Based on ODI50 values presented in Table 1, vegetable oils
were more effective than the essential oils in deterring Queensland fruit fly from laying eggs in artificial fruits. Except for
palm oil, all other vegetable oils (neem, safflower, cottonseed
and linseed) had ODI50 values of less than 5 mL/L that were
similar to their respective RI50 values. In contrast, palm oil
had an ODI50 value (6.2 mL/L) that was about half of its RI50
value (no overlap between the two index values), indicating
that palm oil had a higher effect on fruit fly oviposition than
on fruit fly landing.