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JOURNAL oF VARIATION. 
Nous SOX Xt No. 1. . January 15rH, 1920. 
The Myrmecophiloiwts Lady-Bird, Coccinella distincta, Fald., its 
Life-history and Association with Ants. 
(With two plates.) 
By HORACE DONISTHORPE, F.Z.S., F.E.S., etc, 
(Concluded from Vl. xxxi., p. 222.) - 
The most difficult problem in connection with C. distincta is to 
explain why it is always associated with ants. The beetles, as we 
have seen, do not as a rule hibernate in the nests; nor do the larve 
and pupee live in the nests, nor are the eggs dropped on to them, as is 
the case with Clythra quadripunctata. The lady-birds (and their 
larve) will feed on any plant-lice and could often obtain a richer 
supply of food by visiting trees far away from the rufa nests, as do the 
ants themselves. Therefore it is not a question of food. It 
cannot be to obtain protection ‘from the ants because its near 
ally the seven-spot lady-bird is much more common and occurs 
everywhere miles away from F’, rufa nests. The fact that the 
latter sometimes occurs with distincta on the trees over rnfa 
nests, and also alone in such situations—at Oxshott I frequently find 
septempunctata on fir trees over rufa nests, but have never been able 
to discover distincta there—serves to show the kind of variation in 
habit which may lead to a myrmecophilous mode of life, and not why 
it lives such a life. Wasmann?* considers that distincta has 
adapted itself to such a life through a spontaneous variation, which 
embraced and retained, gave to the species a new direction in evolution, 
and this in spite of the limitation in food-supply which was incidentally 
brought about through this new habit. He believes that it has 
differentiated itseli—not through, but in spite of the operation of 
natural selection—into a true morphological species. This again does 
not explain why it lives with ants, but only how the habit started ; 
moreover | am more inclined to think that the habit was brought 
about gradually, by its ancestors experimenting in a myrmecophilous 
existence, aS we see septempunctata doing at this day. [For other 
examples of a like nature—see my paper “On the Origin and 
Ancestral Form of Myrmecophilous Coleoptera.” Trans. Ent. Soc. 
Lond. 1909 413-29]. I consider the reason for its association with F. 
rufa is that it is a Mullerian mimic of Clythra 4-punctata. In 190024 
I wrote of the latter—‘“I am inclined to think that this beetle is 
a mimic of Coccinella distincta, as it has a strong superficial 
January, 1920. 
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