Polymorphism,taxonomy and host plant associations in Alebra leafhoppers (Homoptera: Cicadellidae: Typhlocybinae)

The taxonomy of a complex of morphologically similar Alebra species is clarified, and the number of adult colour pattern morphs of each in Britain, and their host plant associations, established. Morphological characters are figured for the identification of the four species now recognized, including two that are associated with different species of deciduous oaks and which were previously regarded as colour pattern morphs of A. albostriella. Three nymphal colour pattern morphs are described within the A. albostriella sibling species, two of which are shared, thus supplying further evidence for their close relationship. A key is given for the identification of the species and adult morphs of Alebra in Britain.     

Species status of two colour morphs of Eupelmus vesicularis (Hymenoptera: Eupelmidae) as revealed by allozyme electrophoresis,morphometric and host preference data

Eupelmus vesicularis (Retzius) is considered to be a widespread and polyphagous parasitoid recorded from more than 200 hosts. The aim of this study was to determine whether two colour forms of the putative species represent two different morphs of a single species or a pair of cryptic species. Three different methods – morphometric analysis, allozyme electrophoresis and evaluation of host preferences – were used to investigate the existence of two cryptic species. Bivariate and multivariate analyses clearly indicate two species that are also distinguishable electrophoretically at the Idh-2, G6pdh, Me, Pgm and Xdh loci. The evaluation of host preferences indicates some overlap in host range between the two species.     

Revisiting the saproxylic beetle ‘Propomacrus cypriacus Alexis & Makris, 2002’ (Coleoptera: Euchiridae) using molecular,morphological and ecological data

Propomacrus cypriacus a saproxylic beetle endemic to Cyprus, was described as a species distinct from P. bimucronatus on the basis of a few morphological characters and has been evaluated as Critically Endangered by IUCN, as it depends on veteran trees and has a restricted distribution. Herein we explored the distribution, ecology, morphology and genetic variation of the populations from Cyprus, and we attempted a phylogenetic analysis including related species based on two mitochondrial and one nuclear DNA markers. We also used published mtDNA divergence rates to date cladogenetic events. Despite extensive sampling, we found only a small number of individuals, adding a few additional localities to the known distribution of the species, and we identified two more host species to those previously reported. Morphological examination showed that only the form of male protibiae differs consistently in Cyprus populations compared to those of P. bimucronatus from Turkey and the Lebanon. Nevertheless, genetic analyses do not support a distinct species status for populations from Cyprus, which should instead be considered as a subspecies of P. bimucronatus. Morphological and ecological data further support this conclusion. Cyprus populations have diverged from nearby continental ones in mid to late Pleistocene.     

New damselfly hosts and species identification of an aquatic parasitoid Hydrophylita emporos (Hymenoptera: Trichogrammatidae) in Taiwan

ABSTRACT

The host–parasitoid relationship and species identity of aquatic parasitoids of two damselflies Coeliccia cyanomelas (Platycnemididae) and Psolodesmus mandarinus dorothea (Calopterygidae) from Fushan and Lienhuachih in Taiwan were studied using morphological characters and DNA barcoding sequences. The parasitoids reared from the damselflies’ eggs, and the field-collected parasitoids, were morphologically identified as Hydrophylita emporos (Trichogrammatidae), a recently described parasitoid of the damselfly P. m. mandarinus from Northern Taiwan. The CO1 (cytochrome c oxidase I) gene tree supported the identification as H. emporos, as well as all parasitoid samples from C. cyanomelas, P. m. dorothea and P. m. mandarinus. The sampled H. emporos populations did not differ genetically despite their different host associations. However, some genetic differences were found between H. emporos populations from Northern and Central Taiwan, indicating that the dispersal of H. emporos may be limited by geographical distances. Our results suggest that H. emporos can parasitise not only closely related sister subspecies, P. m. mandarinus and P. m. dorothea, but also phylogenetically distant species of another damselfly family, C. cyanomelas. This is the first record of multiple damselfly hosts for the aquatic parasitoid genus Hydrophylita. This finding implies that the host range of H. emporos and congeneric species may be broader than previously thought.     

Contribution to the knowledge of the genus Pseudomonocelis Meixner, 1943 (Rhabditophora: Proseriata)

A new species of the genus Pseudomonocelis (P. caribbea sp. n.) is described. It is distinguished from congenerics by shape and size of the copulatory organ and relative positions of mouth and genital openings. It is the first species of the genus found in America. Sampling in east Africa (Zanzibar island) revealed two species, attributed to P. pardii and, tentatively, to P. cavernicola, both originally described from Somaliland. Morphological differences between Tanzanian and Somali specimens are reported. The Mediterranean P. ophiocephala, based on extensive morphological and karyological survey of 13 populations, is interpreted as constituting at least two sibling species, distinguishable solely on the basis of karyotype. Results support the notion that the present perception of the contribution of interstitial Rhabditophora to marine biodiversity may be unrepresentative.     

Maintenance of colour polymorphism in the leaf beetle Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae: Paropsini)

Intra-specific colour differences in insects may occur as a result of environmental factors such as food type, temperature and humidity, or may be under genetic control. These colour polymorphisms may result in fitness differences through several mechanisms, including mate selection, camouflage from or warning to natural enemies, and heat absorption. Two colour morphs of adult Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae: Paropsini) are present in the field in mainland Australia and Tasmania: a common green-brown form, and a rare black form. Tasmanian populations were sampled to assess the frequency of each morph at eight localities. The black form represented less than 3% of beetles (N=1724), with the proportion not significantly different between localities. Crossing tests using the two colour morphs of C. agricola showed that the black form was genetically dominant over the common form. To assess whether colour morphs had any fitness differences, we measured pre-oviposition period, fecundity, longevity, adult size and egg hatch rate, which each showed no significant difference between colour morphs. Field sampling of mating pairs and rearing the offspring of field-collected females showed no evidence of non-random mating. Modelling the population over 100 generations confirmed that for this species, melanism is controlled by a dominant but neutral allele, and, thus, is maintained at a constant low level in the population.     

Terellia fuscicornis (Diptera: Tephritidae): biological and morphological adaptation on artichoke and milk thistle

The biology, morphology, and genetics of Terellia fuscicornis on cultivated artichoke and its new recorded host, Silybum marianum, are examined. Morphometrically, the two host‐associated populations were distinct. Except for egg length, all immature stages of the artichoke‐associated population were larger. Principal component analysis, based on head and wing measurements, showed that the adults from both populations clustered into two groups, with the adults reared from artichoke being larger. The ovipositor was significantly longer and blunter in the artichoke‐associated females, reflecting the larger flower heads exploited. Male terminalia measurements showed significant differences between the two populations. Several differences in courtship behaviour were detected between the two populations. Although the two populations show allochronic isolation, sequencing of two mitochondrial genes, ND1 and COI, and one nuclear gene, 18S, revealed no genetic differences between the two populations.     

Geographic variability in the genetic polymorphism of the Isopod,Venezillo evergladensis

Influence of host on hook morphology, soluble protein profile and two polymorphic loci of the marine tapeworms, Hepatoxylon trichiuri and H. megacephalum were studied. It was found that hook lengths of the two parasites differed significantly and that they varied with the host species. Unweighted pair-group analysis of soluble protein similarity indices separated H. trichiuri and H. megacephalum into three groups by fish host species. Allozyme analyses revealed that a polymorphic locus, glucose-6-phosphate dehydrogenase, of H. trichiuri showed significant variations in the allelic and phenotypic frequencies between populations of parasites from different host species, but a second polymorphic locus, esterase, did not show any host-related variation. Owing to the small sample size of H. megacephalum statistical analysis was not carried out for the allozyme study. However, allelic frequencies of the Est locus differed significantly between the two parasites. The possible influence of fish hosts on parasite morphology, protein biochemistry and population genetics was discussed.     

Heleobia maltzani (Westerlund, 1886) (Caenogastropoda: Truncatelloidea: Cochliopidae) from Crete and species-level diversity of Heleobia Stimpson, 1865 in Europe

Morphological characters and partial cytochrome oxidase (COI) DNA sequences were used to investigate intra- and interpopulation differences among three Cretan brackish-water populations of Heleobia maltzani snails. The morphology of male and female reproductive organs of H. maltzani did not differ within studied populations or in comparison with closely related species. In contrast, analysis of shell morphology revealed substantial variation not supported by the genetic data. Genetics results showed surprisingly low differentiation between all Cretan populations and also mainland populations of Heleobia. They also showed that H. maltzani is conspecific with four other European species of Heleobia, thus implying that there is only one species of brackish-water Heleobia in Europe. Such a low level of genotypic differentiation is unusual for typical island species and is most probably the consequence of recent colonization of Crete. Possible scenarios of such processes are discussed.     

The polymorphism of a lygaeid bug Oxycarenus (Oxycarenus) multiformis Samy

Summary

The new species Oxycarenus (Oxycarenus) multiformis Samy has been found to be a polymorphic species. Four colour forms have been found: red, banded, spotted and black. Breeding experiments under laboratory conditions have indicated that dominance is nearly complete in the order given and that the second generation is segregated in the 3:1 ratios.

These colour forms have been given the taxonomic status of a single species on the basis of: (a) identical measurements of external characters, (b) similar morphological characters in the male genitalia, (c) equal fertility of each form, (d) free interbreeding, (e) random mating, (f) occupation of the same geographical regions, and (g) host plant relationship.     

Early life history of the sheepnose (Plethobasus cyphyus) (Mollusca: Bivalvia: Unionoida)

Managing a rare species can be improved with knowledge of its natural history. The sheepnose (Plethobasus cyphyus) is a freshwater mussel recently listed by the US as federally endangered. We used standard methods to study P. cyphyus brooding behaviour, host fishes in the laboratory and under natural conditions, and glochidial morphology. We monitored a population of P. cyphyus in the Chippewa River, WI during spring and summer 2007–2009 and 2011 and found brooding animals between mid-May and early August. Gravid individuals ranged between 5 and 27 yr (mean age ± 1 s.d. = 13 ± 4 yr). Plethobasus cyphyus brooded glochidia in outer gills, which varied in colour from red, orange, pink, cream, or white. We observed mature glochidia more commonly in individuals with cream or white gills and these glochidia were released in a clear, adhesive, mucus matrix. In laboratory trials we found several minnow and topminnow species (29 spp.) served as productive suitable native hosts. The mean number of juvenile mussels released per cyprinid per day was significantly higher for trials conducted at 22–25°C compared with those at 18–20°C, and 83% of trials conducted at 18–20°C using suitable host species produced no juveniles. Glochidia had a unique outline and shell morphometrics that distinguished P. cyphyus from seven other Chippewa River mussel species that produce similar sized glochidia. Using morphometrics we determined that mimic shiners (Notropis volucellus) were natural hosts for P. cyphyus, round pigtoe (Pleurobema sintoxia), and Wabash pigtoe (Fusconaia flava). Releasing mucus-bound glochidia has evolved in a variety of mussel species and may be more common than is currently realized. Our data show that P. cyphyus is a cyprinid host specialist, and propagation efforts for this species can be strengthened through improved access to mature glochidia by using females with cream-coloured gills and increased juvenile production through warmer fish holding temperatures.     

A new species of Munromyia Bezzi (Diptera: Tephritidae) reared from Chionanthus battiscombei (Oleaceae) in northern Kenya

Munromyia marsabitensis sp. nov. is described from the isolated mountains of Marsabit in northern Kenya. It can be distinguished from the two known congeners by the thoracic and abdominal colour patterns, structure of the male and female terminalia, and host plants. Larvae are seed predators, developing within the green, aborted fruits of Chionanthus battiscombei. Over 70% of sampled fruits (n?=?74) were infested with larvae, but nearly all of the individually infested fruits (96.1%) produced only one adult tephritid. Bactrocera biguttula, but not M. marsabitensis, was reared from ripe fruits of the same plant.     

Life history and host utilization pattern of a strepsipteran parasite (Insecta: Strepsiptera) on the Blissine bugs (Hemiptera: Lygaeidae) living under dwarf bamboo leaf sheaths

The blissine bug Macropes obnubilus, which lives aggregately under leaf sheaths of the evergreen dwarf bamboo, is infected by the strepsipteran parasite Blissoxenos esakii. To determine the ecological properties of the bug–strepsipteran system, we conducted field surveys of natural populations of Macropes bugs and Blissoxenos parasites. The parasitism rate of strepsipterans was high throughout the year and was significantly higher in female than in male bugs. Blissoxenos adult males emerged mainly in May, and neotenic adult females released triungulins in August. The triungulins invaded host nymphs, but subsequent larval development did not occur before the bugs matured. At most, two strepsipterans could mature in a host because of spatial limitations. The mortality of triply or more parasitized bugs was significantly higher than that of singly or doubly parasitized bugs, which survived longer than uninfected ones. The heavy strepsipteran infection profoundly affected the host population by causing host reproductive failure.     

A comparative study of the mating call of Pelophylax ridibundus and Pelophylax kurtmuelleri (Anura: Ranidae) from syntopic and allotopic populations

The mating call of Pelophylax ridibundus and Pelophylax kurtmuelleri from three syntopic and five allotopic populations was studied. All recordings were made during the mating season. We tested the hypothesis that the call of P. ridibundus from allotopic populations would differ from that in syntopic populations with P. kurtmuelleri. For the comparative analysis we used univariate and multivariate statistical methods and the following characteristics: call duration, pulse group duration, pulse group interval, pulse group period, pulse group number, minimum, maximum, fundamental and dominant frequencies and pulse energy. Analyses reveal a trait divergence in most of the studied characteristics of the signals, with stronger differentiation between P. kurtmuelleri and P. ridibundus in syntopic populations than between the two species in allotopic ones. The possible evolutionary implications of this divergence are discussed.     

Distinct parasitoid communities associated with host races of the leaf-mining moth Acrocercops transecta on distantly related host plants (Juglandaceae and Ericaceae)

Differences in host-plant species may affect the structure of parasitoid communities of phytophagous insects. Phytophagous insect species often consist of host races, and comparisons between host races enable us to infer the effects of host-plant differences on parasitoid communities. Here, we compare the parasitoid fauna of two host races of the leaf-mining moth Acrocercops transecta, which are associated with either Juglandaceae or Lyonia ovalifolia (Ericaceae). Field collection and subsequent laboratory rearing revealed a significantly higher parasitization ratio in the Juglandaceae race than in the Lyonia race. In the Juglandaceae race the majority of parasitoids were Braconidae, whereas in the Lyonia race the majority were Eulophidae. Furthermore, even within the same host race the most abundant parasitoid species differed between populations with different host associations. Hence, the present results strongly indicate that different host-plant taxa affect the structure of parasitoid communities even within a single phytophagous insect species.     

Patterns of host-plant utilization by leafhoppers in the genus Eupteryx (Hemiptera: Cicadellidae) in Britain

Known host-plant associations are listed for the 16 species of Eupteryx occurring in Britain. A total of 77 species in 17 plant families are exploited. The most frequently represented plant family is the Labiatae. Degrees of specificity range from strict monophagy (four spp.) to broad polyphagy (five spp.). In general, host-plant overlap between species is low. The detailed relationships between three Eupteryx species and three members of the Urticaceae were explored using field populations and laboratory feeding experiments, survival tests and examination of patterns of oviposition. Eupteryx urticae, E. cyclops and E. aurata all utilized Urtica dioica as their primary host plant. However, the only regularly recorded association with other members of the Urticaceae was the host range expansion of E. urticae onto Parietaria judaica in the second generation. These findings were supported by the laboratory experiments. The spatial distributions of E. urticae oviposition sites and levels of attack by mymarid parasitoids were similar in populations on the two plant species. The implications of these results are discussed.     

Genetic diversity in the Carabodes marginatus species group (Acarida,Oribatida, Carabodidae) as inferred from allozymes

Ten populations representing four species of the ‘Carabodes marginatus’ group, as C. marginatus, C. affinis, C. quadrangulus and C. montanus from central Italy have been studied for genetic variation at 16 enzymatic loci by electrophoresis. Morphotypes close to C. marginatus but easily distinguishable by the shorter marginal notogastral setae were also included in the analysis to evaluate their systematic status. Carabodes arduinii, a very different species from the ‘coriaceus’ group, was employed as an out-group. Phylogenetic relationships among different species were studied and inferred data demonstrated that cladogenetic events occurred, even though rates of molecular and morphological evolution do not correlate. Morphotypes related to C. marginatus were genetically very close to the type specimens, but a different pattern of allele frequency was observed in sympatric populations of the two setal forms. Possible explanations for this finding are suggested in relation to historical processes. The rate of gene flow among populations of the two morphs was estimated by both Wright's F _st and Slatkin's Nm methods. These two different procedures yielded contradictory results.