The problem of the outbreak of bed bugs, which is expanding in Europe, recently made its appearance in Greece. Their rapid spread is mainly due to human activities and travel, which give these tiny insects the opportunity to move around in travelers’ luggage and invade new areas. The invasion of bed bugs in Europe, as reported in APE-MPE by director of the Institute of Molecular Biology of the ITE and professor of General Pharmacology of the Agricultural University of Athens it is dramatic, in hotels, on the subway, in places of eating and recreation, there are reports of a “generalized epidemic”.

As Mr. Vontas mentioned, the fight against bed bugs is based on prevention practices (cleaning, etc.) and to a large extent on disinfectants and chemical insecticides (biocides), of natural or synthetic origin. However, according to recent scientific studies, the effectiveness of chemical insecticides has declined dramatically in recent years in some areas such as the US and Australia, due to the development of resistant populations of bed bugs to synthetic insecticides. The effectiveness of certain naturally derived preparations (plant extracts, etc.) used to combat bed bugs is also often not fully established.

Her team of Molecular Entomology of the Institute of Molecular Biology and Biotechnology of the Institute of Technology and Research (IMBB-ITE), in collaboration with the Agricultural Pharmacology Laboratory of the Agricultural University of Athens (GAA), analyzed at a molecular level a very large number of bed bugs collected, with the help of extermination and mycicide companies, from various hotels and short-term real estate rental platforms of Athens and Thessaloniki between July and October 2023. These insects were initially molecularly identified and found to all belong to the species Cimex lectularius, the most common bed bug that spreads in Europe. Subsequently, the genome of these insects was analyzed, in which mutations of resistance to pyrethroid insecticides, the most widespread household preparations used in the fight against bed bugs and insects of health importance, were found. In particular, the L925I mutation was identified in the sodium channel of the nervous system, which interferes with the binding of pyrethroid insecticides to the nervous system of bed bugs, reducing the effectiveness of chemical interventions with these preparations. “This mutation was indeed found in all the insects analyzed (100% of alleles, in all samplings), which probably links the resistance to the observed outbreak and spread of bed bugs in Greece, but also indicates a strong genetic selection pressure ” said the director of the Institute, who added that “this selective genetic pressure is due to the very small number of available insecticides. In other words, when we continuously spray with the same preparations, such as pyrethroids, resistance to them is selected and develops very quickly, while the effectiveness of interventions decreases dramatically.” The small number of preparations, according to Mr. Vonda, is a result of the strict legislation of the European Union and the Green Deal (Green Deal) which imposes a drastic reduction of insecticides, especially neurotoxic ones. It is also related to the small size of the market for bed bugs, which requires specialized insecticides of low human toxicity, which are unprofitable for industry, compared to, for example, the development of pesticides for crops.

“In this context, the application of precision interventions based on scientific data is required, so that the available formulations are utilized, to avoid unnecessary empirical applications that burden the environment but also exacerbate the problem of resistance, and to effectively treat bed bugs and insects of health importance. The analysis of the biological material – the target of the insecticides before the applications, with modern molecular diagnostic methods, as well as the verification of the effectiveness of some preparations with bioassays, are necessary conditions for the design and support of these interventions”, added to APE-MPE the Mr. Vontas, pointing out at the same time that “companies should be incentivized to market additional biocides in order to deal with the serious problems caused by bed bugs”.

Finally, as he added, the intensification of research for the development of new bioinsecticides, compatible with the EU Green Agreement, is required. At IMBB-ITE and GPA, a significant research effort is being made, which is funded by the European Union, for the development of alternative insecticide formulations of microbial origin (bioinsecticides), in light of developments in green biotechnology.

The scientific team of the IMBB-ITE and the Pharmacology Department of the GPA that studies insects of health importance and develops new technologies to deal with them consists of the head of the team Prof. Yiannis Vonda, Ilias Kioulos, Costas Mavridis, Alexandra Grigoriadou and Anastasia Kambouraki.