Outbreak of the South American tomato leafminer, Tuta absoluta, in the Chinese mainland: geographic and potential host range expansion

Abstract

BACKGROUND: In 2017 Tuta absoluta was identified as an invasive species in China. Due to its rapid geographic expansion and the severe crop damage it causes, T. absoluta poses a serious threat to China's tomato production industry. To determine its geographic distribution and host range, intensive surveys and routine monitoring were conducted across the Chinese mainland between 2018 and 2019. The population colonization coefficient (PCC; ratio of colonized sites and prefectures) and population occurrence index (POI; ratio of infested host species and PCCs) were calculated.RESULTS: In northwestern China, T. absoluta populations established in Xinjiang exhibited a medium PCC value (∼0.03). In southwestern China, populations in Yunnan and its five neighboring provinces exhibited high (∼0.50 in Yunnan and Guizhou), or low (<0.02 in Guangxi, Sichuan, Hunan, and Chongqing) PCC values. In the Chinese mainland, infestations of four crop plant species (tomato, eggplant, potato, and Chinese lantern) and two wild plant species (black nightshade and Dutch eggplant) were identified; tomatoes were infested in every colonized province. Chinese lantern and Dutch eggplant are potentially novel hosts. Yunnan, Guizhou, and Xinjiang experienced the most serious damage (POI). In southwestern China, observed damage significantly decreased with increased distance from the first discovery site of T. absoluta to the farthest county of an infested province increased. CONCLUSION: T. absoluta populations are well-established and could potentially spread to other regions of China. The present study helps to inform the establishment of better pest management guidelines and strategies in China and tomato-producing regions worldwide.

Similar Bacterial Communities among Different Populations of a Newly Emerging Invasive Species, Tuta absoluta (Meyrick)

“…First, tomato is the preferred host plant in the different geographical populations of T. absoluta . The T. absoluta diet is narrow, with a preference for tomato (fresh market and cherry tomatoes) over other solanaceous plants in China [ 39 ]. In addition, studies of microbial communities of Aphis gossyphii from different plants and regions in China uncovered no significant correlation between the geographical distance between sampling sites and the Bray–Curtis differences of symbiotic or secondary symbiotic communities, and determined that host plants may have influenced the composition of the associated symbionts [ 51 ].…”

“…As a newly emerging invasive pest, T. absoluta was first detected only a few months apart in the Xinjiang and Yunnan provinces [ 38 ]. Zhang et al [ 39 ] speculated that neither of these provinces was the source of the introduction to the other province. Based on the microbiome results, we propose that Yunnan and Xinjiang populations could have originated from the Spanish population.…”

“…By 2020, this pest had spread to 110 countries and regions [ 37 ]. Recently, the T. absoluta has invaded and established itself in China [ 38 ], spreading to Xinjiang, Yunnan, and other provinces [ 39 ]. Based on genetic population analyses, this pest could have been introduced from two different pathways: a southwest pathway from Myanmar into Yunnan Province, and a northwest pathway from Kazakhstan into Xinjiang Province [ 39 ].…”

“…Recently, the T. absoluta has invaded and established itself in China [ 38 ], spreading to Xinjiang, Yunnan, and other provinces [ 39 ]. Based on genetic population analyses, this pest could have been introduced from two different pathways: a southwest pathway from Myanmar into Yunnan Province, and a northwest pathway from Kazakhstan into Xinjiang Province [ 39 ]. T. absoluta , as a destructive invasive pest worldwide, has attracted considerable attention from many entomologists all over the world.…”

Odor learning improves efficacy of egg parasitoids as biocontrol agents against Tuta absoluta

“…This key pest of tomato has become a significant threat to tomato production in Europe and Africa (Biondi et al 2018;Mansour et al 2018) and has reached China in 2017, the worldwide biggest tomato producer (Zhang et al 2020a). Populations of T. absoluta established first in the province Xinjiang (Zhang et al 2020a), followed by Yunnan (Zhang et al 2020b), Guizhou, Sichuan, Hunan, Guangxi, and Chongqing, causing severe damage in Xinjiang (yield losses up to 86%) and Yunnan (Zhang et al 2021). To control the pest, Chinese tomato growers currently rely on insecticides, including Emamectin benzoate, Avermectin-chlorobenzoyl, Methoxy fenozide, and Chlorantraniliprole (Amire et al 2020), as well as on the microbial pesticide Bacillus thuringiensis (Bt-G033A) (Zhang et al 2020c).…”