Epiphyas postvittana nucleopolyhedrovirus (EppoNPV; Baculoviridae) infects the light brown apple moth and is a major horticultural pest. A neonate primary cell line derived from Epiphyas postvittana supports the growth of EppoNPV and spindle-like inclusion bodies were identified in the cytoplasm of infected cells. To facilitate the purification of these inclusions, a recombinant EppoNPV was developed to replace the polyhedrin gene with GFP. The 1-6 µm bipyramidal microcrystals purified, resembled entomopoxvirus (EPV) spindles and were identified as GP37, an orthologue of EPV fusolin. Fusolin has been identified as an enhancin, and X-ray microcrystallography has revealed that these proteins have all the hallmarks of lytic polysaccharide monooxygenases (LPMOs). The EppoNPV spindles shared similar conserved residues and had primitive tetragonal crystal symmetry with unit cell parameters of approximately 72x72x126 Å and 90x90x90 Å, similar to fusolin. At high alkaline conditions, simulating the insect midgut, the spindles elongated initially to over 10µm in length, flexible protrusions unraveled from the longitudinal ends until a large pointed crystal was observed at up to 30 µm, before eventual dissolution. We propose that a tyrosine dependent pH switch is responsible for crystal expansion and dissolution in a manner analogous to occlusion body (OB) dissolution, and that the similarities between GP37 and fusolin may support a similar mode of action, that of chitin degradation by oxidation.