William Morton Wheeler.
An Australian Leptanilla.
Psyche 39(3):53-58, 1932.

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PSYCHE
VOL. XXXIX SEPTEMBER, 1932 No. 3
AN AUSTRALIAN LEPTANILLA
Harvard University
The very interesting Formicid subfamily Leptanillinee comprises only two genera of minute, yellow, blind and hypogseic ants, namely, Leptanilla, established by Emery as long ago as 1870 and Phaulomyrma, established by G. C. and E. W. Wheeler in 1930 on a male specimen from Java. This genus probably also includes Santschi's L. tanit from Tunis. Of the eleven described species of Leptanilla, four are known only from males; of the remaining seven, five are known only from workers and only two from both workers and females. The geographical distribution of the various species is peculiar. Six of them, namely, L. theryi Forel, vaucheri Emery, exigua Santschi, minusculu Sants- chi, nunu Santschi and tennis Santschi, were taken in North Africa (Algiers, Tunis, Morocco), two, doderoi Em- ery and revelierei Emery, in Corsica and Sardinia (though the subspecies chobauti Emery of revelierei occurs in Mo- rocco), two, havilandi Forel and butteli Forel, in the Malay Peninsula and one, sun-tschii G. C. and E. W. Wheeler, in Java.
During November, 1931, while I was with the Harvard Zoological Expedition in Australia, Mr. D. C. Swan of the Waite Institute at Glen Osmond, S. A., generously gave me some minute ants which he discovered in Western Austra- Pu&e 3953-58 (1932). hup ttpsychu einclub orgIW39-053 html



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54 Psyche [ September
lia. The collection comprises two dozen workers, a female and a number of full-grown larvae, which prove to belong to an undescribed species of Leptanilla. They therefore considerably extend the known geographical range of the genus. Owing to the fact that the Leptanillinae are true members of Silvestri's "microgenton" and that their work- ers and females are very rarely seen, because they come to the surface of the soil only under unusual conditions, such as excessive rainfall, it is too early to regard the various species at present known as covering the entire range of the genus. We should expect careful collecting with the Berlese funnel to bring additional forms to light in South Africa, Madagascar, Asia Minor and India, or even, per- haps, in the warmer parts of the New World. Leptanilla swani sp. nov.
Worker. (Fig. 1, a-d.) Length 1.3-1.5 mm. Pale yellow; legs scarcely paler than the body; teeth and borders of the mandibles reddish.
Head flattened above, oblong, fully 1% times as long as broad, as broad in front as behind, with subparallel sides, rounded posterior corners and feebly concave posterior border. Mandibles narrow, with very oblique 4-toothed apical borders, the terminal tooth curved and acute, the second minute, the two remaining teeth stout and rather blunt, the most basal directed at right angles to the apical border or even slightly backward. Clypeus without distinct posterior suture, its anterior border slightly but distinctly produced in the middle as a broadly rounded lobe, excised at the sides. Antennae moderately stout; scapes reaching nearly to the middle of the head; basal funicular joint nearly 1% times as long as broad, ovoidal, with constricted base ; joints 2-6 distinctly broader than long ; the second basally constricted, the seventh distinctly longer, 8-10 as broad as long, the terminal joint as long as the two preced- ing joints together. Thorax much narrower than the head including the mandibles, flattened dorsally and not deeply notched in profile at the promesonotal suture; pronotum subovoidal, somewhat broader than the mesepinotum, which is longer than the pronotum, with feebly rounded, sub- parallel sides. Petiole much narrower than the epinotum,



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19321 An Australian Leptanilla 55
nearly 1% times as long as broad, gradually narrowed an- teriorly, posteriorly with rounded-subparallel sides. Post-
petiole rounded-trapezoidal, nearly as long as broad, some- what broader than the petiole and somewhat wider behind than in front, its ventral surface convex and projecting. Gaster narrow, elongate-elliptical, anterior border of first segment slightly concave. Sting large, retracted. Legs mod- erately stout, tips of fore metatarsi produced and digiti- form, but not so narrowly as in L. nana Santschi. Shining, with very fine and indistinct piligerous punc- tures. Pilosity white, very short, abundant both on the body and antennae, slightly longer and coarser on the gaster, less conspicuous and more dilute and appressed on the legs. Female. (Fig. 1, e and f.) Length 2 mm.
Color, sculpture and pilosity as in the worker, but the hairs on the gaster very long, though fine, as in the female of L. thmji Forel.




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56 Psyche [ September
Apterous and resembling the worker in form but differing in the following characters: Head more sharply oblong, with straight and more clearly parallel sides. Mandibles falcate, narrow and tapering at the tips, without distinct basal and apical borders, terminating in two small, indis- tinct, closely approximated teeth. Clypeus broader and less produced than in the worker. Thorax decidedly longer than the head plus the mandibles, very low and flat above, the pronotum posteriorly nearly as broad as the head, longer than broad, with feebly rounded, anteriorly converging sides, mesepinotum broader than the head, subtrapezoidal, broadest near the anterior end, roundly subtruncate behind. Promesonotal suture pronounced, straight and transverse in the middle. Petiole regularly oblong, about Iy4 longer than broad, as broad in front as behind. Gaster much larger than in the worker, the postpetiole, which forms its first segment, nearly twice as broad as long, subtrape- zoidal, with straight anterior border. Genitalia similar to those of L. revelierei Emery, but the pygidium with entire, broadly and semicircularly rounded posterior border, not notched in the middle. Hypopygium large, narrowed and bluntly bidentate posteriorly. Legs longer and stouter than in the worker.
Described from 24 workers and a single female taken Oct. 10, 1931 by Mr. D. C. Swan under a large stone at Goyamin Pool, Chittering, Western Australia. L. swani seems to be most closely related to L. revelierei, but the female of the latter has a much shorter petiole. In the long pilosity of the gaster the female of the new form resembles theryi, but in this species the petiole is very different, being distinctly cordate anteriorly instead of oblong.
Dr. G. C. Wheeler, to whom I sent the larvae of L. swani for study, writes me that he found them "extremely inter- esting because of their close resemblance to the larvae of revelieri subsp. sardoa. They even have the 'tympanum' which is difficult to detect unless the specimens are stained. This species differs from sardoa in the following charac- teristics: (1) The head is sharply constricted just in front of the middle so that in dorsal view it is flask-shaped or key- hole shaped ; the posterior half is circular, the middle half



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19321 An Australian Leptanilla 57
is about half as wide and has subparallel sides. (2) The prothorax is sparsely spinulose while the curious structure an its ventral surface has its base densely and coarsely spinulose. (3) The two extremely long hairs at the poste- rior end are lacking in all specimens."
Emery, as is well known, regarded the Leptanillinse as constituting a special tribe of the Dorylinse, but Dr. G. C. Wheeler and I have raised the group to subfamily rank. Unquestionably, Emery, in his paper of 1904, based his opinion very largely on the singular characters of the fe- male, which he regarded as a true dichthadiigyne and com- pared with the female of Aenictus. Strangely enough, Em- ery seems not to have noticed the peculiar falcate shape of the female mandibles, so unlike those of the worker, a char- acter which, taken together with the absence of wings and the single segment of the pedicel, makes the resemblance to the females of the Dorylinse even greater than he supposed. But the males of the Leptanillinse and the larvae, as described and figured by G. C. Wheeler, are so very unlike those of the Dorylinse that we are bound to regard the striking similari- ties of the females as due to convergence. Emery's original interpretation of the thoracic segmentation of the female Leptanilla was incorrect, because he regarded the portion of the thorax anterior to the pronounced transverse dorsal suture as the mesonotum, the portion posterior to the suture as the combined metanotum and epinotum. In a foot-note to his section on the Leptanillinse in the "Genera Insecto- rum" (1910), he recognized his error and adopted the in- terpretation which I have also reached, namely, that the presutural portion is the pronotum, the postsutural the com- bined meso- and epinotum.
The occurrence of indigenous species of Leptanilla on is- lands like Corsica, Sardinia, Java and Australia is signifi- cant. Since the females are apterous and obviously too small and delicate to endure distant transportation in flot- sam and jetsom, we must suppose that they have occupied their present habitats since the islands mentioned were connected with the mainland. The Leptanillinae, therefore, must be very ancient, like many other components of the microgenton (Kcenenia, Pauropus, Scolopendrella, Cam- podea, Iapyx, etc.) L. swani is particularly interesting in



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this connection, because the extreme southwestern corner of Australia, in which it was taken, is. known to possess the oldest and least disturbed fauna of any portion of the con- tinent.
Emery, C.
Studi Mirmecologici. Bull.
Soc. Ent. Ital. 2, 1870, pp. 193-
201, 1 pi.
Emery, C.
Le affinith del genera Leptanilla e i limiti delle Dorylinse. Archiv. Zool. Ital. 2, 1904, pp. 107-116, 9 figs. Em,ery, C. Formicidse, subfam. Dorylinse, in Wytsman's Genera In- sectorum, 1910, pp. 32-33.
Wheeler, G. C.
The Larva of Leptanilla.
Psyche 35, 1928, pp. 85-91,
1 fig.
Wheeler, G. C. and E. W.
Two New Ants from Java. Psyche 37, 1930, pp. 193-201, 2 figs.
ON THE SO-CALLED INTRODUCTION OF HELIOTHIS DIPSACEA L. INTO THE UNITED STATES
Bureau of Entomology, United States Department of Agriculture
Throughout the earlier literature there are scattered ref- erences of the occurrence within North America of this Pa- learctic Heliothid. All of these seem to apply to the in- digenous Heliothis phloxiphagus Grote and the name was dropped from the more recent lists.
A paper by Mr. Fred H. Walker was published in 1928 (Psyche, XXXV, 29-30), definitely stating that the Euro- pean species actually did occur in Massachusetts. Through the kindness of Mr. C. W. Johnson one of the Walker specimens was submitted for examination. Both upon superficial characters and upon male genitalia it is the ordinary American phloxiphagus.




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