[35] Report of the State Entomologist. 131 



Description of the Beetle. 

 The insect, shown in the accompanying figure, is a soft-bodied beetle, 

 three-fourths of an inch in length, of a glossy, dark-blue color, with 

 a large ovate body, short, small, overlapping 

 elytra, without wings, with long legs, the head 

 heart-shaped, abruptly narrowed behind into a 

 neck and bent downward, having the antennae 

 rather short, twisted and larger in the central 

 joints in the male. Its scientific name is Meloe 

 angusticollis Say. 



The female is distinguishable by its antennal 

 joints of nearly uniform diameter, its broader 

 head, and its egg-shaped abdomen before ovipo- ^^^2^;^;^::^, 

 sition so swollen with its burden of eggs that it "^^le. 

 can with difficulty be trailed over the ground. It is considerably 

 larger than the male, measuring nearly an inch in length. 



Habits. 

 This strange-looking insect is popularly known as the oil-beetle, 

 from a peculiarity which it has, when disturbed, of throwing out from 

 the joints of its legs a thick, oily, yellowish fluid of a disagreeable 

 smell, which is said to contain uric acid. It is an interesting species, 

 from the singular habits and transformations of its larva. The eggs are 

 deposited in the ground, probably in the vicinity of bees' nests, whence 

 when hatched, the young larvae, called triungulms, transfer themselves 

 to the bodies of the bees, wasps, etc., and feed upon their juices. 

 They also have been found living as parasites on various flower-flies 

 and on some other Diptera. Their transformation is quite exceptional, 

 in that instead of passing directly from the larva to the pupa, and 

 then to the imago, as do other Coleoptera, exclusive of the blister- 

 beetles, the second larva enters into a quiet stage in which it is known 

 as the pseudo-pupa. It then passes into its third larval stage, in 

 which it is active but does not feed, and afterward enters its pupal 

 stage, thus existing in eight distinct states, counting the egg and the 

 beetle. 



The beetle possesses vesicating properties and is numbered among 

 the blister-beetles. It has been employed as a substitute for the 

 Spanish fly {Cantharis vesicatoria) of the shops and is said to be almost 

 as powerful in its effects. 



The oil-beetle is frequently met with in May, and again in August 

 and September on buttercups {Ranunculus), and is also found creep- 

 ing slowly over grasses and on the ground. 



