London's Pulse: Medical Officer of Health reports 1848-1972

View report page

Greenwich 1962

[Report of the Medical Officer of Health for Greenwich Borough]

This page requires JavaScript

82
The clover or gooseberry mite is harmless to humans and to
household property. It is vegetarian feeding on a wide range of
plants and shrubs and, in some instances, on trees. During the
summer months of July and August the adult females leave their
feeding grounds to seek winter quarters, emerging the following
April to lay eggs on plants in the vicinity. It is during these periods
of migration that they cause concern when they move from their
natural environment into nearby buildings. Some infestations in
fact were reported from houses and flats where natural breeding
conditions were non—existent but where a recent laying of turfs had
occurred in the immediate neighbourhood. On 57 occasions, spraying
of 30 rooms and 56 exterior surfaces with D.D.T. and Kerosene
produced satisfactory results. Such treatment also extended to the
spraying of trees and plants in close proximity to the source of
complaint. A miscible concentrate of malathion has been used
externally on a number of occasions with very good effect.
Wasps. Complaints received implicated three types, the Common,
the German and the Tree wasp. (Vespula vulgaris, V. germanica
and V. sylvesjris).
Fear of the wasp is often misplaced for they rarely sting unless
they are roused or frightened and, contrary to popular belief, wasps
are not entirely harmful for in Spring and early Summer they feed
mainly on insects, many of which are themselves injurious. However,
after mid—summer their diet becomes more vegetarian and the
workers feed on ripening fruit and other sweet substances, thus
effecting serious damage in orchards, sugar warehouses, grain
factories, etc., where they cause considerable wastage of goods.
In houses they become a nuisance during cooking and at meal times
and it is conceivable that they are instrumental in the spread of food
poisoning.
The queen wasp, the only survivor from the previous year's
colony, emerges from hibernation in the Spring to choose a site for
nesting, usually in cavity walls, lofts, under roof tiles and other sites
which evoke a certain ingenuity on the part of the disinfestors in
order satisfactorily to deal with the nuisance.
Seventeen complaints regarding this pest were received and
during the year some 16 nests were destroyed, mainly by means of
HCN gas generated from purpose—made proprietary powder. This
was a decrease of 11 from 1961.
Many other types of infestation were encountered and the