Toxicity and mode of action of Carica Papaya L. (Caricaceae) extracts on Macrotermes bellicosus Rambur (Isoptera; Macrotermitinae)
Tahiri, A.; Assi, M.; Amissa, A.
Cahiers Agricultures 19(4): 267-272
2010
ISSN/ISBN: 1166-7699
Accession: 070633116
The pesticide characteristics of the total extracts of different organs of the papaya tree Carica papaya L. (Caricaceae) were tested on the Macrotermes bellicosus termite species. The effect of these extracts, especially the alcoholic extract contained in the grains of the immature fruit and the hexane extracts contained in the pulp and the grains, are the most toxic. The three extracts have similar and the lowest LD50 (respectively 0,15 +/- 0,0 mg/L, 0,16 +/- 0,0 mg/L and 1,06 +/- 0,0 mg/L). The use of the papaya tree in a traditional environment as a pesticide is greatly justified. The effectiveness of the extracts increases with the concentration of the extract, except in the most toxic grain alcohol extract and the pulp hexane extract, which are more effective in low concentrations. Concerning the mode of action of the papaya tree, contact and inhalation are the main factors of their effectiveness. They can also be transmitted in the colony during social tasks. They do not, however, act when ingested and they are appetite-inhibiting for termites.