Phenacoccus solenopsis Tinsley

MOGHADDAM, MASUMEH & WATSON, GILLIAN W., 2022, The Scale Insects Of Iran (Hemiptera: Coccomorpha) Part 2 The Mealybugs (Pseudococcidae And Rhizoecidae) And Putoidae, Zootaxa 5126 (1), pp. 1-169 : 103-105

Phenacoccus solenopsis Tinsley

( Fig. 45, Plate 2 D, distribution map Fig. 69 H)

Phenacoccus solenopsis Tinsley, 1898 a: 47 . Phenacoccus cevalliae Cockerell, 1902b: 115 .

Field characteristics: Found on aerial plant parts. Body of adult female 1.5‒4.3 mm long, broadly oval, becoming fairly convex at maturity, body contents yellowish ( Zhao et al. 2014); surface covered with a dense layer of white powdery wax, except usually with areas of dark grey bare cuticle (1 pair of patches on the thorax and 3 pairs on the abdomen) forming 2 longitudinal submedian broken lines; lateral wax filaments short and thick, those at the abdominal apex longest.

Microscopic diagnosis: Slide-mounted adult female broadly oval. Anal lobes well developed. Antennae usually each with 9 segments. Legs well developed; hind leg with translucent pores on tibia (specimens that have developed in hot conditions often have a few translucent pores towards apex of femur also—see Fig. 45); claw with a denticle; tarsal digitules pointed at tip and shorter than claw. Cerarii numbering 18 pairs; anal lobe cerarii each with 2 lanceolate setae and a few trilocular pores; anterior cerarii similar. Circulus usually anvil-shaped, flaccid, often staining strongly. Ostioles normal, with inner edges of lips only lightly sclerotized. Anal ring with 3 rows of pores and 6 setae.

Dorsum with frequent small-to-minute lanceolate setae. Multilocular disc pores absent. Quinquelocular pores absent. Trilocular pores scattered throughout. Discoidal pores sparse to very sparse but present throughout body. Oral collar tubular ducts sparse, present on posterior abdominal segments in Iranian specimens (not illustrated).

Venter with long setae; also small lanceolate setae, similar to those on dorsum, present on margins. Multilocular disc pores normally each with 10 loculi, present medially posterior to vulva and along posterior edges of abdominal segments VI and VII, not reaching to margins (but specimens that have developed in hot conditions often have discrete small clusters of multiloculars on submargins of abdominal segments—see Fig. 45); segment VII also with multiloculars on anterior edge, with cuticle between anterior and posterior pore rows in mesal area also with scattered multilocular pores. Quinquelocular pores absent. Trilocular pores and discoidal pores scattered throughout. Oral collar ducts all same size, present across all abdominal segments and medially on thorax.

Distribution: Phenacoccus solenopsis is known from 52 countries in the Afrotropical, Australian, Nearctic, Neotropical, Oriental and Palaearctic Regions ( García Morales et al. 2016) including Iran, where it has been recorded from Bushehr, Fars, Hormozgan, Khouzestan and Sistan & Balouchestan provinces ( Moghaddam & Bagheri 2011).

Host-plants: This species has been recorded on host-plants in 208 genera belonging to 63 families ( García Morales et al. 2016). In Iran, it has been recorded on Amaranthaceae : Amaranthus retroflexus and Chenopodium album ; Apocynaceae : Calotropis procera and Nerium oleander ; Asteraceae : Helianthus annuus , Xanthium strumarium and Zinnia violacea ; Convolvulaceae : Convolvulus arvensis and Ipomoea tricolor ; Cucurbitaceae : Citrullus colocynthis ; C. lanatus , Lagenaria siceraria , Luffa sp. and Momordica charantia ; Euphorbiaceae : Ricinus communis ; Fabaceae : Acacia nilotica ; Malvaceae : Abelmoschus esculentus , Abutilon fruticosum , A. hirtum , Gossypium sp. , and Hibiscus rosa-sinensis ; Meliaceae : Azadirachta indica ; Moraceae : Ficus carica , F. religiosa and Morus alba ; Rutaceae : Citrus sp. ; Pedaliaceae : Sesamum orientale ; Poaceae : Cynodon dactylon ; Rhamnaceae : Ziziphus mauritiana ; Sapindaceae : Dodonaea viscosa ; Scrophulariaceae : Antirrhinum majus ; Solanaceae : Capsicum frutescens , Cestrum noctumum , Nicotiana tabacum , Petunia integrifolia , Solanum lycopersicum , S. melongena , S. nigrum , S. tuberosum and Withania somnifera ; and Verbenaceae : Lantana camara ( Fallahzadeh et al. 2013; Fallahzadeh et al. 2014a; Moghaddam 2013b).

Economic importance: Phenacoccus solenopsis has been found in most southern and cental provinces in Iran on many host-plants, but there is no record of it causing serious damage there.

Natural enemies: Due to its widespread distribution in Iran, many studies have been done on the natural enemies of P. solenopsis there. Its predators include Coleoptera : Coccinellidae : Cheilomenes sexmaculata Fabricius , Nephus arcuatus Kapur , Hyperaspis polita Weise , Nephus sp. , and Scymnus sp. ; and hymenopteran parasitoid wasps recorded were Encyrtidae : Aenasius sp. , Leptomastix flava Mercet and Prochiloneurus bolivari Mercet ( Fallahzadeh et al. 2013, Fallahzadeh et al. 2014b, Fallahzadeh & Japoshvili 2017, Mossadegh et al. 2015, Seyfollahi et al. 2016). Field, laboratory and greenhouse studies have indicated that of its natural predators, Nephus arcuatus and Hyperaspis polita are the most successful at reducing populations of P. solenopsis . The studies also concluded that the hymenopterous parasitoid Aenasius arizonensis (Girault) (= Aenasius bambawalei Hayat ) has the greatest potential for use in the control of this pest ( Mossadegh et al. 2015).

Comments: Phenacoccus solenopsis is probably native to south-western North America and has been introduced accidentally to Iran. The species has been reported causing damage, especially to cotton, in numerous countries ( Hodgson et al. 2008), but there have been no reports of crop injury in Iran.

The accompanying illustration is reproduced from Hodgson et al. (2008), page 7, Fig. 3, with kind permission from the senior author and the Chief Editor of Zootaxa.