W. M. Wheeler.
Concerning Some Ant Gynandromorphs.
Psyche 38(2-3):80-85, 1931.

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Psyche
[ June-September
CONCERNING SOME ANT GYNANDROMORPHS
I. Dinergutundromorphs
In the twenty-sixth volume of Psyche (1919) I described and figured a peculiar gynandromorph of Camponotus (Colobopsis) cdbocinctus Ashmead from the Philippines and designated it as a "dinergatandromorph" because the left half of its head was, that of a male. This individual, therefore, was unlike all previously described ant gynandro- morphs, which are combinations either of male and female or of male and worker components. The correctness of my interpretation was doubted by Santschi (1920) and Emery (1924). The latter conjectured that what I had taken to be the soldier half of the head was really a generalized female-worker component, but I gave reasons (1928) for adhering to my original interpretation. Additional con- siderations might be adduced, but this is no longer neces- sary, because Vandel (1931) has just published a very careful account of a dinergatandromorph of Pheidole pullidulu, in which the union of soldier (right-sided) with male (left-sided) characters in the head is even more extra- ordinary than in my specimen of Cumponotus albocinctus. The more striking character of Vandel's specimen is due, of course, to the much greater differentiation in the shape of the head of the normal soldier, worker and female castes of Pheidole. The body and right side of the head in the specimen are very clearly those of a soldier, and as in the Camponotus, there is no median ocellus, which should be present if that region of the head were female. The bearing of the two cases on the opposed blastogenic and trophogenic hypotheses of the origin of castes in ants, is obvious. The anomalies under discussion must have arisen Pncht 38:80-85 (I93 I). hup Ytpsycht einclub or$rt8/38-080 html



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19311 Ant Gynandromorphs 81
either in the egg or during the larval stage. On the former supposition, the soldier like the male component would be blastogenic and the anomaly would be due to unusual nuclear (chromosomal) or other conditions in the unseg- mented or just segmented egg; according to the blastogenic hypothesis, the soldier component would be due either to special feeding of the undifferentiated female portion of a germinally determined gynandromorphous' organism, or to some shock or other injury to certain tissue areas of the larval or prepupal soma, as in the butterfly gynandromorphs produced by van Someren.
11. Anteroposterior Gynandromorphs
Vandel, while discussing the various hypotheses that have been framed by Boveri, Morgan, Doncaster, myself and others to account for gynandromorphs, calls attention to certain ambiguous cases which may be interpreted either as functional ergatomorphic males or as anteroposterior gynandromorphs, that is, as pathological individuals having the anterior part of the body of the worker type and the gaster and genitalia male. The following are cases of this description :-
(I) Santschi (1921) described three specimens of Cata- glyphis albicans Rogers, taken by Th6ry in a single locality in Morocco, as having the head and thorax of the worker type, but the gaster and well-developed genitalia male. The head, however, was small and furnished with male ocelli. Santschi was unable to decide whether these specimens were gynandromorphs or normal ergatomorphic males of their species. The fact that some species of Cataglyphis have no marriage flight and have males with rather short wings and that there were three of the peculiar specimens seemed to indicate that they were ergatomorphic males. The num- ber of individuals is not important in this connection since in two other cases recorded in the sequel three undoubted gynandromorphs were taken from the same nest. (2) Mayr, in 1868, described a peculiar hermaphrodite ("Zwitter") specimen of Iridomyrmex constrictus Mayr,



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82 Psyche [ June-September
a fossil ant from the Baltic amber. I reexamined and fig- ured this insect in 1914. It has a typically worker head and thorax and a normal male gaster with well-developed genitalia, but the eyes are large and the antennse are 13- jointed and therefore male. The specimen, therefore, re- sembles Santschi's specimens of Cataglyphis even in having some male cephalic characters.
(3) Lomnicki (1914) found in the same colony three very similar specimens of Myrmica rugulosa, with the anterior part of the body as far back as the gaster pre- dominantly female and the gaster male, but with poorly developed genitalia (small in one specimen, retracted and invisible in the others).
Lomnicki's specimens are evidently anteroposterior gynandromorphs, though they exhibit some admixture of maleness in the anterior portion of the body, and perhaps of femaleness in the reduced size of their male genitalia. The Cataglyphis and Iridomyrmex cases are also, I believe, anteroposterior intersexes or gynandromorphs which may, perhaps, have become the only males of their respective species. My reasons for this opinion, developed in my paper on intercastes (1928, p. 229 et seq.), are derived mainly from a consideration of the peculiar conditions in the genus Ponera. Some species of these ants (P. erga- tandria Forel, P. punctatisska Roger, P. mina Wheeler) have males exactly like the workers, except for the geni- talia, while one Mediterranean species, P. eduardi Forel, has, in addition to the usual winged male an ergatomorphic male with worker thorax and abdomen but with the head and genitalia male. The ergatomorphic male of P. puncta- tissima was originally described by Roger as P. androgyna. These ergatomorphic males are therefore transverse, or anteroposterior gynandromorphs which function as the regular males of the species. Additional support for this statement is furnished by three extraordinary specimens of P. coarctata pennsylvanica Buckley, which Professor Clarence H. Kennedy has generously sent me for examina- tion and which he or Miss H. Sheldon will describe in detail. They were taken from a colony nesting in a white



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19311 Ant Gynandrornorphs 83
oak log on a sand-dune on Point Pelee Island, Ontario, in Lake Erie, and are remarkably alike, having black heads of the male type, though the antennas are 12-jointed, except in one specimen which has the left antenna 13-jointed. The thorax and abdomen in all of them is pale brownish-yellow, like the color of callow workers. In two the genitalia are purely female, with small though normally developed sting ; in the other a similar sting is combined with male genitalia appendages! Since the only known males of P. pennsyi- vanica are of the usual winged type with the body black throughout, we must regard Professor Kennedy's specimens as anteroposterior gynandromorphs. The specimen with hermaphrodite external genitalia is obviously intermediate between such a form as the normal ergatomorphic male of P. eduardi, which has a head of the male type with 13- jointed antennae, and the two other specimens with exclu- sively worker abdomen and developed sting. The suppres-
sion of the sting in the former specimen would convert it into an ergatomorphic male, and if its testes were suffi- ciently developed it would be essentially like the normal ergatomorphic male of P. eduardi.
111. Additions to the List of Known Ant Gynandromorphs In 1929 Donisthorpe listed the known ant-gynandro- morphs and gave their number as 49. Vandel has elimi- nated from this list Santschi's Cataglyphis as a doubtful case (Donisthorpe included only one of the three cases mentioned in Santschi9s paper), and has added the two peculiar Myrmica ruginodis Nyl. gynandromorphs described by Emery in 1924 (overlooked by Donisthorpe) and his Pheidole dinergatandromorph, thus making the total num- ber of known ant gynandroromphs 51.
Donisthorpe, how-
ever, omitted a Cardiocondyla gynandromorph described by Swezey in 1926. I have examined this insect in the collection of the Hawaiian Sugar Planters' Experiment Sta- tion and have found it to belong to C. wroughtoni Fore1 var. hawaiiensis Forel, and not to C. nuda minutior Forel, as Swezey supposed. The specimen, which was taken in a compost heap in the garden of the Experiment Station at Honolulu, is a normal female, except that the left eye is decidedly larger and the left antenna of the male type



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84 Psyche [ June-September
and 13-jointed. In the same collection I discovered a second very similar gynandromorph of the same variety, taken on a window pane in Honolulu.
This individual, too, has a
larger left eye but the left antenna, though decidedly of the male type, has only 12 joints. Probably the normal male of C. minutior has 13-jointed antennae, but a specimen in the same collection was found to have both antennae 12- jointed. Adding these two Cardiocondyla gynandromorphs and Professor Kennedy's three Ponera gynandromorphs, the list of these anomalies now totals 56, or if we regard Santschi's three specimens of Cataglyphis and Mayr's Irido- myrmex as anteroposterior gynandromorphs rather than ergatomorphic males, we have 60.
Donisthorpe, H. 1929, Gynandromorphism in Ants. Zool. Anzeig. p. 92-96.
Emery, C.
1924, Casi di anomalia e di parasitism0 nelle formiche. Rendic. Accad. Sc. 1st. Bologna, pp. 82-89, 4 figs.
Lomnicki, J.
1924, On three gynandromorphs of the ant Myrmica rugulosa Nyl. (in Polish). Kosmos, Lwow. 49, pp. 817-830, 5 figs.
Mayr, G.
1868, Die Ameisen des baltischen Bernsteins, Beitrage zur Naturkunde Preussens, Physik. okonom. Gesell. Konigsberg, 1, 102 pp., 5 pis.
Roger, J. 1859, Beitrage zur Kenntniss der Ameisenfauna der Mittelmeerlander, Berlin. Ent. Zeitschr 3, pp. 225-259, 1 pi.
Santschi, F.
1920, Cinq nouvelles notes sur les fourmis. 4. La 39e fourmi hermaphrodite. Bull. Soc. Vaud. Sc. Nat. 53, pp. 175-178.
Santschi, F.
1921, Formicides nouveaux de 1'Afrique du Nord. Bull. Soc. dYHist. Nat. Afr. Nord. 12, pp. 68-77.



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19311 Ant Gynandromorphs 85
Swezey, H. 0. 1926, Gynandromorph Ant. Proc. Hawaii. Ent. Soc. 6, p. 229.
Vandel, A. 1931, Etude d'un gynandromorphe (diner- gatandromorphe) de PheidoZe puZZiduZu Nyl. Bull. Biol. France Belg. 65, pp. 114-129, 2 figs.
Wheeler, W. M. 1914, The Ants of the Baltic Amber. Schrift. physik. okonom. Gesell. Konigsberg 55, 142 pp. 66 figs.
Wheeler, W. M. 1919, Two Gynandromorphic Ants. Psyche 26, pp. 1-8, 2 figs.
Wheeler, W. M.
1928 a, The Social Insects, Their Origin and Evolution. London, Kegan Paul.
Wheeler, W. M. 1928 b, Mermis Parasitism and Inter- castes Among Ants. Journ. Exper. 2001. 50, pp. 165- 237, 17 figs.




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