Pharoscymnus horni (Weise)

Poorani, J., 2025, A review of Pharoscymnus Bedel (Coleoptera: Coccinellidae: Sticholotidini) of the Indian region, Zootaxa 5665 (1), pp. 37-57 : 45-49

Pharoscymnus horni (Weise)

( Figs 1 , 2 , 6–8 )

Pharus horni Weise, 1900: 434 .

Pharoscymnus horni : Korschefsky 1931: 215.— Poorani 2002: 364; Kovář 2007: 570.

Diagnosis. Length: 2.00– 2.20 mm; width: 1.70–1.90 mm. Form ( Fig. 6a–d ) almost circular in male, slightly more elongate in female; dorsum strongly convex and densely pubescent. Ground colour dark brown to almost black in live specimens, dull brown or much paler yellowish brown in preserved specimens, each elytron with a pair of reddish/orange-yellow spots, anterior spot subquadrate and large, posterior spot roundish and smaller. Ventral side uniformly yellowish brown, prosternum and metaventrite sometimes darker brownish. Male genitalia ( Figs 1i–k , 6h–k ) and female genitalia ( Fig. 6g ) as illustrated; coxites ( Figs 1h , 6g ) elongate triangular.

Immature stages. Life stages as illustrated ( Figs 2 , 7 , 8 ). Eggs ( Figs 2a, b , 7a–d , 8a ) are bright yellow and laid singly or in small groups in scale colonies. The larva ( Figs 2c, d , 7e, f ; 8b–d ) is usually slatey grey or brownish and spindle shaped. The pupa ( Fig. 2e , 8e, f ) is yellowish brown to brown and densely setose with the last larval skin attached to the caudal end.

Material examined. INDIA: Tamil Nadu: Podavur, NRCB Research farm, Ex. Aspidiotus destructor on banana, R. Thanigairaj, 10 ex. ( NRCB) ; INDIA: Tamil Nadu: Podavur, NRCB Research farm, Ex. Aspidiotus destructor on coconut, R. Thanigairaj, 10 ex. ( NRCB) ; INDIA: Tamil Nadu: Ariyavur , 25.iii.22, Lat. 10.767995 Long. 78.573237, Ex. Feeding on Ceroplastes sp. on guava, R. Thanigairaj ( NRCB) ; Several specimens received for identification, without label data.

Distribution. India: Widely distributed (Andhra Pradesh; Assam; Bihar; Delhi; Gujarat; Himachal Pradesh; Jharkhand; Karnataka; Kerala; Maharashtra; Odisha; Rajasthan; Tamil Nadu; Telangana; Uttar Pradesh; West Bengal; Lakshadweep Islands); Bangladesh; Sri Lanka; Pakistan; Iran ( Abdolahi et al. 2018). Introduced and released in California, USA, in 1923 but did not establish ( Clausen 1978; Gordon 1985). Flanders (1934) mentioned it was introduced into California, USA, in 1933 for the control of Aonidiella (Chrysomphalus) auranti, Mask. , (citrus red scale) but ‘not recovered after liberation in the field’.

Prey/associated habitat. Hemiptera : Coccoidea: Diaspididae : Andaspis laingi Rao , Andaspis?leucophleae Rao , Aonidiella aurantii (Maskell) , Aonidomytilus albus (Cockerell) , Aspidiella?hartii (Cockerell) , Aspidiotus destructor Signoret , Aspidiotus tamarindi Green , Aulacaspis tubercularis Newstead , Chrysomphalus aonidum (Linnaeus) , Diaspis echinocacti (Bouché) , Duplaspidiotus tesseratus (Grandpre & Charmoy) , Gannaspis glomerata (Green) , Greenaspis decurvata (Green, 1903) , Hemiberlesia lataniae (Signoret) , Lepidosaphes beckii (Newman) , Lepidosaphes piperis (Green) , Parlatoria blanchardi (Targioni Tozzetti) , Pinnaspis strachani (Cooley) , Pseudaulacaspis pentagona (Targioni Tozzetti) ; Coccidae : Coccus viridis (Green) , Saissetia coffeae (Walker) , Ceroplastes sp. on guava (label data); Monophlebidae : Icerya aegyptiaca (Douglas) ; Phoenicococcidae : Phoenicococcus marlatti Cockerell ; Pseudococcidae : Saccharicoccus sacchari (Cockerell) , Coccidohystrix insolita (Green) . Associated with/predaceous on scale insects and sometimes, mealybugs, infesting sugarcane, black pepper, tea, agave, cactus, tobacco, mango, date palm ( Phoenix dactylifera ), rose, Thevetia neriifolia , Croton sparsiflorus , guava (label data), and brinjal.

Seasonal occurrence. Abundant on Thevetia and cactus infested with scales during January–June in and around Bangalore ( Puttarudriah & Channabasavanna 1956). Collected in January and September ( Puttarudriah & Channabasavanna 1957). Collected during March–April and September in South India (label data). Feeds on diaspine scales infesting banana during summer (April–May) ( Poorani et al. 2023). Larvae and adults present during May–December with a peak in September in Pakistan ( Rafi et al. 2005).

Notes. The species referred to as ‘ Platynaspis villosa, Mulsant ,….’ ( Cotes 1896) and ‘ Platynaspis luteorubra ’ ( Stebbing 1903; Ramakrishna Ayyar 1930) from India is P. horni . Puttarudriah’s (1954) record of ‘ Pharoscymnus grimeti Muls. ’ (sic) as a predator of sugarcane mealybug ( Saccharicoccus sacchari ) from the erstwhile Mysore state (now Karnataka) also involves P. horni . Smirnoff (1956) and Chelliah (1965) provided diagnostic descriptions/ illustrations of the genitalia. Puttarudriah & Channabasavanna (1956, 1957) provided brief notes on its distribution in Mysore (south India).

Its biology and field efficacy against sugarcane scale, Gannaspis glomerata (Green) [= Melanaspis glomerata Green ], a major pest of sugarcane in India, has been extensively studied by many workers in different agroclimatic conditions ( Dorge et al. 1972; Rao & Subbarao 1981; Raju & Rao 1982; Raghunath & Rao 1982; Misra et al. 1983; Pawar et al. 1983; Ansari et al. 1989). Das & Gope (1984) studied its biology on tea black scale, Chrysomphalus aonidum (L.) [as C. ficus (Ashmead) ].

Figures

FIGURE 1. Pharoscymnus horni (Weise), diagnostic characters: a) head; b) antenna; c) maxilla; d) prosternal process; e) abdomen, male; f) abdomen, female; g) foreleg; h) coxites; i–k) male genitalia: i) tegmen, lateral view; j) tegmen, inner view; k) penis.

FIGURE 2. Immature stages of Pharoscymnus horni (Weise): a, b) egg; c, d) larva; e) pupa.

FIGURE 6. Pharoscymnus horni (Weise): a–d) dorsal view; e) abdomen, male; f) abdomen, female; g) female genitalia; h–l) male genitalia: h) tegmen, lateral view; i) tegmen, inner view; j) penis; k) penis capsule; l) penis apex.

FIGURE 7. Life stages of Pharoscymnus horni (Weise): a–d) egg; e, f) larva; g, h) adult.

FIGURE 8. Pharoscymnus horni (Weise), life stages: a) eggs; b–d) larva; e, f) pupa; g, h) adult.