Origin and potential for overwintering of Ceratitis capitata (Wiedemann) captured in an official survey in Germany

Abstract

Ceratitis capitata (Wiedemann) is a polyphagous plant pest organism causing serious damage on more than 300 fruit types. Although the medfly is present in Europe, it is so far not established in Germany. In the years 2015–2017, an official survey was conducted by the German Federal Plant Protection Organisations to elucidate the current occurrence of this organism in Germany. While in 2015 only small numbers of flies were captured in traps situated in all German Federal States, a peak of 188 specimens could be trapped in 2016 with a decline to 29 specimens in 2017. Highest abundance of the fruit fly was detected in Southern Germany and at a single spot east of Berlin. The present study aimed to identify the origin of the trapped fruit flies and to assess the general potential of the species for overwintering in Germany. Using two approaches with cytochrome oxidase subunit I (COI), Sanger barcoding sequencing first and subsequent analysis of ten small simple repeat microsatellite loci from literature, the worldwide spread of C. capitata describing three phases could be retraced by analysing samples from Germany and 11 other countries. German and French populations were found to build the most recent stage of this species distribution. Specimens trapped in Germany obviously resulted from different introduction events. They most strongly resembled populations from France and Croatia but were not identical to these populations. We found strong evidence that specimens captured between 2016 and 2017 could not overwinter in Germany.

Larval and adult diet affect phenotypic plasticity in thermal tolerance of the marula fly, Ceratitis cosyra (Walker) (Diptera: Tephritidae)

“…Insects use environmental cues such as photoperiod and temperature (and their interaction) to enter a dormancy period that causes arrestment of development, nutrient reserve storage, metabolic decrease, and an increase in cold resistance ( 84 , 85 ). This means that increasing night length (or decreasing day length) coupled with decreasing autumn temperatures can induce diapause in flies such as Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae), Sarcophaga crassipalpis (Macquart) (Diptera: Sarcophagidae), and C. capitata as a mechanism to survive the winter ( 86 – 88 ). Evidence suggests that changing climatic conditions are impacting many insect species’ ability to overwinter ( 89 ).…”

Evidence that recent climatic changes have expanded the potential geographical range of the Mediterranean fruit fly

“…Thus, we are focusing on more recent data points. Records representing C. capitata detections only, and those that fell well outside the known climatic niche and no evidence of C. capitata overwintering and establishment were considered outliers and thus excluded from the analysis 21 . Data were reviewed for clear outliers with incorrectly typed coordinates and those that evidently showed country or administrative units' centroids.…”

Medfly Population Suppression through Augmentative Release of an Introduced Parasitoid in an Irrigated Multi-Fruit Orchard of Central–Western Argentina

“…The farms were 5 km apart and located at an altitude of 723 m above sea level. The TF was characterized by fruit species such as plum (80 trees), fig (12), quince (6), olive (9), sweet orange (Citrus sinensis (L.) Osbeck) (1), loquat (Eriobotrya japonica (Thunb.) Lindl.)…”

“…This has led to the implementation of internationally recommended standard phytosanitary measures and treatments to avoid any ban on or rejection of fruit exports [5]. Endemic to Sub-Saharan Africa [6], C. capitata has spread worldwide, largely due to its extreme polyphagy [7], wide-ranging thermal tolerance [8], high reproductive capacity, mobility, and multivoltine reproduction [9], as well as its genetic evolution and adaption strategy during its establishment in a new region [10]. These traits have encouraged the pest's fast invasion of new areas and infestation of novel hosts, which have brought about its successful establishment not only in wild environments, but mainly in highly diverse suburban and urban landscapes [11].…”