The body length of an adult Illinoia liriodendri aptera is 1.7 to 2.5 mm. I. liriodendri apterae are spindle shaped and pale green, lightly dusted with wax. There are also yellowish and pink-red forms. For a more detailed description of this species please use the ‘Further info:’ link below.

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Illinoia liriodendri feeds on undersides of the leaves of Tulip-tree (Liriodendron tulipifera). Dense populations can build up resulting in large deposits of honeydew on the leaves.

Sexual forms occur in autumn.

The aphids are restricted to the undersides of the leaves where, early in the season, the clusters of the nymphs can be found behind each of the adult viviparous females

True status in Britain is difficult to determine due to lack of records.

Rarely recorded in Leicestershire and Rutland.

https://influentialpoints.com/Gallery/Illinoia_liriodendri_Tulip-tree_aphid.htm