Lasioseius (Lasioseius)
Creators: name: Moraza, Maria L.
name: Lindquist, Evert E.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Ascidae
Lasioseius

description: Key to species-groups of subgenus Lasioseius (Lasioseius): females.
For a key to the genus and subgenera of Lasioseius, see the key to the world genera and subgenera of the subfamily Blattisociinae by Moraza and Lindquist (2011).
1. Dorsal shield lacking vertical j (1) and paravertical (z1) setae, leaving setae j2 as anteromedialmost pair, slightly behind level of paravertical poroids idj1; posterior region of dorsal shield with 10 or 11 pairs of setae, each of J, Z, S series with less than five pairs of setae; peritremes with anterior apices curving posteromedially above level of setae j2; female ventrianal shield with six pairs of opisthogastric setae; antiaxial face of fixed cheliceral digit with a subapical pointed process........ phytoseioides -group sensu Lindquist, 1964 and de Moraes et al., 2015
— Dorsal shield with setae j1 and usually z1 present, inserted at transverse level of poroids idj1 anterior to setae j2; posterior region of dorsal shield with 13 to 15 pairs of setae, at least the Z -series and usually all series complete with five pairs of setae each; peritremes with anterior apices not curving posteromedially where ending at level beside or short of setae z1; female ventrianal shield with two to six pairs of opisthogastric setae; antiaxial face of fixed cheliceral digit usually lacking a subapical process................................................2
2. Dorsal shield flanked by only two or three pairs of setae (marginals r5, R 1 and ventrolateral ZV5) on soft cuticle; dorsal shield with 16 pairs of setae, post-humeral pair r4 absent; tritosternum with laciniae fused for more than half their length; genua of legs I, II, III with 12, 9 or 10, 7 or 8 setae, respectively, each lacking one or two ventral setae.................................................................... porulosus -group sensu Walter and Lindquist, 1997
— Dorsal shield flanked by five to twelve pairs of setae (elements of marginals r5-6, R 1-6, submarginals UR, and ventrolateral ZV5) on soft cuticle; dorsal shield with 18 to 23 pairs of setae, usually including post-humeral pair r4; tritosternum with laciniae free for usually more than half their length; genua of legs I, II, III usually with 13, 11, 9 setae, respectively, each usually including holotrichous set of 3, 2, 2 ventral setae................................. 3
3. Dorsal shield setae collectively simple (imperceptibly or vestigially tricarinate); setae j2 nearly aligned transversely with j1 and z1; peritremes reach at most to level slightly beyond setae s1 (but not to paravertical setae z1); palptarsus with hyaline anterolateral flap extending from base of apotele to base of cluster of apical setae....................... cassidini -group
— Dorsal shield setae variable in form, but with at least setae j1, r3, Z5 usually tricarinate or tricarinate-pectinate; setae j2 inserted clearly behind transverse level of setae j1 and z1; peritremes variable in extent, but usually reaching to insertions of paravertical setae z1, anteriorly beyond setae s1; palptarsus lacking hyaline flap near base of apotele...................... 4
4. Dorsal shield with post-humeral seta r4 short, simple, similar to r2, and not more than half as long as tricarinate seta s4 neighboring it medially; most dorsal setae tricarinate and moderately long, nearly as long as longitudinal intervals between their bases; anterior pair of sternal setae on weakly sclerotized presternal area, just before anterior margin of sternal shield; sternal shield with anteromedial patch of reticula; tarsus II with one midlateral seta, pl-2, elongated, reaching nearly to base of pretarsus............. floridensis -group sensu Mineiro et al., 2009
— Dorsal shield with seta r4 usually similar in weakly to strongly tricarinate form and over half as long as adjacent seta s4; dorsal setae variable in form and lengths; anterior pair of sternal setae on or off well sclerotized surface of sternal shield; sternal shield variably ornamented; tarsus II with or without one or two attenuated setae........................................................... many other species and undescribed groups of subgenus L. (Lasioseius)
Key to species of Lasioseius cassidini species-group: females.
1. Ventrianal shield with 3 pairs of ventral setae, JV1 on soft cuticle (Fig. 5E); sternal shield reticulate over entire surface; setae st4 and poroids iv3 on soft cuticle (Fig. 5E); metapodal platelets connected or coalesced on each side (Fig. 5E); tarsi II-IV with ventroapical process truncate-spiculate apically (Figs 13G, 14B)............................... L. serripes n. sp.
— Ventrianal shield with 4 pairs of ventral setae, JV1 on shield (Fig. 8D); sternal shield smooth, or weakly lineate along lateral margins; setae st4 and usually poroids iv3 on metasternal platelets; metapodal platelets separate on each side; tarsi II-IV with ventroapical process bluntly pointed, smooth apically (Figs 13H, 14A, C, D).................................. 2
2. Gnathotectum with three elongated tines (Fig. 8C); fixed chela with 9-13 teeth (Fig. 8E); smaller mites, dorsal shield length less than 470μm........................ L. fuscina n. sp.
— Gnathotectum with three short broad tines or irregularly truncate-serrate; fixed chela with 18-28 fine teeth (Fig. 10G); larger mites, dorsal shield length more than 530μm........... 3
3. Setae Z5, S5 thickened, blunt-tipped in distinction to other attenuated dorsal setae (Fig. 10A, B); gnathotectum with three short broad tines (Fig. 10D); poroids iv3 and setae st4 together on slender metasternal platelets (Fig. 10C)............................. L. duobtusisetis n. sp.
— Setae Z5, S5 not conspicuously thicker or blunter than other dorsal setae; gnathotectum truncate-serrate (Fig. 1D); poroids iv3 alone on soft cuticle or with setae st4 on slender metasternal platelets.................................................................. 4
4. Sternal setae st4 on tiny metasternal plates, leaving sternal poroids iv3 on soft cuticle (Fig. 1C); sternal setae st1 on weakly sclerotized presternal region (Fig. 1C); podonotal region of dorsal shield with 23 pairs of setae, including r6; tarsus IV with distal seta av-1 ca 1.3 longer than pv-1 and 2.5 times longer than slender setae l- (1) (Fig. 14A).......... L. cassidini n. sp.
— Sternal poroids iv3 with sternal setae st4 on slender metasternal platelets (as in Fig. 8D); sternal setae st1 on anterior margin of sternal shield; podonotal region of dorsal shield with 22 pairs of setae, r6 on soft cuticle; tarsus IV with distal seta av-1 enlarged, erect, 2.5 times longer than pv-1 and 4 times longer than short, slender setae l- (1) (Fig. 12H)............................................................. Lasioseius sp. (undescribed) ex Chelobasis bicolor
description: Published as part of Moraza, Maria L. & Lindquist, Evert E., 2018, A new species-group with new species of the genus Lasioseius (Acari: Mesostigmata: Blattisociidae) associated with Neotropical hispine beetles in furled leaves ofHeliconia, pp. 62-98 in Acarologia 58 (1) on pages 67-69, DOI: 10.24349/acarologia/20184227, http://zenodo.org/record/4487537