High temperatures trigger urban pests and become chronic throughout the year

Rats, cockroaches and mosquitoes, in this order, are on the podium of urban pests.

Oliver Thansan
Oliver Thansan
16 March 2023 Thursday 05:56
196 Reads
High temperatures trigger urban pests and become chronic throughout the year

Rats, cockroaches and mosquitoes, in this order, are on the podium of urban pests. Pest control actions (to prevent the spread of cockroaches, bedbugs, flies, rodents...) over the past year have skyrocketed in Catalonia, especially in large cities and the Barcelona metropolitan area. This is indicated by data from the Catalan Association of Environmental Health Companies of Catalonia (Adepap), which has been able to confirm this trend by evaluating demand through a survey among its members.

The high temperatures registered last year from the month of May and until well into winter, with successive waves of heat and tropical nights (with temperatures above 20 Cº), in combination with the scarcity of rain, extraordinarily favored the development of pests, which are "increasingly less seasonal and more global" according to this association.

"Last year, the pest control season began in May and lasted until December," says Adepap's technical coordinator, Luis Lozano.

Notices and citizen complaints about the presence of rats have increased by 30%; but the problem is above all due to the fact that now these animals are more "brazen", they do not shy away from human presence after the pandemic and, for this reason -once this correction has been made- it is estimated that the real number of incidents has increased by 10% and 15%.

For its part, the demand for services to eradicate cockroaches has grown by around 25%, largely due to the fact that effective control ceased to be carried out during the pandemic and now they reappear in premises and other facilities. Mosquitoes are a more prolonged plague during the year because "there is always water in the city" and their activity lasts more months at the end of the year.

Six out of ten companies saw an increase in the demand for intervention to deal with rodent control, while in another two out of ten it remained stable.

The most significant increase was concentrated in the large urban centers and, especially, in Barcelona and its metropolitan area.

The great adaptability of rodents and the greater restrictions on the use of some biocidal products, added to "the resistance that these animals have developed to some of the active substances in rodenticides" make it increasingly complex to keep populations low. established tolerance thresholds, says Quim Sendra, president of this association.

In addition, "in urban environments rodents find almost unlimited food (garbage) and water resources," he concludes.

This trend is common in many countries. The French pest control association, La Chambre Syndicale 3D, which brings together 800 companies, has recently published its 2021-2022 comparative report, showing a 35% increase in professional interventions related to rat control.

In the case of cockroaches, the demand for control tasks was maintained or increased for 90% of the companies surveyed, although the most significant increases occurred in Barcelona and its surroundings, as well as in some municipalities of the Vallès such as Sabadell and Ruby.

The blonde or German cockroach, common in indoor facilities, kitchens and homes, registered a slight increase, "possibly due to neglect during the pandemic in some hospitality establishments", according to Adepap's technical coordinator, Luis Lozano.

For its part, in the case of the red or American cockroach, active in sewers (both public and private), "the increase is motivated by its reproductive-colonizing activity, high temperatures and low rainfall"; but the state of maintenance of the sewage networks also has an impact” (amount of organic matter and food available and damage to the network itself). “All this “without forgetting the restrictions on the use of biocides”, explains Lozano.

“Bedbugs travel with tourism. They do not walk, they do not fly, but they travel through our luggage”, say the technicians. Bed bugs (Cimex lectularius) arrive at homes in most cases transported in their own clothes or travel suitcases.

Most of the companies that carry out their control state that they have increased their disinsection activity, and half of those that experienced this increase estimate it to be between 10% and 25%.

"The demand for intervention for bed bugs increased in large cities, where more overnight stays are concentrated due to tourism," explains Quim Sendra. The recovery of tourism, the resumption of large congresses and travel of all kinds "are the main reason for the increase in demand for this service in relation to 2021, when there were still some restrictions due to Covid-19," says Sendra. .

Control activity against flying insects (mosquitoes, flies and black flies) remained stable for half of the companies and increased by a quarter. The rise was concentrated in those municipalities where there has been more water, near rivers, streams, ponds or marshes. "There were also some points of action according to the climatic conditions of each municipality, especially already in autumn, when some rain was combined with the other temperatures", affirms the president of Adepap, Quim Sendra. Those surveyed highlighted Barcelona and its metropolitan area, the demarcation of Lleida, Banyoles and the Alt Penedès region.

On the other hand, interventions on wood insects have remained the same.

With regard to bird control (pigeons, seagulls, parrots...), the companies that provide the service state that either their actions increased or they remained stable. The companies affirm that this increase occurred above all in the large urban centers.

Experts believe that this type of control will continue to rise in the coming years due to rising temperatures and climate change, "which is causing adaptive changes in these birds" and accelerating their reproductive cycle," explains Adepap's technical coordinator. Invasive birds, such as the Argentine parrot, have a very special role, with a high capacity to adapt to our environments, adds Luis Lozano.