Woolly elm aphid

Appearance

Honeydew, the aphid sugary excrement, is produced in droplets that in mature galls coalesce in massive sediment, and the aphids avoid being entrapped in it by producing a powdery hydrophobic wax that coats every element inside the gall. While many invertebrates are known as predators of galling insects (e.g., Stone & Schönrogge, 2003), few bird species have been identified for this role (Burstein & Wool, 1992; László et al., 2014; Moeller & Thogerson, 1978; Schlichter, 1978; Schönrogge et al., 2013; Sunose, 1980). Most of these birds are passerines, chiefly tits, but some are woodpeckers (László et al., 2014; Moeller & Thogerson, 1978; Schönrogge et al., 2013). Compared to smaller woodpeckers (see especially the downy woodpecker Dryobates pubescens), the great spotted woodpecker Dendrocopos major seems very rarely observed while eating from galls: I could read only one report in this respect, of a single bird extracting larvae of the large cigar gall fly Lipara lucens (Kramer, 1917). Although detailed observations made during the subject's feeding activity are scarce, it seems that all the observed bird species were searching in the gall only for its occupants. No bird was reported taking honeydew from within galls, although several bird species do eat honeydew, if freely available (e.g., Latta et al., 2001).

Naming

Synonyms:
1. Afghanaphis ulmi
2. Aphis lanigera var. piri
3. Aphis ulmi
4. Eriosoma lanuginosa
5. Eriosoma taskhiri
6. Schizoneura lanuginosa
7. Schizoneura piri
8. Schizoneura pyri

Food

Host plant range :
1. Malus spp.
2. Pyrus spp.
3. Cydonia spp.
3. Ulmus glabra
4. Ulmus minor