Mylarris Bel:tles. 74H 



Some of them are, some are not. Dr, Pering'uey stated (4) that he had 

 examined beans and peas, and that of the flowers eaten 80 per cent, 

 had been previously fertilized; so in that particular case at least the 

 damage was much less than it appeared. In such cases control 

 measures are hardly necessary. 



Damage to Foliage, etc. — However, considerable damage is some- 

 times done by the beetles, and apparently this damage is not always 

 confined to the blossoms. Mr. Jacobus Faure has called the attention 

 of the writer to two letters on file at the Office of the Division of 

 Entomology, in wiiicb M. cctdata appears in a different role. One 

 letter, from the Waratah Citrus Farm, Brits, Transvaal, states that 

 the beetles did considerable damage to tomatoes, beans, potato foliage, 

 elc. The other letter states that five niuids of potatoes were planted 

 on farm Sweetput, Content Station, Cape Province, that the crop was 

 entirely destroyed by beetles, and that it looked as though a hail- 

 storm had gone tlirough the lands. 



When severe injury is done to crops, etc., one need not hesitate 

 to destroy the beefles. The Division of Entomology recommends the 

 destruction of the insects in all such cases. Even though the larvae 

 of our Mylabris beetles do feed upon the eggs of grasshoppers (a 

 point that has not been definitely established), the fact must be taken 

 into consideration that most of our common grasshoppers feed princi- 

 pally upon grasses, particularly those of the veld; and that the value 

 of this glass is relatively small when compared with the value of the 

 cultivated plants destroyed by the adult beetles. Furthermore, the 

 number of beetles coming to the fields and gardens is usually only a 

 small percentage of the number present in any given locality; there- 

 fore, killing them will hardly upset the " balance of nature." 



Cantharidin. 



Projjerties and f/.'>e5.— Blister beetles are dried and reduced to a 

 powder, which is ased in medicine under the name of " Cant ho rides." 

 From the powder a crystalline substance known as Cantharidin is 

 extiacted. This is occasionally used internally in minute doses as a 

 stimulant and diuretic; but its principal use. which is true also of 

 the powder, is in solutions, tinctures, plasters, etc., where a strong 

 irritant is desired. It has powerful blistering properties. 



Cantharides was formerly much in vogue as an aphrodisiac, but 

 it is now recognized that its action in this respect is not great; and, 

 furthermore, that this aphrodisiacal action apjjears as a rule only 

 after tlie kidneys have been greatly irritated and often injured. 



As a Poison. — Cantharidin is a powerful poison, the fatal dose, 

 according to Blyth (6), ranging from 1 grain upward, although 

 recovery from very large doses has taken place. For purposes of com- 

 parison it may be mentioned that the fatal dose of white arsenic is 

 stated by the same author to be about 2.5 grains. 



Cantharides has been employed as a poison in at least one or two 

 criminal cases; and there have been many cases of accidental death 

 from its internal use, and also, it is said, even from its external use. 

 Biley and Johannsen state (7) that cases are not rare in which cattle 

 have been poisoned by feeding on herbage bearing a large number of 

 blister beetles. They also quote from the work of Robert that when 



