Modern Cockroach Fight
Cockroaches are persistent, elusive and prolific. They are associated with numerous pathogenic organisms, sources of allergens and sometimes a symptom of poor hygiene. Therefore, their presence wherever food is stored, prepared or served is unacceptable.
Controlling cockroach infestations in these environments, however, can be quite difficult. They move easily with goods, reproduce quickly and prefer to live inside cracks and crevices that are difficult to reach.
These challenges are compounded by control methods involving inadequate inspection, insufficient cooperation with the occupants of the premises and excessive reliance on individual products or application methods.
The fact that even high levels of control may be insufficient to prevent a relatively rapid recurrence of infestation makes these challenges particularly difficult.
Understanding the ethology of cockroaches
Although they are very good at adapting to a wide range of conditions, cockroaches need four key resources to survive and thrive – food, water, heat and shelter. They naturally congregate in places where these conditions are present.
The German cockroach, which is the main problem in Europe, requires heat in particular, so it lives almost exclusively indoors. The largest cockroach orientalis, is equally found inside houses as it is outside.
Although the oriental cockroaches can search for food at greater distances than the Germanic cockroaches, they generally do not move more than a few meters from the cracks, fissures and voids in which they gather, to look for food and water.
Both species love the dark and most individuals spend most of their lives in their protected hiding places, going out only to look for food.
They show a preference for highly energetic food and are discouraged from eating excessive greasiness, traces of insecticide, mold or food deterioration.
While males look for food on a daily basis, females spend 75% of their lives without food and can survive 45 days without food as long as they have access to water. Even young nymphs feed relatively little.
The search for food occurs almost only at night and is disturbed by human activity. Individuals from large populations are more active and discern less in their appetites than those from smaller populations because they have to compete more for food.
Since cockroaches are not believed to be able to detect odours a few centimetres away, the ability to find food seems to be related to random encounters along the regular routes of foraging activity based on experience. If they have a good supply of food and water near the nest, individuals may never come into contact with a bait placed a few metres away from them.
The life cycle of about 170 days and the production of ootecas with 30-40 eggs produced every 2-3 weeks, are the reason why the population of Germanic cockroach may increase considerably in a very short time, in spite of a fair level of control.
Better control planning
The challenges of modern cockroach control tell us that with a single gel bait treatment it is difficult to achieve sufficient and lasting control.
Even under the best possible conditions, the natural behaviour of cockroaches rarely makes control of more than 80% possible with a single bait treatment.
In most cases, lasting control requires an integrated approach based on a sound knowledge of cockroach habits, inspection, cleaning and a treatment programme – including final bait placement and crack and crack treatment if necessary.
As cockroaches congregate in protected shelters and feed mainly at night, a thorough inspection of the infested areas is essential to plan targeted treatments.
It is best to conduct inspections at night with a torch and a small flexible mirror to examine less accessible areas for live cockroaches, excrement, dead insects and old ootecas.
Pyrethroids sprayed into cracks and crevices can be very effective in temporarily snidifying cockroaches and identifying occupied sites.
In many cases, glue traps offer the best means of establishing the area and level of infestation. They should be placed in areas commonly used for foraging – particularly hot and humid places such as behind refrigerators and other equipment, floor/wall joints, around the edges of equipment and under furniture, etc.