Studying Forficula auricularia and Eriosoma lanigerum interactions in apple orchards to better understand their distribution for improved crop protection

Tempest, H. (2025) Studying Forficula auricularia and Eriosoma lanigerum interactions in apple orchards to better understand their distribution for improved crop protection. Doctoral thesis, Harper Adams University.

Text Hayden Tempest PhD Thesis - Final.pdf Download (3MB)

Abstract

Malus domestica (Bork; apple), is one of the most important fruit crops worldwide. The woolly apple aphid (Eriosoma lanigerum; Hausmann) has emerged as a serious pest of apple trees over the last 20 years thanks in part to the withdrawal of organophosphate insecticides. Information on the control of E. lanigerum by natural enemies is therefore valuable to apple growers. One important predator of E. lanigerum is Forficula auricularia (L.; common European earwig). This species has been shown to be an effective predator of E. lanigerum in apple orchards, but the control of E. lanigerum provided by F. auricularia appears to be inconsistent. This study aimed to investigate the distribution of E. lanigerum and F. auricularia, their interactions, and potential methods to discover more about the ecology of F. auricularia. Commercial apple orchards in Kent (United Kingdom) were surveyed for the presence or absence of F. auricularia and E. lanigerum from individual trees. Generalised linear modelling was used to investigate which characteristics of trees and orchards were associated with the presence of each species. Molecular gut content analysis was also carried out to determine the frequency of F. auricularia predation of E. lanigerum. Evidence was found for a positive contribution by F. auricularia to E. lanigerum control, but only in conventionally managed orchards. Bare earth in the row bed of the orchards was associated with F. auricularia presence. Detectable DNA was only present in 5% of F. auricularia guts sampled. Unfortunately, the primers used for the molecular gut content analysis amplified Ropalosiphum padi DNA, so the precise frequency of predation of E. lanigerum could not be determined. The impact of artificial F. auricularia shelters on the abundance of F. auricularia and E. lanigerum was investigated. The presence of artificial shelters led to an increase in the number of F. auricularia found during night-time searches, but did not lead to a measurable decrease in the number of E. lanigerum colonies. Different glues were tested to determine their efficacy for attaching tags to F. auricularia, as well as their potential toxicity. Cyanoacrylate based glues are likely toxic to F. auricularia, but also the most effective for attaching tags. Thermoplastic glue was the most effective glue without an apparent toxic effect. Prototype mesocosms were designed and tested for their ability to collect data on F. auricularia behaviour using radio frequency identification (RFID). Minimal movement was detected in the prototype mesocosms, possibly as a result of flaws in the design, or due to the phenological stage of the individuals used for the study. This study has shed light on the interactions of F. auricularia and E. lanigerum interactions within apple orchards. More research is required to understand the variable population dynamics of F. auricularia. Remote monitoring of F. auricularia in the field seems challenging using current technology but there are opportunities to study F. auricularia using mesocosm experiments.

Item Type:	Thesis (Doctoral)
Divisions:	Agriculture and Environment (from 1.08.20)
Depositing User:	Mrs Susan Howe
Date Deposited:	18 Sep 2025 16:05
Last Modified:	18 Sep 2025 16:05
URI:	https://hau.repository.guildhe.ac.uk/id/eprint/18258

Actions (login required)

Edit Item