Mylabris Beetles. 741 



MYLABRIS BEETLES. 



By W. F. ScHLUPr, B.Sc, Entomologist, Scliool of Agriculture and 

 Experiment Station, Potclief.stroom, Transvaal. 



There are a number of native Mylabris beetles that have been known 

 as plant pests since early days. In 1889 Omerod listed (1) several 

 species as injurious and quoted from a correspondent that " all our 

 Mylabridae are scourges," a rather sweeping statement. 



These beetles are included in the family Meloidae (Cantharidae, 

 Mylabridae), a large group generally known by the cosmopolitan name 

 of " Blister Beetles," because of a vesicating property due to the 

 presence of cantharidiu, which, according to some writers, occurs in 

 the blood plasma. On account of a fluid that oozes from their joints 

 they are sometimes also known as " Oil Beetles." Because of a 

 fancied resemblance to the uniform of the Cape Mounted Rifles some 

 of the native forms are called " C.M.H. Beetles." 



Of the above family Dr. Peringuey, Director of the South African 

 Museum, has listed thirty-four native species belonging to the genus 

 Mylabris and twenty-one belonging to the genus Cantharis (2). 



The Meloidae as a rule are not above medium in size, but large 

 species are found among our South African Mylabrids. The species 

 most common at Potchefstroom, Mylabris oculata, a species that is 

 very common also in many other parts of the Union, is about one and 

 one-fourth inch long, and with its black and yellow colouring is a 

 conspicuous insect. As a rule it appears earlier than the fruit beetles 

 (Cetonids), coming about the time the fruit trees bloom. The writer 

 has taken it from bean plants in the low veld (Komati Ward) during 

 the middle of August, and doubtless it appears even earlier there. 



Life-History of Blister Beetles. 



To studies made many years ago by C. V. Riley in America and 

 M. Fabre in France we are indebted for much of our exact knowledge 

 of the life-history of these beetles. The larvae feed upon the egg*s of 

 other insects, and may be divided into two groups, viz. (a) those 

 that subsist upon the eggs of locusts, grasshoppers, and crickets, and 

 consequently do a great deal of good; and {h) those that feed upon 

 the egg's of wild bees. The larvae attach themselves to bees and are 

 thus carried to the nests. They often attach themselves by mistake to 

 other insects, and so get nothing except a free ride. 



Aniong the American species that have been investigated many 

 belong to the first group. T. B. Fletcher states (3) that in India also 

 most of the larvae of the species for which the life-histories are known 

 (several of which belong to the genus Mylabris), are parasitic upon 

 the egQ masses of grasshoppers. In the absence of close studies we 

 may assume that the larvae of many of our South African Mylabrids 

 aie parasitic upon the eggs of locusts and grasshoppers, but this is 

 by no means certain, as all attempts to rear the insects have failed. 



