Phylogeny of Neotropical Lepidocyrtus (Collembola: Entomobryidae): first assessment of patterns of speciation in Puerto Rico and phylogenetic relevance of some subgeneric diagnostic characters

Abstract

Summary A phylogenetic analysis of the Neotropical members of genus Lepidocyrtus was conducted to assess the pattern of speciation in Puerto Rico while testing the phylogenetic information content of two characters used to diagnose subgenera. The analysis included twenty‐two species of Lepidocyrtus from the Neotropical Region for which information on the tergal chaetotaxy of the trunk was available, two species of Holarctic Lepidocyrtus, three species of Pseudosinella, two species of Metasinella used in outgroup analysis and ninety‐two informative characters. The results do not support a monophyletic origin for the Puerto Rican Lepidocyrtus, suggesting the current fauna originated through repeated invasions from abroad. Three instances of endemic speciation can be inferred from the cladograms. The geographical distribution and diversity of colour forms suggest that L. caprilesi and L. paracaprilesi speciated sympatrically, whereas vicariance can explain speciation for L. lepargus and L. maldonadoi. The mode of speciation for L. dispar and L. biphasis remains unclear because the proportion of morphological variation between these species does not fit the proportions expected under the sympatric model suggested by their geographical distribution. The results support an early conclusion regarding appendicular scale distribution as a poor indicator of phylogenetic relationships. Taxa defined using this character are likely to be polyphyletic. The results disagree with a previous study in documenting low levels of homoplasy for the dental tubercle, implying that this character contains phylogenetic information useful in defining subgenera. However, the presence or absence of a dental tubercle is not diagnostic and should be used in combination with other characters. Comparisons of levels of homoplasy in Neotropical and Hawaiian Lepidocyrtus suggest that the relative position of two setae on the second abdominal tergum may be a better subgeneric character than other characters currently in use.

Systematic revision of Entomobryidae (Collembola) by integrating molecular and new morphological evidence

“…The largest two genera Lepidocyrtus and Pseudosinella are simply separated by number of ommatidia, and Pseudosinella includes lineages considered as derived independently from various Lepidocyrtus species (Christiansen ; da Gama ). Phylogenetic works by Christiansen & Bellinger () and Soto‐Adames (, ) further indicated the complexity of Lepidocyrtinae.…”

“…The largest two genera Lepidocyrtus and Pseudosinella are simply separated by number of ommatidia, and Pseudosinella includes lineages considered as derived independently from various Lepidocyrtus species (Christiansen 1961;da Gama 1984). Phylogenetic works by Christiansen & Bellinger (1991) and Soto-Adames (2000 further indicated the complexity of Lepidocyrtinae. Most characters are morphologically fairly conserved and result in well-known difficulties for identifying lepidocyrtins, considered to be among the most problematic collembolan taxa (Deharveng 2004).…”

Collembola, the biological species concept and the underestimation of global species richness

“…). However, this subdivision is not universally accepted, and a general re‐evaluation of many of the characters used has been advocated (Soto‐Adames ). Characters used to recognize genera, subgenera and species within Lepidocyrtinae range from size and shape of the body, or parts of the body, to the many characters within body chaetotaxy (Yosii ; Gisin , ; Szeptycki , ; Mateos , ).…”

First record of Acrocyrtus Yosii, 1959 (Collemobla, Entomobryidae) from Chinese mainland

“…species and questioned the reliability of dental tubercle. Later, Soto-Adames (2000) made a phylogenetic analysis of Neotropical members of the genus, disagreeing with the previous conclusion and considering that this character has phylogenetic information useful in defining Yoshii’s subgenera; he also suggested that dental tubercle should be used in combination with other characters. Considering the availability of this character in most literature descriptions and how easily it can be observed in practice, we considered that its use at generic level is relevant.…”