Insecticidal effects of canatoxin on the cotton stainer bug Dysdercus peruvianus (Hemiptera: Pyrrhocoridae)

F. Stanisçuaski, C. T. Ferreira-DaSilva, F. Mulinari, M. Pires-Alves, C. R. Carlini

Research output: Contribution to journalArticlepeer-review

Abstract

Canatoxin (CNTX) is a variant form of urease isolated from Canavalia ensiformis (Leguminosaea) seeds. A possible role in the plant defense was proposed for CNTX, due to its toxicity upon feeding to the beetle Callosobruchus maculatus, and the hematophagous bug, Rhodnius prolixus. The toxic effect is caused by a canatoxin-derived peptide (∼10 kDa) formed by insect cathepsin-like digestive enzymes. In order to evaluate their potential as bioinsecticides, the effects of CNTX and its peptide were evaluated on a phytophagous hemipteran insect Dysdercus peruvianus, a pest of cotton culture. For the bioassays, the insects fed on gelatin capsules containing powdered cotton seeds, mixed with the freeze-dried protein and other test materials and were observed for survival rate, weight gain and molting. Ingestion of canatoxin, or a recombinant 10 kDa peptide derived from it, severely affected young forms of the insects, delaying their development or leading to their death. In contrast, adults were insensitive to diets containing higher concentrations of canatoxin. Cathepsin-like proteinases predominated and showed distinct pattern of enzymatic activities in midguts homogenates according to the developmental stage of the insect, a fact which may explain the different susceptibility of nymphs as compared to adult D. peruvianus. The data presented confirm the potential use of canatoxin-like proteins and derived peptides as bioinsecticides.

Original languageEnglish (US)
Pages (from-to)753-760
Number of pages8
JournalToxicon
Volume45
Issue number6
DOIs
StatePublished - May 2005
Externally publishedYes

Keywords

  • Canatoxin
  • Canavalia ensiformis
  • Dysdercus peruvianus
  • Insecticide
  • Proteolytic enzymes

ASJC Scopus subject areas

  • Toxicology

Fingerprint

Dive into the research topics of 'Insecticidal effects of canatoxin on the cotton stainer bug Dysdercus peruvianus (Hemiptera: Pyrrhocoridae)'. Together they form a unique fingerprint.

Cite this