Formicococcus Takahashi, 1928

Zhang, Jiang-Tao & Wu, San-An, 2022, A review of the genus Formicococcus Takahashi 1928 (Hemiptera: Coccomorpha Pseudococcidae) of China, with description of a new species, Zootaxa 5188 (2), pp. 157-168 : 158-167

Genus Formicococcus Takahashi, 1928

Formicococcus Takahashi 1928: 253 ; Ferris 1955: 4; Ezzat & McConnell 1956: 35; Wang 1982a: 49, 2001: 112; Tu et al. 1988: 75; Tang 1992: 286; Wu & Zheng 2001: 200.

Type species: Formicococcus cinnamomi Takahashi 1928 .

Planococcoides Ezzat & McConnell 1956: 53 ; Tu et al. 1988: 78; Cox & Ben-Dov 1986: 482; Cox 1989: 3; Tang 1992: 286; Varshney 1992: 56; Ben-Dov 1994: 350; Wang 2001: 140; Williams 2004: 272.

Type species: Pseudococcus njalensis Laing 1929 .

Indococcus Ali 1967: 35 ; Tang 1992: 292; Varshney 1992: 53; Ben-Dov 1994: 203.

Type species: Indococcus pipalae Ali 1967 .

Anaparaputo Borchsenius 1962: 224 ; Wang 2001: 108; Tang 1992: 227.

Type species: Anaparaputo liui Borchsenius 1962 . syn. n.

Diagnosis (adapted from Williams 2004 and Joshi et al. 2020). Body of adult female with anal lobe bar present. Cerarii basically numbering 18 pairs, although sometimes cerarii on head or thorax indistinct but preocular pair (C 2) always present.Anal lobe cerarii each bearing 2 or more conical cerarian setae, each seta with a pointed or flagellate tip. Anterior abdominal cerarii each usually containing more than 2 conical setae; if only 2, then auxiliary setae often present. Cerarii on head and thorax almost always present, each either with 2 or more conical or flagellate setae and a group of trilocular pores, or, if with only 2 enlarged setae, then these sometimes associated with slender auxiliary setae. Sometimes 1 or 2 cerarii on thorax obscure, occasionally reduced to a single conical or flagellate seta but always with at least 1 or 2 trilocular pores next to setal collar. Ostioles prominent. Anal ring normal, situated at apex of abdomen or slightly dorsal in position, bearing 6 or multiple ring setae. Antennae each with 6–8 segments, occasionally with 9. Legs well developed, hind leg with translucent pores present or absent; often tibia + tarsus shorter than trochanter + femur; claw stout, without a denticle. Circulus present or absent. Multilocular pores present, at least on venter of abdomen. Oral rim tubular ducts absent. Oral collar tubular ducts present, at least on venter of abdomen, sometimes also around margins of head and thorax.

Remarks. The adult female of Formicococcus is morphologically similar to that of Paraputo Laing but differs from the latter by presence of an anal lobe bar ( Williams 2004). However, Danzig & Gavrilov-Zimin (2015) considered that the presence or absence of an anal lobe bar is a character that falls under individual variations and instead, used the presence of more than six anal ring setae as a critical generic character state of the genus Formicococcus . However, as discussed by Williams (2004) and Zhang & Wu (2017), the number of anal ring setae is not a robust genus-level character, especially as the number of setae can vary between either side of the anal ring. Herein, we have adopted the view of Williams (2004) and Zhang & Wu (2017), using the presence of an anal lobe bar as a genus-level character distinguishing Formicococcus from Paraputo .

The monotypic genus Anaparaputo Borchsenius differs from other genera by having large oral collar tubular ducts on all abdominal segments and lateral to each anterior coxa. However, this character is also present in some Formicococcus species, such as F. mangiferacola Williams 2004 and F. polysperes Williams 2004 , so we here consider Anaparaputo (which had been placed as a junior synonym of Paraputo by Danzig & Gavrilov-Zimin (2015)) as a junior synonym of Formicococcus .

Taxonomy of Formicococcus species found in China

Formicococcus bambusicola ( Takahashi, 1930)

Pseudococcus bambusicola Takahashi 1930: 1 ; Ben-Dov 1994: 380.

Planococcoides bambusicola ( Takahashi 1930) : Tang 1992: 359.

Planococcs bambusicola ( Takahashi 1930) : Fang et al. 2001: 103.

Formicococcus bambusicola ( Takahashi 1930) : Li et al. 2014: 380–382.

Material examined. CHINA: Guangdong: 2 ♀ ♀, Nanling, Ruyang, on Fargesia sp. , 22.viii.2010, coll. San-an Wu & Yuan Lu.

Host plants. Poaceae : Bambusa sp. , Fargesia sp.

Distribution. China (Guangdong, Taiwan).

Remarks. A good description and illustration of the adult female was given by Li et al. (2014).

Formicococcus bambusus (Wu 2001) comb. rev.

Kaicoccus bambusus Wu 2001: 252 , 254–255, 258.

Formicococcus bambusus (Wu 2001) : Li et al. 2014: 382.

Paraputo bambusus (Wu 2001) : Danzig & Gavrilov-Zimin 2015: 29, 37.

Material examined. CHINA: Guizhou: 6 ♀ ♀, Suiyang, Rangshui , on leaves of Phyllostachys pubescens , 14.viii.2010, coll. San-an Wu. Zhejiang: 9 ♀ ♀, Longquan city, on leaves of Ph. pubescens , 3.viii.2008, coll. Jin Liu ; 2 ♀ ♀, Deqing county , on the stem of Polygonatum odoratum , 11.viii.2003, coll. Yong-sheng Chai ; 13 ♀ ♀, Tianmu Mountain , on the stem of Ph. pubescens , 14.iv.1999, coll. San-an Wu.

Host plants. Asparagaceae : Polygonatum odoratum ; Poaceae : Phyllostachys pubescens .

Distribution. China (Guizhou, Zhejiang).

Remarks. This species was transferred to Paraputo , as P. bambusus (Wu) , by Danzig & Gavrilov-Zimin (2015) because it has an anal ring with six setae. However, the number of anal ring setae is not a robust genus-level character, especially as the number of setae can vary between the two sides of the anal ring. As it has an anal lobe bar on each anal lobe, this species is here restored to Formicococcus . Good descriptions and illustrations of the adult females were given by Wu (2001) and Li et al. (2014).

Formicococcus cinnamomi Takahashi 1928

Formicococcus cinnamomi Takahashi 1928: 253 ; Ezzat & McConnell 1956: 35–27; Wang 1982a: 50, 2001: 113; Tu et al. 1988: 76; Tang 1992: 287; Wu & Zheng 2001: 201; Danzig & Gavrilov-Zimin 2015: 19–20.

Material examined. CHINA: Sichuan: 4 ♀ ♀, Ya’an city, Sichuan Agricultural University Campus , under bark crack of Platanus sp. , 27.vii.2014, coll. Jiang-tao Zhang & Xu-bo Wang. Guangxi: 5 ♀ ♀, Xing’an county , undetermined host, 27.vi.1999, coll. San-an Wu.

Host plants. Ebenaceae : Diospyros sp. ; Lauraceae : Cinnamomum camphora ; Platanaceae : Platanus sp.

Distribution. China (Guangxi, Hubei, Sichuan, Taiwan).

Remarks. Wu (2001) also reported this species from Hubei, Xianfeng county. Good descriptions and illustrations of the adult females were given by Ezzat & McConnell (1956) and Tu et al. (1988).

Formicococcus citricola ( Tang 1992)

Paraputo citricola Tang 1992: 598 ; Danzig & Gavrilov-Zimin 2015: 35.

Formicococcus citricola ( Tang 1992) : Zhang & Wu 2017: 57.

Host plant. Rutaceae : Citrus sp.

Distribution. China (Fujian).

Remarks. A good description and illustration of the adult female was given by Tang (1992).

Formicococcus delonicola Zhang & Wu sp. n.

( Fig. 1 )

Material examined. Holotype Adult ♀ on a slide, China: Yunnan, Xishuangbanna / on Delonix regia (Fabaceae) , ix.2015 / specimens provided by Yi-wei Fang; BFUC. (The label is written in Chinese.) Paratypes: 4 ♀ ♀ (on four slides), same date and locality as holotype; 2 in BFUC, 2 in CFJAU.

Description

Appearance in life: Not recorded.

Slide-mounted adult female (n=5). Body of adult female ( Fig. 1 ) broadly oval, 1.80–2.55 mm long and 1.15– 2.00 mm wide. Anal lobes slightly prominent, ventral surface of each lobe with an apical seta, each 215–232 μm long, ratio of lengths of apical setae to anal ring setae 1: 0.37–0.51, and with a well-developed anal lobe bar. Antennae each 333–360 μm long, 7- or 8-segmented; apical segment longest, bearing 4 fleshy setae. Legs well developed, stout; hind leg measurements in μm: coxa 88–110 long; trochanter + femur 270–300 long, tibia + tarsus 209–237 long; claw stout, 35.0–42.5 long, without denticle; claw digitules knobbed, longer than claw. Ratio of lengths of hind tibia + tarsus to hind trochanter + femur 1: 1.26–1.31. Ratio of lengths of hind tibia to tarsus 1: 0.79–0.88. Translucent pores numerous on hind coxa. Eye oval, located at body margin posterior to antennal base. Labium 235–242 μm long, longer than clypeolabral shield. Circulus present, about 115 μm long and 113 μm wide, situated between abdominal segments III and IV, divided by intersegmental line. Ostioles well developed, each lip with inner edge sclerotized and with 4–12 short setae and many trilocular pores. Anal ring situated on dorsum about half its length from apex of abdomen, 87–97 μm long and 75–89 μm wide, bearing 6 long setae, each 100–132 μm long, longer than diameter of anal ring. Cerarii basically numbering 18 pairs, cerarian setae sometimes with flagellate tips. Anal lobe cerarii (C 18) each containing 6–8 conical setae, each 21.5–26.0 μm long and 7–8 μm wide at base, and a group of trilocular pores. Posterior abdominal cerarii (C 15 –C 17) each containing 3–6 conical setae; more anterior cerarii each usually containing 2 conical setae, but on thorax sometimes reduced to a single conical seta or sometimes cerarius not discernible.

Dorsal surface with short, stiff setae, each 10–15 μm long on head and 17.5–27.0 μm long on abdomen. Trilocular pores, each 3.5–4.0 μm wide, evenly distributed. Multilocular disc pores and oral collar tubular ducts absent. Discoidal pores, each smaller than a trilocular pore, few, scattered.

Ventral surface with slender flagellate setae, each 51.5–75.0 μm long on head and 57.5–80.0 μm long on abdomen. Cisanal and obanal setae present, each 100–132 μm long. Multilocular disc pores, each about 8 μm in diameter, present posterior vulva in single or double transverse rows across median area of abdominal segments IV–VII; sometimes also 1 or 2 on marginal areas of abdominal segment VII. Trilocular pores evenly distributed, fewer than on dorsum. Oral collar tubular ducts of 2 sizes present: (i) a large type, each 9–10 μm long and 4 μm wide, present across posterior medial areas of abdominal segments V–VI, sometimes a few also on medial areas of abdominal segments IV or VII, and forming groups on margins of posterior abdominal segments V–VIII; some also present on head; and (ii) a small type, each 7–8 μm long and 2.5–3.0 μm wide, present across posterior medial areas of abdominal segments V–VII, also 1 or 2 present on abdominal segment VIII. Discoidal pores few, scattered.

Host plant. Fabaceae : Delonix regia .

Distribution. China (Yunnan).

Etymology. The species name is based on a combination of the host plant genus name, Delonix , with the Latin suffix “- icola ” meaning dweller, and is used as a noun in apposition.

Remarks. Formicococcus delonicola is most similar to F. latens Williams 2004 in possessing oral collar tubular ducts on the head and in marginal groups on the posterior abdominal segments. However, it differs from the latter by the following features (condition of F. latens given in parentheses): (i) dorsal setae on abdominal segment VIII short, about same length as other dorsal setae (noticeably longer than other dorsal setae); (ii) anal ring setae longer than diameter of anal ring (shorter than diameter of anal ring or same length); and (iii) cerarian setae sometimes with flagellate tips (conical, without flagellate tips).

Formicococcus eriobotryae Wang 1985 , comb. rev.

Formicococcus eriobotryae Wang 1985: 444, 2001: 114 ; Huang et al. 1986: 277; Tang 1992: 289; Wu & Zheng 2001: 201.

Paraputo eriobotryae ( Wang 1985) : Danzig & Gavrilov-Zimin 2015: 18, 35.

Host plant. Rosaceae : Eriobotrya japonica .

Distribution. China (Fujian).

Remarks. This species was transferred to Paraputo , as P. eriobotryae (Wang) , by Danzig & Gavrilov-Zimin (2015) because it has an anal ring with six setae. However, the number of anal ring setae is not a robust genus-level character, especially as the number of setae can vary between the two sides of the anal ring. As it has an anal lobe bar on each anal lobe, this species is here restored to Formicococcus . A good description and illustration of the adult female was given by Wang (1985).

Formicococcus lingnani ( Ferris 1954)

Planococcus lingnani Ferris 1954: 52 ; Williams 1970: 163; Wang 1982a: 84.

Planococcoides lingnani ( Ferris 1954) : Tang 1992: 361; Wang 2001: 142; Ben-Dov 1994: 352.

Formicococcus lingnani ( Ferris 1954) : Williams 2004: 290; Joshi et al. 2020: 394 .

Paraputo lingnani ( Ferris 1954) : Danzig & Gavrilov-Zimin 2015: 18.

Host plants. Arecaceae : Areca catechu ; Cyperaceae : Cyperus rotundus ; Poaceae : Oryza sativa , Saccharum officinarum , Sorghum bicolor .

Distributions. China (Guangdong), India, Indonesia, Malaysia, Thailand.

Remarks. Descriptions and illustrations of the adult females were given by Ferris (1954), Williams (1970) and Williams (2004).

Formicococcus liui ( Borchsenius 1962) comb. n.

Anaparaputo liui Borchsenius 1962: 224 ; Wang 1982a: 27–28, 2001: 109; Tang 1992: 278.

Paraputo liui ( Borchsenius 1962) : Danzig & Gavrilov-Zimin 2015: 29, 41.

Material examined. CHINA: Guizhou: 4 ♀ ♀, Xingyi city, under bark crack of Ficus virens , 8.v.2017, coll. Jiangtao Zhang & Ming Zhao. Yunnan: 1 ♀, Jinghong city, on Ficus sp. , 25.iv.1957, coll. N.S. Borchsenius.

Host plants. Moraceae : Ficus sp. , F. virens .

Distribution. China (Guizhou, Yunnan).

Remarks. As it has an anal lobe bar on each anal lobe, Anaparaputo liui Borchsenius is here transferred to Formicococcus as Formicococcus liui (Borchsenius) comb. n. A good description and illustration of the adult female was given by Borchsenius (1962).

Formicococcus macarangae ( Takahashi 1940)

Pseudococcus macarangae Takahashi 1940: 18 .

Planococcoides macarangae ( Takahashi 1940) : Tu et al. 1988: 78; Tang 1992: 362; Wang 2001: 143.

Formicococcus macarangae ( Takahashi 1940) : inferred by Williams 2004: 273; Tanaka et al. 2021a: 174 in key (as Formicoccus macarangae ); Tanaka et al. 2021b: 203 in key.

Host plants. Ebenaceae : Diospyros philippinensis ; Euphorbiaceae : Macaranga sinensis , M. tanarius , Mallotus sp. , Ma. japonicus ; Fabaceae : Pueraria montana (= P. lobata ); Moraceae : Ficus microcarpa .

Distribution. China (Taiwan).

Remarks. Tsai (2011) also reported this mealybug on Diospyros philippinensis in Taiwan. A good description and illustration of the adult female was given by Tu et al. (1988).

Formicococcus mumensis ( Tang 1977) comb. rev.

Planococcus mumensis Tang 1977: 34, 1992: 374 ; Wang 1982a: 86, 2001: 150; Danzig & Gavrilov-Zimin 2015: 18, 206, 213.

Planococcoides mumensis ( Tang 1977) : Cox 1989: 3.

Formicococcus mumensis ( Tang 1977) : Williams 2004.

Host plant. Rosaceae : Prunus mume .

Distribution. China (Zhejiang).

Remarks. This species was transferred from Formicococcus back to Planococcus as P. mumensis Tang by Danzig & Gavrilov-Zimin (2015) because it has cerarii without multiple setae and an anal ring with six ring setae. However, as auxiliary setae are present in all the cerarii and the anal lobe cerarii each contain three conical setae, here we follow Cox (1989) in replacing it under Formicococcus . Good descriptions and illustrations of the adult females were given by Tang (1977, 1992).

Formicococcus polysperes Williams 2004

Formicococcus polysperes Williams 2004: 302 .

Material examined. CHINA: Guangxi: 3 ♀ ♀, Jingxi city, on the root of Panax notoginseng , 30.xi.2015, coll. Jun-jing Zhou. Yunnan: 2 ♀ ♀, Ruili city, Nanmao Lake Park, on the root of Ophiopogon sp. , 22.x.2016, coll. Xu-bo Wang & Yao-guang Qin ; 2 ♀ ♀, Jinghong city, Binhe Park , under bark crack of Ficus sp. , 12.x.2016, coll. Xu-bo Wang & Yao-guang Qin ; 2 ♀ ♀, Linchang , on the root of Amomum villosum , 21.v.2016, coll. Zi-lin Yang ; 2 ♀ ♀, Dehong , Coffea sp. , 17.viii.2013, coll. Fu-zhong Wu ; 1 ♀, Baoshan city, Eriobotrya japonica , 3.viii.2012 ; 1 ♀, Jinghong city, Artocarpus heterophyllus , 20.x.2008, coll. Kai-ping Ji ; 1 ♀, Jinghong city, on the root of Musa acuminata , 3.iv.2008, coll. Jin Liu, San-an Wu & Shan-shan Wang ; 15 ♀ ♀, Jinghong city, Xishuangbanna Tropical Flowers and Plants Garden , on the root of Strelitzia reginae , 2.iv.2008, coll. Jin Liu, San-an Wu & Shan-shan Wang ; 1 ♀, Jinghong city, Xishuangbanna Tropical Flowers and Plants Garden , on the root of Dypsis lutescens , 2.iv.2008, coll. Jin Liu, San-an Wu & Shan-shan Wang ; 3 ♀ ♀, Jinghong city, Xishuangbanna Tropical Flowers and Plants Garden , Puccinellia distans , 1.iv.2008, coll. Jin Liu, San-an Wu & Shan-shan Wang.

Host plants. Araceae : Amorphophallus paeoniifolius ; Araliaceae : Panax notoginseng ; Arecaceae : Areca catechu , Cocos nucifera , Dypsis lutescens , Rhapis excelsa ; Asparagaceae : Ophiopogon sp. ; Asteraceae : Ageratum conyzoides , Synedrella nodiflora ; Cyperaceae : Rhynchospora colorata (= Cyperus kyllingia ); Euphorbiaceae : Balakata baccata (= Sapium baccatum ), Macaranga conifera , M. triloba ; Fabaceae : Arachis hypogaea , Delonix regia , Erythrina ; Lamiaceae : Clerodendrum infortunatum ; Meliaceae : Lansium parasiticum (= L. domesticum ); Moraceae : Artocarpus heterophyllus , Ficus sp. ; Musaceae : Musa acuminata ; Phyllanthaceae : Phyllanthus niruri ; Piperaceae : Piper betle , P. nigrum ; Poaceae : Puccinellia distans ; Rubiaceae : Coffea sp. , C. arabica ; Rosaceae : Eriobotrya japonica ; Solanaceae : Physalis minima ; Strelitziaceae : Strelitzia reginae ; Urticaceae : Urtica parviflora ; Zingiberaceae : Amomum villosum , Curcuma longa , Zingiber sp. , Z. officinale .

Distributions. China (Guangxi, Yunnan), India, Malaysia, Philippines, Thailand, Vietnam.

Remarks. Zhang et al. (2015) reported that this species formed fungus-insect galls with Phlebopus portentosus (Berk. and Broome) Boedijn 1951 (Fungi: Boletales : Boletinellaceae ) on the roots of Coffea arabica and Delonix regia in Yunnan. Good descriptions and illustrations of the adult and second instar females were provided by Williams (2004).

Formicococcus robustus ( Ezzat & McConnell 1956)

Pseudococcus crotonis Green : Ayyar 1919: 41 (misidentification in part).

Planococcoides robustus Ezzat & McConnell 1956: 59 ; Avasthi & Shafee 1987: 34; Tang 1992: 364; Varshney 1992: 56; BenDov 1994: 353.

Indococcus pipalae Ali 1967: 35 ; Avasthi & Shafee 1987: 22; Tang 1992: 295; Varshney 1992: 53; Ben-Dov 1994: 204.

Dysmicoccus cucurbitae Avasthi & Shafee 1986: 437, 1987: 16 ; Varshney 1992: 50; Ben-Dov 1994: 128.

Planococcoides bengalensis Ghosh & Ghose 1988: 604 ; Varshney 1992: 56; Ben-Dov, 1994: 350.

Ferrisicoccus cucurbitae ( Avasthi & Shafee 1986) : Tang 1992: 286.

Ferrisicoccus psidii Mukhopadhyay & Ghose 1994: 71

Formicococcus robustus ( Ezzat & McConnell 1956) : Williams 2004: 307; Wu 2009: 57; Joshi et al. 2020: 393 .

Paraputo robustus ( Ezzat & McConnell 1956) : Danzig & Gavrilov-Zimin 2015: 18.

Host plants. Acanthaceae : Crossandra sp. ; Anacardiaceae : Lannea coromandelica , Mangifera indica ; Annonaceae : Annona squamosa ; Apocynaceae : Tabernaemontana sp. ; Arecaceae : Phoenix dactylifera ; Asteraceae : Conyza bonariensis (= C. ambigua ); Cucurbitaceae : Cucurbita maxima , Cu. pepo ; Fabaceae : Acacia nilotica (= A. arabica ), Albizia lebbeck , Erythrina sp. , E. variegata (= E. indica ), Prosopis cineraria (= P. spicigera ), Vachellia nilotica ; Gnetaceae : Gnetum luofuense ; Moraceae : Artocarpus heterophylla , Ficus benghalensis , F. religiosa , Morus sp. ; Myrtaceae : Psidium guajava , Syzygium cumini ; Papaveraceae : Argemone mexicana ; Rhamnaceae : Ziziphus sp. ; Rubiaceae : Coffea arabica ; Rutaceae : Citrus sp. ; Vitaceae : Vitis vinifera .

Distributions. China (Yunnan), Bangladesh, India, Iran, Pakistan.

Remarks. Wu (2009) reported this mealybug from Yunnan on Coffea spp. Good descriptions and illustrations of the adult females were provided by Ezzat & McConnell (1956) and Williams (2004).

Formicococcus schimae Takahashi 1929

Formicococcus schimae Takahashi 1929: 40 ; Tu et al. 1988: 76; Wang 1982a: 50–51, 2001: 116; Tang 1992: 291; Wu & Zheng 2001: 201; Danzig & Gavrilov-Zimin 2015: 24.

Host plant. Theaceae : Schima noronhae .

Distribution. China (Taiwan).

Remarks. A good description and illustration of the adult female was given by Tu et al. (1988).

Formicococcus sinensis ( Borchsenius 1962)

Paraputo sinensis Borchsenius 1962: 224 ; Wang 1982a: 73, 2001: 125; Tang 1992: 312; Danzig & Gavrilov-Zimin 2015: 45.

Formicococcus sinensis ( Borchsenius 1962) : Zhang & Wu 2017: 57.

Host plant. Juglandaceae : Engelhardia sp.

Distribution. China (Yunnan).

Remarks. A good description and illustration of the adult female was given by Borchsenius (1962).

Formicococcus speciosus (Wang 1982)

Paraputo speciosus Wang 1982a: 73–74, 1982b: 316–317 .

Formicococcus speciosus (Wang 1982) : Tang 1992: 291; Wang 2001: 117; Wu & Zheng 2001: 202; Danzig & Gavrilov-Zimin 2015: 24.

Host plant. Theaceae : Camellia oleifera (= C. oleosa ).

Distribution. China (Hunan).

Remarks. Good descriptions and illustrations of the adult females were given by Wang (1982a, 1982b).

Formicococcus yanglingensis Wu & Zheng 2001

Formicococcus yanglingensis Wu & Zheng 2001: 202 , 204; Danzig & Gavrilov-Zimin 2015: 26.

Material examined. CHINA: Beijing: 2 ♀ ♀, Beijing Forestry University Campus , under bark crack of Platanus occidentalis , 20.ix.2016, coll. Jiang-tao Zhang ; 1 ♀, Beijing Forestry University Campus , under bark crack of Platanus occidentalis , 19.ix.2016, coll. Jiang-tao Zhang ; 1 ♀, Beijing Forestry University Campus , under bark crack of Platanus occidentalis , 16.ii.2016, coll. Jiang-tao Zhang & Xu-Bo Wang; 6 ♀ ♀, Beijing Botanical Garden , Koelreuteria paniculata , 20.ix.2008, coll. De-Ping Xiong. Jiangxi: 5 ♀ ♀, Ganzhou city, Yangmeidu Park , under bark crack of Acer palmatum , 23.viii.2016, coll. Jiang-tao Zhang & Qin-gang Dong ; 3 ♀ ♀, Yingtan city, Yingtan Park , under bark crack of Platanus sp. , 14.viii.2016, coll. Jiang-tao Zhang & Qin-gang Dong ; 4 ♀ ♀, Yingtan city, under bark crack of Platanus sp. , 14.viii.2016, coll. Jiang-tao Zhang & Qin-gang Dong. Hebei: 1 ♀, Xingtai city, under bark crack of Platanus sp. , 8.x.2016, coll. Jiang-tao Zhang. Shaanxi: 18 ♀ ♀, Northwest A&F University Campus, Prunus cerasifera var. atropurpurea , 2.ix.1999, coll. San-an Wu.

Host plants. Platanaceae : Platanus sp. , P. occidentalis ; Rosaceae : Prunus cerasifera var. atropurpurea ; Sapindaceae : Acer palmatum , Koelreuteria paniculata .

Distribution. China (Beijing, Hebei, Jiangxi, Shaanxi).

Remarks. A good description and illustration of the adult female was given by Wu & Zheng (2001).

Notes. The species Pedronia acanthodes Wang 1979 was described as new by Wang (1979), subsequently transferred to Indococcus by Tang (1992), and then transferred (doubtfully) to Formicococcus by Danzig & GavrilovZimin (2015). It is not included in this study since, according to Wang’s descriptions (1982a, 2001), it possesses quinquelocular pores on the venter and lacks bars on the anal lobes; we therefore judge that it does not fall within our understanding of the morphology of Formicococcus .

Another species, Drymococcus rhizophilus Borchsenius 1962 , was transferred to Formicococcus , as F. rhizophilus ( Borchsenius 1962) , by Danzig & Gavrilov-Zimin (2015) because it has an anal ring with multiple ring setae. However, the number of anal ring setae is not a robust genus-level character, especially as the number of setae can differ between the two sides of the same anal ring. As the species lacks anal lobe bars, here it is not included in Formicococcus .

Key to adult females of Formicococcus species in the Palaearctic and Oriental Regions

(adapted and modified from Wu & Zheng 2001, Williams 2004, Joshi et al. 2020 and Tanaka 2021).

1(0) Antennae each with 6–8 segments....................................................................... 2

- Antennae each with 9 segments......................................................... F. schimae Takahashi

2(1) Circulus absent...................................................................................... 3

- Circulus present...................................................................................... 4

3(2) Dorsal and ventral surfaces of anal lobes membranous except for anal lobe bars.................. F. dispersus Williams

- Dorsal and ventral surfaces of anal lobes sclerotized, in addition to anal lobe bars................... F. lingnani (Ferris)

4(2) Oral collar tubular ducts present on dorsum................................................................ 5

- Oral collar tubular ducts absent from dorsum............................................................... 6

5(4) Ventral oral collar tubular ducts of 1 size.................................................... F. bambusus (Wu)

- Ventral oral collar tubular ducts of 2 sizes............................................ F. bambusicola (Takahashi)

6(4) Translucent pores absent from hind coxa.................................................................. 7

- Translucent pores present on hind coxa................................................................... 8

7(6) Abdominal cerarii C 15, C 16 and C 17, each containing only 2 conical setae.......................... F. mumensis (Tang)

- Abdominal cerarii C 15, C 16 and C 17, each containing more than 2 conical setae..................... F. eriobotryae Wang

8(6) Ventral surface of each anal lobe sclerotized, in addition to anal lobe bar......................................... 9

- Ventral surface of each anal lobe membranous except for anal lobe bar......................................... 10

9(8) Oral collar tubular ducts confined to venter of abdomen.................................... F. burckhardti Williams

- Oral collar tubular ducts present on venter of thorax as well as abdomen......................... F. matileae Williams

10(8) Ventral setae, including anal lobe bar setae, cisanal and obanal setae, usually (or mostly) slender and flagellate.......... 11

- Ventral setae, including anal lobe bar setae, cisanal and obanal setae, thick, stout and curved....... F. tripurensis Williams

11(10) Anal ring bearing more than 6 setae, and head without ventral oral collar tubular ducts............................. 12

- Anal ring usually bearing 6 setae only, if more than 6 setae (7 or 8), then head with ventral oral collar tubular ducts...... 14

12(11) Margins of abdominal segments with multilocular disc pores................................... F. speciosus (Wang)

- Margins of abdominal segments without multilocular disc pores............................................... 13

13(12) Margins of abdominal segments with ventral oral collar tubular ducts; anal lobe cerarii each with 2 or 3 conical setae...................................................................................... F. cinnamomi Takahashi

- Margins of abdominal segments without ventral oral collar tubular ducts; anal lobe cerarii each with 4 or 5 conical setae................................................................................ F. yanglingensis Wu & Zheng

14(11) Cerarii numbering more than 6 pairs..................................................................... 15

- Cerarii numbering fewer than 6 pairs....................................................... F. yoshinoi Tanaka

15(14) Head with ventral oral collar tubular ducts................................................................ 16

- Head without ventral oral collar tubular ducts............................................................. 24

16(15) Cerarii on head and thorax separate..................................................................... 17

- Cerarii on head and thorax merged to form a continuous row.................................... F. citricola (Tang)

17(16) All cerarii containing short, conical setae................................................................. 18

- Either all cerarii containing many long, conical or flagellate setae forming tufts, or some cerarii on head and thorax containing paired flagellate setae................................................................................ 22

18(17) Abdominal cerarii without auxiliary setae, except for some auxiliary setae in anal lobe cerarii (C 18)................... 19

- Abdominal cerarii containing auxiliary setae.......................................... F. macarangae (Takahashi)

19(18) Ventral submargin of prothorax near each anterior coxa with oral collar tubular duct group.......................... 20

- Ventral submargin of prothorax near each anterior coxa without ventral oral collar tubular ducts..................... 21

20(19) Ventral margins of mesothorax, metathorax and opposite ocular cerarii (C 3) without oral collar tubular ducts.............................................................................................. F. polysperes Williams

- Ventral margins of mesothorax, metathorax and opposite ocular cerarii (C 3) with oral collar tubular ducts.............................................................................................. F. mangiferacola Williams

21(19) Dorsal setae on abdominal segment VIII short, about same length as other dorsal setae............... F. delonicola sp. n.

- Dorsal setae on abdominal segment VIII noticeably longer than other dorsal setae.................... F. latens Williams

22(17) Ventral abdominal margins with multilocular disc pores..................................................... 23

- Ventral abdominal margins without multilocular disc pores.................................... F. formicarii (Green)

23(22) Most cerarian setae elongate conical, but sometimes with flagellate tips; hind femur without translucent pores............................................................................................... F. simplicior (Green)

- All cerarian setae elongate and flagellate; hind femur with translucent pores.................. F. formicarius (Newstead)

24(15) Ventral submargin of prothorax near each anterior coxa without group of oral collar tubular ducts.................... 25

- Ventral submargin of prothorax near each anterior coxa with group of oral collar tubular ducts........ F. liui (Borchsenius)

25(24) All or many dorsal setae conical........................................................................ 26

- Dorsal setae not conical: either short, thick and stiff, or flagellate.............................................. 27

26(25) Abdominal midline with dorsal conical setae associated with trilocular pores, forming dorsal cerarii... F. monticola (Green)

- Dorsal conical setae on abdominal midline not associated with trilocular pores or forming dorsal cerarii................................................................................................. F. sinensis (Borchsenius)

27(25) All cerarii containing short, conical setae................................................................. 28

- Cerarii on head and thorax containing long, paired flagellate setae.............................. F. acerneus Williams

28(27) Hind tibia with translucent pores; cerarii basically numbering 18 pairs.......................................... 29

- Hind tibia with translucent pores absent or very rare; cerarii numbering 11–15 pairs..... F. tectonae Joshi, Bindu & Gullan

29(28) Anal lobe cerarii (C 18) each mostly with 2 conical cerarian setae............................................... 30

- Anal lobe cerarii (C 18) each mostly with more than 2 conical cerarian setae...................................... 31

30(29) Penultimate cerarii (C 17) each with 2 conical cerarian setae................................ F. sibolangiticus Williams

- Penultimate cerarii (C 17) mostly each with 5–7 cerarian setae.................................. F. erythrinae Williams

31(29) Hind coxae noticeably wider and larger than anterior coxae; ventral multilocular disc pores absent from abdominal segment IV........................................................................... F. cameronensis (Takahashi)

- Hind coxae same shape as anterior coxae, and only slightly larger; ventral multilocular disc pores present on abdominal segment IV....................................................................... F. robustus (Ezzat & McConnell)

Figures

FIGURE 1. Adult female of Formicococcus delonicola Zhang & Wu sp. n. A. Ventral flagellate seta on head; B. Trilocular pore; C. Discoidal pore; D. Hind coxa; E. Claw; F. Large type of oral collar tubular duct; G. Small type of oral collar tubular duct; H. Multilocular disc pore; I. Anal lobe cerarius (C18); J. Dorsal seta; K. Cerarius on head.