Strumigenys lucky

This species has the most northern range of any Nearctic species and is known from a few collections taken in four neighboring states (Wisconsin, Minnesota, Illinois, and Iowa). However, in at least one locality (in Waukesha, Wisconsin), this species has been collected multiple times by young myrmecologist Anthony Prothero who provided the only natural history account of S. lucky in personal communications. Prothero found them in a ‘forest’ which used to be a prairie. The forest is almost completely dominated by invasive Buckthorn trees, but random clearings hold many prairie plants. He has located several partial colonies of a few workers and an occasional queen, always under rocks and most commonly during or recently after rain. He expects they are nesting in soil cavities beneath rocks or other debris. The soil in these areas is mostly silt/clay mix.

This species has been misidentified as S. missouriensis, likely due to similarities of clypeal pilosity and shape, for this reason and because they overlap in the eastern portion of S. lucky’s range I have included S. missouriensis in the key but not the synopsis of species in the western region.

Identification
Of species occurring in the western USA, only four have spatulate to spoon-shaped setae on the free margins of the clypeus curving away from the midline, Strumigenys reflexa, Strumigenys missouriensis, Strumigenys pulchella and Strumigenys lucky. Strumigenys lucky is most morphologically similar to S. missouriensis (I believe to be a complex of species requiring taxonomic treatment) but can be separated from the S. missouriensis complex by head pilosity. Strumigenys lucky has long flagellate hairs at apicoscrobal position and at the vertex margin of head. In S. missouriensis these hairs, if present, are shorter stiff and straight; varying in shape from simple to apically expanded; and may not be much longer than the background pilosity. Strumigenys reflexa have setae that curve away from the midline of the head at the nearest point where the outer mandibles and clypeus meet, in S. lucky and S. pulchella, these setae curve towards the midline or are directed ventrally. Strumigenys lucky can be separated from S. pulchella by teeth dentition, in S. pulchella the first two teeth are nearly equal in size with the third tooth smaller than the first two. In S. lucky, the first (excluding first denticle if present) and third tooth are nearly equal in size with the second tooth smaller.

Distribution based on type material
United States.

Nomenclature

 * . Strumigenys lucky Booher, 2021: 227, fig. 38 (w.q.) UNITED STATES.

Type Material

 * Holotype worker. USA, Minnesota, Houston Co.: Winnebago Creek, 31 May 1941, Collectors Jerry L. Cook & J. B. Martin (colony 275), bottom specimen mounted on pin with pinned identifier code (MCZCENT00683064)[MCZC].
 * Paratypes. Three workers and two queens from the same colony (colony 275) all with same collections data as type; one worker, top specimen mounted on same pin as type (MCZC-ENT00683064)[MCZC]; two workers mounted on the same pin (MCZC-ENT00683065) [MCZC]; two dealate gynes (MCZC-ENT00683066, MCZCENT00683067) [MCZC].