Repellent activity of extracts from fruits of Schinus molle var.. areira (Anacardiaceae) against antennectomized adults of Blattella germanica (Dyctioptera: Blattellidae)

SÁNCHEZ CHOPA C; BENZI V; ALZOGARAY RA; FERRERO A

Colonia del Sacramento

Congreso; First Latin American Meeting of Chemical Ecology; 2010

Asociación Latinoamericana de Ecología Química

Blattella germanica (L.) is an important medical insect pest because of their cosmopolitan occurrence and abundance in homes and other buildings as potential carriers of faecal pathogens and major source of allergens. Although the use of synthetic insecticidal is really advantageous for the control of urban pests at short periods, many problems emerge from their utilization after longer periods. As a consequence, it is important to look for alternative control methods. In the current study we tested the repellent effect of hexanic and ethanolic extracts from fruits of Schinus molle var. areira on antennectomized males of B. germanica, in order to determinate the probably location of the chemoreceptors involved in this behavioral response. A 9 cm round filter paper was cut in half. One side was treated with 0.5 ml of the test compound solution, and the other side was treated with either hexane or ethanol, depending upon which solvent was used to dissolve the test material. The papers were allowed to dry for 1 h before being placed in a 10 cm Petri dish arena. Ten antennectomized (remove the antennae at the scape) and nonantennectomized insects were released in the center of each Petri dish, and their distribution was recorded 24 h later. repellence percentages were calculated for each extract. Comparison was performed by using a paired t-test. The repellency decreased a 34% for the hexanic extract and a 50% for the ethanolic extract on antennectomized insects. These results suggest that the chemereceptors involved in this behavioral response are probably located on the antennae of B. germanica and that the hexanic and ethanolic extracts from fruits of S. molle var. areira had volatile compounds that generated an olfactory response on this urban pest.