SCALE INSECTS IN GREENHOUSES. 



By W. Lochhead, Macdonald College. 



Most persons who have ever attempted to grov;^ the larger house plants, 

 such as erotons, oleanders, lemons, date palms, ferns and acalyphs, which 

 find their habitat in tropical regions, have no doubt felt frequently ag- 

 grieved on account of the presence of soft insects which do considerable 

 harm. These soft insects are very diverse in character, some of them hav- 

 ing a mealy appearance, while others are quite scale-like. The erotons and 

 the oleanders are especially troubled with the mealy-bugs, while the lemons 

 and ferns harbor a species of a soft scale called leeanium. 



There are usually two species of the mealy-bugs common in green- 

 houses, the destructive and the long-threaded. Unlike most scale insects, 

 they can move about the plant somewhat freely. It is only when they 



Fig. 1 — Mealy-bugs, a, Destructive Mealy-bug; b, LongTthreaded Mealy-bug; 

 c, eggs In cottony sack. 



become mature that they secrete the cottony sack which is so characteristic 

 of them. Within this cottony sack are deposited the cream-colored eggs, 

 which in a short time hatch out the young mealy-bugs. Fig. 1 shows 

 clearly the appearance of these two mealy-bugs. With regard to reme4ial 

 treatment, probably the best method of dealing with these insects is to wash 

 the plants with a soap solution, or to dip the entire plant in the solution, 

 if such is practicable. In either case the plant should be drenched with 

 cold water to wash off the solution. Another remedy which has been 

 highly commended is an alcoholic extract of Persian insect powder. This 

 is made as follows : Alcohol, ^ pint ; insect powder, 2 ounces. These are 

 allowed to stand for about a week, then filtered and diluted with an equal 

 quantity of water. The solution is then applied with an atomizer. It will 

 be necessary in most cases to repeat the treatment. 



