On the April 5th, 2018 we interview with Mr. André Pontet, an entomologist from the University of Lausanne.

For many people, studying insects is a rather "abstract" job. Can you tell us what are your main activities? What are the covered topics? What projects are you currently working on?

For many years now, I haven’t been doing entomology research, but I get involved in projects that describe the distribution of many insect species. Since my college studies, I have been interested in all the orders of insects, which allowed me to make didactic collections to present in a significant way the diversity of insects in Switzerland. In fact, my research covers various fields: from a studying the genetics of a group of small, tiny-shelled, ground-shelled snails to the neuro-physiology and endocrinology of fishes. Furthermore, I also the study small rodent brain (mouse, rat, Scots mouse) targeting the ontogenesis of locomotor behavior and ultrasonic vocalizations of the Scots mouse. Currently, I am also involved in ornithology, with a study of the temporal evolution of the birds of Lake Geneva, as well as the organization of the territory of the Woodcock in the Pre-Alps.

Where does this passion for entomology come from?

Since I was a child, I had a crazy passion for entomology. I was 6 years old when my mother raised some butterfly caterpillars until they hatched. This last event marked me! During the school holidays, she would take both my brother and myself to show us how to make insects collections, according to the indications given during a radio program, then to a recommended book, then to a butterfly specialist during a public exhibition of his collection. It's anecdotal, but it shows the importance of letting our children getting in touch with mother nature.

Our team is currently working on bed bugs and particularly on Cimex Lectularius. What are the important things to know about this specie?

I would just like to point out the particularity of their reproduction system: to deliver its sexual cells, the male directly pricks the abdomen of the female from the outside. The sexual cells are deposited in a pocket called spermatheca. However, as in other insects, fertilization occurs only during the laying. This detail about mating is interesting because the injury to the female may be the pathway for bacteria that later can infect people stung by these bugs. Transmission of staphylococci and enterococci has been suspected. The life expectancy of a bed bug can exceed one year, during which the female can lay up to 500 eggs, at a rate of one or two per day, which staggers births, thus improving her chances of settling effectively in places that are favorable to it. In addition, she can survive six months without feeding, which differs considerably from lice, for example, that dies quickly once they are away from their hosts. The temporary desertion of an apartment does not solve anything.

The current method for getting rid of bed bugs is eradication. What do you think of that?

Regarding the method or methods of eradication, it depends on what level we are: on a worldwide scale, we will never be able of eradicating bed bugs, it is impossible. We must learn how to live with them! Chemical control is inefficient in the medium or long term. Indeed, it is important to know that all species with large populations and high reproductive rate will undergo a selection of resistant strains to chemicals used against them. Chemical products are a bad approach for long-term eradication. On a building scale, we can probably overcome a bed bug infestation, but it can be difficult, depending on the state of the building (many cracks, insulation, paneling, heating pipes, ventilation...).

Currently, there are several methods to control an infestation. The chemical and thermal methods are the most common, but do not exclude other complementary approaches (bed foot traps for example). The chemical method raises the problem of resistance. Chemical products can be toxic for the residents and their domestic animals. The thermal method is more difficult to apply and takes longer, but can, if it is well conducted, require only one intervention: it consists of heating the indoor air for several days at a high temperature (50 °C) lethal for bedbugs.

In any case, all complementary approaches should be used simultaneously: the traps around the feet of beds, the systematic inspection of the objects introduced into an apartment can be effective, the very frequent use of the vacuum cleaner for mattresses and in places where bed bugs hide, as well as a high hygiene can reduce the risk of contamination. The use of repellents deposited or vaporized in the ambient air could contribute to the success of the prevention, if they are harmless for the residents. Other methods should be considered: it seems to me, for example, that a fight with traps to pheromones, to attract males or scramble could be promising because it is not toxic to humans.

Could there be any consequences for the ecosystem if bed bugs were to be eradicated?

As with all living species, without any exception, bed bugs take part of a complex food chain, in which the role of parasites of all kinds, but also viruses, exists. I do not know if this bug stings other species or if it is strictly subordinate to humans; if it is 100% specific to humans, the consequences of its disappearance would be imperceptible, because the factors affecting human demography are extremely numerous.