Effects of soybean proteinase inhibitor on development, survival and reproductive potential of the sugarcane borer, Diatraea saccharalis

One approach that can be employed in integrated pest management is the use of proteins with antinutritional effects on insect metabolism and developme nt. The antimetabolic properties of soybean proteinase inhibitor (SPI) on g rowth of neonate larvae of the sugarcane borer, Diatraea saccharalis (Fabri cius, 1794) (Lepidoptera: Crambidae) have been evaluated. When incorporated into an artificial diet at 0.5% (w/w), SPI retarded growth rate and develo pment of larvae when compared with larvae fed on artificial diet alone. How ever, larval survival was not significantly affected. The purpose of our re search was to calculate demographic statistics for the sugarcane borer rear ed on diet either with or without semi-purified extract of SPI. Net reprodu ctive rate (R-0), instantaneous rate of increase (r(m)), combined age-speci fic survivorship (l(x)) and age specific fecundity (m(x)) provide informati on about population growth potential. These parameters were measured in ord er to determine the effects of the proteinase inhibitor on the insect's pop ulation dynamics. The observed differences would potentially translate into large reductions in population growth, indicating a potential value of usi ng SPI for protecting sugarcane plants against damage by the sugarcane bore r.