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Issue: Vol. 5875 No. 1: 2 Sept. 2026
Type: Article
Published: 2026-09-02
DOI: 10.11646/zootaxa.5875.1.6
Page range: 94-100
Abstract views: 222
PDF downloaded: 12

Correlated evolution of exaggerated genitalic structures in the minute litter bug Nannocoris Reuter (Hemiptera: Schizopteridae)

Department of Entomology; University of California; Riverside 900 University Drive; Riverside CA 92521; USA
Department of Entomology; University of California; Riverside 900 University Drive; Riverside CA 92521; USA
Hemiptera trait correlation exaggerated genitalic traits Dipsocoromorpha

Abstract

Studies on animal genitalia have long shaped our understanding of patterns and processes of morphological evolution. Coevolution between male and female genitalic structures is predicted to be ubiquitous, regardless of the evolutionary mechanism involved. However, studies that simultaneously evaluate male and female genitalic variation in a comparative phylogenetic framework have remained relatively scarce. We here investigate correlated male and female genital evolution in Nannocoris Reuter (Hemiptera: Schizopteridae), a minute litter bug genus that may be unique among arthropods in the degree and variation of its exaggerated genitalic traits: we here report that the length of the male intromittent organ differs dramatically between species, ranging from 1/8th to 20 times their respective body length, and that this variation is mirrored in the female spermathecal duct. Using a phylogenetic hypothesis for species of Nannocoris, measurements of male and female genitalic features, and phylogenetically independent contrasts, we find that the length of the male intromittent organ and female spermathecal duct are correlated. The mode of evolution that has led to these striking phenotypes is unknown, but we stress that this system has potential for future research in the evolution of male and female genitalic features in general.

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How to Cite

Frankenberg, S. & Weirauch, C. (2026) Correlated evolution of exaggerated genitalic structures in the minute litter bug Nannocoris Reuter (Hemiptera: Schizopteridae). Zootaxa, 5875 (1), 94–100. https://doi.org/10.11646/zootaxa.5875.1.6