Neomyzus are medium-sized aphids with with distinctive black dorsal markings. The lateral frontal tubercles have converging inner sides. Alates have secondary rhinaria on antennal segment IV. They were previously placed as a subgenus of Aulacorthum but differ in several morphological features that place them closer to the Myzus group of genera.
There are about eight Asian species of Neomyzus, including one which is now cosmopolitan.
The apterae of Neomyzus circumflexus (previously known as Aulacorthum circumflexum) are shiny whitish, yellowish or green with black cross bands on thoracic segments, broken along the midline, and a large horseshoe-shaped spot on the back of the abdomen (see first picture below). Antennal tubercles are well developed with the inner faces parallel. The antennae are 1.1-1.5 times the body length and the antennal terminal process is approximately 5-6 times length of base of antennal segment VI. The siphunculi are dusky with a darker flange. They are rather thick and cylindrical and are 1.8-2.3 times the length of the cauda. The cauda is pale, elongate with 4-6 lateral hairs and a single dorsal preapical hair. The body length of Neomyzus circumflexus apterae is 1.2-2.6 mm.
Image of alate copyright Nigel Gilligan, all rights reserved.
The alate is pale green with a black head and thorax (see second picture above). The abdomen has several dark transverse bands of variable width.
The clarified slide mounts below are of adult viviparous female Neomyzus circumflexus (= Aulacorthum circumflexum) : wingless, and winged.
Guest image(s) by permission of Roger Blackman copyright AWP all rights reserved.
The crescent-marked lily aphid is entirely parthenogenetic with no sexual stage in the life cycle. In temperate climates it is primarily a pest of glasshouse crops where it attacks Asparagus, Begonia, Fuchsia and many others. Heavy infestations cause direct harm to many ornamental plants, and the aphids may also transmit viruses. Neomyzus circumflexus has a cosmopolitan distribution.
Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994) and Blackman & Eastop (2006) supplemented with Blackman (1974),Stroyan (1977),Stroyan (1984),Blackman & Eastop (1984),Heie (1980-1995),Dixon & Thieme (2007) and Blackman (2010). 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).