Gynomorphic mandible morphology in the dobsonfly, Corydalus cornutus

Area of Science:

• Entomology
• Zoology
• Insect Morphology

Background:

• Corydalus cornutus, commonly known as the dobsonfly, is a large predatory insect.
• Sexual dimorphism is common in insects, but extreme morphological aberrations can provide insights into developmental processes.
• Understanding intraspecific variation is crucial for accurate species identification and evolutionary studies.

Purpose of the Study:

• To document and describe two aberrant male specimens of Corydalus cornutus.
• To discuss the implications of these findings for the morphological variation within the genus Corydalus and the species C. cornutus.
• To propose a suitable descriptor for these unusual specimens.

Main Methods:

• Morphological examination of two male Corydalus cornutus specimens.
• Comparative analysis with known C. cornutus morphology and related species.
• Literature review on insect sexual abnormalities and morphological variation.

Main Results:

• Two male Corydalus cornutus specimens were identified with significantly shortened mandibles and discrete dentition, deviating from typical male morphology.
• The observed mandibular characteristics are atypical for males of the species, which usually possess large, serrated mandibles.
• The specimens exhibit features that warrant further investigation into their developmental origins.

Conclusions:

• The aberrant male Corydalus cornutus specimens represent a notable deviation in mandibular morphology.
• The term "gynomorphic" is proposed as a descriptor for these specimens, acknowledging the limited information available for classifying them as true gynandromorphs.
• These findings contribute to the understanding of morphological variation and potential developmental anomalies within the Megaloptera order.