Monitoring populations of Popillia japonica (Newman, 1838) over 16 years in the Azorean Islands

Study Extent

The study was conducted in the nine islands of the Azores archipelago. The traps were placed in different locations, considering the pest's arrival, and spread. The entrance places like airports and ports were the first places to have traps for monitoring and detecting the entrance of the pest and as a measure of the pest spread. After the pest arrived, several traps were placed near urban places or houses in agricultural areas, including crops and orchard types, such as maize, plum, banana, potato, coffee, chestnut, fig, orange, several citrus, apple, strawberry, vine, olive, and pastures

Sampling

The survey of Popillia japonica was conducted through regular weekly observation of the entomological material captured in Ellisco traps. In each trap, a double attractant composed of a capsule of pheromone (sexual attractant) and a diffuser of floral attractant was placed, which was replaced every five weeks. This data set presents the weekly records, which were transformed into monthly results. As a rule, depending on the site's topography, it was sought that the distance between traps was 50-100 meters. The placement of the traps began at the beginning of April so that at the beginning of May when the emergence of the first adults of the beetle could be verified, all the traps would have already been installed in the field. The presence of the traps in the field was maintained till November. At the beginning of April, the laying of the traps began, and they were kept in the field until the end of November. In each trap was placed a double attractant consisting of a pheromone capsule (sexual attraction) and a diffuser of floral attractant, which was replaced every five weeks. When the number of captured insects is very high, the number is calculated indirectly through weighing. The average weight of each adult is often measured, as its value varies with the time of year, the type of vegetables eaten, and the location. The average weight of a Japanese beetle adult for the Azores is 0,085 g.

Quality Control

All collected individuals were identified by expert taxonomists in the laboratory.

Method steps

1. The survey of Popillia Japonica was conducted through weekly regular observation of the entomological material captured in Ellisco traps. In each trap, a double attractant composed of a capsule of pheromone (sexual attractant) and a floral attractant diffuser was placed, which was replaced every five weeks. This dataset presents the weekly records, which were transformed into monthly results. As a rule, depending on the site's topography, it was sought that the distance between traps was 50-100 meters. The traps were placed at the beginning of April so that at the beginning of May when the emergence of the first adults of the beetle could be verified, all the traps would have already been installed in the field. The traps in the field were maintained until the end of November

General taxonomic coverage description: Insecta, Coleoptera, Scarabaeidae, Popillia japonica (Newman, 1838) Common names: Scarab beetle, Japanese Beetle

1. Popillia japonica (Newman, 1838)
   common name: Japanese beetle rank: species

The Azores archipelago located in the North Atlantic Ocean (37-40 °N, 25-31 °W), about 1600 km of distance to southern Europe and 2200 km to the northern America. The following delineates the areal extent, maximum altitude, and isolation distance to the near fragment/island of each island: São Miguel, the archipelago's most extensive island, has an area of 757 km² and its topography culminates at an altitude of 1,103 meters above sea level, and its distance to the nearest island of Santa Maria is 97.53 Km. In comparison, the island of Santa Maria has a total land area of 97 km², with its highest geographical point reaching 857 meters. Terceira Island, with a covering area of 402 km², exhibits an elevation of 1,023 meters, and its nearest island (São Jorge) is at 71.67 km of distance. Graciosa, which is relatively smaller, covers an area of 61 square kilometers, with its highest point reaching 402 meters above sea level. It is located 45 km away from the nearest island of São Jorge. São Jorge spans 246 square kilometers and reaches a maximum altitude of 1,053 meters. Its closest neighbor is Pico Island, at 32.42 km. Pico Island, known for housing the highest mountain within Portuguese territory, has an area of 447 square kilometers, and its peak rises to a height of 2,351 meters above sea level. Faial Island, with an area of 173 km², has a top elevation of 1,043 meters and is 34.26 km from Pico Island. Additionally, Flores Island extends across 143 km², and its highest point is 914 meters above the ocean, and the nearest island is Corvo, 30 km away. Corvo, the smallest of the nine islands, has an area of 17 km², and the maximum altitude is 718 meters above sea level. These geospatial metrics define the physical essence of the Azorean archipelago and serve as critical data for ecological, climatological, and geological research actions.