294 research outputs found
Task allocation and reproductive skew in social mass provisioning carpenter bees in relation to age and size
The mass provisioning carpenter bees comprise two tribes,
the Xylocopini and the Ceratinini. Although social nesting
occurs in both tribes, no morphological castes have evolved
and females are totipotent, which makes the tribe as a whole
highly suitable to test predictions of reproductive skew
models. We review current information for the two tribes
with respect to reproductive competition and reproductive
skew and then investigate whether the observed skew fits
with predictions from optimal skew theory. Social nests of
Xylocopa species include a non-foraging guard and a foraging
egg layer who completely dominates reproduction.
Reproductive dominance is settled by aggression, and the
probability of winning this fight is influenced by both age
and size. In Ceratina species, task allocation is also very
clear: one female guards the nest, while the other female(s)
forage(s). Although the guard is usually the first to produce
an egg, her eggs are frequently replaced by those of the forager,
and skew is incomplete.
Using comparisons between species and genera the
impact of ecological constraints on solitary nesting, relative
group productivity and relatedness on reproductive partitioning
between dominants and subordinates are investigated in
a qualitative way. In support of the optimal skew model,
strong constraints on solitary nesting coincided with strong
skew. However, the predicted effects of relatedness and group
productivity on skew were not found. Furthermore, no support
was found for the predictions of the optimal skew model
that high skew coincides with frequent aggressive testing and
risky task performance by subordinates
Foraging behaviour of a blue banded bee, Amegilla chlorocyanea in greenhouses: implications for use as tomato pollinators
© INRA, DIB-AGIB, EDP Sciences 2007Blue-banded bees (Amegilla spp.) are Australian native buzz pollinators that are a promising alternative to the introduction of the bumblebee (Bombus terrestris) for use as pollinators of tomatoes in Australian greenhouses. The foraging behaviour of Amegilla chlorocyanea under greenhouse conditions was monitored in detail. Our results showed that female Amegilla are active foragers that make on average 9 pollen foraging flights per day. Using data about flower visitation, we estimated the number of actively nesting female bees needed for adequate pollination in a commercial greenhouse as 282 per hectare.Katja Hogendoorn, Steven Coventry and Michael Anthony Kelle
The effects of temperature on the development, fecundity and mortality of Eretmocerus warrae: is Eretmocerus warrae better adapted to high temperatures than Encarsia formosa?
Published online in Wiley Online Library: 1 October 2018BACKGROUND: Eretmocerus warrae (Hymenoptera: Aphelinidae) is a parasitoid of the glasshouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae). Here, we compare its potential as a biological control agent at high temperatures to that of Encarsia formosa (Hymenoptera: Aphelinidae), a wasp which is widely sold for control of T. vaporariorum.
RESULTS: Eretmocerus warrae attained the highest estimated developmental rate at 31.4 ∘C and the maximum oviposition rate at 30.5 ∘C. Developmental times of E. warrae at fluctuating temperatures that simulate night-day patterns were similar to those predicted based on constant temperatures. Above the optimum temperature, E. warrae tolerated higher constant temperatures than En. formosa during development and as adults. Using a ramping temperature approach, the critical thermal maximum for adult E. warrae was significantly higher than that of adult En. formosa.
CONCLUSION: Eretmocerus warrae is better adapted to high temperatures than En. formosa, and could therefore be a complementary or superior biological control agent during summer months in hot regions.Tao Wang, Michael Anthony Keller and Katja Hogendoor
Biology, distribution and conservation of green carpenter bee (Xylocopa aeratus: Apidae) on Kangaroo Island, South Australia: Technical report
Richard V. Glatz, Remko Leijs & Katja Hogendoor
DNA barcoding of euryglossine bees and the description of new species of Euhesma Michener (Hymenoptera, Colletidae, Euryglossinae)
This paper launches an open access DNA barcoding project "AUSBS" under the Barcoding of Life Datasystems (BOLD). The aims of the project are to help scientists who lack the necessary morphological knowledge to identify known species using molecular markers, to aid native bee specialists with the recognition of species groups that morphologically are difficult to define, and, eventually, to assist with the recognition of new species among known species. Using integrative taxonomy, i.e. morphological comparison to type specimens in Australian museum collections combined with phylogenetic analysis of a fragment of the mitochondrial DNA cytochrome c oxidase subunit I (mtCOI) gene sequences led to the recognition of four new species of Euhesma Michener (Hymenoptera: Colletidae: Euryglossini) collected during intensive surveys in remote Australian conservation areas, which are described. The new species are Euhesma micans, Euhesma lyngouriae, and Euhesma aulaca in a species group associated with Eremophila flowers, and Euhesma albamala in the walkeriana species group.Katja Hogendoorn, Mark Stevens, Remko Leij
NFATC2 (nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 2)
Review on NFATC2 (nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 2), with data on DNA, on the protein encoded, and where the gene is implicated
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HPA axis related genes and response to psychological therapies: genetics and epigenetics
Background
Hypothalamic–pituitary–adrenal (HPA) axis functioning has been implicated in the development of stress-related psychiatric diagnoses and response to adverse life experiences. This study aimed to investigate the association between genetic and epigenetics in HPA axis and response to cognitive behavior therapy (CBT).
Methods
Children with anxiety disorders were recruited into the Genes for Treatment project (GxT, N = 1,152). Polymorphisms of FKBP5 and GR were analyzed for association with response to CBT. Percentage DNA methylation at the FKBP5 and GR promoter regions was measured before and after CBT in a subset (n = 98). Linear mixed effect models were used to investigate the relationship between genotype, DNA methylation, and change in primary anxiety disorder severity (treatment response).
Results
Treatment response was not associated with FKBP5 and GR polymorphisms, or pretreatment percentage DNA methylation. However, change in FKBP5 DNA methylation was nominally significantly associated with treatment response. Participants who demonstrated the greatest reduction in severity decreased in percentage DNA methylation during treatment, whereas those with little/no reduction in severity increased in percentage DNA methylation. This effect was driven by those with one or more FKBP5 risk alleles, with no association seen in those with no FKBP5 risk alleles. No significant association was found between GR methylation and response.
Conclusions
Allele-specific change in FKBP5 methylation was associated with treatment response. This is the largest study to date investigating the role of HPA axis related genes in response to a psychological therapy. Furthermore, this is the first study to demonstrate that DNA methylation changes may be associated with response to psychological therapies in a genotype-dependent manner
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