Most insects use ovipositors (specialized abdominal appendages) to lay eggs. Their morphology varies extensively based on where and how these eggs are laid: some precisely slice into plants and insert them one by one, others deposit them in sticky piles on top of a surface, and others might deposit them on the end of long stalks -- anything is possible in the insect world!
My master's thesis focused on the ovipositor diversity of Hemiptera, a group which uses piercing-sucking mouthparts to feed on liquid from plants and other organisms. This gives them a unique close relationship with the environment they use for food and egg-laying.
A generalized schematic of typical ovipositor morphology for Cicadomorpha, a hemipteran group containing cicadas and leafhoppers. Valvifers are muscle attachment sites, valvulae are the moving parts that transport the eggs, and the gonangulum attaches to the inner wall of the abdomen. The third valvula acts as a sheath in some species, but can be absent or have a different function in others.
The abbreviations and color codes shown here apply to every diagram in my thesis project.
Producing one of these anatomical diagrams takes a few steps and a lot of time. I had a digital image of the specimen open in Photoshop as well as the physical specimen available under a dissection microscope nearby. Since these are highly 3-D structures, I had to constantly check my work -- and constantly adjust the microscope focus -- until I was confident enough in its accuracy to turn the sketch into vector lineart. This gave me invaluable experience in recognizing contour and drawing three-dimensionally.
A. Agallia constricta (Cicadellidae); B. Synechdoche impunctata (Achilidae); C. Pachypsylla celtidis (Psyllidae).
The third valvula in image B (Synechdoche) is modified into a pair of scoops. This insect uses them to dig into loose debris and lay its eggs in more cryptic environments.
The "median dorsal process" in image C is a mysterious structure unique to jumping plantlice. Entomologists are still unsure of its function.
