Influence of iridoid glycoside containing host plants on midgut β-glucosidase activity in a polyphagous caterpillar, Spilosoma virginica Fabricius (Arctiidae)

▶ Midgut β-glucosidase improves insect-host plant interaction in generalist caterpillars. ▶ Larvae adaptively decrease the β-glucosidase activity in response to the host plant. ▶ The β-glucosidase activity is lower in the plants with more toxic plant glycosides. ▶ The adaptive decrease of β-glucosidase activity enhances the caterpillar's tolerance.