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Peach-potato aphid, Green peach aphidOn this page: Identification & Distribution Biology & Ecology Natural enemies Other aphids on the same host
Identification & Distribution
The apterae of Myzus persicae are generally yellowish-green, but vary from green to yellow to red (see pictures below). They are often darker in cold conditions. The antennae are 0.7-1.0 times the body length, reaching to the siphunculi. The antennal terminal process is usually longer than antennal segment III, 0.90-1.49 times its length (cf. Myzus certus and Myzus dianthicola, both of which usually have the terminal process shorter than antennal segment III). Their siphunculi are slightly swollen towards the darkened tips (cf. Myzus ornatus and Myzus lythri, which both have tapering siphunculi). The siphunculi are 1.9-2.5 times the length of the rather pointed cauda, and at least 0.82 times longer than antennal segment III (cf. Myzus ascalonicus and Myzus cymbalariae, which both have siphunculi less than 0.81 times longer than antennal segment III). The body length of Myzus persicae apterae is 1.2-2.3 mm.
The alate Myzus persicae (see first picture below) has a solid pigmented area occupying the mid-abdominal dorsum from segments 3 to 6, as well as further bars on adjoining segments. Immatures have no visible cauda and shorter siphunculi but otherwise resemble the adult apterae. The colony structure of Myzus persicae on secondary hosts is usually dispersed (see second picture below) (cf. Myzus antirrhinii, which forms large dense colonies).
The micrographs below show an aptera (note the slightly swollen, dark-tipped siphunculi) and an alate, both preserved in isopropyl alcohol.
Myzus persicae persicae may host alternate where its primary host - peach (Prunus persica) occurs. Eggs are laid on the primary host and spring colonies curl the young leaves of peach. However, most of the population overwinters as mobile stages on secondary hosts where it is a polyphagous generalist, feeding especially on herbaceous plants and brassicas. Myzus persicae is a major pest of many of its secondary hosts, including potatoes, sugar beet, lettuce, brassicas and legumes, mainly because it transmits a number of important plant viruses.
Only one subspecies of Myzus persicae is usually recognised, namely Myzus persicae nicotianae. This is a tobacco specialist, albeit it also occurs on a variety of other secondary hosts. In most of its range it is anholocyclic, but its primary host is still Prunus persica.
Biology & Ecology
An extensive review of the natural enemies of Myzus persicae was given by van Emden et al. (1969). Many species of parasitoids have been recorded attacking Myzus persicae, and they are now widely used for control purposes. The most commonly encountered parasitoids, at least in Europe, are given by INRA as Aphidius colemani, Aphidius ervi, Aphidius matricariae, Aphidius picipes, Binodoxys angelicae, Diaretiella rapae, Ephedrus cerasicola, Ephedrus persicae, Ephedrus plagiator, Lysiphlebus confusus, Lysiphlebus fabarum, Praon staryi and Praon volucre in the Aphidiidae, and Aphelinus abdominalis, Aphelinus asychis and Aphelinus mali in the Aphelinidae. Parasitoids of importance noted by CABI are Aphidius colemani, Aphidius matricariae, Trioxys similis and Trioxys angelicae in the Aphidiidae, and Aphelinus semiflavus in the Aphelinidae.
The two pictures below show the parasitoid, Aphelinus asychis, having parasitized Myzus persicae. The first shows the parasitoid emerging from the black aphid mummy, characteristic of aphelinid parasitoids. The second shows the adult Aphelinus with its wings expanded. Members of the Aphelinus species group can be discriminated by the colour of the abdomen, antennae and legs (Shirley et al., 2017).
Both images above copyright Jochem Kuhnen, all rights reserved
The identity of these Aphelinus asychis was confirmed by George Japoshvili in The Netherlands. Aphelinus is a genus of chalcidoid parasitoid wasps that has a long history of use in biological control programs against aphids.
The two pictures below show the mummies and adult of an unidentified Aphidiid parasitoid which we have found parasitizing Myzus persicae in Britain.
A similarly large number of species of predators has been observed attacking Myzus persicae. Amongst the Coccinellidae, Coccinella spp., Hippodamia spp. and Scymnus are highlighted by CABI. Important syrphid species include Episyrphus balteatus, Ischiodon scutellaris, Metasyrphus corollae and Scaeva pyrastri. Additional predators include larvae of Cecidomyiidae and Chamaemyiidae, as well as Anthocoridae and Miridae and larvae of the Chrysopidae.
In Britain we have found Cecidomyiid larva (see first picture below) to be the predominant predator in greenhouse environments.
Other aphids on same host:
Myzus persicae has been recorded on 33 species of the Prunus genus.
Myzus persicae has been recorded on 31 species of the Solanum genus.
Myzus persicae has been recorded on 3 species of the Beta genus (Beta bengalensis, Beta maritima, Beta vulgaris).
Myzus persicae has been recorded on 4 species of the Lactuca genus (Lactuca floridana, Lactuca sativa, Lactuca spicata, Lactuca serriola).
Myzus persicae has been recorded on 8 species of the Brassica genus (Brassica juncea, Brassica napus, Brassica nigra, Brassica oleracea, Brassica rapa, Brassica madritensis, Brassica racemosus, Brassica rigidus).
Myzus persicae has been recorded on 2 species of the Phaseolus genus (Phaseolus coccineus, Phaseolus vulgaris).