Sewer cockroaches have been the most intense pest this summer in Catalonia, although there have also been other mosquitoes, black flies, bed bugs, ticks and rats. This is indicated by a balance sheet from the Catalan Association of Environmental Health Companies (Adepap). The main cause of these spikes is meteorological: persistent drought and sustained high temperatures since spring, which accelerated reproductive cycles: they began to reproduce earlier and more efficiently.
With the arrival of heat, infestations of sewer cockroaches began to be detected in spring, especially in urban areas. The American cockroach (Periplaneta Americana), brown in color and shaped like a date, is the one that has caused the most demand for actions from specialists. With a lower incidence, pests have also been detected in the oriental cockroach (Blatta orientalis, black), as well as the coffee cockroach (Blatella germanica), which is lighter in color and more common indoors. of homes and in the field of restoration.
Quim Sendra, president of Adepap, has described the proliferation of these cockroach populations as worrying, and has considered it a health risk. Cockroaches live and feed in places where there is dirt, and therefore can cause contamination by bacteria – such as salmonella – on surfaces and food, which increases the risk of diseases and allergies.
“It has reached a point where we carry out actions against cockroach infestations throughout the year, although the demand for this service has increased a lot this summer,” says Sendra. Cockroaches are combated mainly with the cleaning and maintenance of the entire system of pipes, drains and sewer manholes.
On the other hand, this year, between June and August, there have been fewer mosquitoes than expected; The summer was being too dry. However, some species, such as the tiger mosquito (Aedes albopictus), only need the small puddles or water left at the bottom of the pots to proliferate, explains Sendra, and points out that this means they can easily appear in urban areas.
Likewise, the rains at the end of August promoted local infestations of tiger mosquitoes and native mosquitoes (Culex pipiens), which will continue throughout the fall if temperatures continue to be high. Adepap expects that, if so, these pests will be more intense than those that occurred during the summer.
In this sense, the concern covers the health field. Some mosquito species are vectors for disease transmission; In the case of the tiger mosquito, it is the vector that transmits dengue. In Spain, eight indigenous cases have been detected in the last six years. The last one was last September in Reus (Catalunya).
Regarding the black fly, “although an increase in proliferation is noted both in Catalonia and the rest of the state, the important treatment campaign carried out by the municipalities and other supra-municipal entities since the end of spring in the main rivers has maintained the tolerance threshold in these spaces,” argues Sendra. The female black fly is also a transmission vector; in this case, from the Onchocerca volvulus parasite, which can cause “river blindness.”
On the other hand, bed bug infestations have been reactivated due to tourism and international travel, and since last year they have already returned to pre-pandemic levels. Adepap considers this pest to be difficult to eliminate because they can hide in mattresses, clothing and sofas. For this reason, it is recommended to wash all clothing used on trips at high temperatures (60 °C), and check and clean belongings and luggage well in an isolated space (such as the bathroom), before storing them.
In recent years in Catalonia, a sustained increase in incidences of the gray rat (Rattus norvegicus) and the presence of the black rat (Rattus rattus) had already been detected in urban environments, where the latter species were not usually seen. The rat is a warm-blooded animal, active and reproductive throughout the year; However, the greater availability of food on the streets during the summer makes this pest more visible during the summer season.
