Exocellobiohydrolase (CBH) that catalyzes the hydrolysis of 1,4-beta-D-glucosidic bonds in cellulose to release the disaccharide cellobiose (PubMed:23733951). The degradation of cellulose involves an interplay between different cellulolytic enzymes. Hydrolysis starts with endoglucanases (EGs), which cut internal beta-1,4-glucosidic bonds in cellulose to reduce the polymerization degree of the substrate and create new chain ends for exocellobiohydrolases (CBHs). The CBHs release the disaccharide cellobiose from the non-reducing end of the cellulose polymer chain. Finally, beta-1,4-glucosidases hydrolyze the cellobiose and other short cello-oligosaccharides into glucose units (Probable). Hydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains. kcat is 10.57 min(-1) for p-nitrophenyl-beta-d-cellotrioside (pNP-G3). kcat is 24.42 min(-1) for p-nitrophenyl-beta-d-cellopentaoside (pNP-G5). Optimum pH is 4-6.5 for p-nitrophenyl-beta-d-cellotrioside (pNP-G3), and 4-8 for p-nitrophenyl-beta-d-cellopentaoside (pNP-G5). Optimum temperature is approximately 25-45 degrees Celsius. High activity is maintained over a wide temperature range. Monomer. Highly expressed in the hepatopancreas (at protein level) (PubMed:20212162, PubMed:23733951). Little or no expression detected in the hindgut or the rest of the body (at protein level) (PubMed:23733951). Unlike most wood-boring animal species, which rely on symbiotic microbes for digestion of woody substrates, the L.quadripunctata genome contains a range of enzymes (including GH7B) capable of lignocellulose digestion. Belongs to the glycosyl hydrolase 7 (cellulase C) family.