Psyllaephagus, Ashmead, 1900

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 : 577-578

Genus PSYLLAEPHAGUS Ashmead

Psyllaephagus Ashmead, 1900:382 . Type species: Encyrtus pachypsyllae Howard , by original designation.

Mirocerus Ashmead, 1904:309 . Type species: Mirocerus peyelae Ashmead , by original designation and monotypy. Synonymy with Psyllaephagus by Trjapitzin & Gordh (1978:636).

Calocerineloides Girault, 1913:111 . Type species: Calocerineloides ramosa Girault , by original designation and monotypy. Synonymy with Psyllaephagus by Noyes & Hayat (1984:330).

Epanagyrus Girault, 1915a:160 . Type species: Epanagyrus punctatiscutum , by original designation and monotypy. Synonymy with Psyllaephagus by Noyes & Hayat (1984:330).

Neanagyrus Girault, 1915a:174 . Type species: Neanagyrus capitatus Girault , by original designation. Synonymy with Psyllaephagus by Dahms & Gordh (1997:305,307).

Anagyropsis Girault, 1917c:136 . Type species: Anagyrus purpureus Girault , by original designation. Synonymy with Psyllaephagus by Noyes & Hayat (1984:330).

Metaprionomitus Mercet, 1921:260-261 . Type species: Metaprionomitus intermedius Mercet , by original designation. Synonymy with Psyllaephagus by Trjapitzin (1967:102).

Shakespearia Girault, 1928:3 . Type species: Shakespearia flabellata Girault , by monotypy. Synonymy with Psyllaephagus by Noyes & Hayat (1984:330).

Psyllencyrtus Tachikawa, 1955:63 . Type species: Psyllencyrtus syntomozae , by original designation. Synonymy with Psyllaephagus by Tachikawa (1981:88).

Calluniphilus Erdös, 1961:413 . Type species: Calluniphilus vendicus Erdös , by monotypy. Synonymy with Psyllaephagus by Graham, 1969:248-249.

Anisodromus Riek, 1962b:283 . Type species: Anisodromus tarsius Riek , by original designation. Synonymy with Psyllaephagus by Dahms & Gordh (1997:305,307).

Ooencyrtoides Hoffer, 1963:568 . Type species: Ooencyrtus albopilosus Hoffer , by original designation (as subgenus of Ooencyrtus Ashmead ). Synonymy with Psyllaephagus by Graham (1969:248).

Propsyllaephagus Blanchard in De Santis, 1964:235 . Type species: Propsyllaephagus trellesi Blanchard , by original designation. Synonym of Psyllaephagus by Noyes (1979:165).

Mercetia Bakkendorf, 1965:139 . Type species: Copidosoma lusitanicum Mercet , by original designation. Synonymy with Psyllaephagus by Graham (1969:248-249).

Kaszabicyrtus Szelènyi, 1971:389 . Type species: Kaszabicyrtus acutigastris Szelènyi , by original designation. Synonymy with Psyllaephagus by Trjapitzin & Gordh (1978:636).

Psyllophagus; Sperber & Collevatti, 1996: 59-63. Misspelling.

Female. Overall length 0.7-2.6mm (extralimital species up to 4mm).

Body generally dark brown, with a weak to moderately strong metallic sheen on head and dorsum of thorax, mesoscutum sometimes very bright metallic green or blue, but often quite dull.

Head at most about 3X as wide as frontovertex; occipital margin narrowly rounded, sometimes acute but never carinate; eye clothed with inconspicuous pale setae, usually about as long as diameter of eye facet or a little shorter; funicle 6-segmented, segments subcylindrical; clava 2- or 3-segmented, apically rounded or with a relatively weak, oblique apical truncation although in some extralimital species the clava may be slightly enlarge with a strong, oblique apical truncation; mandible with one tooth and broad truncation, two teeth and a truncation or two teeth and a truncate upper tooth; palp formula 4-3.

Mesoscutum without notaular lines; posterior margin of mesoscutum hardly produced medially, not overlapping axillae medially; fore wing mostly about 2.2-2.5X as long as broad; usually hyaline, sometimes weakly infuscate, rarely strongly infuscate; marginal vein about as long as broad, rarely more than 1.5X as long as broad; postmarginal vein usually at least half as long as stigmal vein, rarely shorter; mesopleuron not expanded posteriorly so that propodeum laterally is broadly in contact with hind coxa clearly separating mesopleuron from base of gaster.

Gaster occasionally with a small, pale, submedian, reticulate area on anterior margin of Gt3 (visible only on slide-mounted material); hypopygium not reaching apex of gaster, not usually reaching more than two-thirds along gaster; apex of syntergum mostly rounded to slightly acute, very acutely extended in species with an elongate ovipositor; ovipositor hidden or hardly exserted, but in some extralimital species the ovipositor may be very strongly exserted and as long as the gaster or longer; semicircular sheet of second valvifer usually conspicuously enlarged and extended posteriorly, sometimes enormously so and often subrectangular in shape; gonostylus free.

Male. Overall length 0.7-2.2mm.

Similar to female except for structure of antenna and genitalia; some extralimital species have bizarre processes on the face or have a strongly distorted head; antennae vary from filiform with all funicle segments more than 2X as long as broad and clothed in long setae to the segments broadened, sometimes quadrate or transverse and clothed in very short setae; in some extralimital species some or all of the funicle segments may be branched or each segment may be excessively broadened and flabellate; genitalia slender with digiti and parameres well-developed and elongate, each up to 7 or 8 times as long as broad; digitus with one or two apical hooks; paramere with a single seta; cuspis seta absent or present; aedeagus varying from about half as long as mid tibia to much longer than it.

DISTRIBUTION. Cosmopolitan.

HOSTS. Solitary primary endoparasitoids of nymphs of jumping plant lice ( Hemiptera : Psylloidea).

BOCONTROL. To date, three species of Psyllaephagus have been used in classical biological control programmes worldwide: bliteus , pilosus and yaseeni . The first of these, Psyllaephagus bliteus Riek , was introduced into California in 2000-2001 from southern Australia for the control of the red-gum lerp psyllid, Glycaspis brimblecombei Moore ( Hemiptera : Aphalaridae ), a serious pest of Eucalyptus camaldulensis Dehnh. ( Myrtales : Myrtaceae ). It established and quickly became effective in coastal areas but less so in the Central Valley ( Dahlsten et al., 2005). The parasitoid was subsequently introduced into Mexico and Chile from California and Australia in 2000 and released against the same pest. (Trjapitzin et al., 2008; Cuello et al., 2021). It has also been introduced accidentally, along with its host, into many other countries where Eucalyptus camaldulensis is grown, viz: Hawaii, Brazil, Argentina, Portugal, Spain, Morocco, Tunisia, Italy, Greece and New Zealand ( Cuello et al., 2021, Daane et al., 2005). See also below under P. pilosus (p. 594) and P. yaseeni (p. 595).

COMMENTS. Smaller species of Psyllaephagus species are easy to confuse with Ooencyrtus because of the similar squat habitus, generally similar mandibular shape and short marginal vein of the fore wing. The two genera can be separated readily on the shape of the posterior margin of the mesoscutum and the mesopleuron. In Psyllaephagus the posterior margin of the mesoscutum is only weakly angular and medially hardly overhangs so that the axillae appear to be meeting medially, whereas in Ooencyrtus the posterior margin of the mesoscutum is medially convex, distinctly overhanging the axillae distinctly separating them. Further to this the mesopleuron of Psyllaephagus is not expanded posteriorly so that it does not separate the propodeum from the hind coxa and is therefore well-separated from the base of the gaster. In Ooencyrtus the mesopleuron is posteriorly expanded so that it separates the propodeum from the hind coxa and touches, or nearly touches, the base of the gaster. In general, the stigmal vein is much more slender in Psyllaephagus than in Ooencyrtus .

The small, reticulate, submedian area on the anterior margin of Gt3 (see diagnosis above) is not present in all species but is found in some New World, European and African species, and may indicate some sort of phylogenetic relationship.

IDENTIFICATION. 252 species worldwide, including 7 species described below as new. See Trjapitzin 1982, 1989 (keys to 43 and 57 Palaearctic species respectively); Riek, 1962a (revision of 59 Australian species); Noyes & Hayat, 1984 (list of 107 Australian species); Hayat, 2006 (review of 10 Indian species); Berry, 2007 (revision of 7 New Zealand species); Prinsloo, 1981 (revision of 20 Afrotropical species).