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Uroleucon cichorii = Uroleucon cichorii cichorii
Large chicory aphidOn this page: Identification & Distribution Biology & Ecology Other aphids on the same host
Identification & Distribution:
Adult apterae of Uroleucon cichorii (see first picture below) are shining metallic grey-brown with black antennae and siphunculi. The antennal terminal process is 5.4-8.4 times longer than the base of antennal segment VI. The apical segment of the rostrum (RIV+V) is 1.04-1.33 times the length of the second hind tarsal segment (HTII). Nearly all dorsal hairs arise from dark scleroites (cf. Uroleucon sonchiwhere dorsal scleroites on abdominal tergites 1-5 are either absent, or very small). The femora are yellow basally and black on the distal half. The tibiae of Uroleucon cichorii are entirely black (cf. Uroleucon grossum and Uroleucon obscurum which have much of the basal half of the tibiae yellow-brown rather than black). The siphunculi are 1.1-1.7 (normally 1.4-1.6) times the length of the cauda. The body length of the adult Uroleucon cichorii aptera is 2.8-4.9 mm.
The alate (not pictured) has the last rostral segment (RIV+V) 1.05-1.4 times longer than the second hind tarsal segment (HTII). Immatures (see second picture above) are more reddish than the adults.
The large chicory aphid does not host alternate, but lives all year on the upper parts of stems of chicory (Cichorium spp.). It is also frequently recorded from other related composite genera, including Crepis, Hieracium, Hypochaeris and Lapsana, suggesting it is less host-specific than other Uroleucon species. Sexual forms appear in September, and the species overwinters in the egg stage. Uroleucon cichorii is distributed throughout Europe and into Asia.
Biology & Ecology:
We have only found Uroleucon cichorii once, in late summer on smooth hawk's-beard (Crepis capillaris) in Bedfordhire.
Like other Uroleucon species, Uroleucon cichorii can build up to large numbers in late summer.
The hind tibiae are conspicuously black, enabling us to confidently assign this colony to Uroleucon cichorii (=Uroleucon cichorii cichorii) rather than to the closely related Crepis specialist, Uroleucon grossum (=Uroleucon cichorii grossum).
The picture above shows a number of immature Uroleucon cichorii comprising both females and males. Very young immature female viviparae (and probably oviparae) are a deep reddish-brown. As they mature, most of the dorsum becomes metallic grey leaving the posterior area near the siphunculi reddish-brown. Young alate males are green - quite different from the developing females.
Several authors have recorded the parasitoids occurring on Uroleucon cichorii. Tomanovic et al. (2003) recorded Ephedrus niger, Praon volucre, Praon yomeneae, Aphidius funebris and Binodoxys centaureae in their review of aphidiines parasitizing Uroleucon cichorii in the West Palaearctic. Kos et al. (2012) recorded Ephedrus plagiator, Praon volucre, Praon yomenae, Aphidius funebris and Aphidius matricariae parasitizing Uroleucon cichorii in Slovenia.
Other aphids on the same host
Blackman & Eastop list 31 species of aphid as feeding on chicory (Cichorium intybus) and/or endive (Cichorium endivia) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 20 as occurring in Britain (Show British list).