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ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #414222
Research Project: Insect Control and Resistance Management in Corn, Cotton, Sorghum, Soybean, and Sweet Potato, and Alternative Approaches to Tarnished Plant Bug Control in the Southern United States

Location: Southern Insect Management Research

Title: Interspecific competition leads to more long-winged morphs in two sympatric cricket species

Author
item FUJII, TAKEHISA - Kagoshima University
item Reddy, Gadi V.P.
item KURIWADA, TAKASHI - Kagoshima University

Submitted to: Ecological Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2024
Publication Date: 10/15/2024
Citation: Fujii, T., Reddy, G.V., Kuriwada, T. 2024. Interspecific competition leads to more long-winged morphs in two sympatric cricket species. Ecological Entomology. 47:1-12. https://doi.org/10.1111/een.13391.
DOI: https://doi.org/10.1111/een.13391

Interpretive Summary: Understanding the factors that determine the distribution and abundance of organisms is an essential subject in ecology. In this study, we examined the effects of micro-environmental differences, similarities in competitive ability, and niche partitioning on the coexistence of two coexisting trigonidiid ground cricket species (Dianemobius nigrofasciatus and Polionemobius mikado). To segregate the effects of intra and interspecific competition and niche partitioning, we maintained a constant density per rearing container but varied relative abundance of the two species. If niche partitioning is absent, the relative abundance of the two species should not affect a species’ per capita fitness. Furthermore, to investigate whether differences in microenvironment affect interspecific competition, two types of rearing environments were used: one with an open environment with only soil and simple shelter and another that was densely vegetated. If cricket species’ coexistence is based on their microenvironmental preferences, P. mikado would have an advantage in the vegetative test arena, while D. nigrofasciatus would have an advantage in the open test arena.

Technical Abstract: Coexistence mechanisms for species competing for the same resource include resource partitioning, neutrality, and microhabitat preference. We explored the coexistence mechanism of two species of trigonidiid crickets (Dianemobius nigrofasciatus and Polionemobius mikado) that share the same habitat. Dianemobius nigrofasciatus is more common in areas where the ground surface is somewhat open, while P. mikado is more common in more densely vegetated environments. The effects of micro-environmental differences, similarities in competitive ability, and niche partitioning on the coexistence of these species were examined using laboratory experiments. Polionemobius mikado performed better in vegetated test arenas, while D. nigrofasciatus did not significantly differ in its performance in vegetated versus open arenas. Although the adult emergence of D. nigrofasciatus were delayed by the presence of P. mikado, the emergence rate of P. mikado was not significantly affected by D. nigrofasciatus. The presence of P. mikado caused a higher frequency of a long-winged morph (macropterous) of D. nigrofasciatus. The results suggest that D. nigrofasciatus is inferior to P. mikado in interspecific competition, and it, therefore, disperses (as macropterous adults) at greater rates in the presence of P. mikado. Furthermore, it may be that D. nigrofasciatus has been forced to change its preferred microhabitat from vegetative habitats, which are inherently more suitable, to more open environments due to competition. These above mechanisms are thought to allow the two species to coexist in the same general habitat.