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Greenideinae : Greenideini : Mollitrichosiphum nigrum
 

 

Mollitrichosiphum nigrum

Black hairy-tailed aphid

On this page: Identification & Distribution Other aphids on the same host

Identification & Distribution

Adult apterae of Mollitrichosiphum nigrum (see picture & note below) are elongate pear-shaped with the body less than 2.2 times longer than maximum abdominal width (cf. Mollitrichosiphum tenuicorpus, which is more than 2.2 times longer than the maximum width of the abdomen). In life the head, thorax, abdomen and siphunculi are shining black, sometimes with a thin dusting of white wax (cf. Mollitrichosiphum yamabiwae, which is yellow-brown in life). Their antennae are pale except for segments I & II and the apices of segments III-VI, which are dark. The terminal process is about 1.4 times as long as the base of antennal segment VI. The ultimate rostral segment is long and wedge-shaped. The dorsal hairs of the abdomen are thick and long, and mostly pointed (cf. Mollitrichosiphum taiwanum, whose dorsal hairs are mostly bifurcate). The legs are mostly pale brown with dark tarsi. The hind tibiae have 4963 transverse ridges in the basal 0.75 of their length (cf. Mollitrichosiphum yamabiwae, which has less than 40 ridges on the hind tibia). The siphunculi are extremely long, 0.6-0.7 times the body length, slightly swollen in the middle with a distinct flange, and with densely spinulose imbrications. Each siphunculus bears 110130 long hairs. The cauda is semi-round, with 810 hairs. The anal plate is transversely elliptical, with 1622 hairs. Immature Mollitrichosiphum nigrum (see lower part of picture below) are greenish-orange with spinal, pleural and marginal lines of scleroites.

Note: The identity of the aphids pictured below has yet to be confirmed. This species has not previously been recorded from Japan.

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

The alate Mollitrichosiphum nigrum (not pictured) has antennal segment III with 1416 round secondary rhinaria. There are 4953 short transverse ridges in the basal 0.6 of the hind tibia. The veins of the wings and the pterostigma are dark brown. There are large sclerotized dark patches on tergites III-VI. The siphunculi are extremely long, 0.8-1.1 times body length, with 189210 long and short hairs.

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

Mollitrichosiphum nigrum has mainly been found on Meliosma species (Sabiaceae), where they feed on the leaf undersides. They have also been collected from Ailanthus altissima and Elaeagnus pungens (Zhang & Qiao, 2010). Until now Mollitrichosiphum nigrum has only been found in China, whilst the specimens shown here were found in Japan. Hence the uncertainty about the identity of the aphids pictured here as Mollitrichosiphum nigrum. However Mollitrichosiphum is the only genus of aphid that has been found on Meliosma species, and the only species recorded on Meliosma are Mollitrichosiphum nigrum, Mollitrichosiphum yamabiwae, Mollitrichosiphum tenuicorpus and Mollitrichosiphum taiwanum. Of these, only Mollitrichosiphum nigrum is described as black in life; the others are yellow, yellow-brown or pale brown (see Blackman in Aphids on Worlds Plants).

 

Other aphids on the same host

Mollitrichosiphum nigrum has been recorded from 2 species of Meliosma (Meliosma cuneifolia, Meliosma myriantha).

Acknowledgements

We are especially grateful to Akihide Koguchi for allowing us to reproduce the images of Mollitrichosiphum nigrum from his blog page.

We have used the keys and species accounts from Zhang & Qiao (2010) along with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors 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

References

  • Zhang, D. & Qiao, G. (2010). Mollitrichosiphum Suenaga from China (Hemiptera: Aphididae), with the description of one new species. Zootaxa 2608, 124. Full text