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We conducted a review of published information on Tuta absoluta parasitoids for the Neotropical region to (1) corroborate species records, (2) analyze associations including the T. absoluta, other insect and plant hosts and (3) identify research directions for enhancing their use as biological control agents. The literature review shows more than 50 species or morphospecies of Hymenoptera associated with T. absoluta, but less than a half (23) could be confirmed as parasitizing T. absoluta. Erroneous reports or invalid names of species, two new species records were found. Over a 100 pests and non-economically important insect and cultivated and non-cultivated plants directly or indirectly interact with T. absoluta in the region. Four T. absoluta parasitoid species include in their host range predatory insects or act as hyperparasitoids, a negative feature considered for a biological control agent. Five larval parasitoids have a narrow host range and could be considered for classical biological control programs in the areas of new invasion. Six Trichogrammatidae species are commercially used in various countries; of those, T. minutum and T. pretiosum are considered to be moderately generalist, being able to exploit several insect hosts. Apart from Apanteles gelechiidivoris and Pseudapanteles dignus, other native species have been the subject of field studies as biological control agents. The review presented here provides useful insights for identifying species that deserve further evaluation as T. absoluta biological control agents through augmentative or conservation strategies in South America, as well as for potential classical biological control programs in other continents. Keywords Taxonomy • Parasitoid ecology • South American tomato pinworm • Host range • Food webs Key message• We provide a review of published records on Tuta absoluta parasitoids of the Neotropics. • From more than 50 parasitoid species or morphospecies reported, only 23 hymenopteran species were confirmed as T. absoluta natural enemies. • Other insect hosts, their host plants and the current knowledge on their potential as biological control agents were tracked. • The low number of available parasitoids and those thathave not yet been identified suggest that much work remains for optimizing the existing biological control services provided by T. absoluta parasitoids.Communicated by M. Traugott.SPECIAL ISSUE 2019: The South American tomato pinworm Tuta absoluta: recent advances in management methods against the background of an ongoing worldwide invasion.

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1 The South American tomato moth Tuta absoluta is a major pest targeted for biological control by entomophagous insects. Trophic interactions among parasitoids of T. absoluta and other gelechiids feeding on crop and spontaneous wild solanaceous were investigated in north-eastern Buenos Aires (Argentina), with the aim of assisting in the design of conservation biological control strategies. 2 A quantitative parasitoid trophic web was constructed that included five gelechiid leafminers, five solanaceous species and a complex of 18 parasitoid species. 3 The relative abundance of T. absoluta was highest in the Solanum melongena crop, followed by the wild plants Nicotiana glauca, Solanum americanum, Solanum sisymbriifolium and Salpichroa origanifolia. Greater parasitoid species richness associated with T. absoluta was found in the wild plants N. glauca and S. americanum. 4 Pseudapanteles dignus was the main parasitoid of T. absoluta and co-occurred with this pest in four plant species. 5 Parasitism of T. absoluta by P. dignus was observed throughout the year in S. melongena, reaching values up to 33%, whereas it was sporadic and exhibited lower parasitism rates in the noncrop S. sisymbriifolium, N. glauca and S. americanum. 6 The presence of some wild solanaceous plants should be promoted to maintain the T. absoluta-P. dignus interaction in horticultural farms.

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Interspecific interactions between two larval parasitoids of Tuta absoluta (Meyrick) with partially overlapping host niches were studied: the idiobiont ectoparasitoid Dineulophus phthorimaeae De Santis, and the koinobiont endoparasitoid Pseudapanteles dignus (Muesebeck). T. absoluta is an important pest of tomato crops worldwide, and its management could be improved by understanding the competitive interactions and potential coexistence between these two parasitoids. Firstly, a 15-min fixed time laboratory test evaluated the host-searching ability of adult D. phthorimaeae and P. dignus wasps on T. absoluta larvae. Secondly, D. phthorimaeae host discrimination against endoparasitized and non-endoparasitized hosts by P. dignus, at different adult female ages, was experimentally examined. D. phthorimaeae wasps spent significantly more time in general searching in the presence of its competitor than in its absence, but, parasitism was only effective by P. dignus. Older D. phthorimaeae wasps discriminated significantly less than young wasps between T. absoluta larvae parasitized and unparasitized by P. dignus, and an interaction took place by non-concurrent host-feeding. Intra-guild predation of P. dignus larvae by D. phthorimaeae female feeding behaviour might have a minor effect in this system. Results are discussed in the context of literature supporting diverse evidence of coexistence in other parasitoid-host systems, with implications for T. absoluta biological control.

Pseudapanteles dignus (Muesebeck; Hymenoptera: Braconidae) is an American endoparasitoid that attacks the South American tomato leafminer Tuta absoluta (Meyrick; Lepidoptera: Gelechiidae). The interaction between P. dignus and T. absoluta in tomato (Solanum lycopersicum L.; Solanales: Solanaceae) crops has demonstrated that this enemy exhibits some desirable ecological traits as an effective biological control agent of this pest. With the aim of extending the use of P. dignus to other solanaceous crops, laboratory experiments were carried out to assess some life history traits and the parasitism efficiency when parasitizing T. absoluta larvae fed on eggplant (Solanum melongena L.; Solanales: Solanaceae). Rearings and experiments were conducted at 25 ± 2°C, ≈70% RH, and 14:10 (L:D) h photoperiod, and T. absoluta was fed with eggplant. P. dignus developmental times of immature stages were lower (~ 5 d) on S. melongena than on S. lycopersicum. The female did not exhibit a pre-reproductive period, and its oviposition period lasted longer (~ 4 d) than that determined in tomato plants. Adult longevity was ca. 24 d for both sexes. Females produced ca. 61 cocoons during their lives and the maximum daily percentage of parasitism was 50% at the first day of adult emergence. Functional response of P. dignus on eggplant was density-independent of the host density offered, as in tomato plant, and the instantaneous attack rate (a') was 0.24 attacked larvae/ available larvae, in 24 h. Our results indicate that although there are differences, P. dignus would have a similar performance in eggplant and tomato in terms of its efficacy in the control of T. absoluta.

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