Fig. 2. Labial salivary gland glucose oxidase (GOX) activity (2a) and protein levels (2b) after transfer of caterpillars from the plant Medicago trunctula to artificial diet.

Fourth instar Spodoptera exigua caterpillars were transferred from plant to artificial diet for 2, 4, 6 or 12 hours. Transfer times were staggered to ensure that the caterpillar developmental time when salivary glands were dissected is approximately equal. Labial salivary glands from six caterpillars were dissected, pooled and homogenate GOX activity and soluble protein amounts determined. Between six to ten replicates were performed. Points represent mean ± SE. Significantly different means are indicated by alphabetical letters (p ≤ 0.01). 2A. GOX activity (U/mg per pair labial salivary glands) 2B. labial salivary gland protein (mg).