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Aphidomorpha : Aphididae : Pterastheniinae
 

 

Subfamily Pterastheniinae

Biology and Morphology

On this page: Biology Morphology Genera

Biology

The Pterastheniinae is a small subfamily with 5 species in 2 genera (Neoantalus, Pterasthenia). The Neoantalus species differ from Pterasthenia in the absence of wax glands, and alatae having secondary rhinaria on antennal segments III-VI. Both genera are African and mainly associated with woody plants in the Fabaceae (= Leguminosae) such as Milletia, jointvetch (Aeschynomene) and Humularia. Little is known of their biology but some are thought to reproduce parthenogenetically all year. Pterasthenia matileae is attacked by a specific parasitoid, Trioxys pterastheniae. They are found in sub-Saharan Africa.

 

Morphology

Adult Pterastheniinae viviparae are alate or apterous. The legs and sometimes also the antennae are covered with fluffy wax secretions or waxy powdering; the aptera sometimes has stalk-like secretions on the dorsum. In apterae the eyes are compound with triommatidia. The head and pronotum are separated or nearly so. On the front of head there are small antennal tubercles. The fore-femora are enlarged and adapted for jumping, usually in both the apterous and alate morphs. The antennae have a very long terminal process, evenly tapering from base to apex, and with accessory sensoria scattered on either side of the primary rhinarium on antennal segment VI. The first tarsal segments have dorsal setae in alates and sometimes also in apterae; the second tarsal segments have ventral setae of normal lengths. The base of the second rostral segment is without wishbone-shaped stiffening. Wax gland pores are often present on the tibiae. There are no processes on the dorsum of the abdomen except for sometimes small marginal protuberances on the anterior tergites of the alate morph. In apterous morphs and nymphs the dorsal body setae are sometimes accompanied by small cribriform wax gland discs. The siphunculi are cone-shaped or rarely pore-like, and located on tergite VI or between V and VI. The knob of the cauda is egg-shaped or tapering to a slender point. The anal plate is bilobed.

Pterasthenia albata aptera, mount. By permission of Roger Blackman, copyright AWP all rights reserved.

In the alate morph a V-shaped epicranial suture is often developed. On the fore wing the pterostigma is truncate or pointed at apex or with a tendency to become short. The media is simple or with 1-2 branches. The hind wing is reduced in size, with or without an oblique vein. Oviparae are apterous, males alate. The ovipara has the anal segment normal as in vivipara, with 1 pair of subsiphuncular wax gland plates; pseudosensoria are mostly on the hind tibiae, but sometimes also on other tibiae. Some related fossil genera are known (e.g. Oligocallis).

Pterastheniinae Genera

Acknowledgements

We particularly thank Colin Favret and Roger Blackman, who have provided invaluable assistance. Most of the subfamily diagnoses have been taken from Heie & Wegierek (2009b), Quednau (1999, 2003, 2010) and Blackman & Eastop (2021), with additional material from Russell (1982),Stroyan (1977), Stroyan (1984) and many others listed in the references for these pages.

We also thank Roger Blackman for allowing us to reproduce his image, above. Note: Any images on pages that are not individually credited are copyright InfluentialPoints under a Creative Commons Attribution License.

Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).

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