Evolution of female-specific wingless forms in bagworm moths

Area of Science:

• Evolutionary Biology
• Insect Phylogenetics
• Developmental Genetics

Background:

• Winglessness in insects is often a secondary adaptation from winged ancestors.
• Bagworm moths (Psychidae) display extreme sexual dimorphism with wingless females.
• The evolutionary origins of winglessness in bagworms remain unclear.

Purpose of the Study:

• To investigate the evolutionary patterns of wing reduction in female bagworm moths.
• To reconstruct the molecular phylogeny of Asian bagworm species.

Main Methods:

• Molecular phylogenetic analysis using mitochondrial (cytochrome c oxidase subunit I) and nuclear (28S rRNA) DNA sequences.
• Phylogenetic reconstruction of over 30 Asian bagworm moth species.

Main Results:

• Wing reduction in bagworm females occurred in two distinct steps: functional wings to vestigial wings, then to vermiform adults.
• Vermiform (legless, wingless) adult forms evolved independently at least twice within the Psychidae family.
• Phylogenetic analysis supports a parsimonious model of evolutionary wing reduction.

Conclusions:

• Evolutionary changes in developmental systems are crucial for the emergence of diverse wingless insect forms.
• The study clarifies the evolutionary pathways leading to winglessness in bagworm moths.