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Aphididae : Calaphidinae : Panaphidini : Mesocallis


Genus Mesocallis

Mesocallis aphids

On this page: Mesocallis pteleae sawashibae

Mesocallis [Panaphidini]

Mesocallis are pale yellow, slender-bodied aphids with both alate and apterous morphs known in some species. In the alate the epicranial suture is sometimes weakly indicated. The antennae are much shorter than the body, with the terminal process 0.8-1.2 times as long as the base of that segment. Secondary rhinaria are oval to narrow elliptical, with one row along the whole surface of segment III. The rostrum reaches far beyond the first coxae and the apical rostral segment has 2-16 accessory hairs. The compound eye of the apterous morph is often smaller and with fewer facets than in the alate morph. The lobes of the mesonotum are smooth, the abdomen is without spinal processes, and paramedian hairs are mostly on wart-like elevations. In both apterae & alatae the dorsal body hairs have round knobs at the apex. The empodial hairs are flabellate and distinctly longer than the claws. The fore tibiae are often darkened. The siphunculi are pale and truncated without a flange, the cauda is knobbed and the anal plate is bilobed.

Mesocallis aphids mostly feed on trees in the birch family (Betulaceae) including birch (Betula), hornbeam (Carpinus), alder (Alnus) and hazel (Corylus). Eleven species have been described, although some are little known. For example Mesocallis fagicola has been variously reported to feed on Fagus silvatica (Matsumura, 1919) Fagus crenata (Higuchi, 1972), or Betulaceae (Chen et al., 2020), but appears not to have been found since it was first described from Japan in 1919. Mesocallis species are restricted to east Asia.


Mesocallis pteleae (Hippopotamus aphid) East & South-east Asia

All adult Mesocallis pteleae viviparae are alate. Adult alatae have most of the head, thorax and abdomen pale yellow-green, but the anterior of the head is black (cf. Mesocallis alnicola & Mesocallis sawashibae, which have the anterior of the head pale). Antennal segments I-III are black with the rest of the flagellum having dark bands. The terminal process is 0.9-1.2 times as long as the base of antennal segment VI (cf. Mesocallis taoi, which has the terminal process 0.6-0.8 times as long as the base of that segment). The apical rostral segment (RIV+V) is 1.2-1.4 times as long as second hind tarsal segment (HT II) (cf. Mesocallis taoi, which has RIV+V 0.7-0.9 times as long as HT II). The forewing vein Cu1b, is broadly dark bordered (cf. Mesocallis sawashibae, which does not have Cu1b dark bordered). Abdominal tergites I-IV each bear one pair of marginal hairs (cf. Mesocallis corylicola & Mesocallis yunnanensis, which have two or more pairs of marginal hairs on each of those tergites). The fore tibiae and distal 0.1 of the fore femora are black, as well as the distal margin of the hind femora. The tarsi are brown. The siphunculi and cauda are pale. The siphunculi are cylindrical and truncated, and the cauda is knobbed. The body length of the alate Mesocallis pteleae is 1.2-1.6 mm.

Image above by permission, copyright Akihide Koguchi, all rights reserved.

The host of Mesocallis pteleae was given originally as Ptelea trifoliata, but this has turned out to be incorrect. It is now known to feed on species of alder (Alnus), hazel (Corylus), hop-hornbeams (Ostrya) and hornbeams (Carpinus). However some of these records could refer to other closely related aphid species (e.g. Mesocallis carpinicola on Carpinus). The aphids are found scattered on the underside of leaves of host plants. Mesocallis pteleae is currently known from Japan, Korea and China.



Mesocallis sawashibae (Pale-fronted hazel aphid) East & South-east Asia

Adult viviparae of Mesocallis sawashibae are apterous or alate, but the alate appears to be much the commoner morph, so we focus on that for identification. Alatae are mostly pale yellow with the front of the head and the metathorax very pale brown (cf. Mesocallis pteleae, which has the front of the head black). Only the distal parts of antennal segments III-VI are dark (cf. Mesocallis pteleae, which has all of segment III dark). The compound eyes are red. The legs are pale, apart from the distal parts of the mid- & hind tibiae which are pale brown, and the distal parts of the front tibiae which are usually dark (but note the distal parts of the front tibiae are pale in the spring form and in the apterous morph). The antennae are 0.64-0.76 times the body length with the terminal process 0.80-1.25 times the length of antennal segment VI. Antennal segment III bears 6-12 transversely elliptical secondary rhinaria in a row on two thirds of the segment, with no secondary rhinaria on antennal segment IV. The rostrum is rather short, not reaching to middle coxae. The apical rostral segment (RIV+V) is 0.67-1.00 times the length of the second hind tarsal segment (HTII) (cf. Mesocallis pteleae, which has RIV+V 1.2-1.4 times the length of HTII). The fore-coxae are weakly enlarged. Vein Cu1b of the forewing is slightly dark bordered (cf. Mesocallis pteleae, which has Cu1b broadly dark-bordered). Abdominal segments I-IV have short cone-shaped marginal tubercles each bearing a single hair. The siphunculi are cylindrical truncated, the cauda is knobbed with 11-13 hairs, and the anal plate is bilobed.

Image above by permission, copyright Akihide Koguchi, all rights reserved.

Mesocallis sawashibae feeds on trees in the birch family (Betulaceae), specifically hornbeams (Carpinus) and hazels (Corylus). It is commonly found on Carpinus cordata, japanese hornbeam (Carpinus japonica), the asian hazel (Corylus heterophylla) and japanese hazelnut (Corylus mandshurica). The specimens reported here from Japan were found on Corylus. Mesocallis sawashibae is monoecious holocyclic, with oviparae having been found in Japan in October. This species is known from China, Japan, East Siberia, and Korea (North and South).



We have used the keys and species accounts of Matsumura (1919), Quednau (2003) and Chen et al. (2020) 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 identification or 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


  • Chen, J. et al. (2020). Review of Mesocallis Matsumura from China (Hemiptera, Aphididae), with one new species. ZooKeys 1003, 19-30. Full text

  • Higuchi, H. (1972). A taxonomic study of the subfamily Callipterinae in Japan (Homoptera : Aphididae).

  • Matsumura, S. (1919). New species and genera of Callipterinae (Aphididae) of Japan. Transactions of the Sapporo Natural History Society 7(2), 100-115. Full text

  • Quednau, F.W. (2003). Atlas of the Drepanosiphine Aphids of the World. Memoirs of the American Entomological Institute 72, 51.