Illustrating the current geographic distribution of Diaphorina citri (Hemiptera: Psyllidae) in Campeche, Mexico: a maximum entropy modeling approach

Abstract

Diaphorina citri Kuwayama (Asian citrus psyllid) is a quarantine pest found in at least 60 countries, causing indirect damage as a primary vector of pathogens associated with Huanglongbing in citrus trees. Huanglongbing-infected trees die within 3–8 years, accompanied by economic losses in citriculture. D. citri has spread in Mexico to several states and is a high risk to Mexican citriculture due to its ability to cause damage and the lack of a disease cure. The primary objective of this research was to enhance our understanding of the current status of D. citri in southeastern Mexico. This study analyzed the distribution of D. citri in Campeche, Mexico from 2013 to 2020. The study generated 572,619 D. citri records from 40,620 yellow sticky traps deployed in 10 of the 12 municipalities of the state. We employed advanced MaxEnt and DivaGIS software to accomplish this study. Results showed population fluctuations with a peak during June and July from 2013 to 2019 and July and September in 2020. The study found a higher presence of D. citri in Campeche, Tenabo, Carmen, Champotón, and Escárcega and a higher incidence in Citrus latifolia Tanaka ex Q. Jiménez and Citrus sinensis (L.) Osbeck crops. The variance in the number of D. citri adults captured per year and the dispersion index (a parameter measuring the ability of insects to leave one ecosystem and move to another in search of suitable conditions for their survival and reproduction) was greater than the annual mean, demonstrating a spatially distributed, right-skewed aggregate. The elliptical polygon or standard deviation ellipse indicated the tendency for a less elongated ellipse in 2013–2014. From 2015 to 2018 D. citri expanded north towards Hecelchakán and south towards Champotón, Escárcega, and Carmen. In 2019, D. citri expanded north towards Champotón, Campeche, Tenabo, Hecelchakán, and Calkiní. The months with the most activity between 2013 and 2020 were May, June, July, and August, with June having the highest numbers collected. The results of the enveloped tests (parameter measuring how environmental conditions influence the spatial patterns of insect populations) showed the adaptability of D. citri to different conditions. D. citri prefers temperatures of 24.6–27.9 °C and 1,050–1,500 mm of rainfall. Areas with high-risk for D. citri are coastal and northern parts of the study area. Central Campeche is suitable, and southern parts have low to medium risk. Our research shows the relationship between climatic factors and the distribution of D. citri in the state of Campeche, Mexico. Moreover, our findings will be crucial for implementing effective surveillance measures in areas where the probability model indicates the potential presence of D. citri. This is especially significant due to the remarkable adaptability of D. citri to diverse environmental conditions.