184 ROSENBERGIA MEGALOCEPHALA. 



NOTE XVI. 



ON THE MALE OE 

 ROSENBERGIA MEGALOCEPHALA, v. d. POLL. 



BY 



J. R. H. NEERVOORT van de POLL. 



In the foregoing volume of the » Notes", I have described 

 (p. 32) a 9 specimen of a Batocerid belonging to the genus 

 Rosenhergia Rits. , on which I bestowed the specific name 

 megalocephala on account of the enormous development of the 

 head. Having been fortunate enough to procure lately a (ƒ■ 

 specimen, I think it will be of interest to point out the 

 sexual differences, which do not only consist of the usual 

 characteristic of the antennae. Firstly the head and man- 

 dibles are not extraordinarily developed but are well pro- 

 portioned to the size of the insect; the antennae are of 

 course more robust and longer , measuring 75 mm., thus 

 overreaching the body with 30 mm. The thoracic spines are 

 slightly directed upwards , the humeral tooth is somewhat 

 larger, and the flattened granules are less numerous on the 

 apical portion of the elytra. Very misleading is the orange 

 pile on the cheeks along the eyes , as well as the presence 

 of an orange stripe on each elytron , beginning just belovs^ 

 the shoulder and nearly touching the apex. Now it is a well 

 known fact that the spots of the Batocerids are reddish or 

 orange when the insect is alive , but almost all the speci- 

 mens we receive have lost this coloration and show white 

 spots. The 9 I described formerly has also entirely lost this 

 peculiarity, and the orange stripe is only indicated by a 

 streak of more closely set white hairs. As both the typical 

 species [mandihularis and vetusta) have been described from 

 (f specimens , it remains an interesting question whether 

 the large head of the 9 will prove to be a sexual diö'e- 

 rence for the whole genus , or not. 



Notes from the Xjeyden iMiiseum, Vol. LX. 



