It has been suggested that syrphids detect sugars using either the labellum or tarsal receptors and then confirm their presence using sensilla on the ovipositor.
The insects were marked by removal of the central tarsal claw (right for males; left for females).
The following measurements were taken from both fore legs of each of these moths: length of femur, tibia, first tarsal segment and inner tibial seta.
The alate viviparous female has four or more hairs on the first tarsal segment.
Another important morphological character is the number of tarsal segments of apterous viviparous females.
The two most proximal tarsal segments of the prothoracic male legs are shown for each species.
Both breast muscle mass (3 dimensions) and tarsal length (1 dimension) were log-transformed to ensure linearity in the allometric relationship between the two variables.
The anterior legs are sometimes without any dark scales, sometimes with the tips of the joints black and the whole of the last two tarsal joints brownish.
