W. M. Mann.
Some Myrmecophilous Insects from Mexico.
Psyche 21(6):171-184, 1914.

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PSYCHE
A Journal of Entomology
Volume XXI
1914
Published by the Cambridge Entomological Society, Bussey Institution, Harvard University, Forest Hills, Boston, Mass., U. S. A.




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PSYCHE
--
VOL. XXI. DECEMBER, 1914. No. 6
SOME MYRMECOPHILOUS INSECTS FROM MEXICO1 The following notes are based on a small collection made during the months of May, June and July, 1913, in the State of Hildalgo, Mexico. Most of this time was spent at the Guerrero Mill, located below Real del Monte, and at the Hacienda de .Velasco, where I was the guest of Mr. and Mrs. C. W. Van Law. They, together with the other Americans and English in charge of the mines and mills, showed me every hospitality and it is largely due to them that I was able to reside and collect in this interesting locality. I am much indebted to Miss Helen L. Locke, Mr. and Mrs. J. H. Skews and Messrs. Broiderick, Benton, Funston and Calland, not only for assistance of various kinds, but for many desirable specimens which they collected. The material collected has been placed in the collections of the Museum of Comparative Zoology at Cambridge and of Mr. B. Preston Clark of Boston, -
through the kindness of whom the excursion was possible. Although .this region is easily accessible, and unusually interest- ing and rich in insect life because of its ecologically varied nature, it has been largely neglected by collectors. Only a few things have been collected at Pachuca and at Guerrero Mill. Prof. W. M. Wheeler, in looking over the literature on Mexican ants, failed to find Hidalgo cited as the locality for a single species, and I have found no records of other insects from that state. Among the thirty-nine species and varieties of ants collected (an account of these has been published by Wheeler in the Journal of the New York Entomological Society, Vol. XXII, 1914, pp. 37-61) nine were found to harbor guests or parasites. Three of these belong to the genus Formica, one each to Camponotus, Prenolepis, 1 Contribution from the Entomological Laboratory of the Buasey Institution of Harvard University, No. 84.




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172 . Psyche [December
Liometopum and Tapinoma, and two to Pheidole, all of which genera are commonly the hosts of inquilines, Prenolepis less frequently than the others. The inquilines found are mostly undescribed species of genera known to be of myrmecophilous habits, but a new Diaprid, Hemilexis jessei, and a new genus of Bethjlidse, Bruesiella formicaria, both of which are probably parasitic on the host ant, are described. There is also an in- teresting new genus of cockroach, Myrmecoblatta rehni, which inhabits nests of various species of ants, where it no doubt officiates as scavenger. The occurrence of the weevil Liometophilus mni Fall at Pachuca, with the same species of host with which it has been found in Arizona shows that it is definitely associated with this ant.
I have included in this paper a few remarks on the synonomy of some species from north of the Mexican boundary, and erected a new subgenus to contain certain of our species of Cremastocheilus. ORTHOPTERA.
Family BLATTIDB.
Subfamily BLATTINE.
Myrmecoblatta gen. nov.
Female: Body elongate oval, not greatly flattened, the abdomen about as broad as the thorax.
Head almost concealed by the pronotum, only a narrow strip of the vertex showing. Head small, triangular, the vertex somewhat swollen. Eyes well developed, elongate, emarginate on inner border Antennae long and
slender, the first joint thickened, the second small, the third longer than the second and twice the length of the fourth. Thorax longer than broad, convex above, tegmina and wings absent. Abdomen convex above, beneath gradually elevated to the middle, which is therefore broadly carinate. Supra-anal plate semi-orbic- ular, evenly rounded in outline. Cerci large, with eight distinct joints. Sub-
genital plate apparently provided with valves. Last ventral segment completely divided by a V-shaped slit. Legs short and robust, with abundant fine, short hairs. Femora weakly armed beneath, and with a strong spine at apex; tibiae spined at apex and on outer margin.
Male: Form broad. Pronotum entirely concealing the head. Tegmina more than half as broad as long; short, not reaching apex of abdomen, with poorly developed veins. Wings short and broad, less than half the length of tegmina, with poorly developed veins. Supra-anal plate more than twice as long as broad, the sides concave in outline, posterior border notched at middle, rounded on either side. Sub-genital plate broader than long, straight at sides, rounded behind, slightly concave at middle, bearing two equal stylets. Type: Myrmecoblatta rehni sp. nov.




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19141 Manftw~~Mgrmwophi& Insects /TWO. Mexico Mymwcoblatta relui sp. HOT.
Female: (Fig. 1). Length 5 mm. Width 3 mm. Color reddish-brown, the fees lighter, above regularly punctate and finely setose. Thorax longer than
broad Pronotum broader than lonu, with concave posterior border and extended. -
narrowly rounded angles.
M-nd epinota subequal,
with nearly straight sides and
concave posterior border. Ab-
dominal segments 1-7 sub-
equal, with straight posterior
borders, the eighth con-
siderably narrower than the
sevenfit, rounded behind. Cerci
%jointed, a third as broad as
long, aoumbte for apical half
their length; nearly as long as
the sub-genititi plate. Head
abut as broad as long, the
front with an indistinct Y-
shaped suture. Labium ob-
tusely pointed, concealing the
mandibles. Eyes occupying
the aides of the bead, faintly
einarginate on the inner bor-
der. Antennte slender, shorter
than the body, about 3%
jointed; the third joint twice
as long as the fourth, joints
4-13 transverse, the rest did-
bctly longer than broad, and
J%z. 1. Mvm^^
gem & sp. nov.
sub equal; all the joints finely
Ventral surface ot female.
setose. Legs short, rather flat,
the femora armed at apex with a slender curved spine; tibia bearing on the outer border three slender subequal spines, at the apex two long and two shorter spines. Mule: (Fg. 2). length 4.5 m. Width 2 mm. Color and setosity similar to that of female. Pronotum
proportionalfyslightly btoftder
than in the female, the angles
broadly rounded, posterior
border concave. Tegmina wc-
tending a little more than
two-thirds the length of ab-
domen, broadly oval in o h
line, the apex narrowly
rounded; venation not very
Fig. 2.
MyrmecoMatta rehni gen. & sp. nov.
distinct. Wings less than halt
Ventral surface of last gastric segments of male. the length of tegmha. Cerei




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174 Psyche [December
more slender than in the female, longer than the supra-anal plate at middle. Legs and antennae longer than in the female, the latter as long as the body. Nymph: Similar to female, lighter in color. The suture on the front of head is more distinct than in the adult.
Described from one male and numerous females and nymphs taken at Guerrero Mill in nests of Formica subcyanea Wheeler, F. rufibarbis Fab. var. gnava Buckley, and Camponotus maculatus Fab. subsp. picipes Olivier.
Some of the females had oothecse
attached. They were abundant, several occurring in almost every nest, where they are no doubt very efficient scavengers. The genus has no systematic affinities with Attaphila, the only other known Blattid of Myrmecophilous habits, but is more closely related to Blatta, to which it runs in Caudell's key to the genera of this family (Proc. U. S. Nat. Mus. Vol. 44, 1913, p. 601-602).
COLEOPTERA.
Family STAPHYLINIDB.
Pseudolomechusa subgen. nov.
Type : Xenodusa sharpi Wasmann.
This beetle was described by Wasmann from a series which were taken at Cuernavaca, in company with Camponotus auricomus Roger. In one canyon near the Guerrero Mill I found a number of adults, some of them in copula, with colonies of Camponotus maculatus var. picipes, Olivier which was here very abundant. In the immediate vicinity were many nests of Formica microgyna rasilis var. nahua Wheeler and several of T. rufibarbis var. gnava. Buckley. With the former ant three adults of sharpi were taken and with gnava several more, and three larvae, the latter close to the ant brood. As most of the beetles were found with C. picipes (nineteen were taken from one nest) it appears that this is the secondary or winter host and F. gnava the primary or definitive. This heterocious habit is common to all of our species of Xenodusa as far as known. The adult sharpi is very different from the other American species on account of its greatly thickened pronotal margins and shorter antenna1 joints. Seen in profile the anterior border is drawn out beneath into a distinct angle similar to the structure in the species of the European genus Lomechusa.



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19141 Mann-MyrmecophHoiis Insects from Mexico 175 The larva is very different from that of X. cava, the only one known in that stage, which has been described and figured by Wheeler (Jour. N. Y. Ent. Soc., Vol. XIX, 1911, p. 165-166) and closely resembles that of Lomechusa.
Those which I found are
5.5 mm. in length, yellowish-white in color, with short, feeble legs, no eyes, papillose antennae and shallowly impressed vertex. The body is slender and cylindrical, not at all depressed as it is in cava, with an even covering of fine erect hairs. The movements in life were very slow. Considering the pronotal structure and the larval characters sharpi should not be included in Xenodusa sens. strict., but more properly belongs to a distinct subgenus for which I propose the name Pseudolomechusa. Apteronina wasmanni sp. nov.
Length 3 mm.
Head broader than long, rounded at sides, occipital margin straight; clypeus projecting, the anterior border rounded; front broadly depressed, the surface concave, with a longitudinal impression extending to occiput. Eyes rather large, located at sides of the anterior third of head. Antennae long, the first joint about twice the length of the second, which is two-thirds as long as the third; the second joint is sharply constricted near base; fourth joint about half as long as third; joints 4-10 subequal in length, becoming thicker anteriorly; apical joint cylindrical, nearly twice the length of penultimate. Thorax not as broad as head, very slightly longer than broad, rounded in front and at anterior third of sides, posterior to which the sides are straight; posterior border straight; surface slightly concave, with a narrow longitudinal impression at middle. Elytra trans- verse, each as long as broad, together broader than thorax; sides nearly straight; posterior border rounded. Abdomen at base as broad as elytra, broadest behind. Legs long and slender.
Body and legs subopaque, finely punctate, the punctures coarser on the elytra and abdomen; everywhere with fine, recumbant, silky hairs; thorax and sides of abdomen with longer coarse hairs.
Color black, the antennae and legs brownish. Described from several specimens taken with Liometopum apiculatum Mayr at Pachuca and Guerrero Mill. A. schmitti Wasrnann, which lives in company with the same host ant from Colorado to Southern Arizona, has the head longer than broad, the thorax is longer in proportion to the width, the general form is more slender; the color is light ferruginous, except the gaster, which is dark fuscous.
The color of the Mexican form
of the host ant is considerably darker than that of the Arizona variety with which I have taken schmitti, so the beetle in each



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176 Psyche [December
case resembles the ant in that respect.
Besides color the beetle
is similar to the host in pilosity and, superficially, in form, and in life it carries its abdomen erect in a manner similar to the way in which the ant holds its gaster. Nothing is known regarding the biological relation of the beetle to the ant. Dinardella mexicana sp. nov.
Length 2.75 mm.
Head slightly broader than long, rounded at sides and in front, posterior border straight; front with a flattened disc. Eyes medium in size,
flat.
Antennae short, extending to apex of elytra; joints in front of the middle thickest; first joint as long as the two succeeding together; joints 2-3 longer than broad; joints 4-10 transverse; apical joint a little less than twice the length of penultimate. Prothorax as long as broad, broadest at posterior fourth, posterior to which the sides are straight; anterior and posterior borders straight; disc with a faint longitudinal impression. Elytra transverse at base, together considerably broader than thorax; sides slightly rounded; the posterior border of each straight. Abdomen broad and flat; at base as broad as elytra, the greatest width at the third and fourth segments.
Legs short and slender.
Body subshining, finely punctate throughout and covered with a fine mat of yellow pubescence; the thorax and elytra bear scattered, erect, black hairs. Color dark fuscous to piceous, legs and antennae lighter. Described from a small series taken at Pachuca and Guerrero Mill with Liometopum apiculatum Mayr.
Besides being much darker in color D. mexicana differs from D. liometopi Wasmann in the shape of the head, which in the latter species is distinctly triangular and much broader than long; in the thorax not being broader than long, and in having proportion- ately longer elytra.
Zyras (Myrmcecia) tapinomatis sp. nov.
Length 3 mm. Thorax broad; abdomen narrow. Color piceous, except the antennae, mandibles, palpi and tarsi, which are fuscous; shining throughout; the antennae less so than the body. Head not as wide as prothorax, about as long as broad; finely but distinctly punctate. Antennae not extending to apex of elytra, thick; first and third joints longer than broad, second joint small; joints 4-10 as long as broad, each slightly longer than the preceding; apical joint a little shorter than the next two together. Pronotum a little broader than long, with rounded sides, the disc at middle very broadly and deeply impressed, the impression about one and a half times as long as broad; finely punctate. Elytra together broader than long, the sides straight and parallel, punctured similar to pronotum. Ab- domen long and slender; about two-thirds as broad as elytra; very shining; the third and fourth segments each having on the dorsum a prominent tubercle, the anterior of which is the smallest, conical, and bears at the sides a fine mat of re-



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19141 Mann-Mymecophilous Insects from Mexico 177 cumbent yellow hairs; the posterior from above is round, with flat surface and with- out hairs. The median portion of the abdominal dorsum is glabrous; the rest of the body, legs and antennae are thickly though microscopically pilose, the antennae more densely than the other parts.
Described from three specimens taken at San Miguel in nests of Tapinoma sessile Say.
This species is very similar to M. lugubris Casey which I took some years ago in Orcus Island (Puget Sound) with colonies of the same host ant, but differs in the fine punctation of the head and thorax, which in lugubris are reticulate. The thoracic de- pression in tapinomatis is deeper and narrower than in lugubris and the abdomen is proportionally much more slender. Family PSELAPHIDB.
Pilopius major sp. nov.
Female: Length 3.25 mm. Color throughout brown. Head narrower than thorax; from the front twice as long as broad, the sides in front of eyes sub-parallel; vertex foveolately impressed at sides, a thin median carina extending to between the antenna1 tubercles. Eyes large and convex, located at the posterior third of head. Antennae thick, the first joint slightly bent at base, as long as the two succeeding joints together; third joint smaller than the fourth, which is larger than the fifth; joints 5-11 sub-globose, equal in size; apical joint one and three- fourths times as long as penultimate, thickened. Prothorax a little longer than broad, narrowed in front, with rounded sides; base compressed above, with median and lateral foveae; the former is elongate, extending one-third the distance to apex. Elytra together longer than broad, the sides rounded; humeri elevated into thick ridges; discal striae broad, slightly arcuate, extending three-fourths the length of elytra.
Abdomen narrower than elytra and about the same length. Body shining everywhere, finely punctate, with a thin covering of short, scale- like hairs which are more dense in the pronatal fovese and on the occiput and posterior elytral margins.
Described from specimens taken at San Miguel with Prenolepis (Nylanderia) mexicana Forel., one from each of three colonies. The maxillary palpi are short and proportionally smaller than in the other species of the genus that I have seen. This species belongs to the group which includes pulvereus Lec., ocularis Csy. and abruptus Csy., in the latter two of which only the males have been described, but is considerably larger than any of these. The pubescence is much sparser than in pulverius. The other species whose hosts are known are guests of different species of Aphseno-



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Psyche [December
gaster.
Like most other Pselaphids of myrmecophilous habits, few are found in a single ant colony, but they are generally common, there being one or two in almost every nest of the host ant in the localities where they occur.
Family HISTERIDB.
Hetserius helense sp. nov.
Length 2 mm. Color reddish-brown, in some specimens the side margins of the head, the margin of mandible and apex of femur piceous; shining. Form robust, about two-thirds as broad as long. Head above sparsely, coarsely punctate, less so between the eyes and beneath; clypeus about twice as broad as long, finely punctate; front with short yellow hairs. Thorax transverse, its breadth nearly twice the length; broadest at base; front border concave, narrowly margined; sides straight to the constriction, which is located about five-eighths the distance from the anterior angle to base; median portion of disc finely, regularly punctate, with sparse yellow hairs; marginal portion in front of constriction very finely rugose longitudinally and less shining than the remainder of thorax; the anterior border feebly rounded, posterior portion slightly elevated; margin of sides with a rather dense brush of long stiff yellow hairs. Elytra at base distinctly broader than thorax, the width of both together about equal to length; abundantly pilose; apical margin punctate; marginal and humeral striae entire; third and fourth strise extend- ing for five-sixths the length of elytra, carinated for entire length. Propygidium and pygidium finely rugulose, the former with sparse long hairs. Posternurn narrowly margined for half its length; transversely impressed at half the distance from end of margination to anterior border; distinctly excised at anterior border; margined portion shining, smooth behind and finely punctate in front. Anterior tibise nearly a third as broad as long, the front margin posterior to the angle straight, with about eleven elongate denticles. Middle and posterior tibise one-third as broad as long, the outer edge rounded.
There is considerable variation in the shade of color and a little in size. The hairs are rather long, curved, and moderately abundant. In some specimens they are almost entirely absent, probably having been scraped off by the ants. Described from a number of specimens taken in nests of Formica subcyanea Wheeler and F. microgyna subsp. rasilis var. nahua Wheeler. The former ant is the favorite host, as nearly every nest in some localities contained the beetles, while they were found in only one nest of the latter species out of dozens examined. This species, the first known from Mexico, is more closely re- lated to some undescribed forms from our southwestern states than to any of the described species. It is more pilose than any of the species which I have seen, except californicus and an unde- scribed species (hirsutus mss.) from Arizona.



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Mann-Mgrmecophilous Insects from ~exico
Terapus rnnizechi Mars.
Two specimens were taken at San Miguel in nests of Pheidole vasleti var. acolhua Wheeler. In the place where these were found was a stone fence extending for about a half mile, along which were literally hundreds of nests of acolhua. Although I made several visits here and searched many nests in other localities for the beetles no more were found. It is evidently exceedingly rare locally but has a wide distribution in Mexico. Terapus infernalis Fall.
Melanetcerius infernalis Fall.
An account of this species has been given by Wheeler (PSYCHE XVIII, 1911, p.~112-114) who found a number of specimens at Pasadena in company with Pheidole hyatti Emery. One of these was studied by Bickhardt (PSYCHE XIX, p. 97, 1912) who found that the beetle and most of the details of Wheeler's figure agreed with Marseilles description and figure of mnizechi, to which species he referred it. Recently, through the kindness of Mr. J. H. Arrow, I was able to examine in the British Museum a specimen of mnizechi from the Federal District of Mexico. This was un- doubtedly the same as the San Miguel specimens, and these are specifically quite distinct from the Southern California form. In infernalis the propygidium is feebly punctate above and more coarsely beneath, with the upper, smoother portion much smaller than the lower, and there is no sharp line between the two parts. In mnizechi the upper portion is smooth and shining, the lower punctured and opaque, and each part is in strong contrast to the other. The upper part is proportionally larger than it is in infer- nalis. The latter species is smaller, measuring two millimeters while mnizechi measures three.
Family SCARAB BID^.
Cremastocheilus, subgenus Myrmecotonus nov. Type: Cremastocheilus knochii Lee.
I propose this subgenus to contain those species which have the mentum angulate behind.
This character is correlated with the
geographical distribution of the species, all of the species in this group inhabiting the middle and far West. C. wheeleri Lee.




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180 Psyche [December
should be included with these, though in some specimens the mentum is very feebly notched.
The species which belong to Cremastocheilus subgenus Cre- mastocheilus have the mentum distinctly incised behind and are all native of the Atlantic states.
The type of the genus Cre-
mastocheilus is C. castanece Knoch.
Cremastocheilus (Myrrnecotonus) mexicanus West. Several specimens, found with Formica subcyanea Wheeler at Guerrero Mill agree closely with others identified as this species from nests of Formica gnava Buckley in the Huachuca Mts. (Schaeffer) and from the Santa Rita Mte., Arizona (Snow). There is in this series, as in other species in the genus, considerable variation in sculpture and pilosity as well as in size. ~remastocheilus (Mymecotonus) armatus Walker. C. pilisicollis Horn.
Recently I examined the type and several paratypes of C. armatus in the British Museum, and compared with specimens of the form which is identified in collections as pilisicollis Horn. The two are identical, so the latter name must fall into synonomy, as was considered probable by Horn. (Monographic Revision of the species of Cremastocheilus and Synopsis of the Euphorise of the United States.
A single specimen
Proc. Amer. Phil, Soc. XVIII, 1879, p. 390). Family CURCULIONIDB.
Liometophilus manni Fall.
of this curious weevil was taken at Pachuca in the galleries of a colony of Liometopum apiculatum Mayr. The species was first found in Southern Arizona, where it lives with a variety of the same ant. The oily-red color, so character- istic of the chitin in many beetles of myrmecophilous habits, is evident at the middle of the anterior elytral margin, where the scales are absent, probably having been gnawed off by the ants. This is, so far as is known, the only truly myrmecophilous weevil found in North America.
The Mexican specimen (length 4 mm.) is considerably larger than a paratype from Arizona in my collection, and the light-



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19141 Mann-Myr.mecophilous Insects from Mexico 181 colored transverse bands on the elytra are in stronger contrast to the rest of the body, but otherwise the two agree closely. HYMENOPTERA.
Family DIAPRIDB.
Hemilexis jessei sp. nov.
Female: (Fig. 3). Length 3 mm.
Color jet black, except the mandibles,
front of the propleurse, petiole, antennae and legs, which are rufous. Head sub-
globose, as broad as long and about as thick as long, sparsely punctulate, with scattered white pilosity; occipital border rounded, sides in front of eyes very slightly concave.
Mandibles thick and short; bifid at tip. Eyes large, orbicular,
little convex, black, located at sides of head posterior to middle. Ocelli small,
arranged in a triangle. Antennae inserted at bases of flattened tubercles; contigu- ous at base; the scape clavate, about as long as head; apex of scape shortly excavated beneath, unarmed. Pedicel thickened toward apex, as long as the first funicular joint; first funicular joint a little longer than the second, joints 2-6 subequal; the last four subequal, forming a club. Prothorax above very short; in profile tri- angular; the pronoturn thickly covered with white pubescence. Parapsidal furrows shallow, but distinct, extending the length of mesonoturn. Mesonotum feebly, very sparsely punctate. Scutellurn sparsely rugulose longitudinally, transversely Fig. 3. Hemilexis jessei sp. nov. $
depressed posteriorly. Metanotum longitudinally carinate at middleythe surface rugulose.
Petiole cylindrical, twice as long as broad, smooth and shining. Ab-
domen smooth and very shining; somewhat depressed. Legs rather short, the
femora narrow basally, and clavate at apex. Wings extending past tip of abdomen,
the tips rounded; pilose; slightly infuscated; veins yellowish.



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182 Psyche a [December
Described from a series found in several colonies of Formica subcyanea Wheeler about Velasco and near Guerrero Mill. This
is the second American species of Hemilexis as defined by Kieffer (Gen. Ins. Fasc. 124, p. 20, 1911), and differs widely from the other, H. californica Ashmead. Nothing is known regarding the habits of the other species, but jessei and the following variety are undoubtedly closely associated with the ants, probably as parasites on the immature phases. Only one or two individuals were found in each nest. They moved about rather slowly among the ants, which paid no attention to them.
This species is dedicated to my small collecting companion, Master Jesse Van Law.
Hemilexis jessei var. minor var. nov.
Three females which were taken in the same locality and with the same host ant as the preceding form seem to belong to a distinct variety. The size is much smaller (length 1.75 mm.) than in the typical form, and the coloration is lighter. The prothoracic pleurae, scutellum and petiole being light fuscus. Otherwise the two forms are identical.
Family BETHYLIDB.
Bruesiella gen. nov.
Female. Apterous. Head transverse, broader than thorax; face evenly rounded, smooth except small foveae at apex. Antennae 12-jointed, the basal joint much enlarged; inserted at base of clypeus; narrowly separated at base. Mandibles stout, thickened at tips. Eyes well developed, oval, flat. Ocelli absent. Pro- thorax transverse, smooth, with a single large puncture near a feeble longitudinal impression at margin. Mesothorax transverse, the pleurae extended into a thick, nearly perpendicular lamina. Metanotum from above subquadrate, broadest behind, sides feebly, irregularly margined; the posterior border with an acute, interrupted carina. Scutellum absent. Abdomen slender, somewhat depressed. Legs short, stout, the middle and posterior femora swollen, flattened; tibiae spinose, the middle more strongly than the others. This genus runs out at Sclerochroa in Kieffer's table in the Genera Insectorum. (Fascicle 76, p. 10, 1908). The peculiar structure of the mesothorax is quite different from that in any other of the described allied genera. In general appear- ance it bears considerable resemblance to some of the Thynnidse. Type: Bruesiella formicaria sp. nov,
Bruesiella formicaria sp. nov.
Female: (Fig. 4). Length 3.5 mm. Body shining. Head, thorax, anterior portion of first abdominal segment and legs brown, remainder of abdomen black.



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19141 Mann-Myrmecophilous Insects from Mexico 183 Head much broader than long, with straight sides, rounded posterior corners and straight posterior border. Clypeus broadly rounded in front. Mandibles slender, curved; the tip thick. Eyes large and flat, located in front near sides at about half their length from base of clypeus. Ocelli ab- sent. Antennae l%-jointed, short and thick, the first joint swollen, as long as the second and third together; second joint shorter than third, joints 3-11 subequal, cylindrical, longer than broad; apical joint about twice as long as penultinate. Head and antennae shining, minutely punctate, the vertex with four distinct fovese arranged trapezoidally. Prothorax transverse, narrowed in front to form a short, thick neck, sides slightlyrounded; post- erior border concave. Mesothorax transverse, flat above; the pleurae extended into broad, vertical lamellae, which incline slightly backward toward the base. Metanotum narrower than mesonotum, longer than broad, widest be- hind; depressed at middle, the posterior border acutely carinate; posterior surface flat. Abdomen with a short thick petiole; a little longer than head and thorax, sub- cylindrical. Legs stout, the femora enlarged, flattened, middle tibise with five strong spines on outer edge. The entire body with very sparse scattered erect, black hairs, tarsal joints spinose at apex.
Fig. 4.
Described from a single specimen taken with Bruesiella formicaria
Formica rnicrogyna rasilis var. nahua wheeler gen. & sp. nov. Q
at Guerrero Mill.
Family PTEROMALIDB.
Pheidoloxenus wheeleri Ashmead.
A single specimen of this wingless parasite was found with Pheidole ceres Wheeler var. tepaneca Wheeler at Guerrero Mill. Wheeler, who discovered the species in nests of Pheidole instabilis in Texas, considered that it is entoparasitic, either on the ants or their brood.
Family EUCHARIDB.
Orasema tolteca sp. nov.
Female: Length 4 mm.
Head triangular, slightly longer than broad, with convex occipital border and nearly straight sides. Mandibles bidentate, the teeth long
and acuminate; front flat; clypeus and frontal area separated from the remainder of front by a deep impression. Eyes oval, large, very convex; ocelli large and,



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