The EFSA Panel on Plant Health performed a pest categorisation of the citrus fruit midge, Resseliella citrifrugis Jiang (Diptera: Cecidomyiidae), for the territory of the EU. 

This species is not included in EU Commission Implementing Regulation 2019/2072. 

This oligophagous species, which feeds on Citrus spp. fruits, is known to occur in China (provinces of Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi and Sichuan). First-generation adults emerge in April and oviposit on the peduncle and calyx of citrus fruits. Larvae feed on the albedo (the white layer between skin and pulp) of the fruit, which they tunnel. Infested fruit most often drop prematurely. Larvae pupate either within the fallen fruit or in the soil. This species has three main peaks of activity (May, June–July, August–September) and four generations per year in its native range. Mature larvae from the last generation are the overwintering stage. 

Potential entry pathways for R. citrifrugis, such as Citrus spp. plants for planting with foliage and soil/growing media, and soil/growing media can be considered as closed. The citrus fruit pathway remains open from countries where R. citrifrugis is known to occur. Indeed, this species was intercepted in fresh pomelos 11 times from December 2020 to January 2021 in the EU. 

Should R. citrifrugis enter the EU, the ample availability of hosts (Citrus spp.) and the climatic conditions in citrus-growing areas of southern EU Member States would most probably allow this species to successfully establish and spread. Economic impact in citrus production is anticipated if establishment occurs. 

R. citrifrugis satisfies the criteria that are within the remit of EFSA to assess for this species to be regarded as a potential Union quarantine pest. There is uncertainty about the nomenclature of R. citrifrugis and its exact host range. However, because the name Resseliella citrifrugis is used in multiple sources reporting it as a pest of citrus in China, where symptoms, biology and impact are described, these uncertainties do not affect the conclusions of this categorisation.