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Aim Knowledge of how effective interceptions and quarantine measures are in preventing new biological invasions is of paramount importance for maintaining ecosystem function in a rapidly changing world. Here, we determine current macrogeographic population structure and routes of invasion of the Mediterranean fruit fly (Ceratitis capitata) using genetic approaches and reconstruct and test invasion pathway hypotheses in a Bayesian framework. Location Africa, Australia, Greece, Guatemala and Madeira. Methods We sampled 323 C. capitata individuals from 14 locations world‐wide and genotyped all individuals for 11 polymorphic microsatellite markers. We calculated measures of genetic diversity and determined population structure. Moreover, we reconstructed and tested eighteen invasion pathway scenarios in a Bayesian framework using ABC modelling. Results We show a decrease in genetic diversity outside the native range (Africa) into the introduced range (Australia, Greece, Guatemala and Madeira). The most likely invasion pathway scenario closely matched the historical records, with an initial colonization of Europe from Africa and a secondary colonization of Australia from Europe. Moreover, we show an introduction from Greece to the Americas and, finally, a back introduction into South Africa from Europe. Main conclusions Given the lack of new introductions into colonized (non‐African) locations despite increasing trade, and apart from the initial invasion and establishment of the species outside of Africa, we conclude that quarantine and interception measures have been largely successful to date.

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) has shown remarkable range expansion over the past 10years and invaded several new continents including Africa. Here we report results of a detailed assessment of acute high and low temperature survival ability and the plasticity thereof, to test the hypothesis that traits of the thermal niche have contributed to the species' invasion ability. We also assess life-stage-related variation of thermal tolerances to determine potential stage-related environmental sensitivity. The temperatures at which c. 20% of the population survived of B. dorsalis were determined to be -6.5°C and 42.7°C, respectively, when using 2h exposures. Further, four life stages of B. dorsalis (egg, 3rd instar larvae, pupae and adults) were exposed to high and low discriminating temperatures to compare their thermal survival rates. The egg stage was found to be the most resistant life stage to both high and low temperatures, since 44±2.3% survived the low and 60±4.2% survived the high discriminating temperature treatments respectively. Finally, the potential for adult hardening responses to mediate tolerance of extremes was also considered using a diverse range of acute conditions (using 2h exposures to 15°C, 10°C and 5°C and 30°C, 35°C, 37°C and 39°C as hardening temperatures, and some treatments with and without recovery periods between hardening and discriminating temperature treatment). These showed that although some significant hardening responses could be detected in certain treatments (e.g. after exposure to 37°C and 39°C), the magnitude of this plasticity was generally low compared to two other wide-spread and more geographically-range-restricted con-familial species, Ceratitis capitata and C. rosa. In other words, Bactrocera dorsalis adults were unable to rapidly heat- or cold-harden to the same extent as the other Ceratitis species examined to date. These results suggest a narrower thermal niche in B. dorsalis compared to these Ceratitis species - in both basal and plastic terms - and suggests that its geographic distribution might be more restricted in consequence.

The mutualistic association between some ant species and honeydew‐producing Hemiptera has been shown to influence the distribution patterns and abundance of these hemipterans and their natural enemies. We studied the spatial distribution patterns of three ant species, mealybugs and mealybug parasitoids for two consecutive growing seasons on three wine grape farms in the Western Cape, South Africa. During the study period, no ant or mealybug controls were applied. Ant and mealybug monitoring was conducted on a total of 21 ha using a presence/absence sampling system, while parasitoids were collected from infested mealybug females. Spatial analysis by distance indices was used to analyse spatial distribution of insects and ArcView™ was used to map the gap, patch and local association indices where significant association and disassociation occurred. Significant associations were found between some ants and parasitoids, while significant disassociations between the ants Crematogaster peringueyi and Linepithema humile; and also between Crematogaster peringueyi and Anoplolepis steingroeveri were found. Interspecific competition between ant species could play a role in the distribution of parasitoids and mealybugs. Our results stress the importance of monitoring for ants and mealybugs and further highlight the importance of restricted chemical applications against ants during the growing season.

Phlyctinus callosus (Schoenherr, 1826) (Curculionidae, Entiminae, Oosomini) is a species native to the Western Cape province of the Republic of South Africa. It is regarded as a key pest of orchards and vineyards. Detailed observations of its morphology and ecology have shown this species to be a complex of closely related species. In this study we describe the species of this complex, provide morphological and molecular diagnostic tools to distinguish between species, and review their distribution and host plant associations. In all, six species are recognized in the P. callosus complex and five are described as new (P. grootbosensis Haran sp. nov., P. xerophilus Haran sp. nov., P. planithorax Haran sp. nov., P. littoralis Haran sp. nov., P. aloevorus Haran sp. nov.). Sequences of the mitochondrial gene used (cytochrome oxidase I, COI) indicated that P. xerophilus Haran sp. nov. might comprise several cryptic species for which stable morphological features could not be identified at this stage. The species of the genus Phlyctinus appear to be primarily associated with various Asteraceae found in humid, sandy and disturbed habitats.