COIiEOPTERA. 289 



beetle, like Atemeles, belongs to the true guests, and possesses a short 

 broad tongue and aborted palpi, as it is fed by its hosts. It also has 

 patches of yellow hairs on various parts of the body, and the ants 

 obtain a sweet secretion from them. The larva of the beetle, which 

 is very like an ant larva, is fed by the ants, and they even put it on 

 their own brood, so that it may devour them. The voracity of the 

 beetle produces, in colonies where it has been for some time, a lack of 

 the nursing instinct in the ants, and so pseudogynes (or false females) 

 begin to appear, and, of course, whenever these are found, Lomechusa 

 may be certain to occur. It is from these colonies that the beetles 

 spread to other nests. At first, the beetles are kept in check by the 

 ants digging up and carrying about the Lomechusa pupge, as they do 

 their own, which is, of course, fatal to them. My friend, Mr. Hereward 

 Dollman. has kindly drawn the pseudogynes and a queen and ordinary 

 worker, to show how they differ ; also the labium and larva of the 

 beetle, all from the specimens themselves {see plate). 



Dinar da dentata, Gr., was taken by me at Woking (a new locality 

 for it) with Forinica sanf/idnea, in plenty, in May and September. 

 D. hagensi, Wasm., again at Bournemouth with F. exsecta : and over 

 twelve specimens of B. pj/f/maea, Wasm. (see Ent. Record, 1906, p. 217) 

 were taken by Mr. Keys and myself, in Cornwall, with F. rufibarbis war. 

 fiisco-rufibarbis, in September, and the former has taken it in some 

 numbers since. As there is still some doubt in the minds of one or 

 two coleopterists as to whether these three species of Dinarda are 

 distinct or not, I may point out the following facts : — D. dentata is 

 only found with It. sanciuinea, it is the largest of these three, broadest, 

 most robust, and most coarsely punctured. D. hagensi is only found 

 with F. exsecta, it is always of a lighter colour (more yellow), more 

 elongate, and the elytra much broader than the thorax, more so than 

 in the others. Our form is most constant, I have taken over fifty 

 specimens now, and they were all the same. D. pijgmaea is found with 

 F. rufibarbis var. fusco-rufibarbis. It is the smallest of our species, and 

 the thorax is less broad in proportion to the elytra. It varies a good 

 deal, I have a specimen in which the thorax is not broader than the 

 elytra (typical pygmaea, Wasm.), and others in which it is, and Mr. 

 Keys has sent me a specimen in which the antenna are longer and 

 more slender. There are some specimens in the " Power " series of dentata 

 which Mr. Waterhouse had put by themselves, and they evidently look 

 different, and are smaller ; on examining them I found the thorax to 

 be less broad in proportion to the elytra, and I found they came from 

 Weston-super-Mare. Two of Power's three specimens of Atemeles 

 paradoxus also came from Weston-super-Mare, and, as we have seen, 

 that this species is only found with F. rufibarbis var. fusco-rufibarbis, it 

 follows that the ant must occur there, and it is, therefore, exceedingly 

 probable that these specimens of Dinarda were taken with the same 

 ant, as they must have been if they are, as I consider them to be, 

 Dinarda pygmaea. I took the larva of pygmaea in Cornwall, and on 

 comparing it with a specimen of the larva of dentata, kindly given me 

 by Father Wasmann, I find the antennfe are a little longer in the 

 former. 



(To be continued.) 



