Hayhurstia atriplicis

Identification & Distribution:

Hayhurstia atriplicis live on orache (Atriplex) or goosefoot (Chenopodium) inside yellowish pseudogalls (see first picture below). The pseudogalls are formed by rolling the leaves upwards. Hayhurstia atriplicis apterae are green covered with a white wax powder (see picture below). Their siphunculi are very small and slightly swollen with a small flange, and are distinctly shorter than the finger-shaped cauda. The body length of an adult aptera of Hayhurstia atriplicis is 1.5-2.9 mm.

Micrographs of clarified mounts by permission of Roger Blackman, copyright AWP all rights reserved.

Hayhurstia atriplicis feeds on many different species of plants in the goosefoot family, especially Atriplex and Chenopodium. In temperate climates Hayhurstia atriplicis has a sexual stage in the life cycle overwintering as eggs, but there is no host alternation. It is found widely in Europe and Asia, north and central Africa, and in North and central America.

Biology & Ecology:

Moran & Whitham (1990) looked at the host-mediated interaction between Hayhurstia atriplicis, which feeds above ground where it forms leaf galls, and Pemphigus betae which feeds underground on roots. Although the two aphid species never encounter one another directly, they share a common resource, the phloem sap of their host. The authors obtained four major results:

First, the root-feeding aphid Pemphigus betae had no significant effects on its hosts. In contrast, leaf galling by Hayhurstia atriplicis (see picture below) significantly reduced both plant mass and seed set.

Second, competitive interactions between the herbivore species depended on the level of host resistance to leaf galling by Hayhurstia atriplicis. On susceptible plants, leaf-galling colonies of Hayhurstia atriplicis greatly reduced Pemphigus betae numbers but, on plants resistant to galling, Hayhurstia atriplicis colonies were smaller and did not affect Pemphigus betae infesting roots of the same hosts.

Third, the interaction was asymmetrical; although Hayhurstia atriplicis had a strong negative effect on Pemphigus betae, the latter showed no measurable effects on Hayhurstia atriplicis.

Fourth, resistance to leaf-galling aphids was not correlated with resistance to root-feeding aphids.

We have found parasitoid mummies of Hayhurstia atriplicis several times, but each time the parasitoids had already emerged (see empty mummies below).

In Europe Hayhurstia atriplicis, is commonly parasitized by two parasitoids, Diaeretiella rapae and Ephedrus nacheri. Stary & Gonzalez (1991) pointed out that since the aphid parasitoid association is perennial, and Chenopodium groves commonly occur both in farmland and urban environments, they represent reservoirs of useful parasitoids. Diaeretiella rapae in particular is known to have a number of aphid pests in its host range.

Other aphids on same host:

• Hayhurstia atriplicis has been recorded from 16 Atriplex species.

  Blackman & Eastop list 17 species of aphid as feeding on saltbush, orache (Atriplex species) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 10 as occurring in Britain (Show British list).

• Hayhurstia atriplicis has been recorded from about 15 Chenopodium species.

  Blackman & Eastop list 30 species of aphid as feeding on goosefoots (Chenopodium species) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 21 as occurring in Britain (Show British list).

Damage & Control:

There is some evidence that Hayhurstia atriplicis may play a role in the transmission of Potato virus Y (PVY) (Wyman et al., 2012) and Ethiopian Pepper Mottle Virus (EPMV) (Atsebeha et al., 2009). However, Hayhurstia atriplicis does act as reservoir for aphid parasitoids (see above), so its benefits may outweigh its harm.

Acknowledgements Our particular thanks to Roger Blackman for images of his clarified slide mounts. Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994) and Blackman & Eastop (2006) supplemented with Blackman (1974), Stroyan (1977), Stroyan (1984), Blackman & Eastop (1984), Heie (1980-1995), Dixon & Thieme (2007) and Blackman (2010). We fully acknowledge these authors 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).

Useful weblinks

References Atsebeha, S. et al. (2009). Diversity of aphids in the central rift valley of Ethiopia and their potential as vectors for Ethiopian Pepper Mottle Virus (EPMV). Journal of Entomology and Nematology 1(1), 1-6. Abstract Moran, N.A. & Whitham, T.G. (1990). Interspecific competition between root feeding and leaf-galling aphids mediated by host-plant resistance. Ecology 71(3), 1050-1058. Abstract Stary, P. & Gonzalez, D. (1991). The Chenopodium aphid, Hayhurstia atriplicis (L.) (Horn., Aphididae), a parasitoid reservoir and a source of biocontrol agents in pest management. Journal of Applied Entomology 111 (1-5), 243-248. Abstract Wyman, J. et al. (2012) . Winged aphids and Potato Virus Y transmission in Wisconsin. University of Wisconsin - Extension Archives 111 (1-5), 243-248. Abstract