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White sage aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
Adult apterae of Macrosiphoniella ludovicianae (see first picture below) are green or yellowish green, dusted with greyish white wax. The antennae are dusky yellow on segments I & II, and on the base of segment III, and blackish or black beyond the base of III. The rostrum reaches beyond the third pair of coxae, with the apical rostral segment (RIV+V) roughly equal in length to the second hind tarsal segment (HTII). The femora have the apical regions dusky, much like the tibiae (cf. Macrosiphoniella paucisetosa in Canada, which have the femora entirely pale contrasting with wholly dark tibiae). The siphunculi are mostly black, but with a dusky base, and are distinctly longer than the cauda (cf. Macrosiphoniella artemisiae and Macrosiphoniella tanacetaria, both of which have all black siphunculi which are 0.6-0.9 times the caudal length). The cauda and anal plate are dusky greenish-yellow (cf. Macrosiphoniella artemisiae and Macrosiphoniella tanacetaria, which both have a black cauda). The cauda is spatulate, bearing 7-8 lateral pairs of hairs and 4-5 dorsal ones. The body length of adult Macrosiphoniella ludovicianae apterae is 2.0-2.8 mm.
Alate viviparous females of Macrosiphoniella ludovicianae (see second picture above) are similar in colouration to the apterous forms except that the head and thorax are dusky-green, and the hairs are slightly shorter.
The first picture below shows a clarified slide mount of an apterous vivipara of Macrosiphoniella ludovicianae; the second picture shows a live adult with immatures.
First image above copyright Jesse Rorabaugh, no rights reserved;
Macrosiphoniella ludovicianae is monoecious holocyclic on the leaves of Artemisia ludoviciana, but has also been recorded from common mugwort (Artemisia vulgaris). The species is generally common in a wide range of habitats. Oviparae and alate males occur in October. This native North American species is widely distributed in USA and Canada.
Other aphids on the same host
Blackman & Eastop list 11 species of aphid as feeding on white sage, prairie sage, western mugwort (Artemisia ludoviciana) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 3 as occurring in Britain (Show British list).