Mouth parts of the mustard aphid, Lipaphis erysimi Kalt.

The mouth parts of mustard aphid, Lipaphis erysimi Kalt. are piercing and sucking type with three modified maxillary and mandibular stylets. The rostrum is four segmented, apical segment is as wide as penultimate one but longer reflexed backwards and reaching up to the second pair of coxae in the adult, and third pair of coxae in early nymphal stage. Small needle like hypopharynx is continuous with the preoral cavity which is posteriorly connected with the food canal. Two grooved capillary stylets are present on either side of rostrum. Labium is short, cylindrical, flap like in appearance and covers the base of the abdomen. A pair of each protractor and retractor muscles are also present which are connected with the supporting arm of tentorium.