Antennal Sensilla Diversity in Some North American Cicadas (Hemiptera: Cicadidae)

TL;DR

This paper explores the diversity of antennal structures in North American cicadas, suggesting their antennae may play a more important role in sensing the environment than previously thought.

Contribution

The study provides a detailed classification of antennal sensilla types across 30 cicada species, offering new insights into their sensory functions and taxonomy.

Findings

Seven main classes of antennal sensilla were identified in North American cicadas.

Unique sensilla types and organization patterns were found across different genera.

The diversity of antennal structures supports their potential role in host plant and microhabitat selection.

Abstract

Cicadas are known for the songs produced in the mating process. Combining the acoustic behavior with relatively small antennae has meant that antennal sensory functions, specifically olfaction, have been suggested to be poorly developed in cicadas. The selection of specific host plants by many species suggests that the antennae are important in finding these host plants. Scanning electron microscopy was used to visualize the morphology of antennal sensilla found in a diverse group of North American cicadas. The sensilla types and the distribution pattern of each sensillum type found on 30 species from 12 genera, 6 tribes, and 3 subfamilies of North American cicadas are described and/or illustrated. Unique sensilla types and/or organizations of sensilla were found in many of the genera. This diversity provides additional data for taxonomy and phylogenetic analyses. The potential function of the various sensilla types is hypothesized. Although relatively small, the antennae of cicadas are likely to provide significant information about their environment and increase their ability to survive and reproduce successfully.

The use of acoustic communication and the relatively small antennae possessed by cicadas has led to the suggestion that antennal functions, specifically olfaction, are poorly developed in cicadas. The first step in determining antennal functions is to investigate the fine antennal structure. Scanning electron microscopy was used to visualize the morphology of the antennal sensilla in a diverse group of North American cicadas. The sensilla types and their distribution on the antennae of 30 species representing 12 genera, 6 tribes, and 3 subfamilies of North American cicadas are described and/or illustrated. Seven main classes and several subclasses of antennal sensilla were found: sensilla trichodea, sensilla chaetica, sensilla coeloconica, sensilla styloconica, foramina olfactoria, sensilla campaniformia, and sensilla cavitata-peg. Unique sensilla types and/or organizations of sensilla were found in many of the genera and differences between species of some genera were also present. No sexual dimorphism within species was found in the types or organizational patterns of the sensilla. The diversity of sensilla provides additional data for taxonomy and phylogenetic analyses. The potential function of the various sensilla types is hypothesized. Although relatively small, the antennae of cicadas are likely to provide significant information about their environment and increase their survival, including the selection of specific host plants and microhabitat selection observed in many species.

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