Bed bugs have well defined resting sites (sometimes referred to as ‘refugia’) in which many individuals from all the different life stages are found. This harbourage is an essential part of the life cycle of the insect since it is in this area that the young bed bugs pick up the internal microorganisms that are essential to their survival, some of which are also inherited by transovarial transmission through the egg covering. Bed bugs spend the majority of their time in these harbourages, aggregated together under the influence ofaggregation substances (which is exactly why targeted crack and crevice treatments are so crucial). Alarm pheromones are also emitted in response to stress, causing bed bugs to scatter.
Bed Bugs Reproduction
Bed bugs reproduce by traumatic insemination – the male pierces the female abdomen, sperm enters the sperm receptacle and then travels through the blood to reach the ovaries.
Bed Bugs Life Cycle
Bedbugs exhibit incomplete or gradual metamorphosis, from egg, through 5 nymphal stages, to adult. Female bed bugs lay eggs throughout their life, an unusual feature in insects. They generally produce around 2 to 3 per day and since they can live for many weeks, indeed months, each female could produce around 400 – 500 eggs during their lifetime. The eggs are deposited all around the environment in which the bedbug is living. The length of time spent in the five nymphal stages is greatly dependent upon the food resources available (each nymphal instar requires a blood meal for further development), temperature and relative humidity.
The importance of this data is that the temperature dependent life cycle can be manipulated to aid control. In particular, increasing room temperature to 27°C can stimulate eggs to hatch after 5 – 6 days and vulnerable 1st instar nymphs will quickly come into contact with fresh insecticide deposits. It is often thought that higher temperatures will reduce the residuality of insecticides, but at these moderate temperatures this is not the case, especially when microencapsulated insecticides are used. Lower temperatures mean that the time to hatching could be elongated and insecticide deposits are likely to be less effective. Delayed hatching of eggs could also give the false impression that an infestation has been eradicated, only for the bedbugs to reappear in time, especially as the unhatched eggs could remain viable for 3 months and adults can also survive for more than a year without a blood meal. If temperatures were to drop below 13°C, bed bugs become unable to complete their life cycle, although many properties are heated so bed bugs are a year-round problem.