The twigs of Cynips tinctoria hold gallic and ellagic acid. This is obtained when the insect, Quercus infectoria, bore its holes in the twigs to deposit its ova.

• A. The first statement is correct whilst the second statement is incorrect
• B. The first statement is incorrect whilst the second statement is correct
• C. Both statements are incorrect
• D. Both statements are correct

Answer: (D)

Two ideas fit together here. Galls formed on oaks by cynipid wasps are rich in hydrolyzable tannins, including gallic acid and ellagic acid, so the gall tissue itself contains these compounds. The gall develops as the insect lays eggs in the twig; the larva’s presence and secretions trigger the plant tissue to swell into a protective gall around it. The host tree in this context is Quercus infectoria, and the action of the insect laying eggs by burrowing into the twig explains the gall formation. So both statements describe real aspects of these galls, making them true.