Effects of the Biopesticide Spinosad on Eristalis tenax Brain and Motor skills
(2025) BION02 20242Degree Projects in Biology
- Abstract
- The extensive use of pesticides within the agricultural landscape is essential for maintaining sufficient yields and sustaining our growing population, however, their widespread use is not without costs. Increasing evidence shows that pesticides harm many non-target organisms, including those providing vital ecosystem services. Pollinators, for instance, are critical for the fruiting of nearly 75% of major food crops globally, yet worryingly their populations are declining, with pesticide use identified as a key driver. It has been suggested that pesticides derived from natural origins, biopesticides, are less harmful than synthetic alternatives and therefore offer a promising way to minimize this negative effect. In this study, I... (More)
- The extensive use of pesticides within the agricultural landscape is essential for maintaining sufficient yields and sustaining our growing population, however, their widespread use is not without costs. Increasing evidence shows that pesticides harm many non-target organisms, including those providing vital ecosystem services. Pollinators, for instance, are critical for the fruiting of nearly 75% of major food crops globally, yet worryingly their populations are declining, with pesticide use identified as a key driver. It has been suggested that pesticides derived from natural origins, biopesticides, are less harmful than synthetic alternatives and therefore offer a promising way to minimize this negative effect. In this study, I investigated the effects of chronic exposure to field realistic doses of a biopesticide, spinosad, on hoverfly and common pollinator Eristalis tenax. Flies were exposed for 20 days to either a control treatment or a spinosad treatment (0.2 ppm), both provided ad libitum. On days 2, 9, and 20, randomly selected individuals from both treatments were subjected to behavioral assays and brain imaging, to link potential neuroanatomical changes with any behavioral impairments. Results revealed that chronic exposure to 0.2 ppm spinosad significantly increased mortality, in E. tenax. Furthermore, for the surviving individuals, spinosad treated flies had significantly higher occurrence of brain vacuolation at day 9 and 20, than in control flies. Moreover, spinosad caused a decreased visually guided turning response in E. tenax already at day 2, along with a progressive decline in overall activity. These results indicate that field-realistic concentrations of spinosad, legal for use in organic farming, impair brain physiology, sensory processing, and locomotor activity in an important non-target pollinator. (Less)
- Popular Abstract (Swedish)
- Spinosad: en pollinatörs mardröm
Bekämpningsmedel är vanliga i jordbruket för att säkra skördar, men kan ha negativa effekter på nyttiga insekter. Spinosad, ett biologiskt bekämpningsmedel framställt ur bakterier och godkänt inom ekologiskt jordbruk i EU, angriper insekters nervsystem och orsakar muskelsammandragningar, förlamning och död. Mitt experiment visar att spinosad i fältrealistiska koncentrationer även skadar storslamblomfluga, en viktig pollinatör.
Blomflugorna matades med antingen sockerlösning eller spinosad under en 20-dagars period. På dag 2, 9 och 20 undersöktes utvalda flugor genom beteendetester. Dessa undersökte flugornas aktivitet under olika ljusförhållanden samt hur de förhöll sig till rörelser i sin omgivning... (More) - Spinosad: en pollinatörs mardröm
Bekämpningsmedel är vanliga i jordbruket för att säkra skördar, men kan ha negativa effekter på nyttiga insekter. Spinosad, ett biologiskt bekämpningsmedel framställt ur bakterier och godkänt inom ekologiskt jordbruk i EU, angriper insekters nervsystem och orsakar muskelsammandragningar, förlamning och död. Mitt experiment visar att spinosad i fältrealistiska koncentrationer även skadar storslamblomfluga, en viktig pollinatör.
Blomflugorna matades med antingen sockerlösning eller spinosad under en 20-dagars period. På dag 2, 9 och 20 undersöktes utvalda flugor genom beteendetester. Dessa undersökte flugornas aktivitet under olika ljusförhållanden samt hur de förhöll sig till rörelser i sin omgivning (Optomotorisk respons). Efter beteendetesterna mikrospoperades blomflugornas hjärnor, för att koppla beteendeförändringar hos en specifik blomfluga, till potentiella förändringar i dess hjärnstruktur.
Spinosad, många negativa effekter på den positiva insekten
Blomflugorna som behandlades med spinosad, dog i större utsträckning än de som bara fick sockerlösning. I medelsnitt överlevde 75% av flugorna som fick sockerlösning tills dag 20, medan bara 54% överlevde av de fick spinosad. Redan vid dag två påverkade spinosad att flugornas optomotoriska respons negativt. För aktiviteten såg det annorlunda ut. Spinosad ökade initialt aktiviteten hos blomflugorna dag 2, för att sedan minska aktiviteten vid dag nio och 20. Spinosad orsakade även synliga skador i blomflugornas hjärnor, i form av hålrum (vakuoler), se Figur. På dag 20 hade spinosad behandlade flugor över 13 gånger så mycket vakuoler i sina hjärnor som socker-blomflugor
Vad innebär detta i verkligheten?
20-dagars behandling med spinosad dödade blomflugor i stor utsträckning, utöver detta påverkades överlevande individer negativt. I naturen använder sig storslamblomfluga av optomotorisk respons för att anpassa sin rörelse i förhållande till sin omgivning, utöver detta är deras uthållighet är direkt kopplad till hur långt de kan flyga för mat eller för att föröka sig. I mitt experiment understryks att spinosad påverkar båda dessa negativt. Detta är allvarligt, och bör inspirera tankar om förändring i användningen och lagstiftningen av spinosad.
Mastersexamensprojekt i biologi 45 hp 2025
Biologiska insitutionen, Lunds universitet
Handledare: Elisa Rigosi & David O´Carroll
Biologiska institutionen: Sensory biology unit, Vision group (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9215074
- author
- Jansson, Edit
- supervisor
-
- Elisa Rigosi LU
- David O'Carroll LU
- organization
- course
- BION02 20242
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9215074
- date added to LUP
- 2025-11-07 11:56:13
- date last changed
- 2025-11-07 11:56:13
@misc{9215074,
abstract = {{The extensive use of pesticides within the agricultural landscape is essential for maintaining sufficient yields and sustaining our growing population, however, their widespread use is not without costs. Increasing evidence shows that pesticides harm many non-target organisms, including those providing vital ecosystem services. Pollinators, for instance, are critical for the fruiting of nearly 75% of major food crops globally, yet worryingly their populations are declining, with pesticide use identified as a key driver. It has been suggested that pesticides derived from natural origins, biopesticides, are less harmful than synthetic alternatives and therefore offer a promising way to minimize this negative effect. In this study, I investigated the effects of chronic exposure to field realistic doses of a biopesticide, spinosad, on hoverfly and common pollinator Eristalis tenax. Flies were exposed for 20 days to either a control treatment or a spinosad treatment (0.2 ppm), both provided ad libitum. On days 2, 9, and 20, randomly selected individuals from both treatments were subjected to behavioral assays and brain imaging, to link potential neuroanatomical changes with any behavioral impairments. Results revealed that chronic exposure to 0.2 ppm spinosad significantly increased mortality, in E. tenax. Furthermore, for the surviving individuals, spinosad treated flies had significantly higher occurrence of brain vacuolation at day 9 and 20, than in control flies. Moreover, spinosad caused a decreased visually guided turning response in E. tenax already at day 2, along with a progressive decline in overall activity. These results indicate that field-realistic concentrations of spinosad, legal for use in organic farming, impair brain physiology, sensory processing, and locomotor activity in an important non-target pollinator.}},
author = {{Jansson, Edit}},
language = {{eng}},
note = {{Student Paper}},
title = {{Effects of the Biopesticide Spinosad on Eristalis tenax Brain and Motor skills}},
year = {{2025}},
}