Improving knowledge of the cyclorrhaphan larva (Diptera)

A significant factor in the evolution of the Cyclorrhapha (Diptera), the most biodiverse of higher dipteran taxa, is the larva. The larva also has wide-ranging trophic and environmental relationships, including positive and negative impacts on human health and wealth. Despite its importance, the larva is neglected and a low proportion of species are known in this stage. In this paper, factors contributing to larval neglect are reviewed, including: poor attitudes leading to cycles of neglect and shallow treatment; taxonomy that uses adult not larval stages; lack of material in collections; rearing barriers, and presumptions of morphological similarity suggesting that characters will be problematic to acquire and analyse. Neglect is pervasive and affects many subjects; those considered here are: species inventories and rarity assessments for biodiversity and conservation, in which larvae are usually ignored although they can be more cost-effective to sample and a richer source of environmental data; determining larval feeding modes where controversies due to conflicting evidence persist unresolved; and reliance on a limited pool of increasingly old publications whose data are repeated rather than tested and updated with new research. In an attempt to reinvigorate interest, which is the main aim of this paper, poorly assessed larval features possibly significant to cyclorrhaphan diversification are also considered. These include: change facilitated by independently evolvable modules; rapid change enabled by labile trophic morphology; shifts between saprophagy and phytophagy due to opportunities provided by angiosperm evolution; and enhanced adaptive potential resulting in derived more than basal taxa developing adaptations that enable access to new and little used resources. Apart from the need to rear more larvae, a major conclusion from this review is that knowledge will improve when the movement capabilities of larvae are used to inform morphological and taxonomic analyses.     

Larval feeding habits of the Hepialidae (Lepidoptera)

The host-plant relationships of the Hepialidae are discussed in relation to host range and larval tunnelling behaviour. Larvae are mostly phytophagous on live angiosperms, gymnosperms, pteridophytes and mosses. Generally they specialize as feeders of leaf, stem/branch or root tissue, but dietary transitions from leaf to stem and root to stem occur in some species. An early period of mycophagy where larvae feed on fungi or dead decaying plant tissue is recorded in a wide range of species that feed on live embryophytes in later instars. Feeding patterns of the Hepialidae are compared with those of other major lepidopteran taxa and the evolutionary implications of hepialid feeding habits for the origin and derivation of larval host-plant relationships in Lepidoptera are discussed. It is suggested that the developmental transition from mycophagy to phytophagy in the Hepialidae is the result of partial ‘suppression’ of mycophagy in the generalist feeding ancestor of Lepidoptera.     

Identity of Mertensia oblongifolia (Nutt.) G. Don (Boraginaceae) and its allies in western North America

The current status of Mertensia oblongifolia (Nutt.) G. Don and its allied taxa is surveyed. On the bases of continuously coherent morphological characters and/or regionally correlated variations, more than 30 taxa, including species, subspecies, varieties, and 1 forma, previously considered different from M. oblongifolia , are now placed under synonymy of this species. Those taxa currently known as M. fusiformis Greene, M. bakeri Greene, and M. bakeri var. osterhoutii Williams are among the new synonyms. Typification, taxonomy, and morphological problems of M. oblongifolia are discussed.     

A remarkable new species of scuttle fly (Diptera: Phoridae) whose larvae infest chickpea root nodules in India

Metopina ciceri sp. nov. is described on the basis of males with reduced wings, fully winged females, blind females with reduced wings, pupae and larvae. The larvae infest the root nodules of the chickpea, Cicer arietinum L. The blind-morph females are considered to be congeneric with the type species of the genus Typhlophorina Silvestri and this genus is synonymized with Metopina. The males, if procured in isolation, would have been assigned to a separate genus. The evolution of sexual dimorphism and dimorphic females in M. ciceri is discussed in relation to a speculative scenario involving juvenile hormone and heterochrony. It is also speculated that dispersal is undertaken by the sighted fully-winged female morph only. These speculations and the question of whether the infestation of C. arietinum by M. ciceri affects yield remains to be investigated.     

Morphology and spatial constraints in a dorso‐ventrally flattened skull,with a revised species description of Platyallabes tihoni (Poll, 1944)

This study details the morphology of Platyallabes tihoni (Poll, ) as part of a complete revision of the anguilliform clariids. The overall body form of air‐breathing clariids ranges from fusiform to anguilliform genera (Boulenger ; Pellegrin ). Although P. tihoni has the typical external morphological features of other elongate clariids, this study shows that it occupies an intermediate position between fusiform and anguilliform taxa with regards to its cranial and postcranial morphology. The main morphological similarities of anguilliform species are a narrow skull roof with a high level of interdigitation between the bones, the reduced canal bones, a connection between the neurocranium and suspensorium via several processes, an extended tooth patch on the lower jaw, and the hypertrophied jaw muscle complex. Shared features typical for the fusiform species are a low coronoid process on the lower jaw and the posteroventral orientation of the opercular process on the hyomandibula. Platyallabes tihoni shows a series of unique features: an anterior fontanel situated entirely between the frontals, two tooth plates on the prevomer, a reduced height of the suspensorium, the absence of an anterior bony plate on the hyomandibula, a horizontal position of the sphenotic and pterotic, and a toothed entopterygoid. Many of these unique characters are linked to the spatial constraints associated with an extremely flattened skull in this species.     

Partitioning phenotypic variation: genotypic,environmental and residual components from bryozoan skeletal morphology

Using morphometric studies of colonial (clonal) organisms such as Bryozoa grown as replicates in controlled laboratory experiments, phenotypic variation (hard part morphology) can be partitioned into its genotypic and environmental (ecophenotypic) components. The interaction between these, i.e. different genotypic responses to the same environmental change, can also be recognized. Palaeobiological studies are inherently constrained by species concepts based on morphotypes (preserved morphological phenotype). Uncertainties associated with fossil species concepts restrict the deductive resolution potential of fossil taxa in discussions of the broader biological questions of species evolution, ecology, biogeography and phylogeny. The relationship between species-level morphological variation and genetic variation in modern taxa is central to evaluating the viability of fossil morphotypes as biological species. Results from a preliminary study of three genotypes of Electra pilosa L., grown as replicate colonies in tanks comprising different microenvironmental conditions, allow for direct evaluation of morphospecies concepts. Numerical analyses (Cluster Analysis, Principal Component Analysis and Two-way ANOVA) of six morphometric characters demonstrated a strong Genotype control over zooid morphology and limited environmental (Tank) effects with minimal environmental differences among tanks. No significant Genotype by Tank (=environment) interactions were found for any characters. These results demonstrate that it is possible to quantify the extent to which a given trait is plastically expressed in different environments. The strong degree of correlation between morphology and genetics for this species is encouraging for the use of morphotypes as proxies for biological species.     

Adult butterfly feeding–nectar flower associations: constraints of taxonomic affiliation,butterfly, and nectar flower morphology

Butterfly–flower morphological interrelationships were investigated for 108 butterfly species and 20 plants at Nagpur, India. Distinct clusters of higher taxa (families) are disclosed for butterfly morphology and significant morphological and taxonomic associations occur in nectar exploitation. Flower corolla depth generally restricts exploitation by butterflies in relation to proboscis length and butterflies with high wing load indices bias their feeding to plants with massed flowers. However, important exceptions emerge; also, a substantial number of butterflies feed on plants with massed flowers though their proboscises are of marginal length for corolla depths. These butterfly species are significantly smaller, lighter, with lower wing loading and shorter proboscis indices than species which easily access the same flowering plant species. It is suggested that small size and short proboscises could give them a competitive advantage (increased rate of nectar uptake) for exploiting nectar in such situations. The significance of the findings for conservation is discussed.     

New distribution records for the Querétero dusky rattlesnake Crotalus aquilus (Viperidae), with comments on morphology and habitat use

We provide the 1st documented accounts of the Mexican endemic rattlesnake Crotalus aquilus from the state of México. The new records extend the known distribution of the species into a region where it may be sympatric with the superficially similar C. triseriatus . Because these taxa have previously been subject to some taxonomic confusion, we performed a preliminary morphological comparison using individuals of both species obtained from proximal localities. Our analyses support the supposition that these taxa are morphologically distinct. The new localities for C. aquilus are situated in high valleys that have been extensively modified by human settlement and agriculture.     

Cave-dwelling Fulgoroidea (Homoptera: Auchenorrhyncha) from the Canary Islands

Examination of Fulgoroid specimens collected in several caves of volcanic origin on the Canary Islands (Tenerife, El Hierro) has revealed the existence of at least two undescribed troglobitic Fulgoroid species. These are apparently the first records of troglobitic Auchenorrhyncha, not only from the Middle Atlantic Islands, but from the Palaeartic Region. These cavernicolous taxa belong to the families Cixiidae (Tachycixius lavatubus sp. nov.) and Meenoplidae (Meenoplus cancavus sp. nov.). Possible pathways towards the evolution of troglobitic forms in Auchenorrhyncha and ways of speciation—sympatric or allopatric—for T. lavatubus sp. nov. and its epigean relative Tachycixius canariensis (Lindberg) are discussed. These findings suggest that cavernicolous Homoptera are more widely distributed over the world than was previously assumed.     

Observations on Recruitment and Ecology of Razorback Sucker: Lower Colorado River, Arizona-California-Nevada

The Colorado River system downstream from Lake Mohave yielded 42 adult, 19 juvenile, and 39 larval wild razorback suckers ( Zyrauchen texanus ) between 1962 and 1988. Forty-six additional young captured between 1984 and 1987 may have been wild or stocked, hatchery-propagated fish. Wild juveniles of this endemic, imperiled species, with one exception, have not been otherwise known from the Colorado River basin downstream from the Grand Canyon since the 1950s. A majority of adults and larvae were from the river or its mainstream impoundments, while all but one wild juvenile and all presumably stocked fish were captured from irrigation canals. The ecology of artificial canals in which young razorback suckers survive and grow is poorly understood.     

Comparative susceptibility of conifers to knobcone pine dwarf mistletoe

Analysis of morphological characters of Arceuthobium apachecum and A. blumeri indicates there are several geographically consistent differences between these taxa, which supports their current classification at the specific level. Shoot height and perianth lobe number exhibited considerable geographic variation, and some morphological characters examined were continuous. Peak flowering and seed dispersal periods for these species differed slightly Altitudinal, seasonal, and latitudinal variations in flowering and seed dispersal were detected and may be responsible for the differences in phenology between these taxa.     

Taxonomic studies of dwarf mistletoes ( Arceuthobium ssp.) parasitizing Pinus strobiformis

Analysis of morphological characters of Arceuthobium apachecum and A. blumeri indicates there are several geographically consistent differences between these taxa, which supports their current classification at the specific level. Shoot height and perianth lobe number exhibited considerable geographic variation, and some morphological characters examined were continuous. Peak flowering and seed dispersal periods for these species differed slightly Altitudinal, seasonal, and latitudinal variations in flowering and seed dispersal were detected and may be responsible for the differences in phenology between these taxa.     

Diolenius minotaurus sp. nov., a remarkable horned jumping spider from Papua New Guinea (Araneae: Salticidae)

The presence of horn-like projections in jumping spiders is briefly reviewed and a new horn-bearing species from Papua New Guinea is described. Its affinities and aspects of its biology are discussed. Several new morphological features are illustrated by scanning electronmicrographs.     

New data on Hydrobiidae systematics: two new genera from the Iberian Peninsula

The taxon Caprella acanthifera auct., usually considered to be one ‘highly variable’ species, is shown here to consist of a number of closely related species. In this paper three species of the group lacking an axillary spine near the insertion of gnathopod 2 are described and illustrated; the taxa with an axillary spine will be dealt with in a separate paper. This paper redefines Caprella acanthifera Leach 1814, sensu stricto; the nominal taxa C. hystrix, C. calva, C. aspera, and C. leptonyx are considered to be junior synonyms. Also described are C. stella sp.n., from starfish at the Azores and C. cavediniae sp.n., living among algae in the Mediterranean. The sources of apparent morphological variability in caprellids are discussed.     

A new species of Caraiboscia Vandel, 1968 from South America,and a type species for Colombophiloscia gen. n. (Crustacea: Oniscidea: Crinocheta)

The South American genera Caraiboscia Vandel, 1968 and Colombophiloscia gen. n. are examined to establish their phylogenetic relationships in the light of their life histories. A new species is described in the genus Caraiboscia, whereas the latter genus replaces the name Colombophiloscia Vandel, 1968 which is an unavailable name since no type species was chosen by Vandel (1968). The taxa are described in detail and apomorphic characters supporting a sister group relationship are given. The adaptive value of these characters is discussed with respect to their life history and the probability of a convergent evolution.