Ivermectin alters reproductive success, body condition and sexual trait expression in dung beetles.
Ivermectin is a very common parasiticide used in livestock. It is excreted in the dung and has negative effects on survival and reproduction of dung-degrading organisms, including dung beetles. Here we exposed the dung beetle Euoniticellus intermedius to different concentrations of ivermectin in the food and evaluated reproductive success and the expression of traits associated with survival and reproduction under laboratory conditions. It is the first time the effects of ivermectin were evaluated on offspring physiological condition and the expression of a secondary sexual trait. We also registered the number of emerged beetles, sex ratio and body size of emerged adult beetles. Besides reducing the number of emerged beetles and body size, as found in the same and other insects, ivermectin at high doses reduced muscle mass while at intermediate doses it increased lipid mass. Ivermectin changed offspring sex ratio and at high doses increased the size of male horn, which is an important trait defining the male mating success. Our results highlight the importance of regulating parasiticide usage in livestock in order to maintain ecosystem services provided by dung beetles and confirm that contaminants impose new environmental conditions that not only impact on wild animal survival, but also on evolutionary processes such as sexual selection.
CONACYT, Mexico; Instituto de Ecología, A. C. Carretera Antigua a Coatepec 351, El Haya, Xalapa, Veracruz 91070, Mexico. Electronic address: daniel.gt@inecol.mx.
Daniel
D
González-Tokman
Instituto de Ecología, A. C. Carretera Antigua a Coatepec 351, El Haya, Xalapa, Veracruz 91070, Mexico.
Imelda
I
Martínez M
Instituto de Ecología, A. C. Carretera Antigua a Coatepec 351, El Haya, Xalapa, Veracruz 91070, Mexico.
Yesenia
Y
Villalobos-Ávalos
Unidad de Morfología y Función, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Los Reyes de Iztacala, 54090, Tlalnepantla, Estado de México, Mexico.
Roberto
R
Munguía-Steyer
Instituto de Ecología, A. C. Carretera Antigua a Coatepec 351, El Haya, Xalapa, Veracruz 91070, Mexico.
María Del Rosario
MD
Ortiz-Zayas
Instituto de Ecología, A. C. Carretera Antigua a Coatepec 351, El Haya, Xalapa, Veracruz 91070, Mexico.
Magdalena
M
Cruz-Rosales
UMR 5175 CEFE, CNRS-Université de Montpellier, Laboratoire de Zoogéographie, Université Paul-Valéry Montpellier 3, Route de Mende, 34199 Montpellier Cedex 5, France.
Jean-Pierre
JP
Lumaret
D000818:Animals; D000977:Antiparasitic Agents / Q000494:pharmacology*; D049628:Body Size / Q000187:drug effects*; D001517:Coleoptera / Q000187:drug effects* / Q000254:growth & development; D007559:Ivermectin / Q000494:pharmacology*; D008297:Male; D010641:Phenotype; D012098:Reproduction / Q000187:drug effects*; D012744:Sex Ratio
D000977:Antiparasitic Agents; D007559:Ivermectin
Body size; Contamination; Physiological condition; Reproductive success; Sexual selection; Sub-lethal effects