Reduction in Egg Fertility of Aedes albopictus Mosquitoes in Greece Following Releases of Imported Sterile Males

Abstract

Aedes albopictus, an invasive mosquito species, is currently well established in many European countries, posing high risks to human health. A preliminary trial using repetitive releases of irradiated sterile male mosquitoes was designed, implemented and evaluated for the first time in Greece. The main scope of this trial was to investigate the efficacy of sterile insect technique (SIT) on wild population egg hatch rate in Greece using mass-produced sterile male mosquitoes from another country (Italy). The study was conducted in Vravrona area, close to Athens International Airport (Attica Region). The number of eggs laid in ovitraps was similar in all intervention and control plots. However, a significant reduction in egg hatch rate was recorded in the SIT plot in comparison with both control plots starting two weeks after the first release. This trial validates the logistics (transportation, releases handling and monitoring) as a major step towards implementing efficient, environmentally safe control approaches as an additional tool against the invasive Aedes species in Greece and more widely in Europe.

Quality Control Methods for Aedes albopictus Sterile Male Transportation

“…Egg batches were collected daily and kept sealed in the laboratory of the Benaki Phytopathological Institute (BPI) (Kifissia, Greece) or transported to the laboratory of Agricultural Zoology at the University of Thessaly (UTH) (Volos, Greece, driving distance 3 h from BPI). Before trials, eggs were submerged in stale tap mineral water for hatching and rearing [37,[40][41][42]. The flight ability tests were conducted at BPI, whilst for the survival and mating performance tests (effect of mating, food and water stress on male survival and male mating performance) eggs (in oviposition substrates) were transported to UTH and reared there to serve as the respective controls in various tests.…”

“…Since there is lack of information on the quality of males transported from the rearing facilities by air cargo shipment to distant areas and often countries where they are released [37], the current paper presents a list of tests to assess the quality of transported sterilized males. More specifically, we describe the experimental procedures that test whether transportation under realistic SIT operation programs affect the quality of the released males.…”

The Potential for a Released Autosomal X-Shredder Becoming a Driving-Y Chromosome and Invasively Suppressing Wild Populations of Malaria Mosquitoes

“…If sufficient numbers of sterile males are released over a long enough period, the wild population can be effectively suppressed or even eradicated. However, the economic costs of an SIT program that aims for mosquito suppression in very large areas and the need to maintain sterile releases indefinitely, have restricted the implementation of this method to date [but see; ( Zheng et al, 2019 , Hendrichs et al, 2021 ; Balatsos et al, 2021 )].…”

Effects of Selection to Diflubenzuron and Bacillus thuringiensis Var. Israelensis on the Overwintering Successes of Aedes albopictus (Diptera: Culicidae)

“…Despite the encouraging results, certain limitations prevent the wide application of these approaches in the field. Among others, the main limitations in the area-wide application of SIT are the high production and transportation costs of sterilized males required to achieve successful suppression of the wild mosquito populations [14]. On the other hand, the implementation of both RIDL and Wolbachia-based strategies are under strict prohibition in many countries including the European Union due to environmental/ecological concerns, whereas the efficacy of pyriproxyfen autodissemination highly depends on the availability of breeding sites in a given area [13].…”