|De Sousa, Lorena|
|Da Costa, Deomar|
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2013
Publication Date: 3/10/2014
Citation: De Sousa, L.A., Da Costa, D.P., Ferri, P.H., Showler, A., Borges, L.M. 2014. Soil quality influences efficacy of Melia azedarach (Sapindales: Meliaceae), fruit extracts against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). Annals of the Entomological Society of America. 107:484-489. Interpretive Summary: Extracts of unripe chinaberry fruits were collected from six municipalities of Goias state, Brazil, and tested on engorged female southern cattle fever ticks to determine effects on reproduction. Extract from one municipality caused complete reproductive inhibition while the other five showed lesser effects, the lowest being only 17% inhibition. Extract potency was positively influenced by soil elements calcium, magnesium, and phosphorus, and negatively influenced by amounts of silt, potassium, and organic matter. Chinaberry extract can strongly reduce cattle fever tick reproduction, but the potency of the extract is affected by soil factors at collection sites.
Technical Abstract: Hexane extract of chinaberry, Melia azedarach L., unripe fruits obtained from different municipalities of Goias state in Brazil were evaluated on the southern cattle fever tick, Rhipicephalus microplus (Canestrini), engorged females. Hexanic extracts were assayed in decreasing concentrations from 0.25 to 0.0156% for effects on egg production and hatching. Efficacy on engorged females decreased from the extracts of Goiania (100%), Professor Jamil (97.5 ± 3.0%), Pirenopolis (95.1 ± 2.4%), Morrinhos (86.8 ± 9.4%), Caturai (41.8 ± 29.3%) to Bela Vista de Goias (17.1 ± 0.9%). Canonical redundanc~ analysis indicated that the extract bioactivity was positively correlated with soil Ca +, Mg2+ and P and negatively correlated with silt, K+, potential acidity and organic matter. This study demonstrates that M. azedarach hexanic extract can dramatically reduce R. microplus reproductive capacity and that efficacy is strongly influenced by differences in soil constituents at collection sites.