Host range testing of Tamarixia dryi (Hymenoptera: Eulophidae) sourced from South Africa for classical biological control of Trioza erytreae (Hemiptera: Psyllidae) in Europe

Insights into the origin of the invasive populations of Trioza erytreae in Europe using microsatellite markers and mtDNA barcoding approaches

“…Our phylogenetic analysis using mtDNA barcoding also supports this hypothesis, as the individuals from Spain and Portugal (including those from the Canary Islands and Madeira) formed a monophyletic group with those individuals from Pretoria, Tzaneen and Nelspruit, suggesting that the T. erytreae individuals that invaded the Iberian Peninsula have their maternal origin somewhere in the northeast of South Africa. Furthermore, the fact that T. erytreae populations in the Canary Islands have been drastically reduced by its natural enemy Tamarixia dryi (Del Guercio) (Hymenoptera: Eulophidae), a highly specific parasitoid of T. erytreae imported from Pretoria 21 , 22 and released in the archipelago in 2018 23 , also supports the idea that the T. erytreae individuals that invaded the Macaronesia and the Iberian Peninsula have derived from the northeast of South Africa near Pretoria. Nevertheless, considering that Pretoria (Gauteng) is not a citrus growing area, it could be possible that the individuals of T. erytreae sampled in Pretoria could have derived from the neighbouring province of Limpopo, the largest citrus producing area in South Africa 47 .…”

“…The wide distribution of T. erytreae makes any contingency measure a challenging effort 20 . It has been demonstrated that the parasitoid wasp Tamarixia dryi (Waterston) (Hymenoptera: Eulophidae) is a highly specific parasitoid of T. erytreae 21 , 22 , and its use in classical biological control programme has decreased the African citrus psyllid populations in the Canary Islands drastically until they have almost totally disappeared 23 . A T. dryi -assisted biological control program against T. erytreae was also carried out successfully in the Indian Ocean island of Réunion 24 and Mauritius 25 .…”

Laboratory and Field Trials to Identify Sustainable Chemical Control Strategies for Trioza erytreae in European Citrus Orchards

“…Later, this insect appeared in Galicia, in 2014, and in northern mainland Portugal in 2015, and more recently in Asturias, Cantabria, and the Basque Country in 2020 [10,20]. Since it was detected, the insect has spread widely throughout the Canary archipelago, except for Fuerteventura and La Graciosa islands, and in the Iberian mainland, near major citrus-growing areas, such as the Algarve region in Portugal and the Huelva province in Spain [21][22][23][24]. This poses a great risk for the Mediterranean citrus sector and, consequently, the search for sustainable pest control methods to prevent it from spreading is a priority.…”

“…Among the natural enemies of AfCP, the parasitic wasp Tamarixia dryi (Waterston) is effective in controlling the T. erytreae population in its area of origin [39][40][41][42]. This wasp is an ectoparasitoid, which oviposits its eggs on the third to fifth nymphal stages of T. erytreae, and its nymphs feed on them throughout its development [24,43]. Classical biological control with this wasp has effectively reduced the populations of T. erytreae on the islands of Mauritius, Reunion Islands, and St. Helena [41,44,45].…”

“…Such previous and positive results, combined with the lack of effective biological control agents against T. erytreae native to the Iberian Peninsula and Atlantic islands, led to the use of a classic biological control strategy in Spain [23,46]. Urbaneja-Bernat et al [24] carried out a host range test of T. dryi that confirmed that this natural enemy is a highly specific parasitoid, and its introduction in Europe should not affect other psyllid species. Thus, individuals of this ectoparasitoid were collected from several citrus orchards from Pretoria (South Africa) and introduced in the Canary Islands (Spain) to control the population of the psyllid vector (AfCP), showing positive results and spread capabilities [43,47].…”