PMC

Scanning electron micrographs showing peritrophic matrix (PM) of fall armyworm caterpillars reared on BMS-33 callus overexpressing the 33 kDa cysteine protease. (A) Ectoperitrophic from caterpillars reared on nontransformed BMS (magnification = ×500). (B) Ectoperitrophic from caterpillars reared on nontransformed BMS (magnification = ×3,000). (C) Midperitrophic layers from a larva reared on BMS-33 callus (magnification = ×3,500). (D) Endoperitrophic layer from a caterpillar reared on BMS-33 callus (magnification = ×3,500). In this experiment, caterpillars reared on BMS and BMS-33 callus weighed 264.3 ± 2.5 and 68.6 ± 7.7 mg, respectively. The scale is indicated on each micrograph.

Scanning electron micrographs showing peritrophic matrix (PM) of fall armyworm caterpillars that fed on susceptible and resistant corn plants. (A and B) Ectoperitrophic and endoperitrophic layers, respectively, from caterpillars reared on a susceptible plant. (C) Ectoperitrophic layer from a caterpillar reared on a resistant plant. (D) Midperitrophic layer from a caterpillar reared on resistant plant. (E and F) Endoperitrophic layer from a caterpillar reared on a resistant plant. In all cases, the magnification = ×3,000. In this experiment, caterpillars reared on susceptible and resistant plants weighed 89.0 ± 19.6 and 37.3 ± 15.0 mg, respectively. The scale is indicated in each micrograph.

Scanning electron micrographs showing fall armyworm midgut and PM. (A) Excised midgut (mg) from a caterpillar reared on a resistant plant showing the exposed microvilli (mv), PM containing the food bolus (PM + FB), and empty PM (magnification = ×50). (B) PM from a caterpillar reared on a susceptible plant (magnification = ×38). (C) Ectoperitrophic layer (), midperitrophic layers (, ) and endoperitrophic layer () of a caterpillar reared on a resistant plant (magnification = ×500). The scale is indicated on each micrograph.