The Toxicity of a Lipid Transfer Protein (Cc-LTP1) from Coffea canephora Seeds on the Larval Development of Callosobruchus maculatus (Coleoptera: Bruchidae)

In this work, we analyzed the effects of coffee seed proteins, especially Cc-LTP₁ on the larval development of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae), a bruchid pest of beans and the most important insect pest of Vigna unguiculata (L.) Walp. Artificial seed assay, which incorporated the F/0-90 fraction from Coffea canephora seeds, resulted in the reduction of oviposition and caused an inhibition of C. maculatus larval development in a dose-dependent manner. The F/0-90 fraction used at a 4 % concentration resulted in the survival of no larvae. The purified Cc-LTP₁, at a concentration of 0.5 %, also demonstrated effective inhibition of larval development, reducing both females oviposition and the weight and number of larvae. Cc-LTP₁ was also able to inhibit the C. maculatus gut α-amylase activity, and immunolabeling by an anti-LTP serum was observed in the midgut tissues of the C. maculatus larvae. Cc-LTP₁ has shown binding affinity towards microvillar cells, endoplasmic reticulum and mitochondria, as demonstrated by micrographic images taken by a transmission electron microscope. The results from this study indicate that Cc-LTP₁ has insecticidal actions toward C. maculatus and exerts anti-nutritional effects with direct actions on intestinal tissues.