COMPARISON OF 3 METHODS FOR AGE-GRADING OF FEMALE NEOTROPICAL PHLEBOTOMINE SANDFLIES

Changes in appearance of the accessory glands (AG), ovaries (OV) and t he absence or presence of crease marks at the edges of the genital atr ium armature (GA) were compared as methods to age-grade female laborat ory-bred (Lutzomyia migonei) and wild-caught (Lu.youngi, Lu.spinicrass a, Lu. ovallesi) Neotropical sandflies. Dissections at different physi ological stages revealed that all parous and high proportions of nulli parous (4/38 unmated, 12/12 mated) females showed similar residual AG secretions. Hence AG appearance (nullipars with AG translucent, versus yellowish opaque granulated AG previously regarded as signs of parous ness) is unreliable for age-grading. Readily recognizable changes in b oth GA (98% creased) and the OV (100% yellowish with loose ovarioles) indicated that these organs could be employed to discriminate between nulliparous and parous females. Despite finding one misdiagnosed femal e (a nullipar having creased GA indicative of parity), the GA method o f age-grading is recommended because females may be examined satisfact orily at any stage of the gonotrophic cycle. Moreover, the GA characte ristics of pickled or dry preserved sandflies as well as fresh slide-m ounted specimens can be determined easily. Among sixty-five wild-caugh t Lutzomyia females dissected (mostly Lu.spinicrassa and Lu.youngi), t he proportions of specimens yielding preparations suitable for examina tion were 97% for GA, 89% for OV, but only 58% for AG, which reinforce s GA as the preferred character for age-grading.