a yeast diet which is typically regarded as a rich diet. It is generally accepted that psocids
are most successful on a diet in which micro-organisms are present in moderation. The fact that L. bostrychophila is
parthenogenetic means that under suitable environmental and dietary conditions, populations develop rapidly and
certainly much faster than those species restricted to sexual reproduction.
Monitoring – Effective methods for monitoring psocid infestations are essential if prevention and control strategies are to
be successfully implemented. They can be monitored by visual examination, trapping, filth tests and the pallet “knock-
out” test.
Control – Psocids are difficult to control because they are small and can hide in cracks and crevices, so avoiding pesticide
treatments. They can survive long periods without food and are ubiquitous. An integrated approach to control is desirable
which uses all suitable techniques in a compatible manner.
The aim should be to manipulate the environment to the maximum detriment of the insects by denying them access to
some essential requirement. Little can be done to proof buildings and denying them harbourage is difficult although this
can be an option in small kitchens. They don’t like cold, dry conditions and cannot survive at humidities application of dry heat with temperatures of 50-60oC will control psocids. As already said, freezing will kill them. Clearly,any reduction in humidity will also deter moulds which are a significant food source.
Control can be effected by the use of fumigants, space and surface spray treatments and a wide range of pesticides have
been shown to be effective for the control of psocids. Products based on the synthetic pyrethroids permethrin and
deltamethrin and the carbamate bendiocarb are well established in the control of psocids. However, there is evidence that
certain strains of L. bostrychophila featuring mixed function oxidase enzyme systems, which can detoxify and reduce the
effectiveness of some pyrethroid insecticides. This can be overcome by the use of the synergist piperonyl butoxide. PCOs
must therefore, be alert to possible variability in the control achieved using synthetic pyrethroids.
Conclusions
Psocids are ubiquitous pests which have the potential to cause a considerable nuisance, damage stored products and
pose a hazard to health, especially in sensitive individuals.
Evidence shows that complaints to the food industry have increased over the last 35 years, although the reasons are still
unclear. It is likely that psocids will continue to pose significant problems to householders and the food industry, but much
has been achieved in recent years developing a better understanding of the pest which must contribute to improved
control in the future.
Pests and Allergy problems
Other pests which cause allergy problems
Fleas
Heska in Orlando, Florida announced in 1997 a revolutionary breakthrough in flea allergy dermatitis (FAD) testing. Heska’s
team of immunologists has been carefully studying flea biology – the result is the development of novel diagnostic
reagents and detection technology.
The HESKATM Flea Allergy Dermatitis Test is the first test specifically developed for detecting IgE antibodies against flea
salivary antigens as well as whole-body flea antigens.
Flea allergy dermatitis is a common dermatologic disease, and has been traditionally defined as an allergic reaction to flea
bites caused by injection of saliva as the flea feeds. Insect-associated dermatitis is a hypersensitivity to whole-body flea
antigens. Cross reactivity has been shown between whole-body flea allergen and black fly, black ant and cockroach
antigens. Redness, inflammation and itching are caused by the various protein components in flea saliva that can
stimulate an allergic response. The clinical signs related to FAD depend on the degree of immunologic sensitivity and the
level of flea exposure.
Wasps and Bees
A few people are very allergic to things such as insect stings. When exposed to these items they may have a severe
allergic response, also known as anaphylaxis.
In North America and Europe, nearly 100 people a year die from insect stings. Death usually comes within the first hour
after a sting and is attributed to insect allergy and not the toxic effect of the venom. It is thought that heat stroke or heart
attack may be given as a cause of death when actually it was the result of a sting. More children are stung but in older
persons with complicating health problems such as coronary heart disease or chronic bronchitis, death occurs more
frequently. Most of the victims of fatal insect sting have evidence of specific IgE antibodies.
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