Queen lipid content and nest growth in the leaf cutting ant (Atta sexdens rubropilosa) (Hymenoptera: Formicidae)

The relationship between the queens' lipid content and nest growth (population size, biomass and nest architecture) was studied from founding up to 1 year. Nests aged 3, 4, 5, 6, 9 and 12 months were dug in the field, and their dimensions were measured. The ant nest population and fungus garden was also collected. The sample was taken to the laboratory where we counted the worker population and weighed the biomass (fungus plus offspring) and queens. Queens were separated for the determination of lipids. The lipid content in the bodies of queens decreased in the first months, then stabilized (at 4-6 months) before increasing in months 9 and 12. Nest biomass (symbiotic fungus and offspring) and worker population increased over time. The structural growth of the nests was observed by excavating around them. Initially nests (3 months old) had one chamber at an average depth of 15 cm. By 1 year, the nests had three or four deep chambers, and were about 3-4 m deep. Our study contributes to knowledge of the dynamics of the energy-reserve expenditure by queens during colony founding and colony development for up to 1 year. © 2013 Copyright Taylor and Francis Group, LLC.

What is the stimulus for the excavation of fungus chamber in leaf-cutting ants?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Escovopsis trichodermoides sp nov., isolated from a nest of the lower attine ant Mycocepurus goeldii

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

First-year nest growth in the leaf-cutting ants Atta bisphaerica and Atta sexdens rubropilosa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The larval morphology and nest habits of Trypoxylon (Trypargilum) rogenhoferi Kohl 1884 (Insecta: Hymenoptera: Crabronidae)

The present study describes different preimaginal stages of Trypoxylon rogenhoferi examined by Scanning Electron Microscopy (SEM) and compares the results with observations on closely related species. Some notes on the nesting habits of this species, including their spider prey, nest parasites, and development time are provided. In short, T. rogenhoferi proved quite similar to the previous report on T. albitarse although SEM images are rarely presented in such descriptions. In fact the present study emphasized the importance of SEM images to describe fine morphological details that can be useful characters for taxonomic and phylogenetic studies. Images of some earlier development stages (first and second larval instar and egg) are presented for the first time, and compared with the few available data from other hymenopterans.

Nest stolen: the first observation of nest predation by an invasive exotic marmoset (Callithrix penicillata) in an agricultural mosaic

Invasive exotic species can negatively impact local biodiversity. We present here a report of a nest predation of an endemic bird species, variable oriole (Icterus pyrrhopterus) by the introduced black-tufted marmoset (Callithrix penicillata)in an agricultural landscape highly disturbed by human activities. Two nestlings were predated, by adults of the introduced marmoset during two alternate days. Antipredator behavior and vocal mimicry were observed in variable oriole, while copulation was observed in black-tufted marmoset during the predation. The use of mobbing against predators by I. pyrrhopterus was observed and it is described here by the first time. The potential impact of the introduced marmosets to local biodiversity is discussed.

Digging for dead genes: an analysis of the characteristics of the pseudogene population in the Caenorhabditis elegans genome

Pseudogenes are non-functioning copies of genes in genomic DNA, which may either result from reverse transcription from an mRNA transcript (processed pseudogenes) or from gene duplication and subsequent disablement (non-processed pseudogenes). As pseudogenes are apparently ‘dead’, they usually have a variety of obvious disablements (e.g., insertions, deletions, frameshifts and truncations) relative to their functioning homologs. We have derived an initial estimate of the size, distribution and characteristics of the pseudogene population in the Caenorhabditis elegans genome, performing a survey in ‘molecular archaeology’. Corresponding to the 18 576 annotated proteins in the worm (i.e., in Wormpep18), we have found an estimated total of 2168 pseudogenes, about one for every eight genes. Few of these appear to be processed. Details of our pseudogene assignments are available from http://bioinfo.mbb.yale.edu/genome/worm/pseudogene. The population of pseudogenes differs significantly from that of genes in a number of respects: (i) pseudogenes are distributed unevenly across the genome relative to genes, with a disproportionate number on chromosome IV; (ii) the density of pseudogenes is higher on the arms of the chromosomes; (iii) the amino acid composition of pseudogenes is midway between that of genes and (translations of) random intergenic DNA, with enrichment of Phe, Ile, Leu and Lys, and depletion of Asp, Ala, Glu and Gly relative to the worm proteome; and (iv) the most common protein folds and families differ somewhat between genes and pseudogenes—whereas the most common fold found in the worm proteome is the immunoglobulin fold and the most common ‘pseudofold’ is the C-type lectin. In addition, the size of a gene family bears little overall relationship to the size of its corresponding pseudogene complement, indicating a highly dynamic genome. There are in fact a number of families associated with large populations of pseudogenes. For example, one family of seven-transmembrane receptors (represented by gene B0334.7) has one pseudogene for every four genes, and another uncharacterized family (represented by gene B0403.1) is approximately two-thirds pseudogenic. Furthermore, over a hundred apparent pseudogenic fragments do not have any obvious homologs in the worm.

Plays of the 47 workshop. Third series. The crows-nest,

Mode of access: Internet.

The eagle's nest.

Mode of access: Internet.

The owl's nest, a romance,

Translation of: Das Eulenhaus.

The prospector; a tale of the Crow's Nest Pass,

Mode of access: Internet.

Under the storks' nest. A romance.

Mode of access: Internet.