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Aphididae : Eriosomatinae : Grylloprociphilus
 

 

Genus Grylloprociphilus

Beech blight aphids

On this page: Grylloprociphilus imbricator

Grylloprociphilus [Pemphigini]

Grylloprociphilus aphids form large waxy colonies on beech trees. The antennae are 6-segmented, bearing oval, cilated secondary rhinaria. The fore wings have a simple media vein. The hind wings have the media and cubitus originating near the same point. The metafemora (= hind femora) on the sexuparae are distinctly larger than the pro- or mesofemora. The cauda is rounded and indistinct.

Grylloprociphilus differs from Pemphigus, Prociphilus, and Stagona in having the metafemora enlarged. It differs from Pemphigus in having more setae on the apical rostral segment (RIV+V) and in having secondary rhinaria with long cilia. Grylloprociphilus differs from Prociphilus and Stagona in having spine-like setae at the apex of the tibiae.

There is only one species in the genus Grylloprociphilus, Grylloprociphilus imbricator, which lives in North America and host alternates between American beech (Fagus grandifolia) as the primary host and the roots of swamp cypress (Taxodium distichum) as the secondary host. Smith and Pepper (1968) provided a diagnosis of the new genus, and described the new species (originally as Grylloprociphilus frosti).

 

Grylloprociphilus imbricator (beech blight aphid)

The aphids that develop from overwintering eggs of Grylloprociphilus imbricator on American beech (known as fundatrices, not pictured) are approximately 5-6 mm long, and have been said to superficially resemble a termite queen. They have 4-segmented antennae and circular groups of wax pore plates on all segments. These circular groups have large central facets surrounded by very much smaller marginal ones. There are no siphunculi. Each beech blight aphid fundatrix produces thousands of nymphs (see first two pictures below) which often cover the fundatrix, obscuring her from view.

All three images above copyright Katja Schulz under a Creative Commons License.

All Grylloprociphilus imbricator adults are winged. The offspring of a Grylloprociphilus imbricator fundatrix all mature to winged aphids (alatae), one of which is shown in the third picture above. The alatae have oval secondary rhinaria on antennal segments III-V or III-VI. The forewing of the alate has an unbranched media vein, and a broadly rounded cauda. First instars on the secondary host have thickened hind femora.

Grylloprociphilus imbricator host alternates between American beech (Fagus grandifolia) as the primary host and the roots of swamp cypress (Taxodium distichum) as the secondary host. In spring the fundatrices on beech give rise to large colonies with flocculent wax, which can persist and grow through the summer and autumn. Some of the alatae produced on beech migrate to Taxodium roots, where apterae can be found throughout the year. Sexuparae return to beech in November-February where they produce the sexual forms. Grylloprociphilus imbricator is found in eastern states of the USA.

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Acknowledgements

We have used the species account of Smith & Pepper (1968) together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections as the source for the (summarized) taxonomic information we have presented. 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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References

  • Smith, C.F. & Pepper, J.O. (1968). Grylloprociphilus frosti, new genus, new species, from the eastern United States (Homoptera: Aphididae). Proceedings of the Entomological Society of Washington 70(1), 57-59. Full text