Conception and validation of three schematic logarithmic scales to quantify damage of Dactylopius opuntiae (Cockerell, 1929) (Hemiptera: Dactylopiidae), and development of OpiShield mobile application that helps evaluate this damage on the basis of the three logarithmic scales

Dactylopius opuntiae, the primary pest of cactus pear globally, necessitates precise tools for damage assessment to manage it effectively.
Three logarithmic scales with 5, 6, and 7 classes were devised to visually assess wild cochineal infestation levels on cactus.
Using 160 cladode samples with varying infestation levels, these scales were developed and validated by 20 evaluators.
Utilization of these scales significantly enhanced estimate precision and accuracy, with correlation coefficient of concordance of Lin (ρc) ranging from 0.099 to 0.871 without scales, and from 0.163 to 0.999 with scales.
Reproducibility also improved, indicated by intra-class correlation coefficients of 0.577, 0.885, 0.884, and 0.905 for estimates without scales, using 5-, 6-, and 7-class scales respectively.
Building upon these scales, OpiShield, a mobile application aiding in wild cochineal infestation estimation, was developed.

XI International Congress on Cacti as Food, Fodder and Other Uses

A. Azzouzi, H. Anejjar, A. Id-M’hamed, A. Ait Said, R. Lahlali, M. Ait Chitt, A. Boutaleb Joutei, T. Benziane

cactus wild cochineal, cactus pear, schematic logarithmic scale, OpiShield

https://doi.org/10.17660/ActaHortic.2026.1452.32