The community succession of arthropods on a pig carcass in Lebanon: different taxonomic level approaches with faunistic notes

The diversity of arthropods is studied, at family and species level, on a pig carcass during a warm season in an open field in Badghan-Mount Lebanon. Ten orders of arthropods were found associated to the carcass. A total of 1168 specimens of adults Diptera and Coleoptera were collected. Among Diptera, the predator Chrysomya albiceps was dominant on the carcass during the active decay stage and Musca spp. were necrophagous. Within Coleoptera, Creophilus maxillosus (Linnaeus, 1758), Philonthus concinnus (Gravenhorst, 1802), Aleochara lata Gravenhorst, 1802, and Saprinus sp. were the predator taxa. Dermestes frischii Kugelann, 1792 and Necrobia rufipes (De Geer, 1775) were more present during the advanced decay, together with anthicids. In addition to a list of species visiting the carcass, we carried out a multivariate analysis of principal components to explore the relationships between the pattern of presences of 16 insect families and the four decomposition stages during the first 30 days of the carcass decomposition. The groupings of insects during the four decomposition stages show significant dissimilarities, suggesting that the different stages are characterized by different insect associations, as reported in many other previous studies.

Résumé. La succession des communautés d’arthropodes sur une carcasse de porc au Liban : approches à divers niveaux taxonomiques et notes faunistiques. La diversité des arthropodes est étudiée, au rang familial et spécifique, sur une carcasse de porc pendant la saison chaude en milieu naturel, sur le site de Badghan-Mount, au Liban. Dix ordres d’arthropodes ont été trouvés associés à la carcasse. Un total de 1168 spécimens adultes de Diptères et de Coléoptères a été collecté. Parmi les Diptères, le prédateur Chrysomya albiceps était dominant sur la carcasse au stade de décomposition active. Les Musca spp. étaient nécrophages. Parmi les Coléoptères, Creophilus maxillosus (Linnaeus, 1758), Philonthus concinnus (Gravenhorst, 1802), Aleochara lata Gravenhorst, 1802 et Saprinus sp. étaient prédateurs. Dermestes frischii Kugelann, 1792 et Necrobia rufipes (De Geer, 1775) et les Anthicidae étaient plus présents pendant la décomposition avancée. En complément à la liste des espèces visitant la carcasse, nous avons effectué une analyse multivariée en composantes principales pour explorer les relations entre le patron de présence de 16 familles d’insectes et les quatre stades de décomposition au cours des 30 premiers jours de la décomposition. Les groupements d’insectes montrent des dissimilarités significatives, ce qui suggère que les différents stades sont caractérisés par des associations différentes d’insectes, de façon analogue à ce qui a été rapporté dans plusieurs études antérieures.     

Reproductive ecology of <Emphasis Type="Italic">Agave colorata</Emphasis>: the importance of nectar-feeding bats and the germination consequences of self-pollination

Agave colorata is a paniculate agave distributed along the migratory route of the nectar-feeding bat Leptonycteris yerbabuenae. In this paper, we evaluate the importance of nectar-feeding bats in the reproduction of A. colorata in a population in Sonora, Mexico, and describe the germination consequences of self-pollination. We estimated abundance using five plots and set pollination treatments to evaluate the importance of bats. We recorded 14.8?±?6.8 plants/400 m², with a bimodal size distribution. Flowers are protandrous and visited mainly (>?20 visits/plant/30 min) by L. yerbabuenae. Pollination exclusion experiments showed that flowers excluded from diurnal visitors had maximum fruit set values (0.49?±?0.42), while the autonomous self-pollination treatment had the lowest value (0.03?±?0.06). Similarly, the greatest number of viable seeds per fruit was recorded in the diurnal exclusion treatment, while the greatest number of empty seeds was observed in the self-pollination treatment. Fruit set values among untreated plants varied from 32 to 54%, with a mean value of 41.8%. Seeds derived from self-pollination had a narrower window of opportunity for germination compared to seeds derived from nocturnal pollination. Self-pollinated seeds had lower germination, rate of germination or lag time in response to light, osmotic potential and heat shock treatments, compared to other pollination treatments, revealing an inbreeding cost. Overall, our results show that L. yerbabuenae is the likely major pollinator of the studied A. colorata population. However, under pollinator limitation A. colorata may produce seeds by autonomous self-pollination, at a cost expressed as lower germination.     

From mesophilic to thermophilic conditions: one-step temperature increase improves the methane production of a granular sludge treating agroindustrial effluents

Objectives

To assess the effect of one-step temperature increase, from 35 to 55 °C, on the methane production of a mesophilic granular sludge (MGS) treating wine vinasses and the effluent of a hydrogenogenic upflow anaerobic sludge blanket (UASB) reactor.

Results

One-step temperature increase from mesophilic to thermophilic conditions improved methane production regardless of the substrate tested. The biomethane potentials obtained under thermophilic conditions were 1.8–2.9 times higher than those obtained under mesophilic conditions. The MGS also performed better than an acclimated thermophilic digestate, producing 2.2–2.5 times more methane than the digestate under thermophilic conditions. Increasing the temperature from 35 to 55 °C also improved the methane production rate of the MGS (up to 9.4 times faster) and reduced the lag time (up to 1.9 times). Although the temperature increase mediated a decrease in the size of the sludge granules, no negative effects on the performance of the MGS was observed under thermophilic conditions.

Conclusions

More methane is obtained from real agroindustrial effluents at thermophilic conditions than under mesophilic conditions. One-step temperature increase (instead of progressive sequential increases) can be used to implement the thermophilic anaerobic digestion processes with MGS.

     

The wing base of the palaeodictyopteran genus Dunbaria Tillyard: Where are we now?

The structure of insect wing articulation is considered as reliable source of high level characters for phylogenetic analyses. However, the correct identification of homologous structures among the main groups of Pterygota is a hotly debated issue. Therefore, the reconstruction of the wing bases in Paleozoic extinct relatives is of great interest, but at the same time it should be treated with extreme caution due to distortions caused by taphonomic effects. The present study is focused on the wing base in Dunbaria (Spilapteridae). The articulation in Dunbaria quinquefasciata is mainly formed by a prominent upright axillary plate while the humeral plate is markedly reduced. Due to unique preservation of surface relief of the axillary plate, its composition shows a detailed pattern of three fused axillary sclerites and presumable position of the sclerite 3Ax. The obtained structures were compared among Spilapteridae and to other palaeodictyopterans Ostrava nigra (Homoiopteridae) and Namuroningxia elegans (Namuroningxiidae). The comparative study uncovered two patterns of 3Ax in Dunbaria and Namuroningxia, which correspond to their different suprafamilial classification. In contrast to previous studies these new results reveal the homologous structural elements in the wing base between Paleozoic Palaeodictyoptera and their extant relatives of Ephemeroptera, Odonata and Neoptera.     

Heterothallism revealed in the root rot fungi Berkeleyomyces basicola and B. rouxiae

Berkeleyomyces basicola and Berkeleyomyces rouxiae, two sister species previously treated collectively as Thielaviopsis basicola, reside in the Ceratocystidaceae (Microascales, Ascomycota). Both species are important root pathogens of many important agricultural crops and ornamental plants. Although T. basicola has been known for more than 150y, a sexual state has never been found and it has been assumed to be an asexual pathogen. The aim of this study was to determine the mating strategy of the two Berkeleyomyces species. Investigation of the genome sequences of two B. basicola isolates allowed for the complete characterization of the MATlocus, revealing that it has a typical heterothallic mating system with the MAT1-1andMAT1-2 idiomorphs occurring in different isolates. PCR amplification using mating type primers developed in this study, showed that the MAT1-1-1andMAT1-2-1 genes were also present in different isolates of B. rouxiae. Pairing of isolates representing the two mating types of both species,using a variety of techniques failed to produce sexual structures. Although we have found no direct evidence that they reproduce sexually, these fungi are clearly heterothallic with both mating types occurring in some countries suggesting that a cryptic sexual cycle could exist for them.     

Anaerobic biotransformation of hexachlorocyclohexane isomers by <Emphasis Type="Italic">Dehalococcoides</Emphasis> species and an enrichment culture

The biotransformation of hexachlorocyclohexane isomers (HCH) by two Dehalococcoides mccartyi strains (195 and BTF08) and an enrichment culture was investigated and compared to conversion by the obligate anaerobic strain Clostridium pasteurianum strain DSMZ 525. The D. mccartyi strains preferentially transformed γ-HCH over α-HCH and δ-HCH isomers while β-HCH biotransformation was not significant. In case of the enrichment culture, γ-HCH was preferentially transformed over the δ-HCH, β-HCH and α-HCH isomers. Major observed metabolites in both cases were tetrachlorocyclohexene and as end products monochlorobenzene (MCB) and benzene. Dechlorination of the γ-HCH isomer was linked to an increase in cell numbers for strain 195. γ-HCH transformation was linked to considerable carbon stable isotope fractionation with the enrichment factor ε_c?=???5.5?±?0.8‰ for D. mccartyi strain 195, ε_c?=???3.1?±?0.4‰ for the enrichment culture and ε_c?=???4.1?±?0.6‰ for co-metabolic transformation by C. pasteurianum.     

New damsel-dragonflies with “calopterygid”-like wing shape from the Middle Jurassic of China (Odonata: Isophlebioidea: Campterophlebiidae)

The new damsel-dragonflies Zygokaratawia incompleta nov. sp. and Parazygokaratawia azari nov. gen., nov. sp., closely related to the campterophlebiid genus Zygokaratawia, are described from the Middle Jurassic locality of the Daohugou and Chentaizi villages, respectively (Ningcheng County, Inner Mongolia, NE China). Parazygokaratawia nov. gen. and Zygokaratawia share a narrowly reduced cubito-anal area, unique synapomorphy in the Isophlebioptera. Campterophlebiids with this character are only known from the Daohugou biota.