Characterization and distribution of the hydrocarbons found in diapausing pupae tissues of the tobacco hornworm, Manduca sexta (L.).

The cuticular hydrocarbons of diapausing pupae of the tobacco hornworm, Manduca sexta (L.), are composed of two types of hydrocarbons: n-alkanes (3%) and unsaturated hydrocarbons (97%). The integument, fat body, muscle, and hemolymph are composed of three types of hydrocarbons: n-alkanes (9, 6, 9, and 2%, respectively), branched alkanes (75, 85, 80, and 56%, respectively), and unsaturated hydrocarbons (16, 9, 11, and 42%, respectively). The absence of branched alkanes on the cuticular surface indicated that hydrocarbons are selectively synthesized or deposited according to the presence or absence of methyl branches in the molecule. The hydrocarbons consisted of homologous series of n-alkanes from 21 to 41 carbon atoms, monomethylalkanes from 23 to 39 carbon atoms, dimethylalkanes from 25 to 43 carbon atoms, and trimethylalkanes from 33 to 37 carbon atoms. All branched components had methyl groups near the center of the molecule, and the di- and trimethyl branched components had three methylene units between the branch points. Straight chain alkenes, alkadienes, and alkatrienes from 23 to 44 carbon atoms were partially characterized. The percentage composition of each homologous series varied from tissue to tissue.