A 13-year termite (Insecta, Blattodea) monitoring programme in the Azores: Dataset and findings

From 2011 to 2024, the Azorean Government tested two coordinated monitoring programmes across the archipelago to survey four invasive termite species: the West Indian drywood termite, Cryptotermes brevis (Walker, 1853); the yellow-necked drywood termite, Kalotermes flavicollis (Fabricius, 1793); the Western European subterranean termite, Reticulitermes grassei Clément, 1978; and the eastern subterranean termite, Reticulitermes flavipes (Kollar, 1837). The monitoring programme was mostly directed to the detection of C. brevis in new locations. Drywood species were detected on multiple islands, with C. brevis established on six islands (from west to east: Faial, Pico, São Jorge, Terceira, São Miguel and Santa Maria) and exhibiting the highest infestation densities in the urban centres of the three most important islands in terms of economic activity and human population (São Miguel, Terceira and Faial). Kalotermes flavicollis occurs more sporadically, primarily along the south coasts of Terceira, São Miguel and southeast coast of Faial and seldom attains the pest status of C. brevis. In contrast, the two Reticulitermes species remain restricted to localised subterranean infestations: Reticulitermes grassei in Horta (Faial) and R. flavipes near Lajes Air Force Base (Terceira), each detected via house inspection visits. Collectively, these efforts provide the first comprehensive, archipelago-wide dataset on termite presence, laying the groundwork for targeted Integrated Pest Management strategies in the Azores.

Records of Cryptotermes brevis overwhelmingly dominated the monitoring data, comprising 1,801 of the 1,832 total events (98%), a pattern consistent with previous surveys of its rapid spread in the Azorean urban environment. These detections were heavily concentrated on two islands: Terceira (n = 919) and São Miguel (n = 755). In contrast, Faial, Pico and Santa Maria each yielded roughly 40 records and São Jorge only seven. Annual trap-capture counts across all islands increased steadily from approximately 40 captures in 2011 to 154 in 2024, peaking at 185 in 2023.Kalotermes flavicollis was the second most frequently recorded species (n = 24), with most records originating on São Miguel, mirroring its more restricted distribution. The two subterranean termites, Reticulitermes grassei and R. flavipes, were documented exclusively on Faial and Terceira, respectively, consistent with their historically limited foothold in the archipelago.Now established on every surveyed island and exhibiting an upward trajectory in annual detection counts, C. brevis remains the foremost urban termite threat in the Azores. To forestall further structural outbreaks, Integrated Pest Management should place sustained emphasis on early detection - through year-round trap checks - and on heightened public awareness, by encouraging residents to report both the characteristic pin-sized faecal pellets and any termite occurrence observed during swarming periods.