ARS | Publication request: Molecular comparisons suggest caribbean crazy ant from Florida and rasberry crazy ant from Texas (Hymenoptera: Formicidae: Nylanderia) are the same species

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 24, 2012
Publication Date: August 28, 2012
Citation: Zhao, L., Chen, J., Jones, W.A., Oi, D.H., Drees, B.M. 2012. Molecular comparisons suggest caribbean crazy ant from Florida and rasberry crazy ant from Texas (Hymenoptera: Formicidae: Nylanderia) are the same species. Environmental Entomology. 41(4):1008-1018.

Interpretive Summary: In 2002, a new invasive pest ant was found in Houston, Texas, and has been causing significant economic and ecological damage in infested areas. It is morphologically and behaviorally similar to the Caribbean crazy ant. It may cause wildlife to move out of infested areas. The economic impact of Rasberry crazy ant can also be substantial. Large numbers of ants can cause failure of electric equipment by short-cutting circuits and clogging switching mechanisms. In some cases, the ants have caused several thousand dollars or damage and remedial costs. The uncertainty of species identity has significantly affected implementation of research and management of these pest ants. There is an urgent need to identify these ants to species. In this study, 5 novel genes and 3 genomic DNA fragments from Rasberry crazy ant and Caribbean crazy ant were cloned, sequenced, identified and compared. The results strongly suggest that these compose a single species.

Technical Abstract: In 2002, a new invasive pest ant in the genus, Nylanderia (formerly Paratrechina), was found in Houston, Texas. This invasive ant has been causing significant economic and ecological damage in infested areas. Due to the morphological and behavioral similarities to N. pubens Forel found in Florida, this ant was named Nylanderia sp. nr. pubens. So far, morphometric and phylogenetic analyses have not determined if the two ants are the same or separate species. To determine the relationships between the two populations, a molecular approach was undertaken. Five novel genes with various functions from N. pubens (Caribbean crazy ant) and N. sp. nr. pubens (Rasberry crazy ant) were cloned, sequenced and identified, including a chemosensory protein (NpCsp), the cyclophilin-like protein (NpClp), the fatty acid binding protein (NpFabp), the ferritin 2-like protein (NpFlp), and an odorant binding protein (NpObp). Sequences of 4 genomic DNA fragments NpCsp, NpFabp, NpFlp and NpObp, each shared 100% identity between N. sp. nr. pubens and N. pubens. NpClp shared 99% identity, with the only difference at the nucleotide position 358. Comparisons of four partial genomic DNA sequences from Caribbean and Rasberry crazy ants indicated 100% identity for a 710 bp partial genomic DNA sequence of cytochrome oxidase subunit I gene, 99% identity for a 774 bp and a 452 bp partial genomic DNA sequence of NpFabp and NpObp containing non-coding regions, and 100% identity for a 289 bp partial genomic DNA sequence of NpCsp containing only coding region. This study showed that N. sp. nr. pubens in Texas is the same, or at most an intraspecific variant or ecotype of the species in Florida.