How sympatric is speciation in the Howea palms of Lord Howe Island?

The two species of the palm genus Howea (Arecaceae) from Lord Howe Island, a minute volcanic island in the Tasman Sea, are now regarded as one of the most compelling examples of sympatric speciation, although this view is still disputed by some authors. Population genetic and ecological data are necessary to provide a more coherent and comprehensive understanding of this emerging model system. Here, we analyse data on abundance, juvenile recruitment, pollination mode and genetic variation and structure in both species. We find that Howea forsteriana is less abundant than Howea belmoreana . The genetic data based on amplified fragment length polymorphisms markers indicate similar levels of variation in the two species, despite the estimated census population size of H. belmoreana being three times larger than that of H. forsteriana . Genetic structure within species is low although some weak isolation by distance is detectable. Gene flow between species appears to be extremely limited and restricted to early-generation hybrids – only three admixed individuals, classified as F2s or first generation backcrosses to a parental species, were found among sampled palms. We conclude that speciation in Howea was indeed sympatric, although under certain strict definitions it may be called parapatric.     

Molecular analysis meets morphology‐based systematics—a synthetic approach for Chalarinae (Insecta: Diptera: Pipunculidae)

Abstract. This study presents the first phylogenetic estimate for the pipunculid subfamily Chalarinae (genera Chalarus Walker, Jassidophaga Aczél and Verrallia Mik) based on an analysis of one mitochondrial coding (cytochrome oxidase 1) and two nuclear non‐coding genes (28s and ITS2), using parsimony under direct optimization as implemented in poy 4. It completes earlier taxonomic works on these groups. The voucher material used was primarily of Palaearctic origin. The study strongly supports the monophyletic origin of Chalarinae as well as of Chalarus and Verrallia, but failed to recover a monophyletic lineage for Jassidophaga. Whereas the taxa of Jassidophaga with predominantly black‐coloured legs clustered as a monophyletic sister to Verrallia, an Oriental Jassidophaga species with predominantly yellow/light brown‐coloured legs represents a distinct genetic lineage. The Chalarus species included were resolved into eight well‐supported genetic clades: C. angustifrons group, C. basalis group, C. clarus lineage, C. holosericeus group, C. immanis lineage, C. indistinctus group, C. latifrons group and C. spurius group. A phenetic analysis focused on intra‐ and interspecific genetic distances within the subfamily. As a consequence, the eastern Palaearctic C. rectifrons Morakote is proposed as a junior synonym of C. angustifrons Morakote ( syn.n. ). The structure of the C. basalis species group was investigated further with the intersimple sequence repeat (ISSR) primer (GACA)₄.     

Age-Specific Survival and Probable Causes of Mortality in Female Lesser Prairie-Chickens

ABSTRACT Long-term population declines and habitat reductions have increased concern over the status of the lesser prairie-chicken (Tympanuchus pallidicinctus). Robust estimates of demographic parameters are essential for identifying population declines and planning effective management. We evaluated the effects of age and season on the survival of female lesser prairie-chickens at 2 sites in southwestern Kansas, USA. Using telemetry data from a 7-year field study (from 1997 to 2003), we estimated seasonal (Apr—Sep) and annual (Apr—Mar) survival. We also examined daily survival rates of females attending nests during the 26-day incubation period and young during the 14-day early brood-rearing period. We evaluated the probable mortality causes of radiomarked birds by examining evidence at recovery sites. We captured 227 female lesser prairie-chickens (87 yearlings, 117 ad, and 23 age undetermined) and fitted them with radiotransmitters. Estimates of 12-month survival were lower among yearlings (Ŝ₁₂ = 0.429, SE = 0.117) and adults at site I (Ŝ₁₂ > = 0.302, SE = 0.080) than among yearlings (Ŝ₁₂ = 0.588, SE = 0.100) and adults at site II (Ŝ₁₂ > = 0.438, SE = 0.083). The patterns in timing of mortality and age-specific 6-month survival were consistent with those of 12-month estimates at site I from 1998 to 2002, with a peak in mortality during May and June. Females tending to nests or to prefledged chicks had lower daily survival (DŜR_tend = 0.993, SE = 0.001) than females not involved in these activities (DŜR_{failedbreeder} = 0.997, SE = 0.002). We recorded 92 mortalities from April 1997 to March 2003, and 59% and 11% were attributed to predation by mammals and raptors, respectively. Our research suggests that predation during the nesting season can have a major impact on lesser prairie-chicken demography, and conservation efforts should focus on enhancing female survival during the nesting and brood-rearing seasons.     

Three new deep-sea species of Sphaerodoridae (Annelida,Polychaeta) from the eastern tropical South Pacific*

Three sphaerodorid species new to science are described from a manganese nodule area in abyssal depths of around 4150 m in the Peru Basin in the eastern South Pacific. Sphaerodoridium campanulata sp. n. is isolated within the genus, having, apart from spherical macrotubercles, additional dorsal stalked bell-shaped papillae, not previously described. Sphaerodoropsis discolis sp. n. is a species with four rows of dorsal macrotubercles and two pairs of lateral antennae. Sphaerodoropsis translucida sp. n. has six to seven rows of dorsal macrotubercles arrayed in two transverse rows per segment and two pairs of lateral antennae. A brief discussion points to the close relationship between Clavodorum and Sphaerodoridium, and to the present state of Sphaerodoropsis, being inhomogeneous in the characters of the arrangement of the dorsal macrotubercles and the numbers of the lateral antennae. An overview on the latter genus, with an attempt to subdivide it, is given.     

Embryology of Phoronida

Fertilization in the Phoronida appears to be internal. Threedifferent types of eggs were found: (1) Eggs rich in yolk, about125µ in diameter, which are retained in the parent's tube,without a true pelagic life; (2) Eggs moderately rich in yolk,about 100 µ in diameter, brooded up to the actinotrochstage in the lophophoral concavity owing to the nidamental glands,with a more or less long pelagic life; (3) Eggs, yolk-poor,about 60 µ. in diameter, which are directly dischargedinto sea-water and which have a long pelagic life. Cleavage in the Phoronida is total, equal or subequal. The patternis typically radial though biradial in some stages, but thereare instances in which the blastomeres exhibit a spiral appearance. The gastrula arises generally by emboly. The blastocoel is extensivein embryos of type 3 (see above) and virtually obliterated bywall compression in type 2. The blastopore is reduced to ananterior remnant. The differentiation of the ectoderm leads to the formation ofthe preoral lobe, the apical plate, the tentacular ridge, thenephridial anlage, the oesophagus (issued from the posteriorpart of the vestibule) and the mouth which does not originateas a stomodeum; the blastopore is located between oesophagusand stomach. Differentiation of the archenteron (endoderm) produces the stomach,the intestine and the anus which opens by perforation of theectoderm, without formation of a proctodeum. The anus appearsto be independent of the blastopore. The mesodern originates as isolated cells proliferated fromthe anterior and ventrolateral areas of the archenteron, intwo phases. The mesoderm is formed in a modified enterocoelousmanner. The protocoel is produced first from the anterior archentericwall and occupies the cavity of the preoral lobe; the metacoeloriginates from the ventrolateral mesodermal proliferations.The mode of formation of these cavities seems to vary with species.     

The occurrence of sexual reproduction among ant workers

In less than 100 species of ponerine ants, queens no longer exist and have been replaced by mated egg-laying workers. Workers in other subfamilies can lay haploid eggs when queens are removed, but they never reproduce sexually. Ponerine workers are able to mate because they have a spermatheca in most species, foreign males are sexually active near their nests, and their pygidial gland secretions can assume a sexual meaning. Furthermore, ponerine queens are seldom very fecund, and one or several gamergates are able to approximate their egg production. Finally, opportunities for colony fragmentation occur consequent to their life history, and this is a necessary precondition because gamergates cannot start new colonies independently. Many of these characteristics are associated with the limited caste divergence exhibited in this phylogenetically primitive group. Although a few non-ponerine species exhibit some of these preconditions, gamergates have not been found outside the Ponerinae, which alone exhibit the combination of traits leading to queen elimination and worker mating.     

Dermatoscopy and High Frequency Sonography: Two Useful Non-Invasive Methods to Increase Preoperative Diagnostic Accuracy in Pigmented Skin Lesions

Dermatoscopy and high frequency sonography have recently been combined to increase diagnostic preoperative accuracy in the treatment of pigmented skin lesions. In this monocentric study 80 patients with pigmented skin lesions were evaluated clinically, by dermatoscopy, and 20 MHz-sonography followed by dermatohistopathological evaluation; 39 malignant melanomas, 37 common nevi, 3 dysplastic nevi, and 1 nevus Spitz were diagnosed histologically. In 72 of the 80 cases (91.3%) dermatoscopical diagnoses were confirmed by histopathology, compared to only 79% correct clinical diagnoses. For the mere clinical diagnosis of melanoma sensitivity was 79%, specificity was 78% and diagnostic accuracy was 65%. All diagnostic values increased by dermatoscopy: sensitivity reached 90%, specificity was 93%, and diagnostic accuracy was 83%. In order to determine tumor thickness preoperatively tumor thickness was measured by 20 MHz sonography. The correlation of tumor thickness between histometric and sonographic results was determined for nevi (r = 0.93) and melanoma (r = 0.95); 74.3% of melanomas were diagnosed correctly within an 0.2 mm range. Regarding the clinical important limit of 1 mm tumor thickness, 87.2% were diagnosed in accordance with histometric evaluation. An increase of 18% in diagnostic accuracy by dermatoscopy and 87.2% of correctly diagnosed cases of tumor thickness of malignant melanoma by high frequency sonography clearly demonstrate that these methods should be considered standard procedures in the diagnosis of pigmented skin lesions and will facilitate the decision on necessary surgical treatment.     

Effects of temperature on development of Otiorrhynchus sulcatus (Coleoptera: Curculionidae)

Development of the black vine weevil, Otiorrhynchus sulcatus , was investigated at constant temperatures from 9 to 27 ^oC. Pre-adult development was completed in 200 and 130 days at 15 and 24 ^oC, respectively. Eggs and larvae developed at 27 ^oC, but no pupation took place at this temperature. The developmental threshold temperatures for eggs, larvae + pre-pupae and pupae were 6, 2–6 and 12 ^oC, respectively. Reproductive maturation of females took place at temperatures from 12 to 27 ^oC, but only a few females became reproductive at 12 ^oC. Most females at 12 ^oC, like those at 9 ^oC, had a short maturation feed, but the ovaries did not develop. The pre-oviposition period was temperature dependent. The females showed a cyclic oviposition pattern with three peaks. The significance of soil temperatures for the phenology and distribution of O. sulcatus in Norway is discussed.