164 PART IV.
"Mr. SIMPSON explained the construction of the ginneries in
Uganda, and the regulations in force there for ginning cotton.
Mr. KIRBY said that the question of ginnery control could be
viewed from two different aspects: —
(a) The control of pests.
(b) The mixing of seed.
In regard to the first, adequate legislation was in force in
Tanganyika; and in regard to the second, no special measures were
necessary at present where only one variety was grown. This latter
aspect of the question would arise only where special varieties or
qualities of cotton seed are to be distributed.
Mr. KOCH stated that no need for the control of ginneries had
yet arisen in the Union, and that it had not received any consideration
as the ginnery buildings were, for the most part, of excellent
construction and type.
CHAPTER III
* COFFEE.
(Mr. Trench attended for the discussions om matters connected
with coffee.)
BIOLOGICAL CONTROL OF INSECT PESTS, WITH
PARTICULAR REFERENCE TO THE CONTROL OF THE
COMMON COFFEE MEALY BUG IN KENYA COLONY.
Mr. KIRKPATRICK read the following paper (referred to in the
Agenda as T.C.(C)E. & M.2):—
The factors affecting the numerical abundance of insects in
nature are as follows:
(a) Climate.
(b) Food Supply.
(¢) Parasites.
(d) Predatory Enemies.
In a fairly recent Text Book of Entomology it is stated that these
factors are almost wholly beyond man’s control, and reliance for the
suppression of pests is placed mainly on purely artificial means of
destruction or prevention, and agricultural methods such as rotation of
crops and other practices of husbandry (7, p. 374)t
With this statement I venture to disagree entirely. While not
minimising the value of insecticides and such like means of combating
pests, and still less of agricultural methods calculated to modify their
activities, it is in the control of climate and food supply, and in the
intelligent utilisation of the enemies of destructive insects, that the
cheapest, the most efficient. and the most permanent control is to be
obtained.
There are doubtless many insect pests which will possibly always
be best controlled by purely artificial means, while in probably every
instance of an insect suddenly assuming the proportions of a pest, is
it necessary to use known and tried methods. such as spraying,
* For other papers on Coffee see Part 1I., Chapter IV.
bt See list of references on page 194.

2.