Advanced

Identification and spatial negotiation through a hole, and possible influence of individual size

Abrahamsson Kihlström, Klara (2015) BIOP26 20132
Degree Projects in Biology
Abstract
Flying insects are able to negotiate complex environments such as tropical rainforests as well as less complex environments such as flowering meadows although little is known about how they avoid collisions while doing this. In this study, insect negotiation through holes was investigated using Bumblebees Bombus terrestris and Orchid bees Euglossa imperialis as test animals. This was done by allowing the individual to fly through a tunnel with an interchangeable endwall, with a varied assortment of attachable exitholes. The flight position were analysed, and ability to exit through the hole, light intensity, hole shape and/or size and individual size where recorded. We found that orchid bees in general are more willing to fly through holes... (More)
Flying insects are able to negotiate complex environments such as tropical rainforests as well as less complex environments such as flowering meadows although little is known about how they avoid collisions while doing this. In this study, insect negotiation through holes was investigated using Bumblebees Bombus terrestris and Orchid bees Euglossa imperialis as test animals. This was done by allowing the individual to fly through a tunnel with an interchangeable endwall, with a varied assortment of attachable exitholes. The flight position were analysed, and ability to exit through the hole, light intensity, hole shape and/or size and individual size where recorded. We found that orchid bees in general are more willing to fly through holes than bumblebees. However, both species tend to fly through the hole at the safest point, i.e. point furthest from the surrounding edge. In addition, orchid bees tend to fly closer to the safest point than bumblebees do when negotiating larger holes. Lastly, we find no correlation between individual size and capability to negotiate through a hole. (Less)
Popular Abstract
Finding The Way Through A Hole And Questioning If Size Matters

When a flying insect negotiates passages or holes in its environment, it manages to do so without crashing. This is possible because it has the ability to determine the distance to proximate obstacles, which allows it to keep a safe distance from them. Because this ability is mediated by vision, the light in the environment could potentially affect the individual’s ability to fly through passages. How does the size of passages that individuals choose to fly through varies with light intensity and does individual size, and therefore eye sensitivity influence this choice? Is a larger individual more successful when flying through passages than a smaller one?

When an insect... (More)
Finding The Way Through A Hole And Questioning If Size Matters

When a flying insect negotiates passages or holes in its environment, it manages to do so without crashing. This is possible because it has the ability to determine the distance to proximate obstacles, which allows it to keep a safe distance from them. Because this ability is mediated by vision, the light in the environment could potentially affect the individual’s ability to fly through passages. How does the size of passages that individuals choose to fly through varies with light intensity and does individual size, and therefore eye sensitivity influence this choice? Is a larger individual more successful when flying through passages than a smaller one?

When an insect flies through a passage or hole it tends to fly at an equal distance from the surrounding edges, that is, they fly close to what is referred to as “the safe point”. They are able to do this using visual cues. Here, we hypothesise that a variation in light intensity would affect the insect’s precision when flying through passages or holes. We also investigate if the habitat an insect has evolved in affects its ability to avoid obstacles. We do this by testing how well orchid bees Euglossa imperialis, which are found in dense tropical forests, a complex and dark environment, and Buff-Tailed bumblebees Bombus terrestris, which are found in open areas such as meadows, a relatively non-complex bright and dark environment, avoid obstacles. As the visual system is scaled to body size, it is likely that a larger individual would have a greater sensitivity to light and therefore be more successful when flying through holes and passages when the light intensity diminishes.

Bumblebees and orchid bees were allowed to fly through a tunnel ending with different size and/or shape of hole. This was done at a range of different light intensities. Each flight was filmed and the distance from the safe point was measured. To determine if individual body size influences the flight position, each individual was measured dorsally between its wings. In bumblebees the eye length was also measured. The results indicate that orchid bees are more efficient at negotiating holes than bumblebees; orchid bees negotiated closer to the safe point when flying through holes, were able to fly through smaller holes and in lower light intensities than bumblebees. As far as it goes for size, it does not seem to influence any of these parameters.

As orchid bees live in a complex habitat it is necessary for them to be able to avoid a larger amount of obstacles than it is for the Buff-Tailed bumblebees, as they would encounter fewer obstacles in their habitat. In regards to individual size, the bumblebees are highly variable whereas the orchid bees are fairly consistent in body size. Nonetheless it can be concluded that when it comes to orchid bees and bumblebees’ individual body size does not matter.

Advisors: Marie Dacke and Emily Baird
Master´s Degree Project, 60 credits, 2015
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Abrahamsson Kihlström, Klara
supervisor
organization
course
BIOP26 20132
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8081943
date added to LUP
2015-10-21 15:48:59
date last changed
2015-10-21 15:48:59
@misc{8081943,
  abstract     = {Flying insects are able to negotiate complex environments such as tropical rainforests as well as less complex environments such as flowering meadows although little is known about how they avoid collisions while doing this. In this study, insect negotiation through holes was investigated using Bumblebees Bombus terrestris and Orchid bees Euglossa imperialis as test animals. This was done by allowing the individual to fly through a tunnel with an interchangeable endwall, with a varied assortment of attachable exitholes. The flight position were analysed, and ability to exit through the hole, light intensity, hole shape and/or size and individual size where recorded. We found that orchid bees in general are more willing to fly through holes than bumblebees. However, both species tend to fly through the hole at the safest point, i.e. point furthest from the surrounding edge. In addition, orchid bees tend to fly closer to the safest point than bumblebees do when negotiating larger holes. Lastly, we find no correlation between individual size and capability to negotiate through a hole.},
  author       = {Abrahamsson Kihlström, Klara},
  language     = {eng},
  note         = {Student Paper},
  title        = {Identification and spatial negotiation through a hole, and possible influence of individual size},
  year         = {2015},
}