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Aphididae : Aphidinae : Macrosiphini : Paczoskia


Genus Paczoskia

Globe thistle aphids

On this page: Paczoskia obtecta

Paczoskia [Macrosiphini]

Paczoskia aphids have the antennal tubercles unusually well developed. The median frontal tubercle is absent, at least in all the Echinops feeding species. The antennae are 6-segmented, about as long as the body or longer, with rather small, protruding secondary rhinaria confined to segment III in the alate vivipara. The apical rostral segment is very elongated, much longer than the second hind tarsal segment, with a large number of short hairs, all of about the same length. The tergum is membranous with the dorsal hairs on scleroites, and with large ante- and postsiphuncular sclerites. The siphunculi have the reticulated area wider than the part nearer the base. The first tarsal joints have 5 hairs. The cauda is much shorter than the siphunculi. The genus is related to Macrosiphoniella.

There are about 10 shiny brown species of Paczoskia, mostly monoecious holocyclic on Echinops, plus a few on other Asteraceae such as Centaurea and Jurinea. They are mostly found in eastern Europe and western Asia.


Paczoskia obtecta (Horned knapweed aphid) Northern & Central Europe

Adult apterae of Paczoskia obtecta are shiny bronze brown with dark spots, and have bright red eyes (cf. Uroleucon spp. such as Uroleucon jaceicola & Uroleucon jaceae which have dark brown eyes). The antennae (except at base of segment III), siphunculi and cauda are black, and the legs are yellowish with dark segmental apices. The antennal tubercles are also shiny black, and unusually well developed (cf. Uroleucon spp. which do not abnormally large antennal tubercles). The antennae are 1.0-1.5 times the body length, with the terminal process 4.9-6.1 times as long as the base of antennal segment VI. There are 32-50 secondary rhinaria on the basal 0.75 of antennal segment III. The apical segment of the rostrum (RIV+V) is 1.0-1.1 times the length of the second hind tarsal segment (HTII). The bases of the siphunculi are almost ringed by large semicircular antesiphuncular, and less extensive postsiphuncular, sclerites (see first picture below) (cf. Uroleucon spp. which have the antesiphuncular sclerites either absent or fragmented). There are also marginal sclerites. The siphunculi are 1.4-1.6 times the caudal length, with reticulation on the apical 20-35%. The cauda is very long and slender with 9-15 hairs. The body length of adult Paczoskia obtecta apterae is 3.1-4.3 mm.

Image above, by permission copyright Nick Peeters, all rights reserved.

The alate Paczoskia obtecta (see second picture above) is similar to the aptera, except it has a black head and thorax and larger marginal sclerites.

Paczoskia obtecta is monoecious on knapweed (Centaurea spp.). It feeds on the undersides of the lower leaves, and later on the upper parts of stems. It is most likely holocyclic like several other members of the genus, but sexuales are so far unknown. Paczoskia obtecta has so far been found in France, Sweden, Denmark, Germany, Poland, Austria, former Yugoslavia, Hungary and the Czech Republic, and (with this record) now in the Netherlands. It has also been found in Israel.



We are grateful to Nick Peeters for permitting us to reproduce his images of Paczoskia obtecta.

We have used the genus account of Holman (1981) and Hille Ris Lambers (1958), together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections as the source for the (summarized) taxonomic information we have presented. Any errors in 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


  • Hille Ris Lambers, D. (1958). Key to genera of Aphidinae with reticulated siphunculi. In MacGillivray. A study of the genus Masonaphis Hille Ris Lambers, 1939 (Homoptera: Aphididae). Temminckia 10, 23

  • Holman, J. (1981). Species of the genus Paczoskia (Homoptera, Aphididae) confined to Echinops. Acta ent. bohemoslov. 78(2), 105-121.