Figure 2.

Illustration of microbehaviors occurring before and during oviposition. (A) Positioning, where the fly relocates (motion is indicated by the dotted arrow). (B) Tarsal contacts; note that all tarsae are not necessarily simultaneously in contact with the substrate. (C) Labellum contact and feeding: both involve contact of the substrate with the distal mouthparts, the labellum. Labellum contact is limited to this, while feeding is accompanied by peristaltic movements of the proboscis corresponding to food uptake (depicted by the dotted arrow), and an open labellum. (D) Ovipositor contact: this microbehavior happens along with a characteristic bow of the abdomen. (E) Egg pushing: similar to ovipositor contact, but the ovipositor is inserted into the substrate, an egg is engaged into the egg canal (dotted white line), and convulsive movements of the ovipositor are visible (depicted by the dotted arrow). (F) Egg expulsion: the egg is separated from the female’s body, usually inserted into the substrate (dotted white line), but leaving the egg filaments visible (solid white line). (G) Abdomen drumming, where the abdomen as a whole is moved up and down (the double arrowhead indicates the direction of the abdominal movements). (H) Grooming: the fly cleans its head or its body with its legs, in a stereotypical brushing movement (dotted arrows). (I) Abdominal convulsion: the wiggly dotted line depicts the direction of the abdominal movements, when the female’s abdomen contracts and extends like an accordion.