6l8 RUBBER 



breaking up of the earth would probably of itself prevent 

 the greater number of the eggs from hatching out by 

 exposing the egg masses to the drying action of the air 

 and to the attacks of birds and predatory insects, such as 

 ants and beetles, which would readily feed upon them. 

 For the smaller species, poisoned baits, composed of bran 

 mixed with syrup and arsenic, may be laid in the area to 

 be protected. 



The Economic Biologist in British Guiana (Mr. G. E. 

 Bodkin) has recorded an Acridiid (Tropidacris cristata) as 

 destructive to the foliage of Hevea. Zonocerus elegans 

 and Z. variegatus are said to play the same part in the 

 Belgian Congo. 



From the Straits Settlements we have records of three 

 crickets that are said to injure rubber plants. Brachy- 

 trypes achatinus saws seedlings right through, leaving 

 a stump i to 3 in. high, and carries off the tender shoots 

 to its burrow. The same species is reported from the 

 Federated Malay States and Sumatra, in both of which 

 countries it is accused of attacking Hevea. Gymnogryllus 

 elegans is said to behave in the same manner as Brachy- 

 trypes, and a species of Cyrtacanthacris " chews off the 

 tips of Para rubber plants at Singapore." The insects 

 can be brought to the surface and destroyed by pouring 

 dilute phenyl into their burrows. 



In Java a locust (Cleandrus sp.) sometimes splits the 

 young stems of Hevea for the purpose of depositing its 

 eggs in the crevice so formed. 



Isoptera. 



Injury to Hevea in Ceylon by termites is not very 

 serious. Here they are mostly secondary pests. I have 

 examined, at various times, small plants of Hevea, the 

 death of which has been attributed to the so-called 

 " white ants." These insects have been found at the tap 

 roots, the cortex of which has certainly been devoured. 

 In other plants the collar has been the point of attack. 

 Older plants, and even well-established trees, have been 

 found riddled by termites, the insects (sometimes Termes 

 obscuriceps, at others T. redemanni and T. Horni) being 

 taken apparently " in flagrante delicto." But I have 



