Dataset for: Olfactory response of the Andean potato weevil (Premnotrypes spp.) to potato plantlets alone and associated with five mashua (Tropaeolum tuberosum) accessions in olfactometer bioassays in two environments, Lima and Huancayo, Peru (2026)

This dataset contains the counts of laboratory olfactometer bioassays that evaluated the olfactory preference of adult Andean potato weevils (Premnotrypes spp.) for potato (Solanum tuberosum) plantlets alone, potato plantlets associated with mashua (Tropaeolum tuberosum) and mashua alone, to assess the potential of mashua as a natural olfactory barrier against the weevil. The trials were carried out within the project 'Andean Crop Diversity for Climate Change' (GCBC) in two environments in Peru: the CIP headquarters in La Molina, Lima, on the coast (about 240 m a.s.l., February 2026), and the CIP Santa Ana Experimental Station in Huancayo, in the central Andes (about 3,280 m a.s.l., March 2026).

Five mashua accessions from the CIP genebank were evaluated (CIP numbers 203016, 203020, 203021, 203059, 203094): four in Lima and all five in Huancayo. Each trial consisted of ten independent olfactometer runs (replicates) under a completely randomized design, for 90 runs in total (40 in Lima, 50 in Huancayo). In each run ten adult weevils were released in the central chamber of the olfactometer, kept in darkness, and the number of insects found in each arm (potato alone, potato + mashua, mashua alone) and remaining in the central chamber (no choice) was recorded in successive evaluations: three in Lima (time after release not recorded) and four in Huancayo (1, 2, 3 and 24 hours after release).