Nutrient-specific foraging and the role of spiders as biocontrol agents.

Lead Research Organisation: Cardiff University
Department Name: School of Biosciences

Abstract

Spiders are major predators of aphids (and other pests) in cereal crops and are an essential element of pest control in low-input and organic agriculture. However, their economic value to farmers is affected by their density and relative predation rates on pest and non-pest insects. It has been demonstrated in the lab that predators can exercise nutrient-specific foraging to balance their diets (Mayntz et al., Science 2005). Thus, if they have been eating sugar-rich aphids they may preferentially increase predation on protein-rich Collembola or flies.
Spiders cannot survive on aphids alone and agriculturalists require guidance on the need to preserve non-aphid prey within crops. However, nutrient-specific foraging has never been demonstrated in the field. Our aim will be to compare what is available to the spiders with what the spiders have eaten. Major nutrients will be analysed for common prey (e.g. Hawley et al., PlosOne 2014). We will analyse diets of spiders using molecular methods then compare what is available with what is eaten, looking for deviations from random feeding that balance their nutrient intake.
Mesocosm experiments, informed by prey densities in the field and spider diets, will confirm whether nutrientspecific foraging, rather than other factors, is regulating prey choices.
First rotational project - Morphological and molecular identification. This PhD requires expertise in the taxonomy and molecular identification of the species involved. Identification of spiders and 'difficult' prey groups will require training. Relevant species will need DNA barcoding. Training in these areas will primarily be in the lab of WOCS, assisted by JRB at Rothamsted (spiders) and taxonomists in the National Museum of Wales.
Second rotational project - Analysis of prey nutrients. A major element within the PhD will be analysis of the effects of major nutrients on prey choice. The student will learn how to conduct the biochemical analyses needed, supervised by CTM. S/he will analyse relevant species from arable fields, establishing their nutrient content and the effects of crop and season.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M009122/1 30/09/2015 29/09/2023
1799693 Studentship BB/M009122/1 30/09/2016 31/12/2020 Jordan Cuff
 
Description Development of molecular methods for spider diet analysis and macronutrient determination from invertebrates. The diet of spiders has been characterised, finding that they are exhibiting biocontrol of crop pests, but that the pests most consumed are thrips, indicating some potential mismanagement of spiders in agriculture as they are most often viewed as aphid predators. Prey choice in spiders switches to reflect changes in their prey availability following harvest, indicating a need for better consistent provision of spiders with suitable prey.
Exploitation Route Implemented into farmland management for improved biocontrol.
Sectors Agriculture, Food and Drink,Education,Environment

 
Description British Ecological Society Travel Award
Amount £500 (GBP)
Organisation British Ecological Society 
Sector Charity/Non Profit
Country United Kingdom
Start 08/2017 
End 09/2017
 
Description GCRF Network Award: A network for networks: building an interdisciplinary team to define trophic interactions underpinning predator-mediated biological control
Amount £10,000 (GBP)
Organisation United Kingdom Research and Innovation 
Department Global Challenges Research Fund
Sector Public
Country United Kingdom
Start 03/2020 
End 07/2020
 
Description One-off Meeting Sponsorship Grant
Amount £1,000 (GBP)
Organisation The Genetics Society 
Sector Charity/Non Profit
Country United Kingdom
Start 11/2017 
End 11/2018
 
Description Wellcome Trust ISSF3 Public Engagement Grant
Amount £7,425 (GBP)
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 08/2019 
End 09/2020
 
Title PCR primers for the analysis of cereal crop money spider diet 
Description These PCR primers will allow analysis of the diet of cereal crop money spiders (Araneae: Linyphiidae) via DNA metabarcoding. There are currently no other such primers published and these (alongside others developed in collaboration with other groups, mentioned separately) will enable an efficient metagenomic analysis of spider diet in the field. 
Type Of Material Biological samples 
Year Produced 2018 
Provided To Others? No  
Impact These primers have been adopted for use by one internationally recognised lab and by many existing researchers in Cardiff University. Pending publication. 
 
Title Protocol for macronutrient determination in small macroarthropods 
Description This protocol allows the rapid, direct and parallel determination of macronutrients from macroarthropods as small as an aphid. The protocol has been validated and applied and will be submitted for publication imminently. 
Type Of Material Biological samples 
Year Produced 2018 
Provided To Others? No  
Impact This protocol has been adopted by three different research groups so far, with expression of interest from a broader range. 
 
Title Various other dietary PCR primers 
Description I have designed PCR primers for other projects including those for the analysis of the diet of ants, carabid beetles, ladybirds, wolf spiders, nematodes, otters, etc. 
Type Of Material Biological samples 
Year Produced 2019 
Provided To Others? No  
Impact Increased accuracy of dietary analysis and eventual publishing of all primers. 
 
Description Identification and confirmation of a pseudoscorpion species new to Britain 
Organisation Natural History Museum
Country United Kingdom 
Sector Public 
PI Contribution Barcoding of specimens to confirm identification; Contribution to final publication.
Collaborator Contribution Collection and identification of specimens; Confirmation and description of specimens; Writing of final publication.
Impact Publication pending.
Start Year 2018
 
Description Investigation of the chemical cues associated with aphid vectors of barley yellow dwarf virus 
Organisation Rothamsted Research
Department Biological Chemistry and Crop Protection
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution I designed and will lead the work, including all practical and written elements.
Collaborator Contribution Provision of materials and contribution to ideas.
Impact We will write a paper.
Start Year 2019
 
Description Investigation of the mechanisms underlying prey choice in social wasps 
Organisation Indian Institute of Science Bangalore
Country India 
Sector Academic/University 
PI Contribution Concept, design, leading grant writing, organising personnel involved in the project, practical aspects.
Collaborator Contribution Expertise, knowledge, access to facilities and field sites.
Impact A grant has been obtained to fund a network event to build the collaboration and benefit further development of the project. The project spans trophic ecology, molecular ecology, entomology, agriculture, chemical ecology, electrophysiology and landscape ecology.
Start Year 2020
 
Description Molecular analysis of ladybird predation upon aphids and novel PCR primers 
Organisation University of Zurich
Country Switzerland 
Sector Academic/University 
PI Contribution In silico evaluation of PCR primers; Contribution to writing of final publication.
Collaborator Contribution Experimental design; Fieldwork; Lab work; Design of PCR primers; In vitro evaluation of primers; Writing of final publication.
Impact Publication in preparation.
Start Year 2017
 
Description Spider-exclusion PCR primers for analysis of Pardosa sp. diet 
Organisation Karlstad University
Country Sweden 
Sector Academic/University 
PI Contribution Discussion of experimental design; Testing of novel PCR primers in vitro; Sequencing of PCR products to determine success; Writing for final publication.
Collaborator Contribution Full experimental design; Sample collection; Primer design; In silico testing; In vitro testing; Metabarcoding; Preparation of final publication.
Impact Publication in prep.
Start Year 2018
 
Description Spider-exclusion PCR primers for analysis of Pardosa sp. diet 
Organisation University of Guelph
Country Canada 
Sector Academic/University 
PI Contribution Discussion of experimental design; Testing of novel PCR primers in vitro; Sequencing of PCR products to determine success; Writing for final publication.
Collaborator Contribution Full experimental design; Sample collection; Primer design; In silico testing; In vitro testing; Metabarcoding; Preparation of final publication.
Impact Publication in prep.
Start Year 2018
 
Description Collaborative blog 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact I co-founded a blog to discuss ecological themes and questions in a broad context. This is a continuous and evolving platform.
Year(s) Of Engagement Activity 2018,2019
 
Description Farmers' Union Talk, Wenvoe Farmers' Union 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Approximately 30 agricultural professionals attended, many of whom asked questions relating to the research. Some expressed, following the talk, that they had changed their views toward biological control of crop pests and invertebrates as an aspect of their farmland more generally.
Year(s) Of Engagement Activity 2018
 
Description Green Man Festival Einstein's Garden Engagement Activity 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Several themed activities were designed for all ages to educate the public about agriculture and the environment. I designed and led a game to teach families specifically about biological control, integrated pest management and sustainable intensification. Many questions were asked and opinions formed and debated.
Year(s) Of Engagement Activity 2017,2018
 
Description Wellcome Trust ISSF3-funded Animal ARKS of the 21st Century: Engaging people with biobanking and species conservation 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Engagement activities with the public in collaboration with Frozen Ark. Events and games to teach the public about the biodiversity crisis, DNA and how biobanking can help via several games and activities.
Year(s) Of Engagement Activity 2019,2020