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Although the treatments which involved 58 rooms effected
a reasonable measure of success, it must be stated that complete
control can be achieved only by the destruction of the colonies, for
once ants become established in a building, complete elimination
is extremely difficult. Locating each individual nest, especially in
old buildings, is not only extremely difficult but commercially
impractical. As usual, prevention offers the best solution to the
problem namely,
(a) to block or obstruct the entry of the ant,
(b) to keep premises clear and free from crumbs and scraps
of food,
(c) to seal holes and cracks through which ants could enter and
(d) to use an effective insecticide, preferably of a residual
nature.
Cockroaches. The cockroach (Blatta orientalis) and its smaller
relative (Blattella germanica) are well known for their destructiveness, especially in relation to stored organic matter, ranging from
foodstuffs to book bindings. Food is rendered repulsive from
contamination not only with their faeces but also with the
secretion from their scent glands, and the cockroach is strongly
suspected of transmitting to man a number of pathogenic organisms
especially those of an enteric nature.
Cockroaches shun the light and are most active during the
night. Warmth, moisture, darkness and close proximity to food
supplies constitute favourable conditions for breeding.
As was to be expected most of the 77 complaints received concerning this pest came from three large hospitals in the Borough;
very few originated from occupiers of dwelling houses. The construction of such premises offers ideal breeding sites in concealed
and almost inaccessible places. Thorough investigation and treatment with D.D.T. or Dieldrin Concentrate resulted in the infestations being considerably reduced. In all, 77 treatments were
effected involving 325 rooms.
Clover Mite. Three complaints were received, mainly from
tenants in blocks of flats in various parts of the Borough, concerning
small red or dark brown insects (Bryobia praetiosa) found moving
over walls and windows. On each occasion spraying of exterior
surfaces with vermicene and D.D.T. produced satisfactory results.
Wasps. Complaints received implicated three types, the
Common, the German and the Tree wasp. (Vespula vulgaris, V.
germanica and V. sylvestris).
Fear of the wasp is often misplaced for they rarely sting unless
they are roused or frightened and, contrary to popular belief, wasps