Mineral concentrations within cells of galls induced by Hemadas nubilipennis (Hymenoptera: Pteromalidae) on lowbush blueberry: evidence from cryoanalytical scanning electron microscopy

Cryoanalytical scanning electron microscopy was used to examine cellular concentrations of K, P, S, Mg, Ca, Fe, Cu, Ni, and Au in a planed section of an insect gall induced by Hemadas nubilipennis on shoots of lowbush blueberry. Levels of K varied throughout tissues of the gall, with the highest levels within the cytoplasmically dense nutritive cells lining the larval chambers, storage nutritive cells, and peridermal cells. It is postulated that K increases the osmotic potential and size of nutritive cells, thereby facilitating larval feeding. Nutritive cells also contained elevated levels of P and S. Levels of Cu, Ni, Fe, and Au were elevated in epidermal tissues, especially near the stomata.