“…Development of a general paradigm for spiroacetal biosynthesis in Bactrocera sp.The co-occurrence of 1-hydroxynonan-5-one (33) and 6-n-butyl-3,4-dihydro-2H-pyran(34) with spiroacetal 5 in B. cacuminata, and of 2-hydroxyundecan-6-one (51) and 2-methyl-6-n-pentyl-3,4-dihydro-2H-pyran(36) with isomers of 2,8-dimethyl-1,7dioxaspiro[5.5]undecane (4) in B. halfordiae, 45 B. kraussi74 and the giant ichneumon wasp, Megarhyssa nortoni nortoni (Cresson)50,75,76 were the crucial propelling observations in the formulation of our initial hypothesis, with biosynthetically feasible events linking these compounds. Hydration of the pyrans 34 and 36 would provide a mixture of the corresponding pyranol and hydroxyketone (i.e.…”