Pest Management Science (2022) 78, 4533-4543

Ishakh Pulakkatu-thodi, Jason Dzurisin and Peter Follett (2022)
Evaluation of macadamia felted coccid (Hemiptera: Eriococcidae) damage and cultivar susceptibility using imagery from a small unmanned aerial vehicle (sUAV), combined with ground truthing
Pest Management Science 78 (11), 4533-4543
Abstract:
BACKGROUND
Macadamia felted coccid, Acanthococcus ironsidei (Williams) (Hemiptera: Eriococcidae), is a significant pest of macadamia nut, Macadamia integrifolia Maiden and Betche (Protaceae), in Hawaii, and heavy infestations can kill branches, resulting in characteristic dead, copper-colored leaves. Small Unmanned Aerial Vehicles (sUAV) or 'drones,' combined with spatial data analysis, can provide growers with accurate and high-resolution detection of plant stress due to pest infestations. We investigated the feasibility of using RGB (red-green-blue) color images from sUAV to detect dieback caused by macadamia felted coccid infestation and compared sUAV estimates with ground-based damage estimates (ground truthing).
RESULTS
Spatial analysis showed clustering of foliar damage that reflected cultivar susceptibility to macadamia felted coccid infestation, with cultivars 344 and 856 being susceptible, and cultivars 800 and 333 being tolerant. sUAV and ground-based estimates of foliar damage were similar for the cultivar 344, but ground-based assessments were higher than sUAV for cultivar 856, possibly due to the differences in canopy architecture and significant early dieback in the lower canopy. At foliar damage levels <10%, sUAV and ground truthing data were significantly positively correlated, suggesting sUAV may be useful in detecting early stages of macadamia felted coccid infestation.
CONCLUSIONS
Cultivars showed varying susceptibility to macadamia felted coccid infestation and the foliage damage appeared in clusters. sUAV was able to detect the foliage damage under high and low infestation scenarios suggesting that it can be effectively used for the early detection of infestations.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Peter A. Follett

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Acanthococcus ironsidei	Macadamia (Macadamia integrifolia)	U.S.A. (Hawaii)