Parapronematus, Baker, 1965

De VisK, Raf M. J., K, José Dantas Araujo Lacerda, de MoraesK, Gilberto J. & Ueckermann K, Edward A., 2025, Pronematinae (Trombidiformes: Iolinidae) from Brazil, with original and complementary descriptions of taxa as well as with a reappraisal of the subfamily and of Parapronematus, Acarologia 65 (2), pp. 331-372 : 347-351

Reappraisal of Parapronematus

Most of the descriptions of species of this group are rather incomplete. Several of them do not have measurements and none indicates the variability of measurements. Most do not provide scale bars in illustrations. Characters of doubtful value have been used to distinguish species while characters of recognizable value are not always considered. Although complementary descriptions should be done, in this work we could only redescribe P. geminus , as in most cases the museums in which they are deposited do not allow their shipment.

None of the descriptions mentions lyrifissures. However, in our specimens, lyrifissures could be seen in most males and all immatures, despite not always visible in adult females.

Similarly, striae are very fine and indistinct in part of the body of several species. We suppose that they are present but not always visible. In our specimens, digital augmentation shows striae in specimens where striae are not distinguishable under phase contrast microscopic

121: MZLQ 4404).

examinations at 1000 X. It seems that this characteristic is influenced by mounting conditions. We therefore do not consider this a reliable characteristic for distinguishing species based on publications of distinct authors (as used for the characterization of P. citri , e.g.).

As the species are not sclerotized, distances between setae are influenced by the state of the mite when mounted, mounting conditions, as the amount of medium used and the ′pressure′ on the specimens, the presence of folds, etc. These aspects will lead to inaccurate measurements of distance between setae. Thus, we also consider this characteristic inadequate to separate species.

Likewise, length of the dorsal setae on femora III and IV in relation to the width of the segment seems a characteristic of questionable value. We believe that the width or height of femora are also influenced by the mounting conditions. So, any parameter comparing the length of the dorsal setae with the width of the segment may be inaccurate and should preferably not be used to separate species. This type of problem seems of lesser importance in relating the length of eupathidia and length of tarsus I. Hence, in this publication the ratio between the lengths of tc″ζ and of tarsus I is taken into account in the separation of species.

The length of individual setae, even on the same species, can differ significantly, so relative length can also vary, for practical reasons. The tips of the setae can break off and that may be overlooked. We therefore recommend measuring setae of Pronematinae at 1000 X for higher confidence on measurements.

André (1979: 204) considered the description of a new genus based on a single specimen to be unadvisable, except when the specimen exhibits very special characteristics. We propose to extend this suggestion to the description of new species. For Phytoseiidae, Tixier (2012)

concluded that measurement of at least ten specimens is necessary to express variability reliably.

We, therefore, suggest describing new taxa only when several specimens are available, unless the specimen exhibits special characteristics assumed to be of lower variability.

The position of the solenidion on tarsus I is used as a distinctive character in the Parapronematus key of Gupta (2002). However, this is not always clearly presented in illustrations of different species.

The number of setae on tarsi III and IV varies between species, so it could be considered a reliable feature to separate species. However, in P. connarus n. sp., we found two specimens with five setae on tarsi III and IV instead of six in the majority of the specimens. This characteristic is not always clearly stated in the descriptions, and we see discrepancies between the text of descriptions and the respective illustrations (e.g. P. acaciae Baker, 1965 ) and in all descriptions but that of P. formosanus , leg figures are unclear or incomplete.

It is concluded that a revision of the whole genus is necessary, starting with a redescription of its type species and the creation of eventual new genera according to the generic concept of André (1980). Types of P. acaciae can only be studied in the museum where they are deposited. Thus, in this publication we selected characteristics that allow the separation of the species, although many uncertainties remain concerning other characteristics. A provisional re-characterization of Parapronematus is subsequently provided, based on what is available in the literature, the examination of the type specimens of the new species here described ( P.

connarus n. sp.) and the complementary description of P. geminus , provided in this publication.

Additionally, a discussion about the other species placed in the genus is presented, concerning their main characteristics and the limitation of the information available in the literature.