Photorhabdus temperata is an entomopathogenic bacterium that lives in association with nematodes of the family Heterorhabtidae. In this work, the effects of P. temperata infection on the activities of digestive enzymes of the sugar cane stalk borer Diatraea saccharalis were investigated. Lots of 20 larvae were infected by injection of inocules containing 50 bacterium cells directly in the haemolymph. After different periods of infection, larvae were immobilized on ice, dissected and their midgut tissues were rinsed in sterile saline and freezed. After being thawed, the midgut tissues were homogenized and centrifuged (15,000g, 30 min, 4 ^o C) and the supernatant was used for protein and enzymatic determinations. In gel assays using semi-denaturant SDS-PAGE were carried out towards the following substrates methyl-umbellyferyl-a-glucoside (MUaGlu), methyl-umbellyferyl-a-galactoside (MUaGal), sucrose and raffinose. Larvae of control D. saccharalis present three sucrose hydrolases in their midgut, two a-glucosidases and one b-fructosidase. The three sucrose hydrolases were resolved by electrophoresis and in gel assays showed that the activities of all three enzymes decreased following infection. Activities of the sucrose hydrolases started decreasing after 12 h of infection. There are three a-galactosidases in D. saccharalis, all of them decreasing activity after 36 h after infection. Quantitative analysis using chromogenic substrates showed that the activities of the a-glucosidases decreased 50 % after 12 h of infection, while the a-galactosidase activities decreased 70%. Interestingly, the animals died after 48 h of infection, but near 5% of all the enzymes tested remained active in the midgut. By this time, most of the intestinal cultivable resident bacteria was still alive.