Native or nonnative host plants: What is better for a specialist moth?
The enemy release hypothesis (ERH) predicts that the lack of natural enemies, such as herbivores, contributes to the success of nonnative plants as colonizers. Larvae of the Neotropical specialist moth Utetheisa ornatrix (Erebidae: Arctiinae) can feed on unripe seeds and leaves of both native and nonnative Crotalaria species (Fabaceae). Despite some species being able to eat nonnative plants, such behavior can impair the herbivore, as they are not adapted to the alien plant, and still contribute to the success of the nonnative species via enemy release. We tested the performance of the moth from hatching to adulthood fed on two native (C. micans and C. paulina) and two nonnative (C. pallida, C. juncea) host plants. Utetheisa ornatrix performed better (lower development time, heavier pupae and more eggs) on the native host plants than in the nonnative. However, larva performance in nonnative C. pallida was similar to that in the native host plants. Using the larval weight 7 days after hatching from the eggs as a proxy for performance in twelve Crotalaria species (five Neotropical natives, four nonnatives from Afrotropical region, and three nonnatives from India), we found similar results. Crotalaria nutritional compounds, the defensive pyrrolizidine alkaloids and Crotalaria phylogeny did not explain moth performance. Our results give some support to the ERH. The good moth performance in nonnative C. pallida may be related to its high availability as host plant for U. ornatrix, and its longer time since their introduction in Neotropics which would provide opportunity for the moth to adapt.
KeywordsCrotalaria Crotalaria pallida Enemy release hypothesis Pyrrolizidine alkaloids Specialist Utetheisa ornatrix
We acknowledge Andréia Silva Flores for the identification of Crotalaria species, José Carlos da Silva and Daniela Rodrigues for helping in plant and moth rearing. The phylogenetic signal analysis was carried out using the R-script kindly made available by José Hidasi Neto (http://rfunctions.blogspot.com.br/2014/02/measuring-phylogenetic-signal-in-r.html). Ligia Pizzatto helped with English correction and statistical analyses. We also acknowledge to Klaas Vrieling, Rodrigo Cogni, Karina Silva-Brandão, Ligia Pizzatto and two anonymous reviewers for valuable comments in the early draft of the manuscript. Financial support was provided by FAPESP (2011/17708-0) and CNPq (306103/2013-3) to JRT.
- Cunha BP (2017) Caracterização da variabilidade e estruturação genética de Crotalaria pallida (Fabaceae). Dissertation, Universidade Estadual de Campinas, Campinas, São Paulo, BrasilGoogle Scholar
- Flores AS (2004) Taxonomia, números cromossômicos e química de espécies de Crotalaria L. (Leguminosae-Papilionoideae) no Brasil. Dissertation, Universidade Estadual de Campinas, Campinas, São Paulo, BrasilGoogle Scholar
- Hartmann T, Witte L (1995) Chemistry, biology and chemoecology of the pyrrolizidine alkaloids. In: Pelletier SW (ed) Alkaloids: chemical and biological perspectives, vol 9. Pergamon Press, Elmsford, pp 156–233Google Scholar
- Jeffery GH, Bassett J, Mendham J, Denney RC (1992) VOGEL: Análise Química Quantitativa. LTC Editora, Rio de JaneiroGoogle Scholar
- Kearns CA, Inouye DW (1993) Techniques for pollination biologists. University Press of Colorado, BoulderGoogle Scholar
- le Roux MM (2011) A taxonomic study of the genus Crotalaria L. (Fabaceae, tribe Crotalarieae) and a modified infrageneric classification system. Dissertation, University of Johannesburg, South AfricaGoogle Scholar
- Lorenzi H (2000) Plantas daninhas no Brasil: Terrestres, aquáticas, parasitas e tóxicas. Instituto Plantarum, Nova OdessaGoogle Scholar
- McKee R, Enlow CR (1931) Crotalaria, a new legume for the south. USDA Circular 137Google Scholar
- Polhill RM (1982) Crotalaria in Africa and Madagascar. A. A. Balkema, BalkemaGoogle Scholar
- R Development Core Team (2012) R: a language and environment for statistical computing. R Foundation for Statistical Computing, ViennaGoogle Scholar
- Schilthuizen M, Pimenta LPS, Lammers Y, Steenbergen PJ, Flohil M, Beveridge NGP, van Duijn PT, Meulblok MM, Sosef N, van de Ven R, Werring R, Beentjes KK, Meijer K, Vos RA, Vrieling K, Gravendeel B, Choi Y, Verpoorte R, Smit C, Beukeboom LW (2016) Incorporation of an invasive plant into a native insect herbivore food web. PeerJ 4:e1954CrossRefPubMedPubMedCentralGoogle Scholar
- Verçosa D (2016) Variação geográfica e temporal de defesas em Crotalaria pallida (Fabaceae: Papilionoideae: Crotalarieae). Dissertation, Universidade Estadual de Campinas, Campinas, São Paulo, BrasilGoogle Scholar
- Zuur A, Ieno EN, Walker N, Saveliev AA, Smith GM (2008) Mixed effects models and extensions in ecology with R. Springer, New YorkGoogle Scholar