Avaliação da eficácia de extratos oleosos de frutos verdes e maduros de cinamomo (Melia azedarach) sobre Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Abstract

RESUMOExtratos hexânicos obtidos dos frutos de Melia azedarach foram testados sobre fêmeas ingurgitadas e larvas de Rhipicephalus (Boophilus) microplus. Foram produzidos quatro extratos: um de frutos verdes e três com frutos maduros, sendo um com os frutos imediatamente processados, outro com frutos armazenados por cinco meses e um testado após armazenamento do extrato por 2 (dois) anos a 4ºC. Os testes foram feitos em triplicata, em diluições de 0,25% a 0,0156%. A eficácia dos extratos foi avaliada através da comparação da Reprodução Estimada dos lotes "controle e tratado" para fê-meas, da mortalidade para as larvas, e do cálculo das DL50 e da potência relativa para larvas e fêmeas. O extrato de frutos verdes apresentou uma eficácia variando de 3,6% a 100% para fêmeas, e o de frutos maduros variou de 5,2% a 99,7%. Os dois extratos causaram uma mortalidade de 100% das larvas nas maiores concentrações. O extrato de frutos armazenados apresentou eficácia de 14% a 83% sobre fêmeas, enquanto o extrato armazenado em geladeira apresentou eficácia de 8,4% a 100% e ambos não apresentaram efeito larvicida. Os resultados obtidos demonstram uma superioridade do extrato verde, com uma menor DL50 e potência 1,497 vezes superior ao extrato de frutos maduros. Hexanic extracts gotten of the fruits of cinamomo (Melia azedarach) were tested on engourged females and larvae of Rhipicephalus (Boophilus) microplus. Four extracts were produced: one of unripe fruits and three of ripe fruits, being one with the fruits immediately processed, another one with fruits stored for five months and one tested after storage of the extract for 2 (two) years at 4ºC. The tests were made in triplicate, in 0.25%-0.0156% dilutions. The effectiveness of extracts was evaluated through the comparison of the Reproduction Estimate of the groups "controlled and treated" for females, of mortality for the larvae, and of the calculation of the DL50 and the relative power for larvae and females. The extract of unripe fruits presented the effectiveness varying the 3.6% -100% for females, and of ripe fruits it varied of 5.2% -99.7%. The two extracts caused a mortality of 100% of the larvae in the highest concentrations. The extract of stored fruits presented effectiveness of 14% -83% on females, while the extract stored in refrigerator presented effectiveness of 8.4% 100% and both did not present larvicidal effect. The results demonstrate a superiority of the unripe extract, with a minor DL50 and superior power 1.497 times to the extract of ripe fruits.

Perspectives for the use of plant extracts to control the cattle tick Rhipicephalus (Boophilus) microplus

“…The efficacy was greater than what was found by Borges et al (2005), although the egg conversion and hatchability of the ticks did not differ between the two experiments. These in vivo results differed from laboratory test observations (BORGES et al, 1994, 2003, SOUSA et al, 2008, in which it had already been demonstrated that the fruit extracts of M. azedarach had higher efficacy against the females reproductive efficiency.…”

“…Storage of M. azedarach fruits for five months at room temperature caused a decrease in their acaricide effect (SOUSA et al, 2008). Yakkundi et al (1995) observed a 5% reduction in azadirachtin after one month of storage of A. indica seeds and 35% after four months.…”

“…Similarly, hexanic and chloroformic extracts produced a greater inhibition on females reproductive efficiency (100 and 91.5%, respectively) than did ethanolic extracts (46%). Sousa et al (2008) showed that extracts from green fruits were 1.5 times more efficient than extracts from ripe fruits. However, lower efficiency was obtained by Vivan (2005).…”

“…Pulegone was the main compound isolated from the essential oil (RIBEIRO et al, 2010). In addition, tests on this family were carried out using the essential oil from leaves VALENTE et al, 2007;SRIVASTAVA et al, 2008;COSTA et al, 2008;MAGADUM et al 2009;BROGLIO-MICHELETTI et al, 2009 Azadirachtin (BUTTERWORTH; MORGAN, 1971) Salanin (MEISNER et al, 1981) Nimbin, nimbinin (SIDDIQUI et al, 1988) Meliatetraolenone, odoratone (SIDDIQUI et al, 2003) Melia azedarach L. (BORGES et al, 1994(BORGES et al, , 2003VIVAN, 2005;SOUSA et al, 2008).…”

Efficacy of extracts from plants of the Brazilian Pantanal against Rhipicephalus (Boophilus)microplus

“…In Brazil, several plants have been evaluated against R. (B) microplus, highlighting Melia azadirachta (SOUSA et al, 2008), Azadirachta indica (COSTA et al, 2008), Drimys brasiliensis (RIBEIRO et al, 2008b), Piper aduncum (SILVA et al, 2009), Simarouba versicolor (CATTO et al, 2009), Calea serrata (RIBEIRO et al, 2011), Tagetes minuta (GARCIA et al, 2012) and Guarea kunthiana (BARBOSA et al, 2013).…”