Hyadaphis foeniculi (fly honeysuckle aphid) identification, images, ecology, control

Hyadaphis foeniculi apterae on their primary host are greyish-green or light green with the middle part of the dorsum darker green. Their colour is rather more variable on the secondary host, umbellifers (see two pictures below), and they often have reddish brown patches especially around the siphuncular bases. The legs and antennae of Hyadaphis foeniculi are dark. The prosternal sclerite is 1.4 to 2.6 times wider than long, often with a convex posterior margin (cf. Hyadaphis passerinii, which has the prosternal sclerite 2.2-3.6 times wider than long, with a straight posterior margin). Their siphunculi are black and slightly swollen and are 1.05-1.4 times as long as the cauda. The body length of adult Hyadaphis foeniculi apterae is 1.3 to 2.6 mm on the primary hosts, 1.4-2.0 mm on the secondary hosts.

Note: Some authorities only give Hyadaphis passerinii and Hyadaphis foeniculi subspecific status. The characteristics of some Hyadaphis foeniculi populations in southern England that we have found appear to be intermediate between Hyadaphis passerinii and Hyadaphis foeniculi. Hence we cannot be certain about the identification of aphids in the two pictures below.

Hyadaphis foeniculi (fly honeysuckle aphid) aptera and nymph on seed head of hemlock (Conium maculatum) at Rye Harbour, East Sussex on 13/7/14 at 12.04 h.

Three pictures below are of Hyadaphis foeniculi (identification confirmed) from Canada, on secondary hosts in the Apicaceae. The first shows image is an adult aptera on wild parsnip (Pastinaca sativa).

Hyadaphis foeniculi (fly honeysuckle aphid) adult aptera on Pastinaca sativa (panais sauvage, wild parsnip) at Coin rue Sherbrooke et 81ieme, Montreal, Quebec, Canada on 21/7/10; Claude Pilon

Hyadaphis foeniculi alate (see second picture above), also on wild parsnip, is similarly coloured to the aptera and has no dorsal sclerotization. There are often 1-4 secondary rhinaria on the fifth antennal segment. Immatures (see third picture above) shown on angelica (Angelica archangelica) share the same variation in colour as the adults.

The clarified slide mounts below are of adult viviparous female Hyadaphis foeniculi : wingless, and winged.

Hyadaphis foeniculi. Clarified slide mount of adult viviparous aptera.

Hyadaphis foeniculi host alternates with fly-honeysuckle (Lonicera xylosteum) or, more rarely, snowberry (Symphoricarpos) as its primary host. Infested leaves are curled upwards in spring. Hyadaphis foeniculi migrates to various Apiaceae where it forms large colonies on the stems, leaves and flowers. These secondary hosts include hemlock (Conium), fennel (Foeniculum) and parsnips (Pastinaca). The fly honeysuckle aphid is widespread in Europe, especially in the north, extending eastwards to Turkey and Iraq. Hyadaphis foeniculi is also found in North America and Brazil.

Other aphids on same host:

Primary hosts

Hyadaphis foeniculi has been recorded from 16 Lonicera species, and (occasionally) on several Symphoricarpos species.

Blackman & Eastop list 9 species of aphid as feeding on fly-honeysuckle (Lonicera xylosteum) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 3 as occurring in Britain (Show British list).

Secondary hosts

Blackman & Eastop list 18 species of aphid as feeding on hemlock or poison hemlock (Conium maculatum) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 14 as occurring in Britain (Show British list).
Blackman & Eastop list 21 species of aphid as feeding on fennel (Foeniculum vulgare) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 16 as occurring in Britain (Show British list).
Blackman & Eastop list 23 species of aphid as feeding on wild parsnip (Pastinaca sativa) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 18 as occurring in Britain (Show British list).

Acknowledgements

Our particular thanks to Roger Blackman for images of his clarified slide mounts. We are also grateful to Claude Pilon for pictures of Hyadaphis foeniculi in Canada (for more of her excellent pictures see).
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

Hyadaphis foeniculi

Fly honeysuckle aphid, Fennel aphid

Identification & Distribution

Other aphids on same host:

Primary hosts

Secondary hosts

Acknowledgements

Useful weblinks