How might intensification of farming influence dung beetle diversity (Coleoptera: Scarabaeidae) in Maputo Special Reserve (Mozambique)?

There are concerns over the increasing encroachment of humans, domestic livestock, and farming onto Maputo Special Reserve because of the potential for habitat modification. Therefore, differences between an undisturbed area of the reserve and a neighbouring farming area are assessed using dung beetle as indicators. In each of the two areas, pig-dung-baited pitfall traps were used to sample dung beetle assemblages in two contrasting habitats, grassland and forest. Distributional analysis of the 57 species and 36 942 individuals that were captured, showed that species richness, species turnover, relative abundance patterns, and biogeographical composition differed strongly between both habitats and areas under different land usage. However, in analyses that apportion variation, the greatest amounts were related to habitat rather than land usage. Even so, in both habitats, the total and mean number of species per trap was higher in the farmed area than in the reserve although this was a significant trend only in grassland. Furthermore, in grassland, widespread species were better represented in the farmed area than in the reserve whereas in forest, widespread species were poorly represented compared to grassland. Also in forest, Maputaland endemics were better represented in the reserve than in the farmed area. Further work is necessary to separate the different geographical, ecological, and land usage factors responsible for the patterns detected in this preliminary study. Even so, there are clearly differences between the Maputo Special Reserve and the farmed area.     

Legacy effects of top–down disturbances on woody plant species composition in semi‐arid systems

Savanna vegetation is controlled by bottom‐up (e.g. soil and rainfall) and top–down (e.g. fire and herbivory) factors, all of which have an effect on biodiversity. Little is known about the relative contribution of these factors to biodiversity, particularly the long‐term effects of top–down disturbance on patterns of woody plant composition. The aim of this study was to identify if various degrees of disturbance regimes create distinct woody species community assemblages. Data were collected over 1820 plots across Kruger National Park, South Africa. Woody species were identified and categorized into one of three height classes: shrub (0.75–2.5 m), brush (2.5–5.5 m), and tree (>5.5 m). Species richness and composition were calculated for each site and height class. A combination of long‐term fire and elephant density data were used to delineate areas with varying degrees of top–down disturbance (i.e. low, medium and high). Using these degrees of disturbance, species composition was identified and community assemblages constructed according to each disturbance regime. Our results suggest that areas with similar disturbance regimes have similar species composition. Shrub composition was mainly responsive to the number of fires between the years 1941–1990, while tree composition was more responsive to elephant disturbance. A few dominant species were found equally under all degrees of disturbance at all height classes, while others were more regularly found under specific disturbance regimes at particular height classes. This study highlights that while species richness does not appear to be influenced by long‐term, top–down disturbance regimes, species community composition may be responsive to these disturbances. Most species and structural classes persisted across all disturbance regimes, but the long‐term effects of top–down disturbances can influence compositional and structural biodiversity. This information provides context for management policies related to artificial water provision, elephants and fire.     

miR-126 inhibits proliferation of small cell lung cancer cells by targeting SLC7A5

Despite intensive efforts to improve therapies, small cell lung cancer (SCLC) still has a dismal median survival of 18 months. Since miR-126 is under-expressed in the majority of SCLC tumors, we investigated the effect of miR-126 overexpression on the proliferation and cell cycle distribution of H69 cells. Our results demonstrate that miR-126 inhibits proliferation of H69 cells, by delaying the cells in the G1 phase. Short interfering RNA (siRNA) mediated suppression of SLC7A5, a predicted target of mir-126, has the same effect on H69 cells. We also show for the first time that SLC7A5 is a direct target of miR-126.     

Partitioning variance in a physiological trait: desiccation resistance in keratin beetles (Coleoptera, Trogidae)

1. Although variation in physiological traits forms the substance of evolutionary physiology, the way that this variation is partitioned among different hierarchical levels (e.g. population, species, genus) is not well known.
2. In this study variance partitioning is examined in body size, water content, lipid content, rate of water loss, maximum tolerable water loss and survival time at four levels (individual, population, species, genus) in southern African keratin beetles.
3. It is found that most variance in body size, and the physiological traits that are strongly influenced by body size (water and lipid content, maximum tolerable water loss, rate of water loss), is partitioned at the generic level (50–70%), then at the species level (20–50%) and finally at the population (1–9%) and individual (2–18%) levels.
4. On the other hand, variance in survival time, and variance in rate of maximum water loss once the effects of body size have been taken into account, are partitioned mostly at the species level (40–70%), whereas maximum tolerable water loss and lipid and water content show greatest variance at the individual level (63–75%). This is largely a consequence of differences in the extent of scaling of these traits.
5. The results suggest that where possible the effects of phylogeny should be controlled for when examining desiccation resistance in insects using comparative methods, but that confidence in conclusions from previous studies, which have used mass-specific data, is not unwarranted.     

A phylogeny of the families of Scarabaeoidea (Coleoptera)

Abstract. A study, based on examination of thirteen scarabaeoid families, was made of 134 adult and larval characters from the following character suites: 105 adult characters of the antennae, eye, epipharynx, mandible, maxillae, labium, tentorium, trochantin, procoxae, mesocoxae, mesothoracic spiracles, hind wing articulation, hind wing base, hind wing venation, hind wing folding, abdominal sternites, abdominal spiracles, male genitalia, ovarioles and karyotype; twenty larval characters of the antennae, fronto-clypeal suture, stemmata, labial palpi, maxillae, mandibles, legs, stridulatory apparatus, spiracles and ecdysial process; and nine adult and larval biological characters. In order to assess the reliability of different characters in resolving scarabaeoid family relationships, six data sets were subjected to cladistic analysis: the total evidence character set (134 characters), restricted adult character set (thirty-two characters, not including those of the wings), wing character set (seventy-three characters), larval character set (twenty characters), biological character set (nine characters) and re-coded Howden (1982) character set (thirty-nine characters). The complete character set and wing character set both produced phylograms with all nodes resolved; the restricted adult data set, larval data set, Howden (1982) data set and biological data set produced phylograms with diminishing levels of node resolution. The reconstructed phylogeny, from the preferred phylogram of the total evidence character set, shows that the Scarabaeoidea comprises three major lineages; a glaresid, passalid and scarabaeid lineage. The glaresid lineage consists only of the Glaresidae. The passalid lineage comprises two major lines; a glaphyrid line (containing Glaphyridae, Passalidae, Lucanidae, Diphyllostomatidae, Trogidae, Bolboceratidae and Pleocomidae) and a geotrupid line (containing Geotrupidae, Ochodaeidae, Ceratocanthidae and Hybosoridae). The scarabaeid lineage contains those taxa traditionally included within the Scarabaeidae (Aphodiinae, Scarabaeinae, Orphninae, Melolonthinae, Acoma, Chasmatopterinae, Hopliinae, Oncerinae, Rutelinae, Dynastinae, Trichiinae, Cetoniinae and Valginae).     

Evolution of the Scarabaeini (Scarabaeidae: Scarabaeinae)

Abstract. A phylogenetic analysis of the Scarabaeini, based on 244 morphological characters, including 154 multistate and three biological characters, is presented. Tree topologies generated from unweighted data and some weighted algorithms are similar and support only two clades in the tribe representing the genera Scarabaeus L. and Pachylomerus Bertoloni. The only supported subordinate groups treated in this paper as subgenera are Kheper Kirby stat. nov. , Pachysoma MacLeay, Scarabaeolus Balthasar and Sceliages Westwood stat. nov. Drepanopodus Janssens syn. nov. is synonymised with Scarabaeus and six additional names, Madateuchus Paulian, Mnematidium Ritsema, Mnematium MacLeay, Neateuchus Gillet, Neomnematium Janssens and Neopachysoma Ferreira, remain synonyms. A single origin of flightlessness is supported with the subgenus Pachysoma, the most derived lineage in this clade. Rolling dung balls backwards is the ancestral behaviour and predominant mode of food relocation in Scarabaeini, although tunnelling, forward pushing, and carrying also are utilized by some lineages. Pushing food has evolved independently in Sceliages species and S. galenus (Westwood) and a novel mode of forward food relocation by dragging evolved in the subgenus Pachysoma. Feeding on wet dung is the plesiomorphic condition and maintained by the majority of species in the tribe. The most unusual feeding behaviours in the tribe are represented by the obligate millipede-feeding species of Sceliages and the dry dung pellet and/or detritus feeders of Pachysoma.