Exaeretopus tritici Williams

Moghaddam, Masumeh & Watson, Gillian W., 2024, The Scale Insects Of Iran (Hemiptera: Coccomorpha) Part 3 The Soft Scales (Coccidae) And Other Families, Zootaxa 5542 (1), pp. 1-202 : 67-68

Exaeretopus tritici Williams

( Fig. 26 , distribution map Fig. 90G )

Exaeretopus tritici Williams, 1977: 281 .

Field characteristics: Live adult female living on stems and adaxial leaf surfaces; body very elongate oval, yellowbrown to dark brown, almost hemispherical in transverse section. Ovisac not observed.

Microscopic diagnosis: Slide-mounted adult female body very elongate oval. Derm often membranous but some specimens, even young adults, becoming lightly sclerotized. Stigmatic clefts absent. Anal cleft very short.

Dorsum. With numerous spinose setae, slender and pointed. Minute pores numerous and scattered (not illustrated). Preopercular pores present in a median group of about 40‒45, extending forward from anal plates to first abdominal segment. Tubular ducts of 2 types: (i) ducts with a short inner filament and no terminal gland, and (ii) ducts with a long, narrow inner filament and a terminal gland; both types numerous almost throughout, except on head and intersegmental membranes. Anal plates together quadrate, with right-angled outer angles; each plate with a subdiscal seta and 3 apical setae, sometimes longer than subdiscal seta. Anal ring bearing 8‒10 long setae.

Margin. Marginal setae slender but stiff, those on head sometimes present in a double row. With a single stigmatic seta opposite each anterior spiracle, slightly shorter than a marginal seta and curved, pointing anteriorly.

Venter. Derm completely membranous. Setae numerous and scattered, usually much shorter than marginal setae, except for 3 pregenital segments anterior to anogenital fold each with a pair of long setae. Pregenital disc-pores each with 6‒8 loculi, present around anogenital fold and anteriorly on preceding 3 abdominal segments. Spiracular disc-pores each with 5 loculi, slightly smaller than a multilocular disc-pore, present in a band between each spiracle and margin. Tubular ducts of 2 types, same as those on dorsum, present on all segments. Legs well developed, each with a distinct tibio-tarsal articulation and articulatory sclerosis; tarsus strongly curved and with a marked constriction, looking like a pseudoarticulation; claw digitules slender, slightly expanded at tip; tarsal digitules sharply pointed (in Iranian specimens). Antennae each with 7 segments (in Iranian specimens); apical segment with apical tuft of about 10‒12 pointed setae and some fleshy setae.

Distribution: Exaeretopus tritici is only known from Türkiye ( Turkey), Iraq and Iran ( García Morales et al. 2016), where it is found in Lorestan province (Moghaddam & Azad-Bakht, A. 2006).

Host-plants: The species has been recorded on grasses ( Poaceae ) in the genera Bromus , Hordeum and Triticum ( García Morales et al. 2016) . In Iran, it has been recorded on Triticum aestivum (Moghaddam & Azad-Bakht, A. 2006) .

Economic importance: Not of any economic importance in Iran.

Natural enemies: None recorded in Iran.

Figures

FIGURE 26. Adult female of Exaeretopus tritici Williams.

FIGURE 90. Distribution maps of scale insect species in Iran covered in this work. A, Drosicha turkestanica Archangelskaya; B, Ericerus farsicus Moghaddam & Faghih; C, Eriopeltis festucae (Boyer de Fonscolombe); D, Eulecanium ficiphilum Borchsenius; E, Eulecanium rugulosum (Archangelskaya); F, Eulecanium tiliae (Linnaeus); G, Exaeretopus tritici Williams; H, Gossyparia spuria (Modeer); I, Gueriniella serratulae (Fabricius); J, Hadzibejliaspis stipae (Hadzibejli); K, Icerya aegyptiaca (Douglas); L, Icerya purchasi Maskell.