50 THE ENTOMOLOGIST. 



ON THE ABUNDANCE OF OETHOPTERA IN THE ALPS. 

 By W. Harcourt-Bath. 



Next to the Khopalocera, the Orthoptera are undoubtedly the 

 group of insects which are mostly in evidence in the Alps. If 

 they do not display their figures in such an ostentatious way as 

 the frivolous butterflies, they fully make up for that trait by 

 reason of the great noise they create. If they also lack the 

 beautiful colours of their more handsome relations, they ade- 

 quately compensate for any deficiency in this respect on account 

 of the grotesque forms they frequently assume. 



The grasshoppers belonging to the two families Acridiidse and 

 Locustidae certainly constitute some of the most characteristic 

 insect inhabitants of the Alps. They occur by far the most 

 plentifully in the lower valleys of the mountains, especially 

 upon their sunny southern slopes, and rapidly become more 

 scarce the higher one ascends, until at about 9000 ft. above the 

 sea-level they disappear altogether. They commence to make 

 their appearance in the perfect state about the beginning of June 

 in the warmest localities and at the lowest elevations, emerging 

 later and later according to the altitude. August and September 

 are the two best months for collecting them, as they are then in 

 their greatest abundance everywhere. 



The noise they produce is sometimes deafening and perfectly 

 bewildering. I have heard their stridulations on many occasions 

 when travelling at full speed in a fast train ; and sometimes, 

 when traversing grassy or bushy tracts wherein they abounded, 

 it was necessary to speak in a loud tone to a companion only a 

 few yards away to make him understand what I had to say. 



The most plentiful species is undoubtedly the great green 

 grasshopper {Locusta viridissima) , which I have often heard 

 stridulating in thousands on a warm evening. It is a fine sight 

 to see this conspicuous insect flying in the bright sunshine like 

 a large migratory locust, a habit I have never observed in our 

 own country. 



The more robustly-built Decticus verrucivorus I have also 

 encountered in abundance in many localities, especially in the 

 Khone Valley and near Interlaken. As is well known, this insect 

 is employed by the peasants for charming away their warts. 

 Another large species I met with last year on the south side of 

 the Gemmi Pass near Inden. Its stridulations possess a 

 wonderful resemblance to the hiss of a snake, which mimetic 

 habit no doubt serves to protect the insect from the attacks of 

 batrachian reptiles and insectivorous birds. It is of a purplish 

 colour, prettily striped with yellow and brown. This insect 

 belongs to the Acridiidae, a different family to the two preceding. 



The beautiful butterfly locust, Mdipoda cceralescens, occurs in 



