Published online by Cambridge University Press: 10 July 2009
Screening of 38 selected juvenoids on Ceratitis capitata (Wied.) revealed that several aromatic compounds, mostly ethers of 6,7-epoxygeraniol and of 6,7-epoxycitronellol, inhibited hatching when administered to freshly laid eggs as 0·1% acetone solution. Application of juvenoids within 24 h before and after puparium formation caused disturbances in imaginal differentiation. Treated insects developed either into pupa-adult intermediates failing to emerge or into defective adults whose fecundity was severely decreased. Both earlier and later applications of juvenoids were less effective. The most active compound in topical assay on fully grown larvae was ethyl 10,11-epoxy-5-oxa-3,7,11-trimethyl-2-dodecenoate, which inhibited emergence of 50% of treated insects at 0·01 μg/specimen and caused external deformities in 50% of emerged adults at 0·00001 μ/g/specimen. Four other aliphatic compounds (methyl 11-methoxy-3,7,11-trimethyl-2,6-dodecadienoate; ethyl 11-methoxy-3,7,11-trimethyl-2-dodecenoate; isopropyl 3,7,11-trimethyl-2,4-dodecadienoate; and isopropyl 11-methoxy-3,7,11-trimethyl-2, 4-dodecadienoate) and l-ethyl-4[(6,7-epoxy-3,7-dimethyloctyl)oxy] benzene were about five times less active. A concentration of 33 parts /106 of ethyl 10,ll-epoxy-5-oxa-3,7,11-trimethyl-2-dodecenoate in larval food caused deformities in 60% of emerged adults.