Research Article |
Corresponding author: Mariusz Kanturski ( kanturski.m@gmail.com ) Academic editor: Dominique Zimmermann
© 2014 Mariusz Kanturski, Karina Wieczorek.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kanturski M, Wieczorek K (2014) Systematic position of Eulachnus cembrae Börner with description of hitherto unknown sexual morphs of E. pumilae Inouye (Hemiptera, Aphididae, Lachninae). Deutsche Entomologische Zeitschrift 61(2): 123-132. https://doi.org/10.3897/dez.61.8048
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The identity of Eulachnus cembrae Börner, 1950, stat. rev. from Europe, treated as a synonym of E. pumilae Inouye, 1939 from East Asia is clarified based on characters of sexual morphs. The oviparous female and alate male forms of E. pumilae are described and figured in detail for the first time and the poorly known sexual forms of E. cembrae are redescribed and figured in detail as well. Sexual morphs of the two similar species are compared, and significant differences clearly distinguishing those species are presented. A key to the identification of oviparous females and males of E. cembrae and E. pumilae as well as notes on host plants and distribution of these species are provided. The status of E. pumilae in the European aphid-fauna is clarified. Morphological characters of the sexual generation that may be useful for species identification are discussed.
Aphids, Pinus , sexual generation, species identity
The Palaearctic genus Eulachnus Del Guercio, 1909 comprises about 13–18 species of small, narrow-bodied aphids, of which about 12 are known from Europe. They live often singly or in small colonies on the needles of Pinus spp., are hidden while feeding and become very active when disturbed (
E. pumilae was described by
The descriptions of E. pumilae and E. cembrae were based on characters of the viviparous generation, although there were also sexual morphs in the type material of
The aim of this paper is to define the taxonomic status of these two species by morphological and biometric examination of their sexual morphs, especially sexual forms of E. cembrae from the type material. On the basis of the material deposited in the Natural History Museum, London (UK), a description of sexual forms of E. pumilae is provided as well as a redescription of the sexual generation of E. cembrae. Moreover, the role of the characters of the sexual generation is highlighted, especially the underestimated and rather rarely used features of the male genitalia.
E. pumilae. One oviparous female, one alate male, SOUTH KOREA, Seoul, 03.XI.1971, Pinus koraiensis, BM 1984-340, 688g, Paik leg. BMNH.
E. cembrae. One oviparous female, one alate male (from type material), AUSTRIA: East Alps, 21.VIII.1942, Pinus cembra, 1/22, Franz leg. DEIC; two oviparous females, POLAND: Tatra Mountains, Zbocze Żabiego, 07.IX.1977, P. cembra, R2046 4815, H. Szelegiewicz leg. ZMPA; one oviparous female, SWITZERLAND: Valais, Brüchen, 16.X.1985, P. cembra, 7042:10, Bergersen leg. MZLU; one alate male, two oviparous females, Les Plans sur Bex, 12.IX.1966, P. cembra, BM 1984-340 470, D. Hille Ris Lambers leg. BMNH; two oviparous females, one alate male, SLOVAKIA: High Tatra Mountains, Grúnik, 1.IX.1949, P. cembra, BM 1952-537, V. Pašek leg. BMNH; two oviparous females, FRANCE: Ravin de Molières, Mercantour A. M., X.1993, P. cembra, 22025, L. Dalstein leg., one alate male, P. cembra, 22026, L. Dalstein leg., three oviparous females, Risoul 1900 m, (Hautes Alpes), 16.X.1986, P. cembra, 22023, G. Remaudière leg., three oviparous females, P. cembra, 22024 G. Remaudière leg. all MNHN.
The specimens were examined using the light microscope Nikon Ni-U and were photographed with a Nikon DS-Fi2 camera. Drawings were made with a camera lucida. For each of the drawings a magnified view is provided. Measurements are given in mm (Table
Eulachnus pumilae – oviparous female: (a) general view, (b) antennal segments I–IV, (c) antennal segments V and VI, (d) apical segment of rostrum, (e) hind tibia, (f) hind tarsus with HT I parts lengths: b – basal length, d – dorsal length, v –ventral length, i – intersegmental length. Alate male: (g) head, (h) antennal segments I–IV, (i) antennal segments V and VI, (j) apical segment of rostrum, (k) hind tarsus, (l) abdomen.
Measurements (in mm) of oviparous female (n = 1), alate male (n = 1) of Eulachnus pumilae and oviparous females (n = 15) alate males (n = 3) of E. cembrae.
Character | Oviparous females | Alate males | ||
---|---|---|---|---|
E. pumilae | E. cembrae | E. pumilae | E. cembrae | |
Body length | 3.50 | 2.62–3.25 | 2.95 | 2.7 |
Maximal width | 1.37 | 0.90–1.32 | 0.90 | 0.75–0.92 |
Head width | 0.52 | 0.46–0.68 | 0.54 | 0.52 |
Antennae length | 1.32–1.38 | 1.48–1.67 | 0.69–0.70 | 2.11–2.20 |
Ant. segm. III | 0.41–0.42 | 0.48–0.54 | 0.70–0.71 | 0.69–0.74 |
Ant. segm. IV | 0.25 | 0.26–0.28 | 0.41–0.45 | 0.36–0.43 |
Ant. segm. V | 0.26–0.27 | 0.30–0.34 | 0.41–0.42 | 0.45–0.49 |
Ant. segm. VI | 0.24 | 0.26–0.28 | 0.27–0.29 | 0.33–0.35 |
Ant. segm. VIa | 0.19–0.20 | 0.22–0.24 | 0.23–0.25 | 0.27–0.30 |
Ant. segm. VIb | 0.04–0.05 | 0.04–0.05 | 0.04 | 0.05–0.06 |
Hind femora | 1.15–1.20 | 1.10 –1.27 | 1.15–1.17 | 1.22–1.25 |
Hind tibiae | 1.75–1.80 | 1.67–1.97 | 2.02–2.05 | 1.95–2.05 |
HT I basal length | 0.03 | 0.03–0.04 | 0.02– 0.03 | 0.03 |
HT I dorsal length | 0.08 | 0.10–0.12 | 0.10 | 0.11–0.12 |
HT I ventral length | 0.12 | 0.14–0.16 | 0.13 | 0.14–0.15 |
HT I intersegmental length | 0.05 | 0.04–0.05 | 0.04 | 0.04–0.05 |
HT II | 0.20 | 0.24–0.28 | 0.23 | 0.25–0.28 |
ARS | 0.09 | 0.09–0.10 | 0.10 | 0.09–0.10 |
Siphuncular sclerite | 0.08–0.09 | 0.07–0.10 | 0.06 | 0.06–0.08 |
Siphuncular pore | 0.03–0.04 | 0.03–0.04 | 0.03 | 0.03 |
Fore wings length | – | – | 3.12–3.25 | 3.12–3.40 |
Subgenital fig length | 0.25 | 0.13–0.15 | – | – |
Subgenital fig width | 0.40 | 0.33–0.37 | – | – |
Oviparous female (Fig.
Main morphological differences between oviparous females of E. pumilae and E. cembrae AL–antennae length, BL–body length, ANT IV–antennal segment IV length, ANT III – ant. segm. III length, HT I bL–first segment of hind tarsus basal length, HT I dL–HT I dorsal length, HT I iL–HT I intersegmental length, HT I vL– HT I ventral length ARS–apical segment of rostrum, HT II–second segment of hind tarsus length.
Character | E. pumilae | E. cembrae |
---|---|---|
AL/BL | 0.39–0.40 | 0.49–0.57 |
ANT IV/ANT III | 0.59–0.61 | 0.38–0.53 |
HT I bL/HT I dL | 0.38–0.43 | 0.30–0.33 |
HT I dL/HT I iL | 1.45–1.53 | 2.10–3.00 |
HT I bl/HT I vL | 0.25–0.28 | 0.23–0.24 |
ARS/ANT III | 0.21–0.22 | 0.18–0.20 |
ARS/HT II | 0.42–0.45 | 0.35–0.41 |
Pseudosensoria | 100–105 | 32–58 |
ARS accessory setae | 2 | 0 |
Alate male (Figs
Main morphological differences between alate males of E. pumilae and E. cembrae. AL–antennae length, BL–body length, Ant. segm. VIb–antennal segment VI terminal process length, Ant. segm. VIa–ant. segm. VI base length, Ant. segm VI–ant. segm. VI length, ANT III–ant. segm. III length, ARS–apical segment of rostrum, HT II–second segment of hind tarsus length, R III, IV, VI–number of secondary rhinaria on ant. segm. III, IV and VI.
Character | E. pumilae | E. cembrae |
---|---|---|
AL/BL | 0.69–0.70 | 0.78–0.81 |
Ant. segm. VIb/ant. segm. VIa | 0.16–0.17 | 0.19–0.24 |
ANT VI/ANT III | 0.38–0.41 | 0.45–0.51 |
ARS/HT II | 0.43–0.45 | 0.32–0.40 |
ARS/ANT VI | 0.34–0.37 | 0.27–0.29 |
HT II/ANT III | 0.31–0.32 | 0.35–0.38 |
R III | 125–136 | 80–120 |
R IV | 55–64 | 29–42 |
R VI | 11–14 | 4–10 |
ARS accessory setae | 2 | 0 |
Pinus koraiensis (
India (
Oviparous female (Fig.
Eulachnus cembrae – oviparous female: (a) general view, (b) antennal segments I–IV, (c) antennal segments V and VI, (d) apical segment of rostrum, (e) hind tibia, (f) hind tarsus. Alate male: (g) head, (h) antennal segments I–IV, (i) antennal segments V and VI, (j) apical segment of rostrum, (k) hind tarsus, (l) abdomen.
Alate male (Figs
External male genitalia of Eulachnus pumilae (a, c) and E. cembrae (b, d): bp –basal part of phallus with sclerotized arms consists of short proximal (solid arrow), long distal (dotted arrow) part and upper half-circle-shaped structure that surrounds the genital area (arrow-head), P – parameres, C – cauda.
Pinus cembra (
Austria (
Aphids are a group of hemipterans whose classification is still controversial, as evidenced by uncertainties about the identity of many species in this group of insects (
The genus Eulachnus as a whole is an example for a group of aphids which needs revision, because many of the characters that have been used in species discrimination are subject to environmental influences (
According to Fauna Europaea (
Separateness of these two similar species is also reflected by their biology: E. cembrae is a European species, recorded mostly from locations in central European mountain ranges (the Alps, the Carpathians) (
Detailed morphological and biometric analysis of the sexual morphs of the studied species, including type material of E. cembrae designated by Börner, supported by biological data, definitely distinguish the studied species as separate taxa.
1. | Ant. segm. VI/ant. segm. III 0.38–0.53. ARS without accessory setae. Hind tibiae with 32-58 pseudosensoria | E. cembrae Börner |
– | Ant. segm. VI/ant. segm. III 0.58–0.61. ARS with two accessory setae. Hind tibiae with 100-105 pseudosensoria | E. pumilae Inouye |
1. | Antennae length/body length 0.78–0.81. ARS without accessory setae. Ant. segm. IV with 29-42 accessory rhinaria | E. cembrae Börner |
– | Antennae length/body length 0.69–0.71. ARS with two accessory setae. Ant. segm. IV with 55-64 accessory rhinaria | E. pumilae Inouye |
The authors would like to express their gratitude to Diana M. Percy, Paul A. Brown (BMNH, London, UK), Roy Danielsson (ZMLU, Lund, Sweden), Thomas Thieme (DEI, BTL Bio-Test Labor GmbH Sagerheide, Germany), the late prof. Georges Remaudière, Danièle Matile-Ferrero and Thierry Bourgoin (MNHM, Paris, France) for their kind help and for providing the opportunity to examine the material. We would like to thank Łukasz Junkiert (UŚ, Katowice, Poland) for preparing the drawings. We would also like to thank Roger L. Blackman (BMNH, London, UK) for all comments and linguistic improvement of the manuscript. We are very grateful to Andrew Polaszek (BMNH), the anonymous Reviewer and the Editor for all valuable suggestions that have improved the manuscript. Special thanks goes to Sabine Gaal for the linguistic assistance.
We wish to express our gratitude to the Museum für Naturkunde (Berlin, Germany) for waiving the author’s fees.
This research was supported by the „Faculty for Biology and Environmental Protection, University of Silesia Grant for Young Scientists 2013.