Mrs Zinat Jahan Chowdhury1, Timothy Schaerf2, Alfonsina Arriaga-Jimenez1, Zac Hemmings1, Nigel Andrew3

1Insect Ecology Lab, University of New England, Armidale, Australia, 2School of Science and Technology, University of New England, Armidale, Australia, 3Faculty of Science and Engineering, Southern Cross University, Lismore, Australia

Biography:

Mrs. Zinat Jahan Chowdhury is currently doing her PhD research in the Insect Ecology Lab at the University of New England, Armidale. Zinat did her B.Sc. in Agriculture and continued her first MSc in Entomology at Sylhet Agricultural University, Bangladesh. Zinat also completed her 2nd MSc in Tropical Biodiversity and Ecosystems under the Erasmus Mundus Program from the Vrije Universiteit Brussels, Belgium and Universite Libre De Brussels, Belgium. Mrs. Zinat also serves as a faculty member in the Department of Entomology at Sylhet Agricultural University, Bangladesh.

Abstract:

Increasing beetle density limits food resources, which is one of the reasons for competitive behaviour among dung beetles. As a result of competition, individuals are less likely to survive, grow, and produce brood balls. Dung beetles are important ecosystem engineers as they feed and bury dung, help to control parasites, nematodes and flies, and promote soil aeration, nutrient cycling and seed dispersal. Predicting how density induces dung beetle competition, which leads to their reproduction, is crucial. We quantified the interspecific competition of dung beetles via brood ball production of two paracoprid species: Onthophagus binodis and Digonthophagus gazella. This research was divided into two trials: O. binodis was dominant, D. gazella was inferior in trial-1 and vice versa in trial-2. The inferior species was constant (1M+1F), and the density of dominant species was increased as follows: T1 (1M+1F), T2 (1M+2F), T3 (2M+2F), T4 (2M+3F), T5 (3M+3F). The inferior species (1M+1F) was used as a control in both trials. When O. binodis was dominant, the brood number showed a numerical increase from T1 to T5, which was not statistically discernible (p = 0.532). Similarly, there was no statistical difference (p = 0.817) in the brood number of treatments, which decreased from control due to the dominancy of D. gazella. However, the comparative analysis between the two trials showed that brood ball production was 3.2 times higher (p < 0.001) in D. gazella than in O. binodis when dominant. We conclude that density does not affect the production of brood balls for both dominant species of dung beetles, whereas the total number of brood balls differs between the two species.