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Mint aphidsOn this page: Eucarazzia elegans
Eucarazzia have the antennal tubercles well developed, not converging, and quite smooth like the head. True apterae probably have no secondary rhinaria on the antennae, but the few known (alatiform ?) apterae have a few rhinaria on segments III & IV. In the alate, the veins of the wings all have a dark spot where they reach the margin of the wing, but the veins are not bordered with brown or black. The abdominal tergum in apterae is membranous; in alatae there is a central sclerite. The stigmal pores are reniform. First tarsal segments have 3 hairs. Siphunculi are very strongly swollen, with a few rows of hexagonal reticulation at the apex. The cauda is minute, very short and rather acute.
The genus has only one species, Eucarazzia elegans, feeding on mints (Mentha) and other Lamiaceae. It is anholocyclic in warm humid climates, but holocyclic in Iran where there is a hot summer and cold winter. It is probably endemic to the Mediterranean area, Middle East or South Asia, but is now found over much of Europe, Australia, Africa south of the Sahara, western USA and South America.
Eucarazzia elegans (Mediterranean mint aphid) Near cosmopolitan
Adult apterae of Eucarazzia elegans (see first picture below) have a pale yellow-green membranous dorsum, with a few darker green blotches, and sometimes a sparse covering of fine wax. Antennal tubercles are rather low, not converging, and the median frontal tubercle is only just visible. Their antennae are pale with the apices of segments III-VI dark, and a terminal process that is about 4 times as long as the base of segment VI. There are a few secondary rhinaria on segments III and IV. The rostrum does not reach the hind coxae, and the apical rostral segment is about 1.5 times the length of the second hind tarsal segment. The legs are pale, with dark apices to the tibiae. They have strongly swollen siphunculi (cf. most other aphid species on mint, including Ovatus mentharius, which do not have strongly swollen siphunculi). The siphunculi are pale with the basal part of the swollen area and the apex brownish; the swollen part of the siphunculi is 2-3 times as wide as the basal part of the siphunculi, and there is a small but distinct flange. The cauda is pale with 5-7 hairs, hardly longer than wide, and only 0.14-0.17 times the length of the siphunculi.
First two images above, copyright Scott M. Loganboth under a CC BY-NC 4.0 licence,
The alate Eucarazzia elegans (see second & third pictures above) has a dark head and thorax, and a pale green abdomen mostly covered with fine white wax. The only parts of the abdomen not covered by wax are tergites IV-V, which bear a characteristic dark rectangular spinopleural sclerite which links with large postsiphuncular sclerites. There are also small marginal sclerites and a sclerotized bar on tergite VIII. Their wax covering serves to enhance the visibility of the dark markings, which suggests this functions as an aposematic marking. The antennae are dark apart from the base of segment III. Antennal segment III bears 17-24 rather large, scattered secondary rhinaria over nearly its whole length, and there are about 3-9 flatter rhinaria along one side of segment IV. The wings have dark triangular spots at the ends of all the wing veins, and vein Cu1b has a fuscous border for its entire length. Their legs are mainly pale, but with the distal parts of the femora dark, as are the apices of the tibiae, and the tarsi. The siphunculi have the swollen part and the basal area dark, the distal part of the cylindrical section paler. The cauda is pale.
Eucarazzia elegans feeds on the undersides of leaves, shoots, and flowers of mints (Mentha spp.) and various other Lamiaceae including sage (Salvia spp.), catmints (Nepeta) and oreganos (Origanum). In warm and humid climates, Eucarazzia elegans is an anholocyclic species, reproducing parthenogenetically throughout the year. In areas with an arid climate with a hot summer and cold winter the species is holocyclic, with oviparae and both alate and apterous males having been recorded (Wieczorek & Chlond, 2019). Eucarazzia elegans is thought to be Mediterranean in origin, but is now widely distributed outside its native area being found in the Middle East, Central Asia, Pakistan, northern India, southern Poland, Australia, Africa south of the Sahara, western USA and South America.