51 



" Soft-skinned beetles " — soldiers, sailors, glow-worms and 

 their allies — all flesh eaters, are red and black, yellow and black, 

 or dusky yellow brown, and all appear to be uneatable. 



" Carrion feeders " and burying beetles and their allies are 

 black if nocturnal — if diurnal, are very gay with a warning pattern 

 of black and yellow. 



" Dung beetles," if diurnal, are black and yellow, or black 

 and red. Many conspicuous plant-feeders are metallic, shining in 

 bronze, .blue, green or purple, or with two or more of these 

 colours combined. They do not attempt to hide, and many secrete 

 acrid fluids in both larval and adult stages. On the other hand 

 the whole tribe of weevils are coloured to hide and presumably 

 are eatable. Two distant families of beetles mimic the colour- 

 ing of Mutilla, an ant bee with a vicious sting. Others imitate 

 wasps or bees in colour and even in form and gait. Donacia, 

 a genus of edible plant-eaters, mimics the most varied forms of 

 inedible flesh-eaters. For instance, the similarity of a series of 

 Donacia sp. to Elaphrus , Anchomenus albipes and other riparian 

 Geodephaga can hardly escape notice. Here the model is not so 

 common as the copy and the question arises, is this Miillerian 

 rather than Batesian mimicry ? The writer, believing Donacia to 

 be eatable, thinks the mimicry is Batesian. The appearance of 

 Donacia, though in very? great numbers, is for a short time, and 

 follows by weeks the appearance of its models, which enjoy a much 

 longer season. Is it possible that Donacia during its short season 

 enjoys an immunity previously won by the Geodephaga? Have 

 we in this case model and copy not so much contemporaneous as 

 successive? This would introduce a new factor of succession in 

 time into some cases of mimicry. 



A survey of the entire field supports the view that almost all 

 non-vegetarian beetles and many plant feeders are bad eating and 

 court observation. The eatable vegetarians have methods of 

 escaping detection, or elude capture by jumping or dropping into 

 shelter. 



Note. — The following species, figured in colour by Mr. 

 Neale, were used to illustrate the paper : — 



Elater sanguinolentus and Athous nigcr (diurnal and crepuscular 

 shipjacks), Cicindela campestris, Carabus nitens, Bemetrias atricapillus, 

 Brachinus crepitans, Bytiscus marginalis, Paederus sp., Staphylinus 

 coesarius, Silpha 4 maculata (diurnal), Necrophorus vestigator (taken 

 1 pm. near Corfe), Cetonia aurata. Onthophagus sp.. Telephorus sp., 

 Pyrochoa sp., Metoficvs paradoxus, Callidium aim and Clerus formicarius 

 with' Mutilla their model, Hylurgus, Rhagium sp., Clytus arietis, Chryso- 

 mela sp., C tonus sp., Cryptorhynchus lapathi. 



