Southampton Island (Richards 1963. of interest that A. svalbardicum and the two members of the genus founi gen, are endemic. A. svalbardicum distinguished ...
Identification of three previously unknown morphs of Acyrthosiphon svalbardicum Heikinheimo (Hemiptera: Aphididae) on Spitsbergen A . T. S T R A T H D E E , J . S. B A L E , I . D. H O D K I N S O N , W. C . B L O C K , N . R . W E B B , and S. J . C O U L S O N
Ent. scand.
Strathdee, A . T. et al.: Identification of three previously unknown morphs of Acyrthosiphon svalbardicum Heikinheimo (Hemiptera: Aphididae) on Spitsbergen. Ent. scand. 24: 43-47. Copenhagen, Denmark. April 1993. ISSN 0013-8711. Descriptions are given of the previously unknown fundatrix, oviparous female and apterous male of Acyrthosiphon svalbardicum Heikinheimo. The host plant is Dryas octopetala L . The systematic relationship is discussed. A. T. Strathdee & J . S. Bale, School of Biological Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. I . D. Hodkinson & S. J . Coulson, Division of Biological and Earth Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK. W. C. Block, British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge, CB3 OET, UK. N. R. Webb, Furzebrook Research Station, NERC, Institute of Terrestrial Ecology, Wareham, Dorset, BH20 5AS, UK.
Introduction During a visit to Ny-Alesund, Spitsbergen in the summer of 1991 a large number of aphids were collected from mountain avens (Dryas octopetala ssp. octopetala L . ) and have since been identified as Acyrthosiphon svalbardicum Heikinheimo (Blackman, det.). This aphid species was originally described from a single apterous, vivipara (Heikinheimo 1968). This paper describes more material, including the previously unknown fundatrix, oviparous female and apterous male. No alate morphs were found. A l l samples were field collected. Fundatrices were collected in early July, viviparae, oviparae and males in early August.
Descriptions of morphs Fundatrix (Fig. 1). - Similar to vivipara but body more spherical. Third antennal segment comparatively longer than vivipara. I n common with later morphs there is a high degree of colour polymorphism in field collected specimens including pink, brown, green and yellow. Length measurements €> Entomologica scandinavica (Grp 5)
(mm) for key morphological features are given in Table 1. Apterous vivipara (Fig. 2). - Details for this morph are as described by Heikinheimo (1968). Measurements as above are given in Table 2. Ovipara (Fig. 3). - The ovipara is difficult to distinguish from the vivipara. The antennae are slightly longer than in the vivipara but the absence of unborn nymphs (which are visible through the cuticle of the vivipara) is the most reliable distinguishing feature. Unlike other Arctic Acyrthosiphon species the terminal process of the antennae is of similar length to that of the vivipara. Comparative measurements (mm) are given in Table 3. Male (Fig. 4). - Body narrow and cigar shaped. A n tennae and femora comparatively longer than in asexual females. Genitalia normal. Measurements (mm) are given in Table 4. Host plant. - Acyrthosiphon svalbardicum was found exclusively on Dryas octopetala. There was
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ENT. SCAND. VOL. 24:1 (1993)
Figs .-4. Acyrthosiphon svalbardicum Heikinheimo: (1) funda.rix; (2) vivipara; (3) ovipara; (4) male. Scale = 0.5 mm.
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Table 1. Measurements (mm) of fundatrices of Acyrthosiphon svalbardicum Heikinheimo. Aphid Number
Body
Antenna
1 2 3 4 5 6 7 8 9 10 Mean ±SE.
1 27 1.74 1.36 1.37 1.67 1.23 1.16 1.23 1.11 1.42 1.36 ±0.07
0.958 0.993 0.853 1.035 1.050 0.852 0.976 0.919 0.911 0.893 0.944 ±0.022
Antennal Segments 3 0.256 0.256 0.234 0.259 0.302 0.192 0.238 0.215 0.244 0.202 0.240 ±0.010
4 0.149 0.162 0.156 0.189 0.199 0.130 0.170 0.179 0.127 0.132 0.160 ±0.007
5 0.149 0.170 0.149 0.171 0.176 0.173 0.172 0.170 0.130 0.149 0.160 ±0.004
6a 0.127 0.149 0.127 0.138 0.132 0.145 0.138 0.147 0.149 0.130 0.138 ±0.002
6b 0.170 0.170 0.127 0.179 0.134 0.149 0.147 0.134 0.154 0.155 0.152 ±0.005
Siphunculus
Cauda
0.28 0.30 0.27 0.26 0.25 0.25 0.22 0.22 0.22 0.29 0.26 ±0.009
0.17 0.16 0.16 0.16 0.17 0.22 0 17 0.20 0.15 0.14 0.17 ±0.007
Tibia
Femora F 0.36 0.34 0.38 0.37 0.36 0.38 0.34 0.36 0.34 0.34 0.36 ±0.005
M 0.40 0.38 0.43 0.41 0.44 0.39 0.37 0.40 0.36 0.38 0.40 ±0.008
H 0.44 0.53 048 0.43 0.51 0.44 0.44 0.48 0.40 0.43 0.46 ±0.013
F 0.47 0.54 0.44 0.52 0.52 0.47 0.43 0.57 0.47 0.51 0.49 ±0.014
M 0.53 0.58 0.51 0.62 0.56 0.50 0.49 0.59 0.55 0.55 0.55 ±0.013
Rostrum apical segment H 0.77 0.59 0.69 0.68 0.69 0.74 0.64 0.66 0.72 0.70 0.69 ±0.016
0.096 0.091 0.085 0.094 0.089 0.086 0.077 0.104 0.094 0 096 0.091 ±0.002
Table 2. Measurements (mm) of apterous viviparae of Acyrthosiphon svalbardicum Heikinheimo. Aphid Number
Body
Antenna
1 2 3 4 5 6 7 8 9 10 Mean ±SE
1.30 1.25 1.22 1.35 1.18 1.28 1.47 1.37 1.34 1.35 1.31 ±0.03
0.948 0.883 0.824 0.910 0.781 0.959 0.998 0.874 0.835 0 889 0.890 ±0.021
Antennal Segments 3 0.192 0.171 0.190 0.202 0.154 0.193 0.217 0.192 0.152 0.197 0.186 ±0.007
4 0.149 0.164 0.120 0.135 0.118 0.145 0.182 0.133 0.121 0.137 0.140 ±0.006
5 0.173 0.147 0.144 0.168 0.135 0.147 0.169 0.145 0.152 0.149 0.153 ±0.003
6a 0 118 0.120 0.108 0.106 0.116 0.149 0.123 0.118 0.120 0.127 0.121 ±0.004
6b 0.171 0.161 0.142 0.154 0.137 0.205 0.171 0.166 0.169 0.163 0.164 ±0.006
Siphunculus
Cauda
0.29 0.25 0.23 0.27. 0.23 0.24 029 0.26 024 0.22 025 ±0.02
0.16 0.15 0.13 0.17 0.13 0.21 0.22 0.14 0.15 0 16 0.16 ±0.01
Femora F 0.38 0.30 0 31 0.33 0.28 0.30 0.38 0.31 0.29 0.29 0.32 10.011
M 0.43 0.31 0.33 0.39 0.31 0.36 0.41 0.34 0.33 0.35 0.36 ±0.013
Tibia H 0.55 0.47 0.43 0.52 039 0.43 0.48 0.38 0.37 0.39 0.44 10.10
F 0.48 0.46 0.43 0.42 0.39 0.41 0.58 0.46 0.48 0.47 0.46 ±0.017
M 0.66 0.49 0.48 0.49 0.47 0.57 0.61 0.48 0.54 0.50 0.53 ±0.020
Rostrum apical segment H 0.78 0.58 0.53 0.67 0.53 0.69 0.77 0.65 0.63 0 60 0.64 ±0.028
0.133 0.142 0.125 0.122 0.111 0.135 0.132 0.128 0.145 0.127 0.130 ±0.003
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ENT. SCAND. VOL. 24:1 (1993)
E H t SCAND. VOL. 24:1 (1993) -o evidence that other plants found hosts of this species. Locality. gen.
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As previously observed by Heiki Acyrthosiphon calvulum Ossianni brevicorne Hille Ris Lambers are ver rardicum. It is intriguing that and A. svalbardicum share a comm but A. brevicorne has not been foun gen despite being present on the mainland (Ossiannilsson 1959), Swit 1972), Greenland (Hille Ris Lamb Southampton Island (Richards 1963 of interest that A. svalbardicum an the two members of the genus foun gen, are endemic. A. svalbardicum distinguished from other holarctic Acyrthosiphon-Metopolophium ge by the relatively short terminal proce nae, a feature common to all the m
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ENT. SCAND. VOL. 24:1 (1993) •o evidence that other plants found in this area are hosts o f this species. - S;.-Alesur.d. Kongsfjorden,
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Sjsamatic relationships rreviously observed by Heikinheimo (1968) Acyrthosiphon calvulum Ossiannilsson and A. brerkome Hille Ris Lambers are very similar to A. iwflWiiifii inn It is intriguing that A. brevicorne and A. svalbardicum share a common host plant, bat A. brevicorne has not been found on Spitsbergen despite being present on the Scandinavian •M«Btaiid(OssianTiilsson 1959), Switzerland (Meier 19~2|. Greenland (Hille Ris Lambers 1960) and 5 • .' ; Island i Richards 1963). Similarly it is : - ir.-.eres: :hat A. svalbardicum and A. calvulum, the two members of the genus found on Spitsbergen, are endemic A. svalbardicum can reliably be distinguished from other holarctic members of the Acynhosiphon-Metopolophium generic complex by the relatively short terminal process of the anten- at a feature common to all the morphs.
Revised manuscript accepted February 1993.
svalbardicum
47
Acknowledgements We thank Roger Blackman of the Natural History Museum, London for help with identification of the specimens and comments on the manuscript and P. J. Evernnet, M. Anderson, and D. Ruffles who assisted with photography. The work carried out was supported by grant GST/02/534 from the Arctic Terrestrial Ecology Special Topic Programme of the Natural Environment Research Council. References Heikinheimo, O. 1968. The aphid fauna of Spitzbergen. Annls ent. fenn. 34: 82-93. Hille Ris Lambers, D. 1960. Additions to the aphid fauna of Greenland. Meddr Gmnland 159: 1-7. Meier, W. 1972. Erganzungen zur Blattlausfauna der Schweiz I . (Homoptera, Aphididae). Mitt, schweiz. ent. Ges. 45: 1-30. Ossiannilsson, F. 1958. Acyrthosiphon calvulum, n. sp. A new aphid (Hem, Horn.) from Spitzbergen. Ent. Tidskr. 79: 66-68. - 1959. Contributions to the knowledge of Swedish aphids I I . List of species with find records and ecological notes. K. Lantbrukshogsk. Ann. 30: 435-464. Richards, W. R. 1963. The aphididae of the Canadian Arctic (Homoptera). Can. Ent. 95: 449-464.
