Klebrigwerden des Fadenwurms nach Kontakt mit der Zuckmücke, Festhaften des Parasiten, Tätigkeit des Stiletts und Injizieren von Sekret, Eindringen durch die gebohrte Öffnung, Zwischenaufenthalt in der selbstgeschaffenen "Hypodermistasche", Durchbruch durch die Basalmembran und Übergang in die Leibeshöhle, Heranwachsen in der Leibeshöhle, Verlassen des Wirtes.

The film demonstrates the mode of penetration of infectious larvae of the parasite Hydromermis contorta (Nematoda: Mermithidae) into larvae of Chironomus thummi (Insecta: Diptera). The introductory scenes present a Chironomus larva together with infectious larva of the parasite. Then the different phases of penetration into the host are demonstrated: 1. In response to contact with the host the surface of the infectious larva becomes sticky. 2. The infectious larva adheres as a gluing spirale onto the cuticle of the host. 3. Its stylet (pharyngostyl) is thrusted into the cuticle where it injects a cuticle dissolving substance. 4. The infectious larva enters the host through the fabricated hole; thereby the sticky substance on its surface is stripped off and closes the entrance as a plug behind the invading parasite. 5. An intermediary stay of the parasite occurs in an artificial space between the cuticle and the basement membrane ("hypodermal pocket"). 6. The parasite ruptures the basement membrane and moves into the body cavity of the host. The last scenes depict mermithids of different ages within the Chironomus larva and finally the emergence of fully grown parasites out of the host.