177 



PLANT SAWSTATION. 



Entomologicai Notes 



By B. Ernest Green, Government Entomologist. 



(Illustrated.) 



The "Red Slug" (Heterusia cingala) is a tea pest that is constantly 

 cropping up. I have just received specimens from two estates in the Kandy 

 district, on one of which the caterpillars are apparently occurring inconsiderable 

 numbers. This is one of those pests that should be taken in time. Before a 

 large area can be involved there must have been several earlier small broods which 

 would have been easily destroyed if observed. But when once the pest has been 

 allowed to establish itself widely, nothing short of pruning and burning will have 

 any effect. The full grown caterpillar spins a compact cocoon in the fold of a 

 leaf. When burning the prunings, all fallen leaves and rubbish from below the 

 bushes should be swept up and destroyed at the same time. This caterpillar is 

 extensively parasitized by a fly (Tachina sp.) that looks something like an ex- 

 aggerated housefly. It usually happens that these flies eventually get the upper 

 hand, and after reaching a certain crisis the pest is wiped out for the time being. 

 I have often bred as many as five or six larse flies from a single caterpillar. 



The "Red Borer" (Zeuzera coffece) has been reported from a tea estate 

 in Rangalla. This pest is widely but sparsely distributed, and is seldom res- 

 ponsible for any serious injury. 



In my annual report for 1900 (vide Administration Report, R. B. G., 

 1900, p. H. 8), I recorded the destruction of all the young tobacco plants in our 

 experimental plots, by the caterpillar of a minute moth which bred in the succulent 

 stems of the seedlings. I suggested that it might prove a serious enemy to 

 tobacco cultivation in Ceylon. But no further reports of injury were recorded 

 until last month (January)— after an interval of six years — when examples of this 

 same pest were sent in from the Hanguranketta district. A large number of 

 the diseased plants w r ere received,— all of them characterised by the swollen stem 

 (Fig. a.) which has earned for this disease, in Java (where it also occurs), the expressive 

 name " dikbuikziekte " which means " pot-bellied sickness." The moth— which has 

 been identified as Onorimoschema heliopa, Lower— apparently lays its eggs in the 

 bud of the seedling. The young larva bores into the stem and feeds in the 

 succulent heart, forming extensive galleries and chambers. The irritation setup 

 by the action of the insects results in the characteristic swollen condition of the 

 stems- The full-grown larva pupates inside the diseased stem and finally emerges 

 as a minute dull brown moth (Fig. 6.) with a wing expanse of about half an inch. 

 The only practicable treatment is to pull up and burn every affected plant on 

 the earliest appearance of the disease. By these means the larvae and pupae are 

 destroyed before the moth can emerge and infect other plants. I have been 

 informed that the same disease has been observed in the Jaffna district. 



There has been some correspondence, in the local press, about the sup- 

 posed increase of the " Spotted Locust " (Aidarchus miliaria) in the Matale district. 

 Upon enquiry, it would appear that the scare is a somewhat exaggerated one ; 

 but at the same time it is a good thing that attention has been drawn to a 

 possibly serious pest. As usual, at this time of the year, the " dadap " (Erythrina) 

 trees have been partially defoliated by the insects; but this temporary lessening of 

 the shad i! is regarded by many cacao planters as distinctly beneficial. The locusts 



