Acarologia is proudly non-profit, with no page charges and free open access

Transcription

1 Acarologia A quarterly journal of acarology, since 1959 Publishing on all aspects of the Acari All information: acarologia@supagro.inra.fr Acarologia is proudly non-profit, with no page charges and free open access Please help us maintain this system by encouraging your institutes to subscribe to the print version of the journal and by sending us your high quality research on the Acari. Subscriptions: Year 2018 (Volume 58): Previous volumes ( ): 250 / year (4 issues) Acarologia, CBGP, CS 30016, MONTFERRIER-sur-LEZ Cedex, France The digitalization of Acarologia papers prior to 2000 was supported by Agropolis Fondation under the reference ID through the «Investissements d avenir» programme (Labex Agro: ANR-10-LABX ) Acarologia is under free license and distributed under the terms of the Creative Commons-BY-NC-ND which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

2 GENERA OF THE MITE FAMILY STIGMAEIDAE OUDEMANS (ACARINA) BY F. l\j. SUMMERS (University of California, Davis). A few contemporary workers have described and rearranged the stigmaeid mites until the concepts of most of the genera are now much clearer than when the first ones were proposed by KocH (r835-44) and BERLESE (r882-93). However, the spectrum of described species is still too discontinuons to reveal a credible phylogeny or to show how a stable systematic arrangement should be organized. ÜUDEMANS (1927) provided the first comprehensive key to the raphignathoid group of mites which then comprised but one family, the Raphignathidae Kramer, r877. His key proved to be unworkable because difficult quantitative judgments about anatomical details were involved and because its coverage of sixteen genera included at least four genera now classified as dubious --- Caligonus Koch, Homocaligus Berlese, Podaia Oudemans and Storchia Oudemans. GoNZALEZ (rg65) arranged the first key to genera of the stigmaeidae as currently understood. Another key to stigmaeid genera is presented here. Although the latter differs considerably from the key published by GoNZALEZ, the differences are those of arrangement, not of opinion ; both observers share the notion that the distinctions between these genera are most readily perceived in the patterns of dorsal plates on the hysterosoma. The use of schematic figures to illustrate plates and setae of the species chosen to represent each of the genera introduces several complications. The placement of figures si de by si de, for example, those of Ledermuelleriopsis and M ediolata, appear to emphasize the similiarities of the parts illustrated (figs. 4, 5) whpreas, in fact, the two genera are quite dissimilar in respects not shown. The arrangement of figures in a sequence, starting with fully armored backs and proceeding according to the fragmentation and diminution of the dorsal plating, clistorts whatever may be the real affinities between the genera. Acarologia, t. VIII, fasc. 2, 1966.

3 - ZJI SETAE PLATES he le FrG Designations of dorsal plates and dorsal setae (Stigmaeus). Only the setae likely to be confused orthose of uncertain homology are labelecl on the subsequent figures. Family STIGMAEIDAE Oudemans, Stigmaeidae ÜUDEMANS, 1931, Ent. Ber. Nederl. Ent. Ver. 8: 252; BAKER and WHARTON, 1952, An Introduction to Acarology, p , Macmillan Co., N. Y. ; SuMMERS and ScHLINGER, 1955, Hilgardia 23 : ; CuNLIFFE, 1955, Proc. Ent. Soc. W ash. 57 : ; MEYER and RYKE, Ann. Mag. Nat. Hist. (Ser. 13) 2 : Characters. -- Principal internai trunks of tracheal system originate in miclline between basal pieces of the chelicerae but have no obvions stigmata or peritremes. Palptibia bears a pronouncecl claw, sometimes with a small accessory claw close beside its base ; palptarsus usually a short pendant appendage. this and main claw form a claw-thumb complex. Most but not all of the species haves a compound seta or 3-tinecl fork on the apex of the palp tarsus. Genital and anal vestibule closecl externally hy a single pair of anogenital covers. Type gemts. - Stigmaeus Koch, Key to Genera. I. Hysterosoma completely or partly covered by one or more dorsal plates; two or more setae on at least one of the hysterosomal plates which lie anterior to suranal plate (end cap)

4 -232- Hysterosoma essentially without dorsal plating; tiny platelets may occur at bases of setae but none bears more than one seta, suranal plate excepted Hysterosoma in front of suranal plate covered dorsally by one extensive plate having no cross furrows and which be ars 6 or more pairs of setae Hysterosoma in front of suranal plate covered by severa! plates, none with more than 5 pairs of setae Propodosomal and hysterosomal plates integral ; no separa te humeral plates.... Mullederia Propodosomal and hysterosomal plates cleanly separated by humeral suture ; separate humeral plates present Large hysterosomal plate overlaps sidewalls of body almost to pleuroventral line, usually with emphatic sculpturing; cheliceral bases robust but not joined together... Ledermuelleria Large hysterosomal plate covers margins only far enough to bear lateral setae la, lm and li, usually plain or faintly reticulate ; cheliceral bases robust and fused together Cheylostigmaeus 5. Idiosoma spindlelike, at least 3 times longer than wide ; 4 pairs of setae on propodosomal plate, 2 anterior pairs close together near its anterior margin far separated from 2 posterior pairs, the latter disposed in a row across its posterior margin... M acrostigmaeus Idiosoma oval or pyriform in outline, less than 3 times longer than wide; 3-4 pairs of setae on propodosomal plate, 2 anterior pairs not conspicuously separated from posterior pair or pairs Two or more unpaired dorsal plates 1 transect midline of hysterosoma (suranal plate excepted) Not more than one unpaired plate covers any part of middorsal line of hysterosoma (suranal plate excepted) Two pairs of paired platelets on margins of hysterosoma bear individual setae of pairs la and lm ; unpaired plate covering metapodosoma bears 2 pairs of setae, a and b V illersiella No paired platelets on hysterosoma other than humeral plates ; unpaired plate covering metapodosoma bears 3 pairs of setae, a, b and la One pair of subcapitular setae ; palptarsus much longer than small tibial claw; terminal sensillum of palptarsus minute, lanceolate or with splayed tip and 3 barely identifiable prongs ; postocular bodies prominent M ediolata Two pairs of subcapitular setae ; palptarsus scarcely longer than strong tibial claw; terminal sensillum on palptarsus an obvious trident with 3 substantial prongs ; no postocular bodies Ledermuelleriopsis 9 One unpaired dorsal plate of hysterosoma bears 5 pairs of setae or 5 setae on each half if this plate divided lengthwise IO No plate on dorsum of hysterosoma bears more than 4 pairs of setae II ro. Intercalary plates present as a pair of small sclerites bearing only setae li ; seta la on large midian plate ; not isolated on separa te paired platelets.... Agistemus Intercalary plates not separated from principal hysterosomal plate; setae la originate on a pair of isolated marginal platelets V illersia 1. In 3 species of Mediolata the dorsal plating is imperfectly subdivided by feebly developed transverse grooves or sulci.

5 -233- rr. Four pairs of dorsal setae on propodosoma (humeral setae excluded) ; setae lm on separa te lateral zonal plates Stigmaeus Three pairs of dorsal setae on propodosoma (humeral seta excluded) ; setae lm and c on one median plate or on a pair of plates but never separated from each other... Zetzellia 12. Chelicerae completely joined together close to their basal ends to form a U-shaped unit on which are located 2 short, straight peritremes ; several pairs of ultralong dorsal setae ; each true claw with 2 pairs of very short, ca pi tate tenent hairs.... Barbutia Chelicerae not joined together; no peritremata apparent ; true claws smooth, without tenent hairs Each dorsal hysterosomal seta (except suranals) originates on a very small, separate platelet; tip of palptarsus bears 3 or 4 eupathid-like setae ; empodial shaft extends beyond ends of stubby claws before giving rise to pairs of ray lets... Apostigmaeus Dorsal setae of hysterosoma (except suranals) not set on platelets; palptarsus bears only 2 apical setae, one of which is straight, stout and pointed; empodial shaft branches into ray lets before it extends beyond ends of claws Eryngiopus M ULLEDERIA VvT ood. (Fig. 2). Mullederia Wood, rg64, New Zealand ]ourn. Sei. 7 : Characters. - Globate forms having mouthparts as in Ledermuelleria. Dorsal plating thickened, with pronounced reticulate or dimpled ornamentation. Two plates cover entire dorsum ; one principal plate covers propodosoma and most of hysterosoma, with humeral sulcus absent or represented by an indistinct, feeble groove ; a small suranal plate covers posteriormost tip of opisthosoma. No separate humeral plates. Hysterosomal section of principal dorsal plate bears 5 pairs of setae (not counting humerais) ; second dorso-medians (b) of Ledermuelleria appear to be absent in this genus. Each tarsus with a bell-shaped pad or membranous arolium arising beneath claws; empodium rod-like, with 2 pairs of raylets. Type Speàes. - Mullederia arborea Wood, 1964, by original designation. M ullederia is the only genus in the family in which the propodosomal, hysterosomal and humeral plates are integral. The genus presently comprises three species : M. lineolata (Meyer & Ryke), M. neomaculata (Meyer & Ryke) and AI. arborea Wood. The first two occur in South Africa and the latter in New Zealand. A key for distinguishing the three species is given by WooD (r964). LEDERMUELLERIA Oudemans. (Fig. 3). Ledermulleria ÜUDEMANS, 1923, Ent. Ber. Nederland. Ent. Ver. 6: rso; SUMMERS, I957a, Proc. Ent. Soc. Wash. 59 : 49-50; MEYER and RYKE, 1959, Annals and Mag. Nat. Hist. ser. 13, 2 : 216.

6 234- Characters. - Deep-bodied forms with short, robust legs and mouthparts. Gnathosoma carried in an inferior position, partly covered by overhanging propodosoma. (helicerae not fused together. Terminal sensillum on palp-tarsus a strong trident having 3 very distinct prongs. Dorsum almost completely covered by 3 unpaired plates, one covering propodosoma, one covering most of hystero- 1 1 he MULLEDERJA ARBOREA LEDERMUELLERJA SEGNIS de 4 he LEDERMUELLERJOPSJS PLUMOSA MEDJOLATA P/NI

7 -235- soma to margins of venter, one covering posterior extremity of opisthosoma (suranal plate); the first two overlap at humeral sulcus; anterior margin of suranal plate usually tucked under posterior margin of larger hysterosomal plate. Paired humeral plates large but displaced to ventrolateral position. Major plates generally ornamented : extensively dimpled or crinkled to appear reticulate or with closely spaced fenestrations of nearly uniform diameter. Dorsal setae : 13 pairs, including ventrally displaced humerais ; propodosomal plate bears 4 pairs, large hysterosomal plate bears 6 pairs. Type Species. - Caligomts segnis Koch, by original designation. Ledermuelleria is now known to contain 24 definable species. Most of these have been described or re-described by SUMMERS (1957 a), SuMMERS and PRICE (1961) and CHAUDHRI (1965). SuMMERS and PRICE listed 7 species described by other authors which were not incorporated into their key to species. Two of these L. favosa Sellnick, 1932, and L. longisetosa Willmann, 1956, have been incorporated into an extended key provided by CHAUDHRI. Two other species, L. neomaculata and L. lineolata, both described by lvieyer and RYKE, 1959, have been referred by Woon (1964) to another genus, Mullederia Wood. The status of the other 3 species is not yet resolved. These are Raphignathus brevis Banks, 1910, Ledermulleria oudemansi Thor, 1930, and Caligonus collarti Cooreman, The author has casually examined numerous odd lots of stigmaeids in the collections of others and has concluded that the number of species already described in Ledermuelleria represents but a small beginning in the development of a potentially large genus. Indications are that the mite fauna associated with sandflies and their relatives will alone yield a rich harvest of species belonging to this genus. LEDERMUELLERIOPSIS Willmann. (Fig. 4). Ledermülleriopsis WILLMANN, 1951 Sitzungsber. Osterr. Akad. Wissensch. Mathem.-natum. Kl., Abt. I, 160 : 140 ; SuMMERS, 1957a, Froc. Ent. Soc. W ash. 59 : Characters. - General organization and plate ornamentation as in Ledermuelleria. Dorsal plating of hysterosoma portioned into subequal metapodosomal and opisthosomal plates by an additional transverse sulcus ; setae a, b, la on metapodosomal plate, setae c, lm, h on opisthosomal plate. Posterior extremity covered by a single suranal plate with 2 pairs of setae, as in most stigmaeid genera. Type species. - Ledermülleriopsis triscutata Willmann, 1951 by original designation. The following couplet indicates several distinguishing features of the only two described species : Dorsal setae bushy ; depressions in dorsal plates sufficiently separated to appear as rounded or oval dimples plumosus Willm., 1951

8 -236- Dorsal setae lanceolate, with pointed tips ; cuticle between depressed areas raised to form a polygonal meshwork or reticulum triscutata Willm., rgsr There is an unusual chronology in the founding of this genus. WILLMANN merely named the genus and type species, L. triscutata, in his first publication on the subject (1951 b) but in the same publication the species listed second, L. plumosus, was described. The definition of the genus and the description of the type species did not appear until two years later (1953). The essential difference between Ledermuelleria and Ledermuelleriopsis is the divided dorsal hysterosomal plate in the latter. The two genera can easily be confused because deutonymphs of at least 3 species of Ledermuelleria (e.g., rhodomela, schusteri, pectinata) have a transverse sulcus across the midsection of the hysterosoma, thus dividing the dorsal plating precisely as in Ledermuelleriopsis. It is also now known that the males of sorne species (but not ali) of Ledermuelleria (e.g., parviseta, ottavii) have a Ledermuelleriopsis-like dorsal plate arrangement. It therefore follows that only mature females can be assigned with confidence to one or the other of these genera. The realization of these complications prompted the author to re-examine specimens from which Ledermuelleriopsis plumosus was illustrated (SuMMERS, 1957 a, figs. rr-15) in order to confirm that specimens identified as females are really mature specimens of Ledermuelleriopsis plumosus and not misidentified deutonymphs of Ledermuelleria pectinata. The specimens in question have the vaginal sclerotization characteristic of mature stigmaeid females generally whereas available deutonymphs of Ledermuelleria pectinata have no observable vaginal sclerotization. CHEYLOSTIGMAEUS Willmann. (Fig. 6). Cheylostigmaeus WILLMANN, rgsr, Banner Zool. Beitr., Mus. Alexander Koenig 2 : ; rgsz, V erojjtl. I nst. M eeresforsch, Bremerhaven r : 160. Characters. - Robust stigmaeids with very strongly developed mouthparts and setae. Terminal sensillum on palptarsus conspicuously three-pronged. Chelicerae adnate but with septum persisting. Two principal plates cover dorsum but do not overlap or encase body sidewalls. Humeral plates in lateral or dorsalateral position. Plating with or without reticulate ornamentation. Thirteen pairs of dorsal setae ; four pairs setae on integral prepodosomal plate, 6 pairs of hysterosomal plate. Dorsal setae usually stout, straight or nearly so, tapered to points, smooth or with few barbs; a hyaline sheath invests setae of sorne species, sheath rounded or bulbous at tip. In males, one or more segments of palpus may bear knobby or spinous apophyses; rostrum also may have marginal processes or lamellae originating close to bases of anterior subcapitular setae m.

9 -237- Type Species. - Cheylostigmaeus grandiceps Willmann, 1951, by original designation. This potentially important genus is a most difficult one with which to work for at least two reasons. The few specifie characters hitherto pinpointed require very clear, symmetrically mounted specimens. And, as WrLLMANN first appreciated, the males are somewhat easier to speciate than are the females. Most field samples are seldom rich enough in specimens to assure the matching of the sexes and rarely good enough to provide series adequate for quantitative studies. Insofar as it is not yet possible to develop a comprehensive key to all of the described species, one sex or the other, identifiers will be obliged to consult descriptions listed below. C. grandiceps WrLLMANN, 1951, Banner Zool. Beitr. Mus. Alexander Koenig 2 : {female); 1953, Sitzungsb. Osterr. Akad. Wissensch., Mathem.-naturw. KI., Abt. I, 162 : (male and female). C. scutatus (Halbert) = Raphignathus scutatus HALBERT, 1920, Froc. Roy. Irish Acad., section B, 35 : 142 (female) ; WrLLMANN, 1952, Verojjtl. Inst. M eeresjorsch. Bremerhaven 1 : 160 (male). C. angustimaxillatus WrLLMANN, 1951, Banner Zool. Beitr. Mus. Alexander Koenig 2 : (female); WrLLMANN, 1953, Sitzungsb. Osterr. Akad. Wissensch., Mathem.-naturw., Abt. I, 162 : (male). C. pannonicus WrLLMANN, 1951, Sitzungsb. Osterr. Akad. Wissensch., Mathem.-naturw., Abt. I, 160 : (male). SuMMERS, 1957, Pan-Pacifie Ent. 33 : (female). C. austriacus WrLLMANN, 1951, Sitztmgsb. Osterr. Akad. Wissensch., Mathem.-naturw., Abt. I, 160 : (male). C. longisetosus WrLLMANN, 1951, Ibid. 160 : (female). C. salinus EVANS, 1954, Froc. Zool. Soc. London 123 : (female). C. howellsi EVANS, 1954, Ibid. 123 : (female). C. marinus WrLLMANN, 1957, Abh. naturw. Ver. Bremen 35 : (both sexes). C. tomlus SuMMERS, 1957, Pan-Pacifie Ent. 33 : (male) ; SuMMERS and EHARA, 1965, Acarologia 7 : 58 (female). C. multidentatus SuMMERS and EHARA, 1965, Ibid. 7 : (both sexes). C. californicus SUMMERS and EHARA, 1965, Ibid. 7 : (both sexes). Willmann (1952) published a key to males for five of the nine species known from Europe, and Summers and Ehara (1965) developed keys for both sexes of four North American species. The work of adding new species to this genus is apt to require close attention to fine structural details and series long enough to fix adequate confidence limits on measurement data. VrLLERSIA Oudemans. (Fig. 8). Villersia ÜUDEMANS, 1927, Ent. Ber. Nederland. Ent. Ver. 7 : 263. Characters. - With the general features of Ledermuelleria. Humeral area of each side has 2 small setiferous plates in addition to humeral plate ; anterior plate

10 CHEYLOSTIGMAEUS PANNONICUS VILLERS! ELLA QUADRISCUTATA VILLERS la SUDETICA STIGMAEUS AN TRODES

11 front of humeral sulcus bears seta de of propodosoma, posterior plate behind sulcus first dorsolateral hysterosomal la. Humeral plate displaced to ventrolateral position. Type Species. Villersia vietsi Oudemans, 1927, by original designation. The species of record are V. vietsi Oudemans, 1927, V. sudetica Willmann, 1956, and V. oudemansi Meyer and Ryke, This gemis is evidently another satellite of Ledermueller1:a. The type species V. vietsi, was illustrated by ÜUDEMANS in a plate of unpublished figures (Leiden Museum No. 6g6). Notes on the reverse side of this plate indicate that he reconstructed sorne of the details from memory because the specimen was damaged during the investigation. WrLLMANN (1955) also illustrated V. vietsi. He added detail of a pair of perforated plaques just in front of the humeral plates. These appear to be a pair of the callosities noted by SuMMERS and PRICE (1961) for certain species of Ledermuelleria. The hysterosomal plate of V. su.detica is incised laterally, one pair of emarginations at the metapodosomal-opisthosomal juncture and a second pair near the midsection of the opisthosoma, between setae c and li. The characters of V. oudemansi Meyer and Ryke, 1959, vary somewhat from ÜUDEMAN's concept of the genus. A Villersia stage occurs in Ledermuelleria. Specimens having the plate characters of V iller si a have been collected in California. All are deutonymphs of a species of Ledermuelleria close to but not on specifie with deutonymphs of L. lacuna. VrLLERSIELLA Willmann. (Fig. 7). Villersiella WILLMANN, 1953, Sitzungsb. Osterr. Akad. Wissensch., Mathem.-natum. Kl., Abt. I, r62 : 488-go. Description. - In respect to dorsal plate pattern, this genus falls between V illersia and Stigmaeus. Dorsum of hysterosoma bears 8 plates, 4 median unpaired plates and 2 pairs of paired plates, as follows : a median metapodosomal plate with setae a and b, a pair of adjacent marginal plates bearing setae la, an anterior opisthosomal plate (median zonal of Stigmaeus) with setae c and an adjacent pair of lateral zonal plates with setae lm, a posterior opisthosomal plate (intercalary) with seta li, and a suranal plate bearing setae le and e. Type Species. - Villersiella quadriscutata Willmann, Monotypic. WrLI.MANN's illustration of V. quadriscutata (1953, fig. 3) suggests that the chelicerae are fused together as in Cheylostigmaeus. That Villersiella is a close relative of Cheylos#gmaeus is borne out by the fact that the deutonymphs of five species of Cheylostigmaeus known to the writer have a plate pattern distinguishable from that of Villersiella in only one respect. The latter bears its intercalary setae

12 -240- li on a single median intercalary plate whereas these nymphs of Cheylostigmaeus have paired intercalary plates, each with one seta li. AGISTEMUS Summers. (Fig. 10). GoNZALEZ, 1965, Univ. Cali Agistemus SuMMERS, 1960, Proc. Ent. Soc. Wash. 62 : 234 jornia Publ. Ent. 41 : Characters. - Chelicerae not fused together. Palptibial claw weil developed ; accessory claw present as a slender spine. Terminal sensillum on palptarsus tipped with 3 very minute, short prongs. One pair of eyes, one pair of larger vesicles or postocular bodies near posterior margin of propodosomal plate. Twelve pairs of dorsal setae, usually finely barbed, rarely smooth. Dorsum of hysterosoma incompletely covered by two unpaired plates (median, suranal) and one pair of paired intercalary plates. Median plate bears 5 pairs of setae ; this plate usually entire but may be incompletely partitioned into right and left halves. One or 2 pairs of paragenital setae in female. Type Species. - Caligonus terminalis Quayle, 1912, by original designation. Mites of this genus have compact, ovoid bodies and moderately long legs. The dorsal plating is weakly developed and generally plain ; a few species have a reticulate ornamentation. They are found on plant foliage ; those now known are mostly arboreal. Their association with plants is a complex one and probably relates to the prevalence of other microarthropods, particularly tetranychids, on the " host ". Several of the species have been observed to prey on spider mites (GoNZALEZ, rg61 ; MUMA, rg61 ; EHARA, 1962), on crawlers of a scale insect (EHARA, 1962), on tydeids and citrus rust mites (Mm--rA, 1961). GoNZALEZ (1961) noted that A. longisetosus is facultatively phytophagous, on Viburnum, in Chile. Twenty of the twenty-five known species were described by GoNZALEZ (1963, 1965). His second paper (1965) on this group includes a key to females of all but two of these. Two species described from Japan by EHARA (1964) are not incorporated. STIGMAEUS Koch. (Fig. g). Stigmaeus C. L. KocH, 1836, Deutschlands Crustaceen, Myriapoden und Arachniden, Fasc. 4, No. 9 Stigmaeodes G. CANESTRINI, 1889, Atti d. reale Ist. Ven. d. Sei., Lettre ed Arti (Ser. 6) 7 : ; ÜUDEMANS, 1923, Ent. Ber. Nederl. Ent. Ver. 6 : 140. Stigmaeus (Stigmaeus) RERLESE, 1910, Redia 6 : 205; ÜUDEMANS, 1923, Ent. Ber. Nederl. Ent. Ver. 6 : 142.

13 -241- Characters.- Stylate chelicerae prominently displayed in front of propodosoma, incompletely retractile, right and left members not fused together. Terminal sensillum on palptarsus conspicuously three-pronged. Dorsum incompletely covered with plates, dimpled or reticulated in most species. Median propodosomal plate covers area bounded by three or four pairs of setae, its surface ornamentation modified or absent over semitransparent ocular fenestrae ; separate auxiliary platelets bearing posterolateral setae de may occur near each shoulder margin. Dorsal hysterosomal skeleton comprises two median unpaired plates (median, suranal) and three to five pairs of smaller, usually paired plates (humerais, marginais, median zonais, lateral zonais, intercalaries). Thirteen or fourteen pairs of dorsal setae, usually barbed, sometimes forked or triramous ; preocular, humeral and intercalary setae often conspicuously longer than other dorsals. Two pairs of dorsal eupathid setae on tarsus I, setae of both pairs characteristically recurved. Empodia with three pairs of raylets, capitate or pointed. Type Species. - Stigmaeus cruentus Koch, 1836, designated by BERLESE, Generic identifications sometimes may be made quickly with spot characters which show well in a majority of the species : a stout 3-branched sensillum on the apex of palptarsus ; median hysterosomal plate bears the first two or three pairs of dorsocentral hysterosomal setae and is scarcely wider than the area bounded by the origins of these setae ; the dorsal eupathids on tarsus I tend to loop backward. The structure, number and disposition of plates and setae provide the chief criteria for distinguishing species. Approximately forty species are currently recorded for Stigmaeus (SuMl\IERS, 1962). Nine of these are so sketchily described that their identities and affinities are in doubt. According to present knowledge the questionable species are : cruentus Koch, 1836 ; megacephalus Koch, 1836 ; comatulus Koch, 1838 ; kermesinus Koch, 1841 ; bicolor Canestrini and Fanzago, 1876 ; elongatus Berlese, 1886 ; simrothi Mola, 1907 ; confinis Berlese, 1910 ; antrodes var. reticulatus Halbert, A key to thirty-one of the species is given by SUMMERS (1962). ZETZELLIA Oudemans. (Fig. rr). Zetzellia ÜUDEMANS, 1927, Ent. Ber. Nederl. Ent. Ver. 7 (r58) : 263; SuMMERS, rg6o. Froc. Ent. Soc. Wash. 62 : ; GoNZALEZ, rg65, Univ. Cali]. Publ. Ent. 41 : Zetsellia (sic!) BAKER and WHARTON, 1952, Acarology. Macmillan Co., N. Y., p Characters. - Chelicerae not fused together. Palptibial claw prominent, accessory claw setiform. Terminal sensillum on palptarsus a modified trident, three prongs very short but usually discernible. One pair of eyes and a pair of ill-defined postocular bodies present. Body plates delicately sclerotized. Propodosomal plate bears only 3 pairs of setae ; setae de of sorne stigmaeid genera absent in this genus. Humeral setae set on small independent shoulder plates.

14 -242- Hysterosoma co, ered by a complex of plates. Median hysterosomal plate integral or represented by a complement of r-3 pairs of smaller plates; 4 pairs of setae - a, b, c and lm - borne on this one plate or on the platelets derived from it ; setae c and li of the same side never on separate platelets. One pair of marginal plates with setae la, one pair of intercalary plates with setae li, and a single suranal plate complete the dorsal sclerotization. Two pairs of paragenital, 3 pairs of anogenital setae AGI STE MUS FLESCHNERI ZETZELLIA MALI Genotype : Zetzellia methlagh Oudemans, 1927 ; by original designation. Zetzellia has a gnathosomal organization much like Agistemus but, in respect to dorsal plate patterns, the genera Zetzellia and Stigmaeus are more difficult to separate. A useful recognitional character concerns the relations of the first two dorosolateral setae la and lm to the plates on which they arise. In Zetzellia, the maximum number of setae carried by the median hysterosomal plate is 4 pairs : dorsocentrals a, b, c and lm of the dorsolateral series. Seta la occurs on a separate marginal plate. Incomplete sclerotization over the dorsocentral area may result in an isolation of seta a and sometimes b on satellite platelets which may be regarded as components of a median plate complex. But c and lm on the same side are not known to occur on separate plates. In Stigmaeus, c and lm invariably occur on

15 -243- different plates, with lm situated on a distinct lateral zonal plate. In Agistemus, both la and lm share one plate with the 3 dorsocentrals a, b, and c. The species best known is Z. mali (Ewing). At times this species develops significant populations on pome and stone fruit trees and is regarded as beneficiai. It has been observed to feed on eggs of Bryobia (NESBITT, 1946) and on varions stages of the European red mite (PARENT and LERoux, 1956 ; VAN DE VRIE, 1963). GONZALEZ (1965) added six species to the genus and set up the first key to species. ZETZELLIOPSIS Willmann. Zetzelliopsis WrLLMANN, rgs6, Ceskoslovenskd parasitologie III : 238-g. Type : Zetzclliopsis paxi V/llm., 1956 (original designation). This genus presents a problem in systematics which cannot be resolved without reference to V!ILLMANN's type specimens. Although WrLLMANN placed the genus between Ledermuelleria and Zetzellia, the diagnosis given does not separate it from Ledermuelleria as currently understood. The location of the suranal plate as partly underlying the principal hysterosomal plate and the transverse division of the hysterosomal plate into two components in the male were emphasized in the original description. Neither character is diagnostic. APOSTIGMAEUS Grandjean. (Fig. 13). Apostigmaeus GRANDJEAN, 1944, Arch. Sei. phys. nat., se Période, z6 : ros; MEYER and RYKE, rgsg, Annals Mar;. Nat. Hist., Ser. 13. z : zzs-6; SUMMERS, rg64, Froc. Ent. Soc. W ash. 66 : 184. Characters. - Idiosoma slender, somewhat spindle-shaped. Chelicerae separately movable, not fused together. Palptarsus bears a cluster of 4 minute sensory setae (eupathids) instead of a terminal trident. Dorsal plating very restricted and delicate. Propodosomal plate reduced, confined to midportion of this body section ; only 2 pairs of propodosomal setae, ae, and be, arise on this plate. Hysterosomal plating restricted to minute platelets, one platelet for each seta except suranals. Tip of opithosoma partly covered by a pair of suranal plates, each plate with 2 setae. No obvions eyes. Dorsal setae : 13 or 14 pairs; propodosoma bears 4 pairs excluding humerais he. Four pairs of paragenital (aggenitals of Grandjean). Shaft of empodium projects beyond tips of claws before branching to produce 3 pairs of capitate raylets. Type Species. - Apostigmaeus navicella Grandjean, Monotypic. Apostigmaeus is a minor but clear-cut genus for which the type species was thoroughly described and illustrated by Grandjean. The nomenclature of body Acarologia, t. VIII, fasc. z, rg66. r6

16 -244- and appendicular setae applicable to raphignathoids generally was described in this contribution. To date, only species have been described. These are separable according to the couplet below. F ourteen pairs of smooth dorsal setae ; 2 setae on femur IV ; length of 3rd paragenital seta considerably exceeds other 3 paragenitals navicella Grandjean, 1944 Thirteen pairs of plumose dorsal setae ; 3 setae on femur IV ; ali 4 paragenital setae about equal in length pacificus Summers, 1964 Another possible candidate for the genus, as mentioned by GRANDJEAN, is Raphignathus striatus Thor, ERYNGIOPUS Summers. (Fig. I4) Eryngiopus SuMMERS, Proc. Ent. Soc. W ash. 66 : Characters. - Idiosoma slender, pyriform, with plating almost obsolete. Chelicerae separate, independently movable. Terminal sensillum on palptarsus a single, lanceolate or spinelike element, not a trident or cluster of separate eupathids. One pair of eyes. Dorsal setae : 13 pairs, short, with small range in length between setae of different pairs. Posterior subcapitular seta n and one or two pairs of ventral body setae ultralong ; seta n extends anteriorly at least to base of palptibia. Propodosomal plating comprises one or a pair of delicate sclerites covering all or a part of interocular area ; setae ae and be only on this plate or plates. Dorsal plates absent on hysterosoma except for suranal plate bearing setae le and e. Two or three pairs of paragenital setae. Shaft of empodium short, does not project beyond tips of claws before giving rise to 3 pairs of capitate raylets. Type Species. - Eryngiopus gracilis Summers, 1964; by original designation. This genus may be confused with Apostigmaeus because the generic features are inconspicuous. In Apostigmaeus the palptarsus bears a crown of 4 minute, single eupathids on its apex, and all of the dorsal setae of the hysterosoma originate on small platelets, one per seta, except suranals e and le which occur together on a common plate. Eryngiopus species have a single spinelike apical sensillum on the palptarsus and the dorsal hysterosomal setae are not set on platelets, suranals excepted. Four other differences occur but these may fail to hold as generic characters when additional species are discovered. The two species of Apostigmaeus have no eyes, 4 pairs of paragenital setae, relatively short subcapitular setae n, and stubby claws shorter than the unbranched axis of the empodium. All of the Eryngiopus species have eyes, 2 or 3 pairs of paragenital setae, ultralong subcapitular seta n, and an empodium on which raylets arise between the claws. Su:vi MERS (r964) provided a key for the four described species.

17 he Oc 0 ~' 0 1, 0 lm Ir MACROSTIGMAEUS SERPENTINUS APOSTIGMAEUS NAVICELLA M r:n\ 10, " 0 \ 1 0 o t e ' 0 0 lrn lrn 0 0 :, 0 0 1, 0 0 0,. 0 J; ERYNGIOPUS GRACILIS BARBUTIA ANGUINEUS

18 MACROSTIGMAEUS Berlese. (Fig. 12). Stigmaeus (Macrostigmaeus) BERLESE, 1910, Redia 6 : 204, 207. Macrostigmaeus Berlese, ÜUDEMANS, 1923, Ent. Ber. Nederl. Ent. Ver. 6 (130) : 145. Mites of this genus have not been seen by the writer ; it is possible only to paraphrase BERLESE's description of M. serpentinus, and to supplement with significant features as shown in his illustration (his fig. 22) or subsequently mentioned by ÜUDE:IiANS. Characters. - Chelicerae independent, fixed and movable digits relatively long, about equal. Palp with tibial claw; tarsal segment short. Idiosoma fusiform, at least 3 times longer than wide, with 2 well-marked transverse sulci separating propodosoma, metapodosoma and opisthosoma; an additional sulcus subdivides opisthosoma in front of suranal setae. Two large dorsal shields (Ouds.), one on propodosoma, other on metapodosoma, with fine longitudinal striae overall (Berl.). Fourteen pairs of slender dorsal setae, median setae relatively short, laterals longer ; 4 pairs on propodosoma, 2 anteriormost pairs located close together and far in front of 2 posterior most pairs; 3 pairs on suranal region. No eyes apparent. Legs I and II widely separated from III and IV. Empodium comprises 2 pairs of capitate raylets, one pair much longer than other. Length 550 f.l, width go [L Type Species. - original designation. Stigmaeus (M acrostigmaeus) serpentinus Berlese, 1910 ; by BERLESE (1910) included two species, serpentinus and anguineus, in his original subgenus. ÜUDEMANS (1923) eliminated the subgenus by creating a new genus Barbutia based on anguineus. At the same time he raised Macrostigmaeus to full generic rank. The name "W acrostigmaeus bakeri McGregor, 1959, is the senior synonym of a mite presently accommodated in Eryngiopus. In an attempt to obtain more information about the genus Macrostt:gmaeus Berlese, the writer recently borrowed from the U. S. National Museum the halotype of M acrostigmaeus bakeri McGregor, A study of the specimen revealed that this mite had also been described at a later date under the name of Eryngiopus longurius Summers, It seems improbable that the type species of JYJ acrostigmaeus and Eryngiopus are congeners. Therefore the best option appears to be to retain the species in the newer genus. Eryngiopus longurius Summers thus becomes a synonym of Eryngiopus bakeri (McGregor), new combination.

19 BARBUTIA Oudemans. (Fig. 15). Barbutia ÜUDEMANS, 1927, Ent. Ber. Nederland. Ent. Ver. 7: 260; SUMMERS, Froc. Ent. Soc. W ash. 66 : 191. Characters. - Small, emphatically fusiform species, with humeral sulcus clearly a line of body flexion. Chelicerae joined together basally to form a U-shaped stylophore. Short peritremata located on dorsomedian surface of stylophore. One pair of eyes. Idiosoma with no obvious plates. Thirteen pairs of dorsal setae, several pairs ultralong. Genital and anal apertures in female proximate but not sharing common covers. Genital covers without setae. Three pairs of paragenital setae. Pretarsi sessile ; true claws diminutive, each claw with 2 pairs tenent hairs, these very short, capitate. Empodium minute, with possibly 2 pairs of capitate raylets. Type Species. - Stigmaeus anguineus Berlese, 1910 ; by original designation. There have been no subsequent changes or additions. The occurrence in California of Barbutia anguineus (Berl.), type species, was reported by SVMJ\IERS (1964). MEDIOLATA Canestrini. (Fig. s). Mediolata G. CANESTRINI, 1889, Atti real. Ist. Veneto Sei., Lett. Arti 7 (Ser. VI) : Characters. - Cheliccrae entircly separated or imperfectly joined together, with persisting septum ; adnate condition sometimes difficult to observe. Palpus noticeably elongate, terminal segment extends to about middle of tarsus I. Palptibia bears a small, inconspicuous claw ; accessory claw absent. Palptarsus outthrust as forward extension of palp axis, not pendant as in claw-thumb arrangement, its apical sensillum lanceolate or with splayed tip on which 3 minute prongs are barely discernible. One pair of subcapitular setae. One pair of eyes with refractile bodies and one pair of enlarged postocular bodies behind eyes. Dorsum extensively plated ; plating subdivided into a series of unpaired elements by 2-4 weakly developed transverse sulci or sutures : 1 propodosomal plate covers tergal area of propodosoma ; suranal plate encases posterior extremity ; 1 to 3 plates cover tergal area of hysterosoma. Twelve pairs of dorsal setae ; posteralateral setae on propodosomal plate of most species have been called humeral setae he. Three pairs of paragenital setae, four pairs of anogenital setae. Pretarsal claws plain ; empodium rodlike, with at least 2 pairs of short, capitate raylets. Type Speàes.- Stigmaeus longirostris Berlese 1887; designation of type appears to have becn overlooked until ÜUDEMANS (1923) did so in his synonymy of Eupalopsis.

20 Type specimens have not been preserved as far as now known and the concept of the genus bas been nebulous. ÜUDEMANS (1923) sank the genus under Eupalopsis. SuMMERS (1960) disposed of 3 Eupalopsis species by moving them to other genera. The classical species thereafter remaining in Eupalopsis were : maseriensis (C. and F.), longirostris (Berl.) and pini (Can.). GONZALEZ (1965) obtained sufficient new evidence to conclude that maseriensis, type of Eupalopsis, is really a eupalopsellid whereas longirostris and pini are stigmaeids. He therefore resurrected M ediolata and re-defined it as far possible according to CANES TRINI's original concept based upon longirostris. But since so little knowledge about longirostris bas been perpetuated, GoNZALEZ salvaged the genus by using one of CANESTRINI's own species, pini, as the better known model. New species have been described recently by SUMMERS (1960) and GoNZALEZ (1965). The latter organized a key to eight species. Not included are M. longirostris (Berl., 1887) and two questionable species : Eupalopsis retieulata Berl., 1910, and E. pinieola Ouds., REFERENCES BAKER (E. W.) and (G. W.) WHARTON, An Introduction to Acarology. The Macmillan Co., N. Y., 465 p. BANKS (N.), New American mites. Proc. Ent. Soc. Wash. 12 : BERLESE (A.), Acari, Myriapoda et Scorpiones hucusque in Italia reperta. Ordo Prostigmata. Patavii, Portici. BERLESE (A.), Acari nuovi. Manipulus V. Redia 6 : CANESTRINI (G.), 188g. - Prospetto dell'acarofauna Italiana, Famiglia dei Tetranychini. Atti. reale lst. Veneto Sei., lett. arti. 7 (Ser. 6) : CANESTRINI (G.) and FANZAGO (F.), Nuovi Acari Italiani (Seconda serie). Atti. Soc. Veneto-Trentina Sei. nat. 5 : CHAUDHRI (W. M ), New mites of the genus Ledermuelleria. Acarologia 7 : CooREMAN (J.), Notes sur quelques acariens des Alpes françaises. Soc. Royal Ent. Belg. Mém. 27 : CUNLIFFE (F ), A proposed classification of the trombidiforme mites. Proc. Ent. Soc. W ash. 57 : 209-zr8. EHARA (S ), Notes on sorne predatory mites (Phytoseiidae and Stigmaeidae). ]apanese ]ourn. Appl. Ent Zoot. 6 : EHARA (S.J, Predaceous mites of the genus Agistemus in Japan (Acarina : Stigmaeidae). Annot. Zool. Japon. 37 : EvANS (G. 0.), Sorne new and rare species of Acarina. Proc. Zool. Soc. London 123 : EwrNG (H. E ), New species of economie mites. ]ourn. Econ. Ent. 10 : 499 GoNZALEZ (R. H.), 196r. - Contribucion al conocimiento de los acaros del manzano en Chile central. Univ. Chile Estac. Exper. Agron., Bol. Tech. No. II : GoNZALEZ (R. H.), Four new mites of the genus Agistemus Summers, Acarologia 5 :

21 -249- GoNZALEZ (R. H.), A taxonomie study of the genera Mediolata, Zetzellia, and Agistemus (Acarina : Stigmaeidae). Univ. California Publ. Ent. 41 : GRANDJEAN (F.), Observations sur les acariens de la famille Stigmaeidae. Arch. Sei. Phys. Nat. 26 : HALBERT (J. N.), The acarina of the seashore. Proc. Royal Irish Acad. (B) : 35 : HALBERT (J. N.), Notes on acari, with descriptions of new species. J ourn. Linn. Soc. London 35 : KocH (C. L.), Deutschlands Crustaceen, Myriapoden und Arachniden. Regensberg. KRAMER (P. M.), Grundzüge zur Systematik der Milben. Arch. f. Naturgesch. Neue Folge (Berlin) 43 : McGREGOR (E. A.), A new stigmaeid mite from Arizona (Trombidiformes, Stigmaeidae). Proc. Ent. Soc. Wash. 61 : MEYER (M. K. P.) and RYKE (P. A. ].), Mites of the superfamily Raphignathoidea (Acarina : Prostigmata) associated with South African plants. Ann. Mag. Nat. Hist. (13) 2 : MoLA (P.), Nuovi acari-parassiti. Zool. Anz. 32 : MuMA (M. H.), 1g6r. - Mites associated with citrus in Florida. Univ. Florida Agr. Exp. Sta. Bull. 640 : NESBITT (H. H. ].), Three new mites from Nova Scotian apple trees. Canad. Ent. 78 : ÜUDEMANS (A. C.), Acarologischen aanteekeningen LXXI. Ent. Ber. Nederland. Ent. Ver. 6 : ÜUDEMANS (A. C.), Acarologischen aanteekeningen LXXXVIII. Ent. Ber. Nederland. Ent. Ver. 7 : ÜUDEMANS (A. C.), Acarologischen aanteekeningen CVIII. Ent. Ber. Nederland. Ent. Ver. 8 : PARENT (B.) and LERoux (E. ].), Note on Mediolata mali (Ewing) (Acarina: Raphignathidae) as a predator of the European red mite. Canad. Ent. 87 : 487. QuAYLE (]. H.), Red spiders and mites of citrus trees. Univ. California Agr. Exp. Sta. Bull. 234, p. 499 SELLNICK (M.), Eine neue Ledermülleria-Art. (Acar.). Zool. Anz. 99 : SuMMERS (F. M.), 1957a. - American species of Ledermuelleria and Ledermuelleriopsis with a note on new synonymy in Neognathus. Proc. Ent. Soc. Wash. 59 : SuMMERS (F. M.), 1957b. - Two mites of the genus Cheylostigmaeus, including a new species from Point Barrow, Alaska. Pan-Pacifie Ent. 33 : SuMMERS (F.M.), Several stigmaeid mites formerly included in Mediolata redescribed in Zetzellia Ouds. and Agistemus, new genus. Proc. Ent. Soc. Wash. 62 : SuMMERS (F. M.), The genus Stigmaeus (Acarina : Stigmaeidae). Hilgardia 33 : SuMMERS (F. M.), Three uncommon genera of the mite family Stigmaeidae (Acarina). Proc. Ent. Soc. Wash. 66 : SmrMERS (F. M.) and EHARA (S.), Revaluation of the taxonomie characters in four species of the genus Cheylostigmaeus Willmann (Acarina : Stigmaeidae). Acarologia 7 :

22 -250- SuMMERS IF. M.) and PRICE (D. W.), 196r. -New and redescribed species of Ledermuelleria from North America. Hilgardia 31 : SuMMERS (F. M.) and (E. I.), ScHLINGER Mites of the family Caligonellidae (Acarina). Hilgardia 23 : r. THOR (S.), Results of the Swedish Zoological Expedition to Egypt and the White Nile, No. 20. Acariden aus Agypten und dem Sudan. I Teil. K. \V. Appelbergs Boktryckerie, Upsala. THOR (S.), Beitrage zur Kenntnis der invertenbraten Fauna von Svalbard. Skrifter om Svalbard og Ishavet N r. 27. In Adolph Hoel's Norges Svalbard og Isha vs-un ders0 keiser. VAN DE VRIE (M.), Observations on the ecology of predatory mites (Phytoseiidae) on fruit trees. Mitt. Schweiz. Ent. Gesellsch. 36 : WILLMANN (C.), 1951a. - Die hochalpine Milbenfauna der Mittleren Hohen Tauern, insbesondere der Grossglockner-Gebietes IAcari). Banner Zool. Beitr. Mus. Alexander Koenig 2 : WILLMANN (C.), 1951b. - Untersuchungen uber die terrestrische Milbenfauna im pannonischen Klimagebiet Osterreichs. Sitzungsber. (jsterr Akad. Wissensch., Mathem. naturw. Kl. Abt. I, 160 : 136-qr. WILLMANN (C.), Die Milbenfauna der Nordseeinsel Wangerooge. Verofftl. Inst. Meeresforsch. Bremerhaven 1 : WILLMANN (C.), Milben aus den ostlichen Alpen. Sitzungsber. d. Osterr. A!?ad. Wissensch., M athem.-naturw. Kl. Abt. I, 162 : WILLMANN (C.), Milben aus dem Südwestlichen Sachsen. A bh. u. Ber. staat. Mus. Tierkunde-Forschungs.-Dresden 22 : WILLMANN (C.), Milben aus dem Naturschutzgebiet auf dem Spieglitzer (Glatzer) Schneeberg. Ceskoslovenska Parasita!. 3 : 2II-273 WILLMANN (C.), Revision einiger Milbengattungen und arten von der Küsten Nord- und Ostsee. Abh. naturw. Ver. Bremen 35 : Woon (T. G.), A new genus of Stigmaeidae (Acarina, Prostigmata) from New Zealand. Nezf' Zealand Journ. Sei. 7 :