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Fly honeysuckle aphid, Fennel aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
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.
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).
Three images above by permission, copyright Claude Pilon, all rights reserved.
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 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:
Hyadaphis foeniculi has been recorded from 16 Lonicera species, and (occasionally) on several Symphoricarpos species.