Eulecanium tiliae (Linnaeus)

(Fig. 25, Plate 2G, distribution map Fig. 90F)

Coccus tiliae Linnaeus, 1758: 456 . Eulecanium tiliae (L.); Fernald 1903: 197. Eulecanium ibericum Hadzibejli, 1960: 316 . Eulecanium gyrcanicum Hadzibejli, 1967: 719 .

Field characteristics: Adult female body short, broadly oval, strongly convex; dead female dark brown. Does not produce an ovisac.

Microscopic diagnosis: Slide-mounted adult female body broadly oval; without stigmatic clefts; anal cleft relatively shallow.

Dorsum. Derm entirely membranous in young female, but becoming highly sclerotized at maturity. Setae finely spinose, scattered throughout. Pores of 1 type, circular, with a granulate surface, present throughout. Preopercular pores and duct tubercles absent. Tubular ducts present throughout, each with a short, broad outer ductule, a thin inner ductule and a small terminal gland. Anal plates together quadrate, each plate with posterolateral margin distinctly convex on some specimens; each plate with 3 or 4 apical or subapical setae and 1 or 2 setae along inner margin (not illustrated). Anal opening surrounded by a strongly sclerotized area. Anal ring bearing 6–8 setae.

Margin. Marginal setae of 2 types: (i) stout, straight, bluntly spinose setae on lateral margins, numbering 5–11 on each side between anterior and posterior stigmatic areas; and (ii) long flagellate setae fewer, present at anterior and posterior ends of body and occasionally elsewhere, not extending onto anal cleft margins. Spiracular setae numbering 2 or 3 in each stigmatic area, all subequal in size and shape.

Venter. Derm completely membranous. Pregenital disc-pores mostly each with 10 loculi; abundant around anogenital fold and extending posteriorly to margin of anal cleft; and across all preceding abdominal segments and meso- and metathorax; a large group also present mesad to each procoxa and usually with 1–3 mesad to each antenna. Spiracular disc-pores each with 5 loculi, present in a narrow band between margin and spiracle. Ventral microducts restricted to a narrow band mesad of submarginal band of tubular ducts. Ventral tubular ducts of 2 types: (i) a duct with a long outer ductule, present in a broad marginal band round entire margin; (ii) a smaller duct, present medially on all abdominal and thoracic segments. Three pregenital segments each with a pair of long setae; smaller setae present on other abdominal segments; and with a pair of small and a pair of larger setae between antennae. Legs rather variable, sometimes poorly developed, with tibia and tarsus fused, sometimes more developed with tibia and tarsus separate but without a tibio-tarsal articulatory sclerosis (as in Fig. 25); each claw usually bent at approximately right-angles to tarsus; tarsal and claw digitules well developed with small swollen apices. Antennae each with 5 or 6 segments.

Distribution: Eulecanium tiliae is known from 45 countries in the Nearctic, Oriental and Palaearctic regions (García Morales et al. 2016); in Iran, it is found in Esfahan, Fars, Kerman, Kermanshah, Khorasan –e Jounobi, and Sistan & Balouchestan provinces (Bodenheimer 1944b).

Host-plants: The species has been recorded on host-plants in 35 genera belonging to 17 families, but likes Rosaceous hosts (García Morales et al. 2016). In Iran, it has been recorded on Pistacia khinjuk ( Anacardiaceae), Cydonia oblonga and Malus domestica ( Rosaceae) (Moghaddam 2013).

Economic importance: The species is widely distributed in most parts of Iran, including western areas, and is a potential threat to many kinds of fruit trees.

Natural enemies: Numerous natural enemies of E. tiliae have been recorded from Iran, including the parasitoid wasps ( Hymenoptera): Coccophagus lycimnia (Walker) and C. piceae Erdos ( Aphelinidae); Blastothrix brittanica Girault, B. ilicicola Mercet, B. sericea (Dalman), Metaphycus punctipes (Dalman) and Microterys lunatus (Dalman) ( Encyrtidae); and Pachyneuron muscarum (Förster) ( Pteromalidae) (Davoodi et al. 2004; Lotfalizadeh & Gharali 2008; Ebrahimi 2014).