none A description of morphological characters of different immature stages, in order to recognize this species are included. Aspects on biology and ecology of Apanteles ayerzai respect his hostes: Ascia monuste and Leptophobia aripa in S. S. de Jujuy (Argentina) are also evaluated. Life cycle and development; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Host parasite relationships; Land and freshwater zones; Neotropical region; South America Ascia monuste; Leptophobia aripa (Pieridae ); Hymenopteran parasites; Apanteles ayerzai; Parasite biology, exit route; Distribution, field & laboratory study; Host parasite relationships; Apanteles ayerzai (Hymenoptera) exit route, laboratory study; Prevalence; Apanteles ayerzai (Hymenoptera), seasonal prevalence; Argentina; San Salvador de Jujuy; Hymenopteran parasite biology, host parasite relations & distribution Apanteles ayerzai (Braconidae); Life cycle; Stage duration & morphology, laboratory study; Lepidopteran hosts; Ascia monuste & Leptophobia aripa, host parasite relations; Distribution, field & laboratory study; Host parasite relationships, parasite exit route, lab study; Prevalence; Ascia & Leptophobia (Lepidoptera), seasonal prevalence; Argentina; San Salvador de Jujuy; Biology, host parasite relations & distribution