Key to US Myrmecina species

Key to United States species of Myrmecina based on workers, modified from Deyrup (2015) and MacGown (2023).

1

• Head, mesosoma, and waist shiny, with reduced parallel carinae, interrugal rugoreticulation lacking; propodeal spine blunt, pre-propodeal spine lacking (Fig. 2A) => Myrmecina davisoni
• Head, mesosoma, and waist with strong sculpture, conspicuous parallel carinae present with rugoreticulation in between carinae; propodeal spine acute, small triangular pre-propodeal spine present (Fig. 2B) => 2

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  MacGown (2023), Figure 2. (A) Myrmecina davisoni showing the overall lack of sculpture and single blunt propodeal spine and (B) M. americana showing the coarse sculpture and acute propodeal spine with small pre-spine-like process.

2

• Total length 2 mm or less; postpetiole with a distinct ventral process that is directed anteriorly (Fig. 3A); color dark reddish brown => Myrmecina cooperi

Head of Myrmecina cooperi worker

Profile of Myrmecina cooperi worker

• Total length greater than 2.0 mm; postpetiole concave below, lacking a conspicuous process (Fig. 3B); color reddish brown to blackish brown => Myrmecina americana

Head of Myrmecina americana worker

Profile of Myrmecina americana worker

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  MacGown (2023), Figure 3. (A) Myrmecina cooperi with arrow pointing to anteriorly directed ventral postpetiolar process and (B) M. americana with arrow pointing to ventral area of postpetiole showing concavity; forward projecting process lacking.
• 

  Ventral surface of postpetiole of M. americana.

References

• Deyrup, M. 2015. A new species of Myrmecina (Hymenoptera: Formicidae) from southeastern North America. Florida Entomologist 98: 1204-1206.
• MacGown, J.A. 2023. Description of a new species of Myrmecina (Hymenoptera: Formicidae: Myrmicinae) from the southeastern United States. Transactions of the American Entomological Society 149(1): 109-117 (doi:10.3157/061.149.0106).