Lamyctes Meinert 1868

Genus Lamyctes Meinert, 1868

Hollington & Edgecombe (2004) placed Lamyctes in a well-supported phylogenetic group with Henicops and Paralamyctes. While Lamyctes species are found on all continents except Antarctica and on many oceanic islands, Henicops is limited to Australia, New Zealand and New Caledonia and Paralamyctes is found in Australia, New Zealand, southern South America, India, Madagascar, and South Africa (Hollington & Edgecombe 2004).

The worldwide distribution of Lamyctes is mainly, if not entirely, due to two or three Lamyctes species spread by human agency, and most populations probably have thelytokous parthenogenesis—accounting for the ease of distribution (Enghoff 1975; Enghoff et al. 2013; Iorio 2016). There are 42 currently recognized species of Lamyctes (Bonato et al. 2016). Of these, Lamyctes emarginatus Newport is found in continental North America, and L. coeculus Brölemann and L. africanus (Porat) have been reported from Hawaii (hence not included in the key). The USNM has L. coeculus specimens from the early 20th century intercepted at quarantine in Norfolk, Virginia, Houma, Louisiana, and Boston, Massachusetts. Auerbach (1952) reported it from a greenhouse in Urbana, Illinois, but there is no other documentation of any established populations of this species in North America north of Mexico (but see the discussion below of Buethobius translucens Williams & Hefner, 1928).

Unlike the blind L. coeculus, all of the recorded North American species have a single ocellus on each side of the head. Interspecific similarities in the coxal pore formulae and antennomere counts are within the range of variation found in L. emarginatus (see Zapparoli & Shelley 2000), and raise the question as to how many of the supposed species from North America may really be distinct. Mercurio (2010) expressed the opinon that L. tivius, L. pius and L. pinampus are synonyms of L. emarginatus, and the same may be true of L. diffusus and L. caducens (these latter two were incompletely described from single specimens), leaving no native Lamyctes species in North America. No male specimens of any of Chamberlin’s species have been reported. Indeed, the existence of any endemic species of Lamyctes in the Northern Hemisphere is questionable. It is worth noting that of the 42 species currently recognized, only four (aside from L. africanus, L. coeculus and L. emarginatus, the anthropochoric species) have been described from the Northern Hemisphere outside North America, three of these from islands (Bonato et al. 2016). It is very likely that these four northern hemisphere nominal species, as well as the North American species described by Chamberlin, may be synonyms of one or the other of the three “hitchhikers.”