SpotCard: an optical mark recognition tool to improve field data collection speed and accuracy.

BACKGROUND: When taking photographs of plants in the field, it is often necessary to record additional information such as sample number, biological replicate number and subspecies. Manual methods of recording such information are slow, often involve laborious transcription from hand-written notes or the need to have a laptop or tablet on site, and present a risk by separating written data capture from image capture. Existing tools for field data capture focus on recording information rather than capturing pictures of plants. RESULTS: We present SpotCard, a tool comprising two macros. The first can be used to create a template for small, reusable cards for use when photographing plants. Information can be encoded on these cards in a human- and machine-readable form, allowing the user to swiftly make annotations before taking the photograph. The second part of the tool automatically reads the annotations from the image and tabulates them in a CSV file, along with picture date, time and GPS coordinates. The SpotCard also provides a convenient scale bar and coordinate location within the image for the flower itself, enabling automated measurement of floral traits such as area and perimeter. CONCLUSIONS: This tool is shown to read annotations with a high degree of accuracy and at a speed greatly faster than manual transcription. It includes the ability to read the date and time of the photograph, as well as GPS location. It is an open-source ImageJ/Fiji macro and is available online. Its use requires no knowledge of the ImageJ macro coding language, and it is therefore well suited to all researchers taking pictures in the field

The mechanics of nectar offloading in the bumblebee Bombus terrestris and implications for optimal concentrations during nectar foraging.

Nectar is a common reward provided by plants for pollinators. More concentrated nectar is more rewarding, but also more viscous, and hence more time-consuming to drink. Consequently, theory predicts an optimum concentration for maximizing energy uptake rate, dependent on the mechanics of feeding. For social pollinators such as bumblebees, another important but little-studied aspect of foraging is nectar offloading upon return to the nest. Studying the bumblebee Bombus terrestris, we found that the relationship between viscosity (µ) and volumetric transfer rates (Q) of sucrose solutions differed between drinking and offloading. For drinking, Q ∝ µ-0.180, in good agreement with previous work. Although offloading was quicker than drinking, offloading rate decreased faster with viscosity, with Q ∝ µ-0.502, consistent with constraints imposed by fluid flow through a tube. The difference in mechanics between drinking and offloading nectar leads to a conflict in the optimum concentration for maximizing energy transfer rates. Building a model of foraging energetics, we show that including offloading lowers the maximum rate of energy return to the nest and reduces the concentration which maximizes this rate by around 3%. Using our model, we show that published values of preferred nectar sugar concentrations suggest that bumblebees maximize the overall energy return rather than the instantaneous energy uptake during drinking.This work was supported by a Biotechnology and Biological Sciences Research Council PhD Studentship under grant BB/J014540/1 to J.G.P

Strawberry varieties differ in pollinator‐relevant floral traits

Publication status: PublishedA rising global population will need more food, increasing demand for insect pollination services. However, general insect declines conflict with this demand. One way to mitigate this conflict is to grow crop flowers that are easier for insects to find and more rewarding to those that visit them. This study quantifies variation in the pollinator‐relevant traits of nectar and pollen production, flower size and flower shape in commercial strawberry, finding significant variation between varieties in all traits. Bumblebees could learn to distinguish between the extremes of variation in flower shape, but this learning is very slow, indicating that this variation is at the limit of that which can be detected by bumblebees. Bee preferences for nectar of differing sugar concentrations at field‐realistic volumes were consistent with previous observations at larger volumes, suggesting that it is valid to translate lab findings to the field. This study builds on our knowledge of the range of pollinator reward present in a single cultivated species and of the impact of field‐realistic levels of variation in floral traits on bumblebee preferences

Strawberry varieties differ in pollinator‐relevant floral traits

Abstract A rising global population will need more food, increasing demand for insect pollination services. However, general insect declines conflict with this demand. One way to mitigate this conflict is to grow crop flowers that are easier for insects to find and more rewarding to those that visit them. This study quantifies variation in the pollinator‐relevant traits of nectar and pollen production, flower size and flower shape in commercial strawberry, finding significant variation between varieties in all traits. Bumblebees could learn to distinguish between the extremes of variation in flower shape, but this learning is very slow, indicating that this variation is at the limit of that which can be detected by bumblebees. Bee preferences for nectar of differing sugar concentrations at field‐realistic volumes were consistent with previous observations at larger volumes, suggesting that it is valid to translate lab findings to the field. This study builds on our knowledge of the range of pollinator reward present in a single cultivated species and of the impact of field‐realistic levels of variation in floral traits on bumblebee preferences

Evolution of the chloroplast genome.

We discuss the suggestion that differences in the nucleotide composition between plastid and nuclear genomes may provide a selective advantage in the transposition of genes from plastid to nucleus. We show that in the adenine, thymine (AT)-rich genome of Borrelia burgdorferi several genes have an AT-content lower than the average for the genome as a whole. However, genes whose plant homologues have moved from plastid to nucleus are no less AT-rich than genes whose plant homologues have remained in the plastid, indicating that both classes of gene are able to support a high AT-content. We describe the anomalous organization of dinoflagellate plastid genes. These are located on small circles of 2-3 kbp, in contrast to the usual plastid genome organization of a single large circle of 100-200 kbp. Most circles contain a single gene. Some circles contain two genes and some contain none. Dinoflagellate plastids have retained far fewer genes than other plastids. We discuss a similarity between the dinoflagellate minicircles and the bacterial integron system