The number of invasive insect species identified in Türkiye is approaching 60, as climate change, global trade and expanding transportation networks accelerate their spread.
Professor Izzet Akça, head of the Entomology Department at Ondokuz Mayıs University’s Faculty of Agriculture, told Anadolu Agency (AA) that Türkiye is home to between 25,000 and 30,000 insect species.
Akça said nearly 60 invasive insect species have been identified as having entered Türkiye at different times, while emphasizing that not every insect that becomes common in an area should be considered invasive.
"For an insect to be considered invasive, it must enter a region where it does not naturally occur, establish itself, spread rapidly and cause economic or ecological damage,” he said.
Among the invasive species posing the greatest economic challenges in Türkiye are the brown marmorated stink bug, citrus longhorn beetle, Asian tiger mosquito, vampire moth and tomato leaf miner (Tuta absoluta).
Akça said the brown marmorated stink bug and other invasive species can cause significant losses in fruit and vegetable production by reducing both yields and product quality.
The Asian tiger mosquito poses an additional concern because of its potential impact on public health, he said.
Akça noted that invasive species have become increasingly common in different parts of Türkiye in recent years, with their high reproductive capacity and ability to feed on a wide range of plants making them particularly difficult to control.
He said climate change is contributing to their spread but is not the only factor.
"Global trade, logistics networks and human mobility also play an important role,” Akça said, noting that warmer conditions can allow species with high reproductive capacities to produce more generations.
He cited the brown marmorated stink bug as an example, saying it can feed on more than 300 plant species, while the citrus longhorn beetle can survive on numerous fruit and ornamental plants.
International transportation can also carry invasive insects over long distances. Akça said brown marmorated stink bugs can travel hundreds of kilometers on the exterior of vehicles, allowing them to reach new regions.
The brown marmorated stink bug was first detected in Türkiye in 2017 and has since spread from the Black Sea region toward the Marmara region and central parts of the country, he said.
Multiple methods needed
Akça stressed that chemical spraying alone is not enough to control invasive insects and that their life cycles must be understood as part of an integrated approach.
He said the samurai wasp, which has been used successfully in biological control programs in several countries, has been released in different parts of Türkiye to combat the brown marmorated stink bug.
However, he said biological control must be supported by other measures, including chemical control when necessary.
Akça also highlighted the importance of distinguishing invasive insects from other species that pose health risks.
"Ticks are not insects. They belong to the mite group,” he said, noting that their populations have increased with climate change and that they are important for human health because they can transmit Crimean-Congo hemorrhagic fever.
Akça added that most insects are not harmful, with only around 1% to 3% considered harmful. Between 20% and 30% are beneficial, while many others play essential roles in decomposition, soil formation and ecosystem functioning.