216 r September, 



distributed. KnoAvn locally, in common with all black similarly-shaped 

 beetles — regardless of exact species — as " hardback." 



L. tumulosus Burm.— An uncommon coastland species. Occurs 

 commonly in the West Indian island of Barbados. 



Di/scinetus geminatus Fabr. — A common species at the arc lamps 

 in Georgetown. On the advent of heavy rains especially after drought 

 swarms of these beetles appear at artificial lights and often cause serious 

 inconvenience at the dining table and other social and domestic functions. 

 The larvae apparently breed in the decaying vegetable matter at some 

 distance below the surface of the soil. Many thousands are destroyed 

 by a heavy fall of tropical rain which floods the land. Occurs also in 

 the interior. 



D. lidentatus Burra. — This beetle is a pest of sugar-cane. The 

 adult form bores into the stems and rooting systems. They are more 

 prevalent at certain times of year than others. It is only during recent 

 years that this insect has developed into a serious nuisance. As many as 

 38,000 of these beetles have been collected by gangs on one sugar estate 

 during one year. The life-history occupies about 100 days. 



Mr. Harold Moore, a local entomologist, has investigated the life- 

 history. He Avrites as follows : — 



" The ' hardback ' eggs are milk-white and globular, their shortest and 

 longest diameters at the time of batching being about 2 mm. and 2| mm. 

 respectively. A few days earlier they may be 1| mm. and 2 mm. At time of 

 deposition they are probably a good deal smaller even than this. They are 

 laid in the earth about the cane stools at a depth of about 2 to 5 or 6 inches 

 below the surface. At the close of the incubation period the young larva can 

 be discerned in a curled attitude through the esg-shell, the red mandible « 

 being very distinctly visible. 



Thft newly hatched larva is white, with red mandibles, and short reddish 

 hair. The head soon becomes yellow. Shortly after feeding begins the larva 

 becomes darker owing to the contained earthy matter being visible through its 

 transparent skin. Eggs obtained on 23rd were hatching on the 29th and 30th 

 of the month, but they had probably been laid some days before I got them. 

 The legs are six in number, rather long and slender. 



The adult larva is dirty white, save the posterior end which is dark brown 

 to almost black on account of the accumulated excrement. The segments are 

 wrinkled and clothed with short reddish hair, while the head is yellow. The 

 duration of the larval life is not known, but it probably extends to several 

 months. 



The pupa is enclosed in an earthen cell, rough externally but smooth and 

 neat internally. The duration of this stage is also not known, but is probably 

 short as compared with that of the larva." 



