William Morton Wheeler.
The Australian Ant Genus Mayriella Forel.
Psyche 42(3):151-160, 1935.

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19351 Australian Ant Genus Mayriella 151 THE AUSTRALIAN ANT GENUS MAYRIELLA FOREL Biological Laboratories, Harvard University The primitive Meranopline genus Mayriella was estab- lished by Fore1 more than thirty years ago for a minute worker ant, M. abstinens, taken by Gilbert Turner in Queens1and.l Since that time, except for brief considera- tion in Emery's volume on the Myrmicinse in Wytsman's "Genera Insectorurn" and citation in a few faunal lists, the insect has remained unn~ticed.~ This neglect is due no doubt to its rare or very local occurrence and diminu- tive size. I find in my collection only a small number of specimens which are clearly referable to Mayriella, but they belong to two species. One of them is a worker of an undescribed species, another a cotype of abstinens receivedL from Prof. Forel. There are also specimens of two sub- species of this form and the series of one of them com- prises several females. The male Mayriella, unfortunately, is still unknown. In the following pages I include descrip- tions and figures of these forms, which are of interest in connection with two other primitive genera of Meranoplini, namely Willowsiella and Romblonella, which I have recently des~ribed.~ It seems advisable also to amplify Forel's gen- eric diagnosis and to redescribe abstinens from the cotype. Mayriella Forel
Worker. Monomorphic, minute, thickset, with hard, sculptured integument.
Head rather large, shaped much
^Forel, A. Rev. Suisse Zool. 10, 1902, pp. 452-454. ZViehmeyer
(Ent. Mitteil. 13, 1924, p. 26) has, indeed, described a Mayriella
overbecki from Trial Bay, New South Wales, but I fail
to detect anything in his account that does not apply to the typical M. abstinens.
3J?ormicidse of the Templeton Crocker Expedition, 1933. Proc. Cala. Acad. Sci. 21, 1934, p. 174-176, Fig. 1 and "Two New Genera of Myrmicine Ants from Papua and the Philippines, Proc. New Eng- land Zool. Soc., 1935, pp. 1-9, Fig. 2.




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152 Psyche [September
as in Meranoplus. Eyes set obliquely, slightly in front of the middle of the head, moderately large and convex, but consisting of comparatively few hemispherical facets (only 4 or 5 in the greatest transverse diameter), elongate- elliptical, produced inferoanteriorly as a distinct point. Ocelli absent. Mandibles rather small, with short, oblique, 4-toothed apical borders. Clypeus short, its posterior por- tion forming an elevated, laterally marginate plate, termi- nating on each side anteriorly in a small, sharp tooth and extending back between the frontal carinae. In profile the outline between the anterior edge of the median plate and the anterior border of the clypeus is strongly concave. Frontal carinae widely separated, subangulate, laterally ex- panded and lamellate anteriorly but not reaching the sides of the head and hence more as in Triglyphothrix than in Meranoplus, continued backward as two sharply, only mod- erately divergent ridges which form the mesial borders of broad, deep, supraocular scrobes that are rounded pos- teriorly and each large enough to contain the whole folded antenna. Frontal area distinct, frontal groove obsolete. Antennae 10-jointed ; scape short, first funicular joint con- spicuously enlarged, joints 2-7 short and transverse, the seventh longer than the others which are small and nar- row, the two terminal joints forming a large club, the last joint of which is much larger than the penultimate, as long as the remainder of the funiculus without the first joint. When the antenna is folded into the scrobe, the club is turned mesially so that it overlies and conceals nearly the whole scape and fits into the space between the plate and depressed lateral portion of the clypeus. Thorax short and stout, the pronotum large, moderately convex, with sharply rectangular humeri and submarginate sides ; prome- sonotal and mesoepinotal sutures obsolete, the latter re- placed by a dorsally transverse, longitudinally costate groove; epinotum short and narrow, sloping, armed with a pair of teeth or spines which are placed low down; metasternal angles distinct but rounded. Petiole and post- petiole with well-developed but not enlarged nodes, the petiole subpedunculate anteriorly, with an anteroventral tooth. Gaster much as in Meranoplus, oval, with about



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193.51 Australian Ant Genus MawUa 153
three fourths of its dorsal surface consisting of the first segment. Sting apparently vestigial. Legs short ; middle and hind tibisa spuriess; tarsal claws slender and simple. Female. Very similar to the worker but decidedly larger and differing in the usual sexual characters. Eyes larger, with their pointed anterior ends terminating' near the corners of the clypeus. Ocelli small, not closely approxi- mated. Thorax narrower than the head; pronoturn short, truncated anteriorly, with sharply rectangular humeri; mesonoturn large, flattened above. Pedicel and gaster pro- portionally stouter than in the worker, the latter more elongate-elliptical. Wings long, narrow, pubescent, the an- terior pair with well-developed, elongate pterostigma, open submarginal cell, a single long cubital cell and a small, discoidal cell; hind wings nearly veinlesa. Genotype: J.Vayriella, abstinens Forel
Mayriella resembles both WilIowsieHa and Romblonella in the shape of the head and thorax, the position of the eyes and the absence of promesonotal and mesoepinotal sutures but differs from both in its much smaller size and in the number of antenna1 joints, which ia 11 in Willow- siella and 12 in Romblonella, with 3-jointed clubs. Moreover, the former of these genera lacks antenna1 scrobes and both have the petiole greatly enlarged. This is true also of the postpetiole in Romblonella.
No observations have been published on the habits of Mayriella. My note-book shows that on Nov. 2, 1914, I tumid at Cairns, Queensland, three small colonies of M. ubstinens nesting in sand. Each nest was a small regu- lar crater slightly more than an inch in diameter, with a minute central entrance. Each colony comprised between 50 to 100 workers, which were huddled together with their scanty brood in small chambers only about an inch beneath the surface of the sand. The nests, except in their diminu- tive size, were exactly like those of several of the smaller species of Meranoplus (oceanus, nun,us, etc.) which are common in sandy spots in the open Australian bush, Al- though I collected several of the abstinens workers I have since been unable to find them among my mounted ma- terial and suspect that they must have been lost among



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154 Psyche [September
much larger ants collected on the same day and placed in the s,ame vial. The type of the subsp. venustula,, described below was taken by the late Mr. A. M. Lea "in rotting leaves," that of spinosior sp.
nov. by the same collector
"among fallen leaves."
The workers of the four known forms of Mayriella may be separated by means of the following table. 1. Epinotum armed with spines which are at least twice as long as the diameter of their bases; petiolar node truncate above in profile; anterior corners of post- petiole distinctly produced and subdentate. ........ spinosior sp. nov.
Epinotum armed with teeth, which are not longer than the width of their bases; petiolar node with rounded summit; anterior corners of postpetiole not pro- duced ....................................... 2. 2. Head, thorax and pedicel dark brown; sculpture coarse. abstinens venustula, subsp. nov.
Head, thorax and pedicel paler, yellow-brown ; sculpture finer ........................................ 3. 3. Epinotal teeth blunt, shorter than the width of their bases ; postpetiole above smooth and shining. ....... abstinens Fore1 (typical)
Epinotal teeth acute, as long as the width of their bases; sculpture coarser; postpetiole above finely punctate, subopaque ........... abstinens hackeri subsp. nov. Mayriella abstinens Fore1
(Fig. 1 a - c)
Worker. Length 1.4-1.5 mm.
Head subtrapezoidal, slightly longer than broad, nar- rower in front than behind, with rounded sides and pos- terior corners and broadly sinuate posterior border. Man- dibles rather flat, with straight external borders. Elevated median plate of clypeus subtrapezoidal, slightly longer than broad, broader in front than behind, its surface distinctly concave, its anterior border broadly emarginate between the teeth. Antenna1 scapes short, scarcely reaching to the posterior fourth of the head, thin at the base, swollen in the middle; first funicular joint keg-shaped, one and one-



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Australian Ant Genus Mayrielkt
half times as long as broad, joints 2-6 twice as broad as long, the seventh distinctly longer, the eighth slightly broader than long, one-third as long as the more swollen ter- minal joint.
Thorax less than twice as long as broad; pro- mesonoturn excluding the neck narrower than the head, sub- trapezoidal, anteriorly twice as broad as posteriorly, with feebly rounded anterior and nearly straight, marginate anterior and lateral borders; in profile rising rather abruptly from the neck, moderately and evenly rounded above, slightly sloping behind to the short, feebly costate, transverse mesoepinotal groove or impression ; base of epinotum quadrate, sloping with slightly raised anterior border and marginate sides, the marginations enlarging below to form a pair of small, blunt, flattened teeth, which are shorter than their basal diameter; epinotal declivity much shorter than the base, continuing down in the same sloping plane between the metasternal lobes. Petiole but little longer than broad, narrowed anteriorly, its node broader than long, subrectangular, with straight, trans- verse anterior border and straight, parallel sides; in pro- file subcuneate, higher than long, with straight ascending anterior slope, meeting the shorter, evenly convex posterior slope at a distinct angle; ventral surface of petiole straight and horizontal, the tooth at its anterior end blunt and translucent. Postpetiole from above nearly one-third broader than the petiole, one and one-half times as broad as long, rounded-oblong; in profile broadly rounded above, ventrally slightly convex in the middle. Gaster about as
large as the head, convex above and below, its anterior border concave in the middle, its anterior corners mar- ginate on the sides.
Shining; head, thorax and petiole more subopaque; man- dibles smooth, sparsely and very finely punctate; sides of clypeus transversely rugulose, its elevated median plate smooth and shining. Head, thorax, petiole and ventral portion of postpetiole very finely and microscopically, the scrobes, neck, pleurae, posterior surface of epinotum, the petiole and ventral portion of the postpetiole more coarsely and evenly reticulate; front of head also feebly, longitu- dinally rugulose, its posterior corners and the promesono-



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156 Psyche [September
turn with a coarser, superimposed reticulate rugulosity and with the spaces between the rugules occupied by shallow, circular foveolae, the cavities of which, however, exhibit the fundamental microscopic reticulation. Node of post- Fig. 1. a, Mayriella abstinens Forel, worker in profile; b, head of same dorsal view; c, thorax an,d pedimcel, dorsal view; d, M. abstinens hackeri subsp. nov., epinotum and pedicel å´o worker in profile; e, wing of female; f, M. spinosior sp. nov., epinotum and pe.dicel of worker, dorsal view; g, same in profile.
petiole smooth and more shining than the petiolar node; raster, legs and antennae very smooth and shining. Pilosity white, erect, long, and very sparse on the body, more abundant, much shorter and finer on the appendages oblique on the antenna1 scapes and funiculi, subappressed on the femora and tibiae.




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19351 Austrdian Ant Genus Mavriella 157
Head, thorax and pedicel yellowish-brown or testaceous ; mandibles, antennae, gaster and legs, including the coxse, paler, clearer yellow; mandibular teeth brown. Redescribed from a single cotype specimen from Mackay, Queensland (Gilbert Turner). As previously suggested, Viehmeyer's M. overbecki from Trial Bay, New South Wales, seems to me to be synonymous with the typical form of abstinens. The female, which he described very briefly, appears to be very similar to the corresponding caste of the following subspecies.
Mayriella abstinens hackeri subsp. nov.
(Fig. 1, d - e)
- Worker. Of the same size and otherwise very similar to the typical abstinens, but the promesonotum is slightly narrower and the teeth on the epinotum are distinctly larger, as long as broad and acute, the petiole somewhat shorter, with the anterior slope of the node concave instead of straight in profile, so that it forms a sharper angle with the convex posterior slope.
Head, thorax and petiole more shining and the sculpture of the head and promesonotum distinctly finer, the super- imposed rugulosity more delicate, less distinctly longitu- dinal on the front, with the round foveolse shallower though more numerous on the head. Postpetiolar node not smooth as in the typical abstinens but like the node of the petiole very finely and densely punctulate.
Long, sparse pilosity on the body as in the type, but the hairs on the antennae and legs distinctly shorter, sparser and appressed.
Color as in the type but the most mature specimens have the gaster concolorous with the head, thorax and pedicel. Female. Length about 2.7 mm.
Differing from the worker in the following characters: Head fully as broad as long or slightly broader; eyes larger, more than twice as long as broad, with about eight facets in their greatest transverse diameter. Mesonotum as broad as long, narrowed and bluntly pointed anteriorly ; scutellum semicircular, flattened ;
base of epinotum scarcely longer
than the declivity, the teeth stouter. Posterior slope of



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158 Psyche [September
petiolar node flat, meeting the slightly concave anterior slope at somewhat less than a right angle, the transverse summit formed by their juncture distinctly sinuate in the middle. Postpetiolar node oblong, nearly twice as broad as long.
Reticulate rugosity of head and pronoturn much coarser than in the worker, with abundant, deeper, circular foveolsa; mesonoturn and scutellum smoother, without reticulate rugules and with smaller and more scattered foveolse, espe- cially on the anterior and median portion of the mesono- turn. Scrobes, pleurae and epinotum regularly and sharply reticulate-rugulose, or rather coarsely, densely and evenly punctate ("thimble-punctured," to use the French exprea- sion) ; petiole and postpetiole less shining and more coarsely punctulate than in the worker. Gaster and legs under a high magnification very finely and superficially shagreened. Pilosity as in the worker but the long sparse hairs on the body are proportionally shorter and more flexuous and on the gaster more numerous.
Head, thorax and pedicel darker and more ferruginous than in the worker; each ocellus with a round black spot at its inner orbit; posterior border of scutellum and a pair of large elongate parapsidal spots dark brown. Membranes and veins of winga clear and colorless, pterostigma brown. Described from four workers and six females taken July 20, 1915, by Mr. Henry Hacker near Brisbane, Queensland. Mayriella ahstinens venust ula subsp. nov. Worker. Length 1.3 mm.
Very similar structurally to the typical abstinens even in the shape of the epinotal teeth, which though distinctly larger are nevertheless blunt and shorter than their basal diameter. Longitudinal costee in the mesoEplnotal groove more distinct. Anterior slope of petiolar node slightly con- cave in profile and therefore more as in the subap. hack&. Head, thorax and pedicel less shining owing to the greater sharpness of all four components of the sculpture namely the basal microscopic reticulation or punctulation, the coarser, even thirnble-puncturing of the serobes, neck, pleurae, epinotum and ventral and lateral surfaces of the



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19351 Australian Ant Genus MayrieZZa 159 petiole and postpetiole, the superimposed reticulate rugulo- sity and the foveolation of the head and promesonotum. The rugules are longitudinal only on the anterior expanded portions of the frontal carinse; the foveolse are abundant and regularly distributed on the head and anterior half of the promesonotum, its posterior half being thimble-punc- tured like the epinotum; the nodes of the petiole and post- petiole are more strongly punctulate than in the typical abstinens and its subsp. hackeri, though more shining than the basal portions of their respective segments. Pilosity as in the typical abstinens.
Head, thorax and pedicel much darker, being dark brown and contrasting sharply with the clear yellow coloration of the mandibles, antennae, legs and gaster. Described from a single specimen taken by Mr. A. M. Lea "in rotting leaves" on Mt. Tambourine, Queensland. Mayriella spinosior sp. nov.
(Fig. I, f - g)
Worker. Length 1.3 mm.
Of the same size as abstinens but differing in the fol- lowing structural characters : Head broader, fully as broad as long", more rectangular, with somewhat more angular posterior corners, less sinuate posterior border and more widely separated frontal carinse. Median elevated plate of clypeus shorter, with less developed teeth and more semi- circularly excised anterior border. Sides of promesonotum less distinctly submarginate, humoral angles less acute, mesoepinotal groove shallower and the epinotal teeth re- placed by spines which are fully twice as long as their basal diameter, nearly as long as the base of the epinotum and directed upward and outward and somewhat back- ward. Petiole as long as high, its node in profile truncated above owing to what corresponds to the posterior slope in abstinens being annulate in the middle. The anterior bor- der of this truncated area, which is subtrapezoidal and slightly broader behind than in front, is sharply margin- ate. Postpetiole from above of similar shape but reversed, that is, broader in front than behind, with the anterior corners distinctly produced and bluntly subdentiform. An- terior corners of gaster not marginate.




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160 Psyche [September
Mandibles finely longitudinally striate at their external borders. Sculpture of head and promesonoturn decidedly coarser than in any of the forms of abstinens, consisting of the basal microscopic reticulation overlaid by a regular polygonally reticulate rugosity, without rounded foveolse in the meshes. The rug= are distinctly longitudinal on the front of the head. Thimble-punctuation of the scrobes, neck, pleurae, epinotum and ventral portions of the petiole and postpetiole finer than in abstinens venustula; the nodes subopaque, finely and densely punctate.
Pilosity pale yellowish, in length and distribution like that of the subsp. ha'ckeri.
Thorax, pedicel and gaster yellowish ferruginous, the head somewhat darker and more brownish; mandibles, an- tennse and legs, including the coxse, brownish yellow.; man- dibular teeth brown.
Described from a single specimen taken by Mr. A. M. Lea "among fallen leaves" in the Cairns District, Queens- land.




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