Kermes quercus (Linnaeus)

(Fig. 66, Plate 4E, distribution map Fig. 91A)

Coccus quercus Linnaeus, 1758: 455 . Chermes reniformis Fourcroy, 1785: 230 . Coccus cambii Ratzeburg, 1844: 194. Physokermes reniformis (Fourcroy); Targioni Tozzetti 1869: 41. Kermes reniformis (Fourcroy); Signoret 1875: 553. Kermes quercus (Linnaeus); Cockerell 1894: 178.

Field characters: Young adult female yellowish brown; pre-reproductive adult female spherical, dark brown to black, without visible body segmentation but dorsum divided by 1 longitudinal and 6–8 deep, wide transverse black furrows. Post-reproductive female kidney-shaped, with shallow longitudinal medial depression posteriorly; cuticle becoming heavily sclerotized with maturity (Podsiadło 2014).

Microscopic diagnosis: Slide-mounted young pre-reproductive adult female pear-shaped, with fused segments. Dorsal and ventral setae stout and spine-like, present throughout. Antennae each with 2 or 3 segments, with 3 or 4 spine-like setae apically. Labium subtriangular, with three segments, apical segment with 4 pairs of setae. Legs reduced, pointed distally, each composed of three segments: coxa, trochanter + femur, tibia + tarsus and claw. Spiracles well developed and sclerotized, each with associated multilocular disc pores, posterior spiracle diameter larger than that of anterior spiracle. Anal ring situated near posterior end, with a complete margin with 2 short setae posteriorly but without pores.

Dorsum with tubular ducts of various sizes, scattered, most numerous anteriorly, sparse posteriorly; bilocular pores numerous, scattered.

Venter with tubular ducts of 1 type densely grouped in a horseshoe-shaped submarginal to marginal band on prosoma, less frequent on submarginal areas of abdomen. Disc-pores (each with 3‒8 loculi) present in groups, each group surrounding a spinelike seta; present around margins and forming segmental rows across median areas of abdomen. Multilocular pores, each with 12 loculi, in clusters across medial areas of abdominal segments and forming 6 or 8 longitudinal lines abdomen.

Distribution: Kermes quercus is known from 24 countries in the Palaearctic region (García Morales et al. 2016); in Iran, it has been recorded from Ilam and Kermanshah provinces (Moghaddam 2013).

Host-plants: The species is oligophagous, having been only found on Quercus spp. ( Fagaceae) (García Morales et al. 2016).

Economic importance: Kermes quercus is of no economic importance in Iran.

Natural enemies: None recorded in Iran.