Effects of imidacloprid and octopamine on the honey bee (Apis mellifera) trophallaxis social network

Murphree, Sarah Magdalena

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https://hdl.handle.net/2142/116271 Copy

Description

Title

Effects of imidacloprid and octopamine on the honey bee (Apis mellifera) trophallaxis social network

Author(s)

Murphree, Sarah Magdalena

Issue Date

2022-07-19

Director of Research (if dissertation) or Advisor (if thesis)

Robinson, Gene E

Committee Member(s)

• Dolezal, Adam
• Alleyne, Marianne

Department of Study

Entomology

Discipline

Entomology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• honey bee
• network analysis
• trophallaxis
• entomology
• neonicotinoid

Abstract

Honey bees (Apis mellifera) have been used as environmental sensors for chemical and nuclear compounds, either by tracking individual mortality, individual behaviors, or by tracking accumulated titers of toxins in individuals, honey, or wax. Tracking mortality does not capture sublethal effects, tracking individual behaviors (such as the proboscis extension response) are restricted to lab conditions, and tracking toxins requires time to build up concentrations and is often very intrusive or destructive. Instead, I was interested in using colony-level behavior as a sensitive and responsive biological sensor. In particular, the behaviors of foraging and trophallaxis – the exchange of fluid and information between bees, through which outside resources are spread rapidly – are attractive candidates because they link bees to the surrounding environment. I used an automatic high-throughput monitoring system, called the “bCode” system, which involves bee barcode technology and machine learning-based behavioral detectors, to test whether changes in the trophallaxis social network can be tracked and used as an indicator of environmental toxins. In this study, all the individuals in paired colonies, composed entirely of one-day-old adult worker honey bees, were barcoded and placed into observation hives connected to an outdoor mesh enclosure, where they were provided sucrose solution at a feeder monitor, ad libitum, for 13 days. During the last four days, the colonies were treated (or not) via the sucrose solution at the feeder monitor. The treatments I selected were imidacloprid, a commonly used neonicotinoid pesticide, or octopamine, an endogenous biogenic amine. By dividing the colony into task groups (either foragers or non-foragers) and calculating individual- and colony-level static network measurements, I found statistically significant decreased movement and trophallaxis rates for non-foragers compared to foragers for both treatments, decreased movement rates for foragers treated with imidacloprid, and increased movement and trophallaxis rates for foragers treated with octopamine. In contrast, colony-level results showed no difference with either treatment. I speculate that these effects on individual behavior are consistent with the concept of “social immunity” to bolster colony health in the face of these “contaminants”. In summary, while there are many factors that may not make the bCode system a viable option for a deployable biological sensor now, this study showed that it is a helpful tool to track a biologically relevant behavior that responds to environmental conditions.

Graduation Semester

2022-08

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Sarah Murphree

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