Factors Affecting Occurrence of Damage by Coraliomela quadrimaculata and Paysandisia archon on Palm Trees (Arecaceae) in an Urban Setting of Argentina

Abstract

In Argentina, only two insect species significantly damage urban palms: Coraliomela quadrimaculata (Coleoptera: Chrysomelidae) and Paysandisia archon (Lepidoptera: Castniidae), the latter having recently reached pest status in several European countries. This study analyses factors associated with palm trees and patches that influence the incidence of damage caused by these insects in a big city of central Argentina. Twenty-four palm groups were surveyed in the urban area, and variables were measured at two scales. At the patch scale: number of palm species, palm density, and distance to the city centre; at the palm scale: geographic origin of palm species, trunk diameter, palm height, number of fronds, and degree of isolation. Presence/absence of damage was analysed using multiple logistic regression models. The results revealed a higher prevalence of damage caused by C. quadrimaculata compared to P. archon, with a significant relationship between palm abundance and the proportion of damage for the former species. The damage by C. quadrimaculata increased with the number of fronds, while wider trunks made palms more susceptible to P. archon. Neotropical palm species were less affected by P. archon but more prone to C. quadrimaculata damage. Palms were more vulnerable to C. quadrimaculata in monospecific patches, whereas P. archon caused greater damage in denser and plurispecific patches. Urbanisation strongly influenced C. quadrimaculata damage but had no detectable effect on P. archon. Understanding the differing impacts of C. quadrimaculata and P. archon is essential for developing targeted management strategies. This is particularly urgent for C. quadrimaculata, whose population is increasing in Argentina. Further research is crucial to better understand the factors driving P. archon damage, given its high invasive potential and significant impact as an emerging pest.