Anicetus, Howard, 1896

Noyes, John Stuart, 2023, ENCYRTIDAE OF COSTA RICA (HYMENOPTERA: CHALCIDOIDEA), 4 Subfamily Encyrtinae: tribes Arrhenophagini, Habrolepidini, Cerapterocerini, Cheiloneurini, Trechnitini, Cercobelini, Polaszekiini, Protyndarichoidini, Gahaniellini and Syrphophagini (part), mainly primary parasitoids and hyperparasitoids of Coccoidea and Psylloidea (Hemiptera), Taxonomic Monographs on Neotropical Hymenoptera (Oxford, England) 2 (11), pp. 1-921 : 504-505

Genus ANICETUS Howard

Anicetus Howard in Howard & Ashmead, 1896:639. Type species: Anicetus ceylonensis Howard , by monotypy.

Asteropaeus Howard, 1898:231 . Type species: Asteropaeus primus Howard , by monotypy. Synonymy with Anicetus by Peck (1951:500).

Habrolepopterygis Girault, 1915a:86 . Type species: Habrolepopterygis felix Girault , by monotypy. Synonymy with Anicetus by Girault (1916b:302).

Paraceraptrocerus Girault, 1920b:184 . Type species: Paraceraptrocerus africanus Girault , by original designation. Synonymy with Anicetus by Trjapitzin (1989:302).

Krishneriella Mani, 1935:421. Type species: Krishneriella ceroplastodis Mani , by monotypy. Synonymy with Anicetus by Hayat (1976:49).

Female. Overall length about 0.8-1.90mm (up to 2.7mm in extralimital species).

Body not dorsoventrally flattened; generally pale orange to dark brown, sometimes metallic in darker species; fore wing infuscate, hyaline at apex and usually also at base, infuscate area enclosed subapically by a characteristic curved, more strongly infuscate band.

Head without conspicuous, setigerous punctures on frontovertex; scrobal area delimited dorsally by a strong, slightly curved, transfacial carina; dorsal surface of transfacial carina without a band of dense setae; scrobes relatively broad and shallow, meeting dorsally; mandible, in Costa Rica species, with three teeth, upper tooth apically rounded or transversely truncate, extralimital species may have the middle tooth broadly rounded or truncate or only one tooth and a broad truncation; palp formula 4-3; antenna inserted near mouth; antennal scape strongly broadened and flattened, subrhomboidal or subtriangular in profile; upper margin of scape angular about half way along its length, its distal margin often dorsally flattened and shiny; upper margin of pedicel often flattened and shiny, sometimes polished; pedicel mostly strongly ventrally produced, enclosing F1; pedicel and flagellum strongly flattened; funicle 6-segmented, segments transverse, mostly strongly so, at least some segments with a strong ventral projection; clava 3-segmented, in Costa Rica species at least as long as pedicel and funicle combined, but in many extralimital species clava much shorter than funicle, sutures sometimes only partial, sensory area greatly enlarged, so that clava has a strong, oblique apical truncation.

Mesoscutum, in many species with a line of scattered pore-like structures along the mid-line (Fig. 1292); fore wing about 2.3-2.7X as long broad, postmarginal and stigmal veins more or less connected by a naked, hyaline streak; marginal vein at least 1.5X as long as broad, mostly at least 3X as long broad, postmarginal and stigmal veins well developed; apex of postmarginal vein delimited by a single relatively long setae; basal cell usually with a large area devoid of setae with area below parastigma and marginal vein naked, extralimital species may have basal cell entirely setose; filum spinosum present.

Gaster about as long as thorax, apex of syntergum rounded; hypopygium at least about 2X as broad as long, often strap-like; paratergites absent; ovipositor varying from hidden to strongly exserted, gonostylus free, varying from about as long as mid tibial spur to more than 4X as long in some extralimital species.

Male. Length about 0.6-1.5mm.

Head subtriangular in profile with vertex flat; frontovertex with polygonally reticulate sculpture; antenna inserted high on head, a little above lowest eye margin; scape slightly broadened and flattened, all funicle segments longer than broad, subcylindrical and clothed with whorls of long setae, the longest of which are at least 2-3X as long as diameter of segments; clava entire, but sometimes appearing two-segmented because of a median constriction; fore wing about 2.3-2.5X as long as broad, hyaline; venation similar to female but marginal vein often less than 2X as long as wide; phallobase with a single apical hook on each digitus, aedeagus slender, apically acute.

DISTRIBUTION. Cosmopolitan except higher latitudes.

HOSTS. Species of the genus have been recorded as primary parasitoids of soft scales ( Hemiptera :

Coccidae ), especially of the genera Ceroplastes Gray , Pulvinaria Targioni Tozzetti and Saissetia Deplanche ( Noyes, 2019) . Records from Diaspididae ( Hemiptera ) require confirmation.

BIOCONTROL. To date, eight named species of Anicetus have been utilised in classical biocontrol programmes aimed at various soft scale insects ( Hemiptera : Coccidae ) in different parts of the world. Most of these introductions were unsuccessful because the parasitoid was not released or did not become established. Anicetus ceroplastis Ishii and beneficus Ishii & Yasumatsu were introduced into Israel from Japan in about 1960 for the control of Ceroplastes floridensis Comstock but did not establish (Rivnay, 1968) and in about 1980 Anicetus dodonia Ferrière was imported into Israel for the control of the same scale, but was not released (Argov & Rössler, 1988). Anicetus beneficus and ohgushii Tachikawa were imported into the former USSR for the control of Ceroplastes sinensis Del Guercio sometime prior to 1988 but were not released (Izhevsky, 1988). Anicetus annulatus Timberlake was released in California ( USA) from Japan for the control of Eucalymnatus tessellatus (Signoret) (Smith, 1923), and again in about 1951 and 1981 for the control of Coccus pseudomagnoliarum (Kuwana) and Saissetia oleae (Olivier) , but these control attempts failed (Bartlett in Clausen, 1978; Kennett, 1988). Anicetus parvus Compere was imported into Australia in 1935 from Africa for the control of Gascardia destructor Newstead , but was not released (Wilson, 1960). However, Anicetus communis Annecke and nyassicus (Compere) from South Africa were released in Australia between 1968 and 1974 for the control of the same scale and have been attributed with at least partial control of the pest (Sands et al., 1986). The most important species of the genus to be used in biocontrol programmes has been Anicetus beneficus . This species has been used successfully for the control of Ceroplastes rubens Maskell since 1946 in Japan (Yasumatsu, 1958; Takagi, 2002) and was introduced from there to Australia in 1955 and 1977 (Smith, 1986) and South Korea in 1975 (Choi & Lee, 1989) where it successfully controls the pest. More recently, it was released in Papua New Guinea from Japan in 2002 and has become successfully established (Krull & Basedow, 2005).

COMMENTS. Anicetus belongs to group of largely unrelated genera where the females are structurally similar, all having a strongly flattened scape, strongly broadened or flattened flagellum and strongly infuscate fore wings. The majority of these genera have been delimited and defined by Annecke (1967) in his excellent study of the group. Anicetus can be distinguished from these and other similar genera by having the unique combination of a strong transfacial carina clearly separating the interantennal prominence from the frontovertex, a strongly flattened scape and flagellum and the main infuscate area of the fore wing delimited distally by a curved, darker band followed by a hyaline area. See also comments under Ammonoencyrtus (p. 519).

IDENTIFICATION. Worldwide about 60 species known. See Annecke, 1967 (World species of Anicetus and Paraceraptrocerus ), Trjapitzin & Ruiz Cancino, 2009 (New World) and Trjapitzin, 2010a (New World, Hawaii, Australia); also Prinsloo & Mynhardt, 1981 (Afrotropical species), Hayat, 2006 ( India), Sugonjaev, 2005 ( Vietnam), Sharkov, 1988 (Palaearctic), Xu & Li, 1991 ( China) and Xu & He, 1997 ( China).