Alaptus Westwood, 1839

Serguei V. Triapitsyn, 2017, Revision of Alaptus (Hymenoptera: Mymaridae) in the Holarctic region, with taxonomic notes on some extralimital species, Zootaxa 4279 (1), pp. 1-92 : 6-7

Alaptus Westwood, 1839

Alaptus Westwood 1839: 116 (key, etymology [footnote]), 119 (diagnosis), 120 (mentioned), 144. Type species: Alaptus minimus Westwood , by monotypy.

Alaptus Westwood : Walker 1846: 49 (key), 50 (short diagnosis); Foerster 1856: 120 (brief diagnosis); Dalla Torre 1898: 428 (catalog); Perkins 1905: 197 (diagnosis); Girault 1908: 179 –182 (history, distribution, host associations, diagnosis), 193– 194 (key); Girault 1910: 244 (list of species, discussion); Girault 1911b: 323 (list of North American species); Girault 1912: 126 –127 (key to Australian species); Girault 1929: 9 –10 (key to North American species, brief diagnosis); Soyka 1937: 74 –75 (overview); Soyka 1939a: 17 (overview); Soyka 1939b: 30 (key to European species), 31 (list of non- European species); Debauche 1948: 53 –56 (diagnosis, discussion, list of, and key to European species); Soyka 1948: 74 – 75 (key to females of European species); Debauche 1949: 9 –10 (diagnosis, key to African species); Soyka 1949: 12 –13, 15 (placed in family Alaptidae within superfamily Alaptoidea); Kryger 1950: 29 (key), 31–33 (nomenclatural history, diagnosis, remarks); Nikol’skaya 1952: 540 (key); Hincks 1959: 138 –139 (historical review, diagnosis), 140–141 (key); Annecke & Doutt 1961: 9 (short diagnosis, distribution, comments); New 1969: 181 –192 (biology); Hellén 1974: 14 (diagnosis, key to species in Finland); Trjapitzin 1978: 521, 523 (key to European species); Schauff 1984: 42 –43 (diagnosis, comments); Noyes & Valentine 1989: 21 –22 (diagnosis); Yoshimoto 1990: 23 –24 (synonymy, diagnosis, list of New World species); Beardsley & Huber 2000b: 5 –7 (brief diagnosis, key to Hawaiian species); Triapitsyn & Huber 2000: 612 (remarks); Lin et al. 2007: 20 –21 (synonyms, brief diagnosis, list of Australian species); Huber 2009a: 235 (key); Huber 2009b: 18 –19 (short diagnosis); Huber et al. 2009: 284 (brief comments); Pricop 2010b: 92 (list of nominal species from Europe); Anwar & Zeya 2014: 31 –32 (brief diagnosis and key to Indian species).

Parvulinus García Mercet 1912: 332 –333. Type species: Parvulinus auranti García Mercet , by monotypy. Synonymized under Alaptus by Girault 1913a: 221.

Metalaptus Malenotti 1917: 339 –340. Type species: Metalaptus torquatus Malenotti , by monotypy. Synonymized under Alaptus by Girault 1917: 1 and then listed under Alaptus by Debauche 1948: 53, 55 and Debauche 1949: 9.

Metalaptus Malenotti: Malenotti 1918 : 81 (diagnosis).

Parvulinus Mercet : Nikol’skaya 1952: 540 (key).

Alaptus (Parvulinus) Mercet : Thompson 1958: 565.

Diagnosis. Both sexes: body very small (much less than 1 mm long), length of slide-mounted specimens (excluding the exserted part of ovipositor in females) 0.18–0.68 mm; mandible 2-dentate; fore wing posterior margin with a basal incision (as in Fig. 129 ); tarsi 5-segmented; mesosoma sessile, mesophragma strongly projecting into gaster, midlobe of mesoscutum usually with a pair of adnotaular setae. Female: antenna almost always with funicle 5-segmented and clava entire, except rarely funicle with a minute sixth segment (F2) in some specimens from the Australasian and Oriental regions, as noted by Lin et al. (2007) and illustrated by Anwar et al. (2015) for A. indicus Anwar & Zeya. Male: antenna with flagellum 8-segmented.

Mandibles are usually not enlarged in Alaptus except in one undescribed species from Bella Vista, Buenos Aires Province of Argentina, in which they are very large ( Fig. 1 ). I have examined 4 females and 1 male in MLPA, mounted on 3 slides (collected on 20.xii.1963 and 25.xii.1963 most likely by A.A. Ogloblin, and labeled by him as “Huevos de Psocides Tronco Eucalyptus ” [eggs of psocids Eucalyptus stem] under his manuscript name “ Alaptus mandibularis ”.

Species recognition in this diverse genus outside of Europe and also perhaps the Nearctic region is usually quite difficult (most taxa were described without providing proper diagnoses and not in a revisionary context); of diagnostic importance are body size and color, proportions of the antennal segments, chaetotaxy on the fore wing, and ovipositor length. But because of often a considerable intraspecific variation in some of them, there are not too many good diagnostic characters to help separate some similar species of Alaptus . Good quality specimen preparation on microscopic slides is almost always required for accurate identification of these minute wasps. In Europe, however, with experience the most common species may be generally recognized from properly critical point-dried and card- or point-mounted specimens.

Classification. Alaptus is a readily recognizable genus in the Palaearctic region, so any appropriate generic key to the Mymaridae can be used for its identification: Annecke & Doutt (1961) for the world genera, Schauff (1984) for the Holarctic genera, Triapitsyn & Huber (2000) for the Palaearctic genera, and Pricop (2013) for females of the European genera. Long after Perkins (1912) based his subfamily Alaptinae (within family Alaptidae) on Alaptus, Viggiani (1989) placed it in the mymarid subfamily Mymarinae , tribe Alaptini Perkins, based solely on the structure of male genitalia, but later Lin et al. (2007) and Huber (2009a) treated it as a member of the informal Alaptus group of genera.

Distribution. Cosmopolitan.

Hosts. See New (1969), Huber (1986), Triapitsyn (2002), and Noyes (2016). The reliable host records of Alaptus spp. are from eggs of various Psocoptera ( Enock 1895, 1915; Bakkendorf 1934; Ghesquière 1939; Kryger 1950; Hincks 1959, 1960; New 1969; Huber 1986; Viggiani & Jesu 1988; etc.). All other, non-psocopteran, host records need confirmation and are almost certainly incorrect due to inadequate rearing methods, particularly those from various Coccoidea ( Hemiptera ) on plant material placed in rearing cages; these are not considered in this review and are therefore purposely omitted. Other aspects of biology of Alaptus species are mostly unknown except for a few European species (e.g., New 1969; Broadhead & Cheke 1975; Cheke 1977) and one Nearctic species ( Spruyt 1927); although, based on the analysis of the known host records, its seems that at least some of the species tend to be oligophagous or even polyphagous within an ecological niche: those parasitizing psocid eggs on leaves do not generally parasitize those on bark and vice versa ( New 1969).

Figures

FIGURES 125 – 129. Alaptus pallidicornis (125 — St. Ignatius Jesuit College, Valkenburg, Limburg, Netherlands; 126 – 129 — Groenendael, Flemish Brabant, Belgium). 125, ♀ habitus of one of the two W. Soyka’s invalidly designated “ neotypes ”; 126, ♂ head and mesosoma; 127, ♀ habitus; 128, ♂ habitus; 129, ♂ fore wing.

FIGURES 1 – 2. 1, Alaptus sp. ♀ (Bella Vista, Buenos Aires, Argentina), head (frontal view); 2, F. Enock’s slide of A. fusculus ♀.