Recycled paper products as substitutes for gelling agent in screwworm (Diptera: Calliphoridae) larval diet

Absorbent recycled paper products were tested and compared with a sodium polyacrylate gelling agent, Aquatain, for solidifying larval diets of the screwworm, Cochliomyia hominivorax (Coquerel). A recycled newsprint product, Terra-Mulch. when mixed,with water and dietary ingredients produced a diet medium of homogeneous texture that supported lard a growth and development comparable to the standard diet prepared with the gelling agent. Biological yields as calculated from number of pupae per tray from both the diets were similar. Three other types of recycled paper products were tested. Although less homogeneous in texture, these diets were as good as the diet with Terra-Mulch. There were no significant differences in the mean larval and pupal weights, no. of pupae/tray, percent emergence, oviposition, percent hatch, and percent longevity. When tests were conducted through eight consecutive generations, no adverse effect was noticed in any of the life history parameters. Terra-Mulch is inexpensive and biodegradable compared with the gelling agent Aquatain that is expensive and not biodegradable. Replacing Aquatain with Terra-Mulch in the screwworm larval diet for mass rearing may result in an annual savings of more than half a million U.S. dollars in costs of material and labor.