of the same queen ant and share
the same kinship. However, other ants, even those from the same species, share no common kinship when they inhabit
different nests. Instead, they are intense rivals, competing for common food sources.
Ants from a given nest are believed to use individual or group odours, distinctive to the nest they inhabit, although the
composition of the chemicals involved remains undetermined. However, the composition of the hydrocarbons, which act
as a signal for species recognition, must be identical between residential and visiting ants, as they are members of the
same species… you would think.
The tests the team conducted bore interesting results. The profiles of composite hydrocarbons showed great variety from
one colony group of ants to another, or were distinct in each type of ant tested. There was also diversity in ants from a
queen-less nest. But samples taken from ants in the same nest with a queen were identical. This is due to the queen which
will entice nearby worker ants around her by use of a pheromone. In approaching, the workers initiate physical contact.
Accordingly, cuticular hydrocarbons are exchanged among a swarm of individual ants, leading to chemical consistency
of ants in the same colony.
Grooming
Grooming also plays a major part in “spreading” the same hydrocarbons among ants in the same colony. They use two
methods. One is to remove cuticular hydrocarbons from the partner by licking, then storing them in a special gland. The
other is to secrete them from the same gland for use in coating and grooming its own body.
Psocids
Psocids
“Sosids,” as the proper pronunciation is, are booklice and there are over 3000 species of them to be found across the
world, although less than 50 are associated with human activities, including food storage and processing. But, their
significance as pests has increased over the last 35 years, which has been a matter of considerable interest to the Society
of Food Hygiene Technology, which ultimately led them to sponsor a survey among their members.
The results were published in 1984 and, although they helped to define the problem, they highlighted the need for further
research, as many questions about them still remain unanswered.
Psocids are widely distributed and typically favour dark places. They infest domestic premises, raw material stores,
manufacturing, distribution and retail premises; museums have also been infested and a wide variety of commodities may
be infested, including those which are of animal and vegetable origin, particularly farinaceous materials.
A four-fold problem
Nuisance – Psocids are a nuisance in industry because they interfere with production and threaten the integrity of
products, so reducing the quality and wholesome nature of the food.
They are typically associated with newly completed homes – damp building materials, plaster, etc., foster the growth of
mould on which the insects feed. Also, they are regularly encountered in food cupboards where they infest cereals, flour,
sugar, gravy thickener, etc..
Direct feeding damage – Psocids are not usually associated with damage caused by feeding activities, but direct
damage to commodities is possible and particular problems may be experienced when valuable articles, such as furs,
books, etc., become infested.
Transmission of micro-organisms – Micro-organisms and their spores will survive passage through the psocid gut and
may be carried on the surface of their bodies. Psocids may therefore, disseminate spoilage organisms, or even possibly
pathogens.
Health hazard -There is no evidence that psocids are vectors of disease. Nevertheless, they may eat tapeworm eggs
and harbour their larvae and so act as intermediate hosts for such parasites. Despite this, there is increasing evidence
that the insects may be a source of environmental allergens. The main impact of psocid infestations in homes is regarded
as psychological, with reactions which are occasionally disproportionate to any real threat.
Major Pest Species – L. bostrychophila is the major psocid pest encountered in domestic premises, accounting for over
90%, and is usually associated with consumer complaints. It is not generally found in commercial food handling
situations. The various psocid species tend to be associated with particular situations.
Environmental Factors – Psocids are vulnerable to dessication at humidities specific temperature and humidity data, coupled with data for the intrinsic rate of increase were considered, L.
bostrychophila ranked amongst other major stored food pests in terms of adaptability and pest potential. Egg laying
ceases at temperatures L. bostrychophila thrives on
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