Family ERIOCOCCIDAE Cockerell

The higher classification of the Eriococcidae (felt scales) and related family-groups is far from being settled. There are no morphological characters that are found exclusively in all the taxa within the Eriococcidae; Ferris (1957) grouped them because they lack any of the morphological features that distinguish other scale insect families. Miller & Gimpel (2000) provide a useful summary of the fluctuating opinions on the higher classification of the Eriococcidae and closely related family-groups like Beesoniidae, Cerococcidae, Cryptococcidae, Dactylopiidae, Kermesidae and Micrococcidae over time. The Eriococcidae as present understood is thought to be paraphyletic (Cox & Williams 1987); molecular analyses using 18S support this hypothesis, indicating that it is comprised of several distinct evolutionary clades (Cook et al. 2002; Cook & Gullan 2004; Gullan & Cook 2007; Gwiazdowski et al. 2006; Hodgson 2002, 2020; Hodgson & Hardy 2013; Nan et al. 2013; Vea & Grimaldi 2016).

The Eriococcidae currently contains about 681 species in 109 genera worldwide (García Morales et al. 2016). It is the fourth largest family-group of scale insects after the Diaspididae (2,711 species), Pseudococcidae (2,047 species) and Coccidae (1,239 species). The felt scales recorded in Iran number 17 species, belonging to six genera.

Appearance in life: The felt scales are very diverse. The adult females secrete a felted white, grey, or yellowish wax ovisac that encloses the body. The posterior end of the ovisac has a small opening that allows the first-instar nymphs to escape. Body colour varies from pink or red to purple, green or brown. The posterior end of the ovisac has a small opening that allows the first-instar nymphs to escape. However, some eriococcids living under the bark produce little or no ovisac secretion and are often pink or red (Miller et al. 2014).

Diagnostic characters (using terminology from Kozár et al. (2013)): Slide-mounted adult female mostly elongate oval, often with well-developed, long, and sometimes sclerotized anal lobes (Fig. 47A), which bear strong dorsal spines or setae (normally three), similar in shape to enlarged marginal setae; each anal lobe often with a long apical anal lobe seta; the shapes and sizes of spines and setae are highly variable between species and genera. Antennae (Fig. 47B) each with 3–7 segments; setae on antennae mainly hair-like but apical and subapical segments also with strong, blunt, falcate sensory setae. Each frontal lobe (Fig. 47C) situated near antennal base, developed but smaller than basal antennal segment, present or absent; sometimes a sensory frontal tubercle present in similar position; sometimes both present. Labium (Fig. 47D) usually with 3 segments, but sometimes reduced to 2; basal segment (when present) bearing 2 setae. Eyes situated on venter, usually near margin. Legs usually well developed; hind leg coxa (Fig. 47E) often with translucent pores; tibia sometimes shorter than tarsus, always with 4 distal setae and sometimes with 1 median seta also; claw (Fig. 47F) normally with a denticle and always with two digitules, these usually longer than claw and knobbed. Derm seldom with bilocular, trilocular or simple pores but often with oval disc (cruciform) pores (Fig. 47G). Derm normally with distinctive microtubular ducts (Fig. 47H); macrotubular ducts (Fig. 47I) often of 2 sizes. Dorsum and margins usually with conspicuous enlarged conical setae (Fig. 47J). Anal ring (Fig. 47K) normally sclerotized, with pores and 6 or 8 setae. Sclerotised triangular cauda on dorsum anterior to anal ring, present or absent. Vulva ventral (Fig. 47L) situated between abdominal segments VII–VIII or VI–VII.

KEY TO GENERA OF ERIOCOCCIDAE IN IRAN, based on slide-mounted adult females.

1(0) Tarsal and claw digitules all with acute tips....................................... Neoacanthococcus Borchsenius

- Tarsal digitules with capitate (knobbed) tips; claw digitules usually capitate, rarely spine-like........................ 2

2(1) Enlarged spinose setae restricted to margin or anal lobes only. Mostly on grasses............ Anophococcus Balachowsky

- Enlarged spinose setae present over entire dorsum. Hosts various............................................... 3

3(2) Hind tibia with 5 setae (median seta present). Microtubular ducts short. Mostly on herbaceous plants. Rhizococcus Signoret

- Hind tibia with 4 setae (median seta absent). Microtubular ducts long. Mostly on woody plants....................... 4

4(3) Dorsal spinose setae much shorter than a marginal seta. Dorsum of anal lobes with robust setae............ Uhleria Cooke

- At least some dorsal spinose setae about same length as a marginal seta. Dorsum of anal lobes with hair-like setae........ 5

5(4) Dorsum with macrotubular ducts only near margins. In life, ovisac not covering dorsum completely. Mostly found in bark crevices of elm (Ulmus spp.) but sometimes on other hosts.................................... Gossyparia Signoret

- Dorsum with macrotubular ducts throughout. In life, ovisac covering entire body. Feeding locations various, hosts various (sometimes including Ulmus spp.).................................................... Acanthococcus Signoret