An analysis of phonotactic behaviour in the cricket Gryllus bimaculatus
Creators: name: Sarmiento-Ponce, Edith Julieta
Publisher: name: Apollo - University of Cambridge Repository
Year: 2019
Subjects: phonotaxis
animal behaviour
insect behaviour
bioacoustics
insect bioacoustics
insect
insects
cricket
crickets
gryllus bimaculatus
female cricket
male cricket
phonotactic behaviour
trackball system
walking behaviour
subtrate effect
male calling song
lifetime study
female choosiness
phonotaxis and lab colonies
bu-spotted field cricket
male phonotaxis
female phonotaxis
song pattern recognition

description: This thesis represents a comprehensive examination of the phonotactic behaviour (i.e. attraction to sound) of the female Gryllus bimaculatus under laboratory conditions. Chapter 2 is the first study to analyze the effect of substrate texture on walking performance in crickets. Substrate texture is found to play an essential role in the phonotactic responses of G. bimaculatus. Smooth substrate texture has a detrimental effect due to slipping, whereas a rough texture results in optimal walking performance due to the friction with the walking legs. Chapter 3 represents the first detailed lifetime study analysing phonotaxis in crickets. My results demonstrate that the optimal age to test phonotaxis in G. bimaculatus females is from day 7 to 24 after the final moult. I also found that selectiveness was persistent with age. These findings contradict the female choosiness hypothesis. This study is also the first to describe the effect of senescence on phonotaxis in insects, as responsiveness decreases with age. Chapter 4 compares the phonotactic behaviour of female crickets from different laboratory-bred colonies. From six tested cricket lab colonies, I found three groups statistically different from each other. Females raised under laboratory conditions at the University of Cambridge and Anglia Ruskin University were most reponsive at a frequency of 4.5 kHz, whereas females bred in Tokushima University in Japan were tuned towards a higher frequency of 5 kHz. These results suggest a degree of artificial allopatric speciation. Comparisons with crickets bred under low-quality conditions in a local pet shop demonstrate a loss of responsiveness, indicating that breeding conditions have a direct effect on phonotactic responsivity. Chapter 5 is the first study to report the presence of phonotaxis in males of G. bimaculatus. Previously it was unknown if G. bimaculatus males were able to perform phonotaxis, given that they were only recognised as endurance signal producers. In the present study, only 20% of the studied males (N=70) performed a weak phonotactic response. This finding has potential ecological implications in terms of male cricket territory establishment, and male-male interactions in the wild, which are discussed. Chapter 6 explores the song pattern recognition of the female G. bimaculatus by changing the duration of either the first, second or third pulse of the chirps. A long first pulse decreased the phonotactic response whereas phonotaxis remained strong when the third pulse was long. Chirps with three pulses of increasing duration of 5, 20 and 50 ms elicited phonotaxis, but the chirps were not attractive when played in reverse order. The data are in agreement with a mechanism in which processing of a sound pulse has an effect on the processing of the subsequent pulse, as outlined in the flow of activity in a delay-line and coincidence-detector circuit.
description: I am deeply grateful to my Mexican financial body CONACyT (Consejo Nacional de Ciencia y Tecnologia) and the Cambridge Trust for funding my PhD. Doing my PhD at the Department of Zoology at the University of Cambridge has been the most intellectually and personally rewarding experience in my whole life. I had the deep honour of attending several international conferences, from Argentina to India, to give oral presentations of my PhD projects. Thanks to the great generosity of the travel grants provided by the Royal Entomological Society, Newnham College Cambridge, the Guild of Friends, the Company of Biologist, the Cambridge Philosophical Society, and the Department of Zoology at the University of Cambridge. I am very grateful to The Royal Entomological Society for publishing my conference research reports and one outreach paper on insect acoustic communication. I was very fortunate that our research photo (taken by Prof Javier Ortega-Hernandez) was featured on the cover of the Antenna magazine.