Variation in sperm formation patterns in jumping plant-lice (Hemiptera: Psylloidea): a light microscopic study

Area of Science:

• Entomology
• Zoology
• Evolutionary Biology

Background:

• Sperm formation patterns in sternorrhynchous jumping plant-lice (Psylloidea) are crucial for understanding insect evolution.
• Existing data on spermiogenesis in this infraorder is limited, necessitating further investigation.

Purpose of the Study:

• To review and describe the patterns of sperm formation in jumping plant-lice.
• To identify and classify distinct chromatin reorganization patterns during spermiogenesis.
• To evaluate the utility of these patterns in elucidating phylogenetic relationships within Psylloidea.

Main Methods:

• Review of existing literature and new light microscopy studies on sperm formation.
• Analysis of chromatin reorganization during spermatid metamorphosis in 143 species across seven psylloid families.
• Classification of observed patterns into five distinct types (I-V).

Main Results:

• Five distinct sperm formation patterns (Types I-V) were recognized, with Types II, IV, and V described for the first time in jumping plant-lice.
• Type I, the most widespread, represents the plesiomorphic condition of spermiogenesis in Psylloidea.
• Types III, V, and IV are potentially autapomorphic or synapomorphic for specific subfamilies, while Type II appears to be a homoplasy.

Conclusions:

• Sperm formation patterns are largely stable within psylloid subfamilies.
• These patterns provide valuable characters for phylogenetic analyses within the Psylloidea infraorder.
• The study expands the understanding of spermiogenesis diversity and its evolutionary implications in jumping plant-lice.