Distinguishing larval instars of the vegetable leafminer Liriomyza sativae (Diptera: Agromyzidae).
Measurements of either the length of mouth hooks or the cephalopharyngeal skeleton showed clear separation between larval instars of Liriomyza sativae. Mouth hooks of 1st-instar larvae also differed morphologically from those of later instars. Larval instars were distinguished under a dissecting microscope at 200x magnification, enabling rapid separation of freshly-collected specimens. The growth ratio of cephalopharyngeal skeletons between 1st- and 2nd-instar larvae was higher (1.75) than between 2nd- and 3rd-instar larvae (1.56). Growth ratios calculated from published reports on other Liriomyza species were typically very similar to those of L. sativae.