Part VII] Beeson : Life History of Toon Borer. 
69 
abundance of toon in the vicinity. The larger and more compact the 
planted area, the smaller will be the relative number of trees to be 
banded. The width of the protective zone is roughly estimated at 
1,000 to 500 yards, but no experiments have been carried out on the 
flight of the moths, or the distance travelled by migrating larvae. 
Collection and Destruction of Larvce. —The number of larvae varies 
very much from tree to tree ; not uncommonly, 500 may be found on 
one tree at one visit. At the period of maximum abundance, a cloth- 
bag with a draw-string and a tin funnel- shaped mouth-piece will be 
found useful; the contents of the bag when full can be emptied into a hole 
in the ground and buried. 
Cost of Sack-Banding and Collection. —The cost of sack-banding 
and collection of larvae during the experimental work of 1916 works 
out at about 2 annas per tree, including the cost of sacking, string, 
nails, number plates, extra labour, etc. But this represents the cost 
of the experiment. In control measures where it is not necessary to 
number the trees with tin plates, count and preserve the larvae, or make 
visits so frequently, the cost is probably considerably less than one 
anna per tree. 
Grease-Band Experiments 
As an alternative to the sack-band method of control, the effect of 
deterrent grease-bands was tested in May 1915. Various preparations 
of crude oil, tar, etc., were used, but of all the materials only “ Tangle¬ 
foot ” (U. S. A. manufacture) possessed any appreciable effect. The 
Tanglefoot was applied to the trunks of the trees at breast-height 
in bands 2" wide. 
Its odour had no deterrent effect either on descending or ascending 
larvae or to early—or late—stage individuals. The larvae on reaching 
the band were occasionally deflected from their paths, but eventually 
entered the sticky band and commonly reached the opposite side. 
Second and third stage larvae usually failed to pass through the band 
and died in the grease, but mature larvae as a rule found no difficulty 
in passing through the barrage. 
On the 14th May, 34 robusta larvae (15 third stage and 19 fourth stage) 
heavily smeared with Tanglefoot, were collected from grease-banded 
trees, and confined in rearing cages. The third stage larvae readily fed 
on fresh fruits supplied to them, within a few minutes of receipt. On 
the 16th May, 11 more tangle-footed larvae were caged. On the 18th 
May, 26 larvae were observed to have prepared cocoons and pupated. 
On the 1st June 1 live, and 18 dead moths were found inside the cage. 
Thus out of 45 larvae which had passed through a Tangle-foot band, 
[ 214 ] 
