INSECT PESTS OF DATES IN MESOPOTAMIA. 295 



Adults fly to light from April to September and do great damage by boring through, 

 leaf-bases and stems of inflorescences in the crown of the tree. I have seen a 

 garden littered with bunches of nearly ripe dates felled by this insect, which can 

 be a most serious pest. I presume that the females lay their eggs in the burrows 

 they make. Beetles of this species may also frequently be found in burrows in the 

 hard trunks of living or dead palms, and I believe that these burrows are made 

 either by the adult or the larva, but I have no proof that this is so. When these 

 burrows are numerous they interfere seriously with the nutrition of the tree, and 

 they sometimes cause it to break off in a high wiiid. The larva of a large Lamelli- 

 corn, which I believe is this species, lives in the crown of the date-palm among 

 the leaf-sheaths, etc., and bores its way through the bases of leaves, the bases 

 of fruit-bearing stems and the young leaves before they unfold. Sometimes it bur- 

 rows inwards towards the actual growing point. It appears to have a predilection 

 for fairly young trees, between the 10th and 20th year. It is an interesting fact 

 that the larva of 0. rhinoceros occasionally adopts the same habit, and lives in the 

 crown of coconut trees, especially if they are decayed (Burkill) ; it is of course 

 well-known that this larva normally inhabits piles of vegetable refuse, and old 

 thatch and palm leaves which are lying on the ground. Such a habit would I 

 think be impossible for the larva of 0. elegans ; for owing to the extreme desiccation 

 of Mesopotamia it is generally impossible to find any decaying material of any sort 

 in the gardens. 



Treatment. — The presence of the adult or larva in the crown of a palm is known 

 from the immense quantity of chewed vegetable fibre which passes through them 

 and falls from the mouth of the burrow. When he sees this the Arab cultivator 

 chmbs the tree and endeavours to extract the insect with the short heavy knife 

 with which he prunes his palms, and in so doing he frequently commits much 

 havoc himself. 



As Prell's 0. elegans is very little known and was described from the female 

 I have asked Mr. Arrow to re-describe the species. His description which is as 

 follows is founded on a series of ten collected by W. E. Evans, C. F. C. Beeson 

 and others. 



" Oryctes elegans, Prell. This species has hitherto been known from its female 

 only, examples of that sex taken at Fao having been described in a German perio- 

 dical in July 1914 (Entom. Mitt, iii, p. 210.) It is one of the smallest repre- 

 sentatives of the genus Oryctes, males ranging from 28 to 34 mm. in length, females 

 from 34 to 36 mm. It is narrower in shape and rather less convex than 0. deser- 

 torum, Arrow (found in the same region) and the upper surface is more smooth 

 and shining, the elytra being almost devoid of the punctation occurring on the 

 latter species, but possessing a deeply incised line on each side of the sutural edge 

 instead of the row of dots found in 0. desertorum. The two points of the clypeus 

 diverge more widely and are separated by a rounded, instead of an angular excision. 

 The armature of the head and prothorax scarcely differs from that of the other 

 species, but the posterior edge of the thoracic cavity is rather more sharply toothed 

 in the female, and rather less so in the male, which has only a very slight blunt 

 projection there, not distinctly bicuspid as in 0. desertorum. The cephalic horn 



