Occurrence of midgut perimicrovillar membranes in paraneopteran insect orders with comments on their function and evolutionary significance - Silva, Carlos P.; Silva, José R.; Vasconcelos, Fábio F.; Petretski, Marílvia D. A.; DaMatta, Renato A.; Ribeiro, Alberto de Freitas; Terra, Walter Ribeiro (Arthropod Structure & Development, 2004)