Trehalulose is also produced in the silverleaf whitefly,Bemisiaargentifolii,and excreted in its honeydew.11The enzyme fromwhiteflies was a 116 kD membrane-associated polypeptide,which was able to convert sucrose to trehalulose.11Enzymeassays with sucrose plus14C labeled glucose or fructosesubstrates suggested that theB. argentifoliiisomerase catalyzedthe transfer of fructose using sucrose as the glucosyl donor. Thelargest family of glycoside hydrolases GH13 contains 35subfamilies, with varying substrate and product specificity(hydrolases and transferases), but all act via the same catalyticdouble displacement mechanism.22Erlose and oligosaccharidesformed from further successive additions of glucose wereobserved in New Zealand beech honeydew honey arising fromthe scale insectUltracoelostoma assimile, suggesting theinvolvement of a related enzyme with sucrose acting as theglucose dono