Antennal cropping during colony foundation in termites

Theodore Evans,Michael Lenz,Christine Nalepa

doi:10.3897/zookeys.148.1854

Abstract

The literature on pairing and mating behavior in termites indicates that a number of distal antennal segments in dealates of both sexes are often removed during colony foundation, with terms such as amputation, mutilation and cannibalism typically employed to report the phenomenon. Here we propose the use of the phrase ‘antennal cropping’ to describe the behavior, and assess naturally occurring levels of its occurrence by comparing the number of antennal segments in museum specimens of alates and dealates in 16 species of Australian termites (four families), supplemented by analyzing published data on Coptotermes gestroi. Dealates had significantly fewer antennal segments than alates in 14 of the 16 termite species, with both exceptions belonging to the family Termitidae. Levels of antennal cropping were not significantly different between the sexes but did vary by family. Dealates in the Kalotermitidae removed the most segments (41.3%) and those in the Termitidae removed the fewest (8.9%). We discuss the biological significance of this phylogenetically widespread termite behavior, and suggest that controlled antennal cropping is not only a normal part of their behavioral repertoire but also a key influence that changes the conduct and physiology of the royal pair during the initial stages of colony foundation.

Highlights

Several studies of colony foundation in termites note that the antennae of newly flown alates are typically undamaged, but the terminal antennal segments in both sexesCopyright Christine A
The phenomenon has been described as amputation (Heath 1927), mutilation (Heath 1903), and ‘mild’ or ‘restrained’ cannibalism (Mensa-Bonsu 1976, LaFage and Nutting 1978), and in all documented examples the removal of the antennal segments occured shortly after pair establishment
Schedorhinotermes actuosus had the highest number of antennal segments, around 19, and Ceratokalotermes spoliator had the fewest, with about 13

Summary

Introduction

Several studies of colony foundation in termites note that the antennae of newly flown alates are typically undamaged, but the terminal antennal segments in both sexesCopyright Christine A. Several studies of colony foundation in termites note that the antennae of newly flown alates are typically undamaged, but the terminal antennal segments in both sexes. Are removed during colony establishment (Heath 1903, Imms 1919, Mensa-Bonsu 1976, Hewitt et al 1972, Costa-Leonardo and Barsotti 1998). In this study we used counts of antennal segments in museum specimens of alate and dealate Australian termites to begin characterizing the nature of ‘antennal cropping’, which we advocate as a more neutral term to describe the behavior. Our goals were to establish the phylogenetic extent of the behavior, to determine the precision of the act, and to describe the variation between sexes, among species, and among families

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