Hyadaphis foeniculi Passerini Homoptera Aphididae
Natural History
Distribution. Coriander aphid is found in the Mediterranean regions of Europe and Africa and east to central and southern Asia. It was first found in North America in 1997, in Florida. Honeysuckle aphid has a similar Eurasian origin, but is now cosmopolitan, having invaded North and South America, Australia, New Zealand, and southern Africa. It invaded North America in 1900s or earlier, as it was known from California and Connecticut before 1910. Honeysuckle aphid is suspected of being a complex of species.
Host Plants. These species cause damage by infesting Umbelliferae, including such vegetables as carrot, celery, fennel, parsley, and parsnip, but also spices such as caraway, Carum carvi; cumin, Cuminum cyminum; dill, Anthum graveolens; and sweet cumin, Pimpenella anisum. Coriander aphid, but not honeysuckle aphid, affects coriander. These food crops are summer, or secondary, hosts. Alternate secondary hosts include water parsnip, Berula erecta; water hemlock, Cicuta sp.; poison hemlock, Conium maculatum; hemlock parsley, Conioselinum chinense; wild chervil, Cryptotaenia canadensis; and cow parsnip, Heracleum sp. The primary host of coriander aphid is unknown, but for honeysuckle aphid it is, as its common name suggests, honeysuckle. Various honeysuckle species are suitable, including Lonicera caprifolium, L. ciliosa, L. etrusca, L. japonica, L. periclymenum, and L. xylosteum. A common alternate primary host is snowberry, Sym-phoricarpos sp.
Natural Enemies. The natural enemies of these aphids are not well-documented, but likely they are similar to those of other leaf-feeding aphids such as green peach aphid, Myzus persicae (Sulzer). The wasp parasitoids known to attack honeysuckle aphid are Aphidius salicis Haliday, Diaeretiella rapae (M'Intosh), and Ephedrus persicae Froggott (all Hymenoptera: Bra-conidae).
Life Cycle and Description. These Hyadaphis spp. seem quite similar in appearance and biology, though as noted earlier, the primary host of coriander aphid is unknown. Honeysuckle aphid occurs on both summer and winter hosts throughout the summer months in Colorado. Sexual forms are found on the summer hosts and winter hosts in the autumn. The following description is based on honeysuckle aphid.
- The eggs initially are greenish, but soon turn black. The elliptical eggs measure about 0.51 mm long and 0.22 mm wide. They are deposited on the primary host.
- The female developed from the overwintering egg is pale-yellow with greenish splotches on the abdomen and often orange around the base of the cornicles. The legs, antennae, and cornicles are darker distally. The body length is about 1.5 mm. Wingless (apterous) parthenogenetically reproducing summer adults are greenish or grayish-green, and dusted with white, waxy particles. The abdomen near the base of the cornicles is darker. The antennae, legs, and cornicles are black. These aphids measure about 1.5-2.0 mm long. In the winged (alate) parthenogenetic form, the head and thorax are dark green. The abdomen is green with mottled areas of darker green, and with dark patches laterally and at the base of each cornicle. The base of the cornicles and the distal portions of the legs are dark. The wings are transparent though the veins are dusky-brown. The alatae measure only about 1.3-1.5 mm long. The female is yellowish with a brownish head, the appendages dusky. Her body length is 0.84-1.15 mm. The male is similar to the winged alatae in appearance, though perhaps a bit darker and slightly smaller is size.
Honeysuckle aphid was described by Essig (1938), Palmer (1952), Cottier (1953), Bodenheimer and Swir-ski (1957), and Blackman and Eastop (1984). Coriander aphid was treated by Bodenheimer and Swirski (1957) and Blackman and Eastop (1984); the latter publication included a key to differentiate these species.
Damage
These aphids contaminate the foliage, rendering it unmarketable. They may also build to particularly high densities on flower heads. Although honeysuckle aphid attains high densities on honeysuckle, it is not the species responsible for the witches broom deformities that plague honeysuckle in northern areas; this deformity is generally caused by Hyadaphis tataricae (Aizenberg) (Voegtlin, 1984). Honeysuckle aphid is capable of transmitting over 20 plant viruses, including celery crinkle leaf mosaic, celery mosaic, and celery leaf spot. Although coriander aphid is not a known vector of plant viruses, as yet it is poorly studied.
Management
These are generally minor pests which are suppressed, if necessary, by foliar application of insecti cides. Care should be taken to treat the underside of the foliage.
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