With reference to the functional distribution of ES proteins of W. magnifica, relevant literature on other myiasis-causing flies, and the understanding of W. magnifica’s parasitic nature, we selected four gene families (peptidases, cuticle proteins, heat shock proteins (hsp), and immune response) and conducted an investigation into their expression patterns across different developmental stages, with special attention given to the parasitic larval stages. The gene discussed is LAP3; the disease is myiasis.