Entomology How bed bugs multiply

Bed bugs - strong together

Raleigh (USA) - Bed bugs rarely come alone, and for good reason: the blood parasites benefit in various ways from close contact with their conspecifics. Among other things, this accelerates the development of the larvae into adult insects. It is not yet known which signals are received during group formation and how they are processed. The earlier achieved sexual maturity and the proximity of possible sexual partners ensure faster reproduction, so increase biological fitness, report American biologists in the "Journal of Medical Entomology".

"Our observations also show that the development of newly hatched larvae does not depend on contact with adult bedbugs and that eggs are sufficient to trigger a new infestation," says Coby Schal of North Carolina State University in Raleigh. His research team compared the development time of young bed bugs (Cimex lectularius) to adult insects under different conditions. In a first series of experiments, the biologists placed a single larva or a group of five in plastic containers and supplied the animals with rabbit blood three times a week. The isolated larvae required 29.6 days to last molt. In the group of five, on the other hand, they were fully grown after 27.5 days, a time reduction of 7.3 percent. Further experiments showed: During development in a group of 50 larvae of the same age, it made no difference whether ten additional adult bed bugs were added.

For a larva that would develop without contact with others, it would not be a major disadvantage if it reached sexual maturity a little later because of the lack of a sexual partner. But in a group, accelerated development is very beneficial as it enables faster reproduction. Apart from that, these animals also have a higher chance of survival, because together they create a more humid microclimate that protects against dehydration. The researchers now want to elucidate the exact mechanism by which growth and development in the group accelerate. They do not rule out that odorous substances released by the larvae could act as signals that trigger faster maturation.

The approximately five millimeters large, wingless bed bugs feed on the blood of warm-blooded creatures. The larvae require a blood meal before each molt. In human dwellings, the nocturnal parasites hide in cracks and crevices in walls and furniture during the day - also under wallpaper and behind picture frames. You will be attracted by the breath and body odor of the sleeping person. Your stings cause prolonged, severe itching.

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