i8o 
A VISIT TO THE RUBBER PLANTATIONS 
affected by scale, some of them quite badly, the insect appearing to have 
practically destroyed the lactiferous tubes, so that the outer bark pre- 
sented a curious shrunken appearance. This scale, as far as I was able 
to observe, only appeared where neither undergrowth nor weeds were 
in evidence round the foot of the tree. All of the trees thus affected were 
uprooted and burned. I brought samples of the stems back to the 
United States, however, and through the courtesy of the experts at the 
Connecticut Agricultural Experiment Station at New Haven, and the 
Bureau of Entomology at Washington, I was able to identify the dis- 
ease and also to discover simple remedies. The reports of the two ento- 
mologists follow : 
Dear Sir: Your letter with specimens has been referred to me. 
The tree seems to be attacked by two species of scale insects , the large 
brown one is a Lecanium, and the small, glassy, greenish yellow one is 
an Asterolecanium. We do not have the literature by which I can 
determine them specifically. From a knowledge of simliar species 
found in this part of the country, I should expect that a thorough spray- 
ing with kerosene emulsion or whale oil soap would destroy them, though 
of course experience is needed to know just how strong to make the 
mixture. I should try some of these made in the proportion recom- 
mended in published bulletins, and if it did not kill them. I should use 
somewhat stronger mixtures. 
Very truly yours, 
W. L. Britton, 
State Entomologist, The Connecticut Agricultural Ex- 
perimental Station, New Haven, Connecticut. 
Dear Sir: The scale insects upon the twigs which you sent repre- 
sent the akee fringed scale ( Asterolecanium pustulous), and Lcnaci- 
odiaspis rugosus ( f ) . This Asterolecanium is very common and very 
injurious in the West Indies. It works principally upon akee, oleander, 
fig, and hibiscus. Mr. Maxwell-Lefroy. the government entomologist 
to the West Indies, in pamphlet series No. 7 of the Imperial Department 
of Agriculture for the West Indies, recommends kerosene emulsion for 
the control of this insect. His formula and method of preparation is 
as follows: “Kerosene emulsion: Dissolve one-half pound of hard soap 
in one gallon of water ; add two gallons of kerosene to the hot liquid, 
and immediately churn with a syringe or force pump until the mixture 
becomes creamy. This is a stock solution. Make up to thirty-three 
gallons. Use only rain or soft water." 
