length of paired ocelli, chaetotaxy of male maxillary and labial palps.

The sabellid genera Anamobaea Krøyer, 1856 and Notaulax Tauber, 1879 are two of the most attractive polychaete worms in coral reefs. Anamobaea is represented by two Caribbean species and Notaulax with 24 species from around the world, six of them previously known to tropical America. During examination of fouling biota and sclerozoans from Mexico, Anamobaea orstedii Krøyer, 1856 was found in coral reefs from the southern Gulf of Mexico and three species of Notaulax were identified to the Mexican Pacific, two of them being new species to science. Anamobaea orstedii Krøyer, 1856 is first reported as sclerozoan of dead coral from the southern Gulf of Mexico. An amendment to the generic diagnosis of Anamobaea is provided, based on the presence of a higher number of skeletal cells than previously recorded; height, shape and exposition of the anterior peristomial ring; the non-fusion of dorsal collar margins to faecal groove; shape of collar chaetiger and abdominal chaetae and distribution and shape of radiolar ocelli. Notaulax californica (Treadwell, 1906) is reported as fouling in buoys and docks from the Gulf of California. Two new species of Notaulax are described: the former was found in hull and dock fouling from La Paz (Gulf of California) and the second one as sclerozoan of oysters from a dock fouling in Acapulco (south Mexican Pacific). In addition, reproductive features are described for the first time for A. orstedii which is a simultaneous hermaphrodite with female and males gametes found within the same segments of abdominal region. Oocytes develop synchronously and sperm morphology (spherical nucleus and rounded acrosome, four spherical mitochondria and a long free flagellum) suggest an adaptation to broadcast spawning and external fertilisation. Species of Notaulax here examined were gonochoric, with gametes distributed in abdominal segments.

Lithobius (Ezembius) brachyspinipes sp. n. (Lithobiomorpha: Lithobiidae), recently discovered in Yiyang County, Luoyang City, Henan Province, China, is described, is morphologically similar to Lithobius (Ezembius) multispinipesPei et al, 2016 from Xinjiang Autonomous Region, but is distinguishable by having a different size of the posterior two ocelli, a different morphology of the second article of the female gonopod, and apical claw third article of female gonopods, and legs 14 plectrotaxy. A table of the main morphological characters of Chinese Lithobius (Ezembius) species is presented.

Simple Summary Butterfly wing color patterns are diverse, but they can be understood as modifications of the common scheme called the nymphalid groundplan. The discal spot is relatively small, but it is one of the important components of the nymphalid groundplan. Using many hindwing specimens of the family Nymphalidae, the morphological and spatial diversity of the discal spot was studied. The discal spot is expressed as a small or narrow spot, a pair of parallel bands, a diamond or oval structure, a large dark spot, a few fragmented spots, or a white structure. The discal spot is always located in a central portion of the wing defined by the wing veins, and this portion is sandwiched by a pair of bands of the central symmetry system, another important component of the nymphalid groundplan. On the basis of these results, the present study revises the nymphalid groundplan in minor points; the discal spot is an independent and diverse miniature symmetry system nested within the central symmetry system. Due to the involvement of wing veins to define the locations of the discal spot, the present study suggests the possible developmental dynamics of butterfly color pattern formation that produces color pattern diversity. Abstract Diverse butterfly wing color patterns are understood through the nymphalid groundplan, which mainly consists of central, border, and basal symmetry systems and a discal spot. However, the status of the discal spot remains unexplored. Here, the morphological and spatial diversity of the discal spot was studied in nymphalid hindwings. The discal spot is expressed as a small or narrow spot, a pair of parallel bands, a diamond or oval structure, a large dark spot, a few fragmented spots, or a white structure. In some cases, the discal spot is morphologically similar to and integrated with the central symmetry system (CSS). The discal spot is always located in a distal portion of the discal cell defined by the wing veins, which is sandwiched by the distal and proximal bands of the CSS (dBC and pBC) and is rarely occupied by border ocelli. The CSS occasionally has the central band (cBC), which differs from the discal spot. These results suggest that the discal spot is an independent and diverse miniature symmetry system nested within the CSS and that the locations of the discal spot and the CSS are determined by the wing veins at the early stage of wing development.

Background Eye pigmentation genes have been utilized as visible markers for constructing genetic control prototypes in several insect vectors of human disease. Here, orthologs of two ommochrome pathway genes, kynurenine 3-hydroxylase (kmo) and cardinal, were investigated in Plutella xylostella, a globally distributed, economically important pest of Brassica crops. Results Both somatic mosaic and germline mutations were efficiently created using the CRISPR/Cas9 system, and null mutant strains of Pxkmo and Pxcardinal were obtained. A frame-shift mutation in Pxkmo caused yellow compound eyes at adult stage while an in-frame mutation lacking two amino acids resulted in a hypomorphic red eye phenotypes. In contrast, Pxcardinal-deficient moths with a frame-shift mutation exhibited yellow eye pigmentation in newly emerged adults which turned to red as the adults aged. Additionally, differences were observed in the coloration of larval ocelli, brains and testes in Pxkmo and Pxcardinal yellow-eye mutant lines. Conclusions Our work identifies the important roles of Pxkmo and Pxcardinal in P. xylostella eye pigmentation and provides tools for future genetic manipulation of this important crop pest.

The color patterns on the wings of butterflies and moths are among the most complex manifestations of pattern formation in nature. The complexities of these patterns arise from the diversification of a conserved set of homologous elements known as the Nymphalid Ground Plan that can change color, shift position, expand, or disappear altogether. Recent work has shown that the anterior-posterior axis of the butterfly wing may also have an important role in the development and evolution of wing-pattern diversity. Here we characterize the anterior-posterior axis by mapping expression domains of key regulatory genes onto the wing. We show that the butterfly wing can be subdivided into four primary regions, with the boundaries of these domains arising at the positions of the M1, M3, and Cu2 wing-veins. We find that the correlation among variation in the border ocelli is strongest for those within the same domain. We show how these domains may be used to determine phenotypic outcomes by surveying the frequency of color boundaries, tail development, and wing shape discontinuities across five major butterfly families: Lycaenidae, Nymphalidae, Papilionidae, Pieridae, and Riodinidae. Of the more than 200 genera we surveyed in this study, color pattern discontinuities emerge most often at the boundary veins M1, M3, and Cu2, and shape discontinuities and tails at veins M3 and Cu2. These findings reveal a hitherto unrecognized mode of evolution of patterning in the Lepidoptera.

The nymphalid groundplan (NGP) has proven to be extraordinarily useful in the study of butterfly color patterns because it allows for the identification of homologous elements across species. It has long been thought that the NGP is broadly applicable to all Lepidoptera, implying that the characters which make-up butterfly color patterns are homologous to those found in the moths. However, this conjecture remains mostly untested. We analyzed the wing patterns of the hyper-diverse arctiid tiger moths, which are represented worldwide by approximately 11,000 species, and found that the color patterns of these animals can be parsed into a limited toolkit of homologous characters. Some of the pattern elements identified, such as the basal and central symmetry system, are present on the NGP, but their morphology is often quite different from what is seen in the butterflies. The border ocelli of the NGP appear to be absent altogether in the Arctiidae, and conversely, two distal pattern element we term the ‘van Bemmelen’ and ‘terminal’ bands are present in the color patterns of many arctiids, but are not represented on the NGP. In light of the observed differences, we derive a new theoretical groundplan based on the original NGP that we refer to as the ‘arctiid archetype.’ This model provides a comprehensive framework for understanding how the wing patterns of these animals develop, and yields novel insight into their evolutionary history.

A new, diminutive species of Rock Gecko Cnemaspis tubaensis sp. nov. of the C. kumpoli group, is described from Tuba Island, Langkawi Archipelago, Kedah, Peninsular Malaysia and is differentiated from all other species in the kumpoli group by having a unique combination of morphological and color pattern characteristics, including a maximum SVL of 37.0 mm; 10 or 11 supralabials; eight or nine infralabials; 15–18 semi-linearly arranged paravertebral tubercles; lateral caudal furrow present; lateral caudal tubercles on the anterior portion of the tail; caudal tubercles not encircling tail; five or six precloacal pores; 28 or 29 subdigital lamellae on the fourth toe; smooth ventrals; smooth subcaudals with an enlarged median row of scales; subcaudal region light-grey and speckled with yellow; absence of light-colored ocelli on the shoulder; no yellow postscapular band; dorsum light-brown with sage-green blotches and black spots; flanks with scattered yellow spots; absence of black gular markings in both sexes; and 13.0–22.0% uncorrected pairwise sequence divergences in the NADH dehydrogenase subunit 2 gene (ND2). Cnemaspis tubaensis sp. nov. is the fourth species of Cnemaspis to be described from the Langkawi Archipelago and underscores the underestimated biodiversity of the islands which is in need of more thorough herpetological inventories.

A new species of praying mantis, Vates phoenix sp. nov. (Mantidae, Vatinae), is described from localities within Rio de Janeiro and São Paulo states, Brazil. This is the first record of Vates from the Atlantic Rainforest biome. The new species is unique among its congeners in having, among other features, strongly reduced cuticular projections above the lateral ocelli, structures otherwise well developed and produced in all other species of Vates. Remarks on the natural history and biogeography of Vates, in relation to this new finding, are further discussed.

Lithobius (Ezembius) varioporussp. nov. (Lithobiomorpha, Lithobiidae), recently discovered from Longquanguan Town, Fuping County, Baoding City, Hebei Province, China, is described. Morphologically it resembles to Lithobius (Ezembius) laevidentata Pei, Ma, Hou, Zhu & Gai, 2015 from the Xinjiang Autonomous Region, but can be easily distinguished from the latter by the Tömösváry’s organ, slightly smaller than the adjoining ocelli, no secondary sexual modifications on male tibia 14 and 15, posterior accessory spine of legs 14 and 15 present and the number of coxal pores varying considerably from three to eight. The main morphological characters of the known Chinese species of the subgenusEzembius Chamberlin, 1919 based on adult specimens are presented.

A new marine benthic diatom, Pleurosira nanjiensis sp. nov., is described from the rocky intertidal zone of the Xiaochaiyu Island of the Nanji Islands in China. Its morphology was examined with light and scanning electron microscopy. Molecular phylogeny was reconstructed based on SSU rRNA and rbcL gene sequences. Pleurosira nanjiensis differs from congeners in possession of a combination of morphological features including the domed valve with broadly lanceolate, elliptical or circular valve outline, two elevated marginal ocelli, two (rarely three) rimportulae, and radiate striae.

The fauna of bristletails of the genus Lepismachilis Verhoeff, 1910 in Montenegro and Serbia includes only one species L. (Berlesilis) targionii (Grassi, 1887) with 2 + 2 eversible vesicles on abdominal urocoxites II–VI. Three new species of this genus are described: L. (Lepismachilis) prijepolja sp. nov., L. (Lepismachilis) limensa sp. nov. from Serbia, and L. (Lepismachilis) alexandrae sp. nov. from Montenegro. All described new species belong to the species group of the subgenus Lepismachilis s. str. with 2 + 2 eversible vesicles on abdominal urocoxites II–V. Lepismachilis prijepolja sp. nov. differs from L. y-signata Kratochvíl, 1945 and L. notata Stach, 1919 by the color, drawings and ratios of the compound eyes; ratios of sensory field on fore femur of male, number of divisions of ovipositor. Lepismachilis limensa sp. nov. differs from L. hauseri Bitsch, 1974 and L. abchasica Kaplin, 2017 by ratios of paired ocelli, sensory field on fore femur of male; ratios and chaetotaxy of maxillary and labial palps. Lepismachilis alexandrae sp. nov. differs from L. abchasica by the drawings of the compound eyes; ratios of paired ocelli, sensory field on fore femur of male; number of divisions of the parameres and gonapophyses. A list of the Machilidae occurring in Balkan Peninsula is also provided.

An eyespot, a smooth cuticular structure situated posteroventral or ventral to the lateral ocelli, has been documented in at least 60 species in 46 genera and six families of scorpions. The eyespot was confirmed to be absent in 89 genera, 115 species and seventeen families. In the present contribution, the ultrastructure of the eyespot, median and lateral ocelli of the Vietnamese chaerilid scorpion, Chaerilus julietteae Lourenco, 2011, is investigated using transmission electron microscopy. As in the buthid scorpion, Parabuthus transvaalicus Purcell, 1899, the eyespot of C. julietteae differs from the median and lateral ocelli in lacking a dioptric apparatus and pigment granules in the retinula and pigment cells, implying that its function is nonvisual. The presence of an eyespot is documented across Chaerilidae Pocock, 1893, confirming that it is diagnostic and probably synapomorphic for the family. Based on ultrastructure and position, the eyespot of scorpions appears to be a highly modified lateral ocellus that lost its lens and visual function during disintegration of the compound lateral eye.

Recent discoveries of fossil nervous tissue in Cambrian fossils have allowed researchers to trace the origin and evolution of the complex arthropod head and brain based on stem groups close to the origin of the clade, rather than on extant, highly derived members. Here we show that Kerygmachela from Sirius Passet, North Greenland, a primitive stem-group euarthropod, exhibits a diminutive (protocerebral) brain that innervates both the eyes and frontal appendages. It has been surmised, based on developmental evidence, that the ancestor of vertebrates and arthropods had a tripartite brain, which is refuted by the fossil evidence presented here. Furthermore, based on the discovery of eyes in Kerygmachela, we suggest that the complex compound eyes in arthropods evolved from simple ocelli, present in onychophorans and tardigrades, rather than through the incorporation of a set of modified limbs., The arthropod head is complex and its evolution has been difficult to reconstruct. Here, Park et al. describe new specimens of the Cambrian stem-group euarthropod Kerygmachela that preserve evidence of primitive compound eyes and a unipartite brain, providing insight into the structure of the early arthropod head.

The evolution of eyes and their constituent photoreceptor cells in Metazoa in general and in Protostomia in particular remains unresolved with present morphological and developmental genetic data. This is mainly due to the lack of comprehensive ultrastructural data in some lineages, such as in the spiralian taxon Nemertea. The eyes of the derived Neonemertea possess rhabdomeric photoreceptor cells, considered typical of the protostome lineage. In the more basally branching palaeonemertean lineages, ultrastructural data on the eyes are wanting. Ultrastructural investigation of the eyes of the larva of the palaeonemertean Procephalothrix oestrymnicus reveals that, although in a similar position as the eyes of adult neonemertean species, the eyes in palaeonemertean larvae differ fundamentally from the expected protostomian type: They consist of one shading-pigment cell that forms a closed optical cavity embedded in the epidermis. Apart from basally distributed shading-pigment vesicles, the pigment cell apically possesses epidermal cilia and microvilli as well as sub-apical, tubular lens vesicles. Two ciliary photoreceptor cells project flattened ciliary membranes into the optical cavity formed by the pigment cell, whereas their basal portions are situated outside of the optical cavity, next to the shading-pigment cell. Although the structure of the eye in P. oestrymnicus is unparalleled in Nemertea, ciliary photoreceptor cells have been found in larval eyes of several other spiralian lineages. Occurrence of additional ciliary-type eyes in Spiralia deepens the doubts regarding the validity of the hypothesis of an exclusively rhabdomeric line of visual photoreceptor cell evolution in Protostomia.

Insects have exquisitely adapted their compound eyes to suit the ambient light intensity in the different temporal niches they occupy. In addition to the compound eye, most flying insects have simple eyes known as ocelli, which assist in flight stabilisation, horizon detection and orientation. Among ants, typically the flying alates have ocelli while the pedestrian workers lack this structure. The Australian ant genus Myrmecia is one of the few ant genera in which both workers and alates have three ocellar lenses. Here, we studied the variation in the ocellar structure in four sympatric species of Myrmecia that are active at different times of the day. In addition, we took advantage of the walking and flying modes of locomotion in workers and males, respectively, to ask whether the type of movement influences the ocellar structure. We found that ants active in dim light had larger ocellar lenses and wider rhabdoms compared with those in bright-light conditions. In the ocellar rhabdoms of workers active in dim-light habitats, typically each retinula cell contributed microvilli in more than one direction, probably destroying polarisation sensitivity. The organisation of the ocellar retina in the day-active workers and the males suggests that in these animals some cells are sensitive to the pattern of polarised skylight. We found that the night-flying males had a tapetum that reflects light back to the rhabdom, increasing their optical sensitivity. We discuss the possible functions of ocelli to suit the different modes of locomotion and the discrete temporal niches that animals occupy.

— Two new species of Friesea from the Western Cape province in South Africa, F. stevenchowni sp. nov. and F. capensis sp. nov., are described. Friesea capensis sp. nov. is easily distinguished by the lack of ocelli and anal spines, while F. stevenchowni sp. nov. is distinguished from other sub-Saharan species of the genus by a combination of characters including two anal spines in the position of m1, tibiotarsi with chaeta M present, 3+3 chaetae on the thoracic tergum I and 5+5 eyes. An identification key is provided for Friesea species that are found in sub-Saharan Africa.