Archetype

Homology Weekly: Hypopygium

Last week’s post featured the acidopore: a modification of the ventral plate in the last visible segment of the abdomen in females, as it occurs in the formicine subfamily of ants (e.g., wood ants, carpenter ants, weaver ants). Counting from front to back, this ventral plate is part of the seventh abdominal segment and is denoted by a special term in insects: hypopygium (pl. hypopygia). It is colored in red in the images below.

Abdomen of a Leptogenys sp worker from Nepal, profile view (Scanning Electron Micrograph, Roberto Keller/AMNH)

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Tags: Abdomen, Hypopygium, Leptogenys, Morphology

Homology Weekly: Acidopore

Acidopore of a Formica fusca worker (Scanning Electron Micrograph, Roberto Keller/AMNH)

It is popular knowledge that ants secrete formic acid. What most people don’t know is that only a well-defined subgroup of species have this capacity. Female ants in the subfamily Formicinae have an acid producing gland that sprays its content through a special opening at the rear end of their abdomens, aptly called the acidopore. › Continue reading

Tags: Acidopore, Ants, Formic Acid, Formica, Morphology