PIGMY MANGOLD BEETLE. 81 



these little Beet plants has the earth partly removed, and the roots 

 laid bare, then these minute beetles may be observed at their 

 destructive work. They perpetrate their devastation still under- 

 ground ; often the stalks of the young plants, before these have as yet 

 reached the surface, are destroyed beneath the seed-beds, so that the 

 plants come to nothing." * 



Later on it appears that if the weather is favourable these minute 

 beetles come above ground, and extend their attacks to the leaves, 

 sometimes causing total destruction ; but in case this attack has not 

 taken place until the plants are fairly advanced in growth they may 

 get over it. 



The description quoted by John Curtis (see ' Farm Insects,' p. 395) 

 gives in short compass a good description of the infestation : — " We 

 learn from M. Baziu that this minute beetle is generated in great 

 numbers, destroying the buds as they appear, and, on removing the 

 clods of earth, one often sees enormous quantities. It does not 

 content itself at a later period by attacking the root, but when it is 

 fine weather it comes out of the ground, ascends the stem, and devours 

 the leaves. These little creatures often appear in families on a plant 

 of which in a few hours nothing remains but a leafless stalk, which 

 presently withers and dies." — (J. C.) 



On warm evenings the beetles come out of the earth, and rising in 

 the air they pair. (See ' Praktische Insekten-Kunde,' by Dr. E. L. 

 Taschenberg.) 



The maggots are believed to feed at the roots like the beetles, but 

 excepting that they originate the coming more severe and general 

 attack they are not recorded as doing much harm. 



The above descriptions of injuries agree so well with what had 

 happened to the samples that, joined to Prof. Barker's observations of 

 the beetles in connection with their destructive work, it appears to me 

 that we have now found the cause of the severe injury to the young 

 Mangolds which has been reported of late years. The excessive 

 minuteness of the beetles, and likewise their subterranean habits, 

 have doubtless been the reason for their escaping field observation, and 

 consequently none of them reaching me, together with the plants 

 when drawn from the ground. But the above observations will be 

 enough for identification of the attack should it again occur, and if in 

 this case I could have some specimens of the little beetles forwarded 

 in a piece of quill, together with the samples of the injured young 

 Mangold, we should be able to trace out the matter fully, and guard 

 against recurrence. 



* ' Die Tierische schadlinge, und Nutzlinge, &c., Praktische hand-buch ' (p. 259), 

 von Dr. J. Ritzema Bos. Berlin, 1891. 



