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1. Morphometric analysis of European species of the genus Aphis (Sternorrhyncha: Aphididae) inhabiting Ribes

Creator:
Rakauskas, Rimantas
Type:
article, model:article, and TEXT
Subject:
Aphididae, Aphis grossulariae, A. schneideri, A. triglochinis, morphometry, systematics, and currant aphids
Language:
English
Description:
A review of the literary data on the life cycles and host plant relationships of Aphis grossulariae Kaltenbach, A. schneideri (Börner) and A. triglochinis Theobald is presented. Morphometric analysis of the three species revealed insufficient discriminative value of the majority of characters commonly used in the keys. A modified key to fundatrices, apterous and alate viviparous females, gynoparous and oviparous females and males is presented.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Natural hybridisation between Aphis grossulariae and Aphis schneideri: morphological evidence (Sternorrhyncha: Aphididae)

Creator:
Rakauskas, Rimantas
Type:
article, model:article, and TEXT
Subject:
Aphididae, Aphis grossulariae, A. schneideri, hybridisation, systematics, and currant aphids
Language:
English
Description:
Morphometric analysis of 176 natural samples of A. grossulariae Kaltenbach, 1843 and A. schneideri (Börner, 1940) was performed, using 308 alate and 750 apterous viviparous females from 25 countries altogether. Morphologically intermediate specimens of presumably hybrid origin were noticed in 63 (35.79%) samples, comprising 12.67% of all apterous and 4.87% of all alate viviparae studied. 31 sample originating from 11 countries had 50% or more intermediate specimens of one or both morphs. "Rich" samples (having 4 or more specimens of the same morph) with the prevailing numbers of hybrid morphotypes were from the Netherlands, Russia (Moscow and Stavropol regions), Moldova, Turkey (Ankara) and Tajikistan (Dushanbe). Present data are discussed in the context of possible natural hybridisation between A. grossulariae and A. schneideri (see also Rakauskas, 1999a, 1999b). Canonical discrimination functions are being advocated as more powerful tools for separating between the two species when compared with single morphological characters or ratios commonly used in the keys.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public