Abstract: In order to analyze the large-scale structure of the genome of Norway spruce (Picea abies Karst.), a pseudo-testcross genetic linkage map was built using markers of six different types, belonging to the low (amplified fragment length polymorphisms, simple sequence repeats) or high (sequence-specific amplified polymorphisms, inter-retrotransposon amplified polymorphisms) copy-number fraction of the genome, and including expressed region-derived markers (expressed sequence tag polymorphisms). Twenty seven and 23 linkage groups of at least four markers were obtained for the female and the male parent maps, respectively. A subset of these linkage groups coalesced into 13 bi-parental linkage groups through markers shared between the two maps. This map was used to investigate the frequency of each marker type over chromosomes and the distribution of marker types relative to each other, using autocorrelation techniques. Our results show that, while the composition of chromosomes is homogeneous, low- and high-copy-number markers tend to occupy separate regions of the linkage groups, and that expressed sequences are preferentially associated with microsatellites and separated from retrotranspo sons. These results indicate that the spatial structure of Norway spruce chromosomes is not homogeneous.

Abstract: In Neotropical rainforest canopies, phytotelmata (“plant-held waters”) shelter diverse aquatic macroinvertebrate communities, including vectors of animal diseases. Studying these communities is difficult because phytotelmata are widely dispersed, hard to find from the ground and often inaccessible. We propose here a method for placing in tree crowns “artificial phytotelmata” whose size and shape can be tailored to different research targets. The efficacy of this method was shown while comparing the patterns of community diversity of three forest formations. We noted a difference between a riparian forest and a rainforest, whereas trees alongside a dirt road cutting through that rainforest corresponded to a subset of the latter. Because rarefied species richness was significantly lower when the phytotelmata were left for three weeks rather than for six or nine weeks, we recommend leaving the phytotelmata for twelve weeks to permit predators and phoretic species to fully establish themselves.

Abstract: In myrmecophilous Lepidoptera, mostly lycaenids and riodinids, caterpillars trick ants into transporting them to the ant nest where they feed on the brood or, in the more derived 'cuckoo strategy', trigger regurgitations (trophallaxis) from the ants and obtain trophic eggs. We show for the first time that the caterpillars of a moth (Eublemma albifascia; Noctuidae; Acontiinae) also use this strategy to obtain regurgitations and trophic eggs from ants (Oecophylla longinoda). Females short-circuit the adoption process by laying eggs directly on the ant nests, and workers carry just-hatched caterpillars inside. Parasitized colonies sheltered 44 to 359 caterpillars, each receiving more trophallaxis and trophic eggs than control queens. The thus-starved queens lose weight, stop laying eggs (which transport the pheromones that induce infertility in the workers) and die. Consequently, the workers lay male-destined eggs before and after the queen's death, allowing the colony to invest its remaining resources in male production before it vanishes.

Abstract: In members of the cricket subfamily Eneopterinae (Orthoptera, Grylloidea), songs with powerful high-frequency (HF) harmonics have evolved, which likely represents a distinctive acoustic adaptation. In this study, we analysed or reanalysed the songs of the three eneopterine genera present in the Neotropics to evaluate whether they also possess high-amplitude HF components. We present new data and combine several lines of evidence to interpret or reinterpret the calling signals of a representative species for each genus. We used new recordings in order to detect and analyse potential HF components of the songs. Stridulatory files were measured, and stridulation was studied using high-speed video recordings. The results suggest that all eneopterine genera from the Neotropics use HFs to communicate, based on the rich harmonic content of their songs. Strikingly, the Neotropical eneopterines possess high dominant frequencies, recalling the patterns observed in the tribe Lebinthini, the most speciose tribe of the subfamily distributed in the Western Pacific region and in Southeast Asia: Ligypterus and Ponca show dominant harmonic peaks, whereas Eneoptera possesses unique features. The three species under study, however, deal differently with HFs.

Abstract: In French Guiana, the population growth will result in an increase in demand for agricultural products and thus, will lead to an increase in the amount of tropical forests converted into cropland or pasture. Impacts of different agricultural systems on greenhouse gas (GHG) fluxes have not been studied in French Guiana. In this context, the fire-free chop-and-mulch method was used to convert a tropical forest site to agriculture. This study focused on soil nitrous oxide (N<inf>2</inf>O) emissions and we compared four land uses: (1) the undisturbed tropical forest, (2) recently converted grassland and recently converted croplands (fertilized soybean/maize rotation) with either (3) disk tillage or (4) no tillage.N<inf>2</inf>O measurements were obtained through the chamber technique and conducted over a 1-year period (measurements began 19 months after the forest was cleared). N<inf>2</inf>O fluxes were related to soil parameters measured at each sampling date: nitrate and ammonium contents, gravimetric water content (GWC) and temperature. Through the entire period, the mean (± standard error) and median N<inf>2</inf>O fluxes were 3.8 ± 0.5 and 2.7 gNha-1day-1, respectively for undisturbed tropical forest and 2.4 ± 0.9 and 0.8gNha-1day-1, respectively for grassland (mowed Brachiaria ruziziensis). For croplands, no significant difference was found for N<inf>2</inf>O emissions between both agricultural practices. The mean (± standard error) and median N<inf>2</inf>O fluxes were 8.5 ± 1.2 and 4.0 gNha-1day-1, respectively for disk tillage plots and 8.5 ± 1.3 and 3.6gNha-1day-1, respectively for no tillage plots. Nitrogen inputs (due to the application of fertilizer or due to the mineralization of crop residues) led to higher N<inf>2</inf>O fluxes, resulting in significantly higher mean N<inf>2</inf>O emissions from croplands compared to the forest, when only considering land use effect on N<inf>2</inf>O fluxes in a statistical model. The soil nitrate content, GWC and temperature had a significant positive effect on N<inf>2</inf>O fluxes. Taking into account these soil parameters in another statistical model, N<inf>2</inf>O emissions from croplands were not higher than the natural N<inf>2</inf>O emissions from tropical forest soils. Our results suggest that, if more forest will have to be converted in the course of the expected population growth in French Guiana, it could have low impact on the soil N<inf>2</inf>O fluxes (similar to natural fluxes from forest) with the improving of farming techniques (for example modification of the splitting of N-fertilizer) in the cropping plots. © 2015 Elsevier B.V.