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

Abstract

One approach that can be employed in integrated pest management is the use of proteins with antinutritional effects on insect metabolism and development. The antimetabolic properties of soybean proteinase inhibitor (SPI) on growth of neonate larvae of the sugarcane borer, Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) have been evaluated. When incorporated into an artificial diet at 0.5% (w/w), SPI retarded growth rate and development of larvae when compared with larvae fed on artificial diet alone. However, larval survival was not significantly affected. The purpose of our research was to calculate demographic statistics for the sugarcane borer reared on diet either with or without semi-purified extract of SPI. Net reproductive rate (R 0 ), instantaneous rate of increase (r m ), combined age-specific survivorship (l x ) and age specific fecundity (m x ) provide information about population growth potential. These parameters were measured in order to determine the effects of the proteinase inhibitor on the insect's population dynamics. The observed differences would potentially translate into large reductions in population growth, indicating a potential value of using SPI for protecting sugarcane plants against damage by the sugarcane borer.

Biochemical Analysis of a Castor Bean Leaf Extract and its Insecticidal Effects Against Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae)

“…larval weight, larval development, pupal weight, and/or nutritional indices affected by feeding on diets containing trypsin inhibitors (Ramos et al 2009, Pompermayer et al 2001. In the present work, the relative metabolic rate and the metabolic costs were increased by the addition of the extracts to the diet, which could be explained by the presence of a trypsin inhibitor, as S. frugiperda larvae has been shown to overproduce digestive enzymes when feeding on substrates containing such molecules (Paulillo et al 2000), which leads to an increase in energy expenditure due to a higher metabolic rate.…”

Mechanisms of sugarcane response to herbivory

“…Several reports have been able to show directly that proteinase inhibitors can inhibit the activity of insect digestive proteinases in vitro (for a review, see Jongsma and Bolter, 1997). Soybean proteinase inhibitors incorporated into an artificial diet fed to sugarcane borers (D. saccharalis) have produced adverse effects on the growth, development and reproductive potential of this pest (Pompermayer et al, 2001). This observation has allowed us to obtain transgenic plants with increased resistance to the sugarcane borer (manuscript in preparation).…”

Digestive enzymes during development of Ceratitis capitata (Diptera:Tephritidae) and effects of SBTI on its digestive serine proteinase targets

“…Plant proteinase inhibitors, a-amylase inhibitors, lectins and chitin binding proteins are usually expressed in response to herbivore insects, pathogens and wounding (Ryan, 1990;Botella et al, 1996;Koiwa et al, 1997;Sales et al, 2001) and may affect development by interfering in the proteolytic processes of a wide range of potentially damaging organisms, including bacteria, fungi, nematodes (Haq et al, 2004) and insects (Terra and Ferreira, 1994;Pompermayer, et al, 2001;Falco and Silva-Filho, 2003). The effects on insects can be observed when digestive enzymes are inhibited or when defense proteins bind to the gut structures of larvae and insects (XavierFilho, 1993).…”