Identification, sexual dimorphism, and allometric effects of three psyllid species of the genus Psyllopsis by geometric morphometric analysis (Hemiptera, Liviidae)

Abstract

Jumping plant lice (Hemiptera: Psylloidea) are considered important vectors of plant diseases and also economically important pests in agriculture and forest ecosystems. Three psyllid species Psyllopsis repens Loginova, 1963, Psyllopsis securicola Loginova, 1963, and Psyllopsis machinosus Loginova, 1963 associated with the ash tree Fraxinus are morphologically very similar. So far, their distinction has been possible only by comparing their male and female genitalia. In this research, forewing shape and size characteristics, sexual dimorphism and their allometric effects, using geometric morphometric analysis, were examined for identification purposes. The results showed significant differences in wing shape and size between the species studied. Based on the results, two species P. machinosus and P. securicola can be differentiated with the vein M1+2, as in P. securicola the vein M1+2 is located between Rs and M3+4 veins, but the vein M1+2 is closer to the vein M3+4 in P. machinosus; also, P. repens can be differentiated from the two species P. machinosus and P. securicola by vein M. Hence, the veins M1+2, M3+4, Rs and M were the most important wing characters for discrimination of the three species, especially in the field. The analysis also showed significant differences in wing shape and size between male and female of the three species, and the allometric analysis showed that significant shape differences still remain in constant size in P. machinosus and P. repens. Geometric changes in the forewings of both sexes for the three species are illustrated.

Molecular and morphometric identification of pistachio psyllids with niche modeling ofAgonoscena pistaciae(Hemiptera: Aphalaridae)

“…Sexual dimorphism in the wing shape is also known from other psyllids, such as two species associated with ash, viz. Psyllopsis machinosus Loginova and P. repens Loginova (Shamsi Gushki et al ., 2018). The more elongate forewings in the females of A. pegani may have better flight properties helping an efficient dispersal in search of new food sources.…”

“…In their study of three Psyllopsis species using geometric morphometrics, Shamsi Gushki et al . (2018) showed that the best characters to separate the three species are found in the apical half of the forewing, related to the veins Rs, M, M 1+2 and M 3+4 . Similar results were obtained in the present study, where the differences concern mainly vein Rs as well as the distances between landmark 7 to fore and hind margin, and between landmarks 11 to 6 and 1.…”

“…In geometric morphometrics, prior to the analysis of shape, the non-shape variation must be removed from the analysis and then graphical illustrations of the shape can be generated. Although most studies have focused on separating populations within a species, some have analyzed morphological similarities and differences between species (Gómez et al ., 2014; Mitrovski-Bogdanović et al ., 2014; Shamsi Gushki et al ., 2018).…”

Sexual size and shape dimorphism in Brachydesmus troglobius Daday, 1889 (Diplopoda, Polydesmida)

“…The GM approach has been widely used to describe intersexual differences of morphological traits in arthropods (Benítez 2013;Fernández-Montraveta and Marugán-Lobón 2017;Gushki et al 2018;Vesović et al 2019). In millipedes, intersexual morphological differences were previously described by Ilić et al (2019) using the GM technique.…”

Molecular, morphometric and digital automated identification of three Diaphorina species (Hemiptera: Liviidae)

“…Morphometrics is a useful method for analyzing shape and addressing a wide range of questions including evaluating phenetic differences between taxa (e.g., Burckhardt and Basset, 2000; Serbina et al ., 2015; Serbina and Mennecart, 2018; Shamsi Gushki et al ., 2018; Lashkari et al ., 2020). In geometric morphometrics, the shape is usually conceptualized and has been defined as those components of form which remain after removing the size (Kendall, 1977; MacLeod, 2017).…”