Wild flower resources and insect honeydew are potential food items for Elasmus flabellatus Maria Villa, Sónia A. P. Santos, António Mexia, Albino Bento, José Alberto Pereira To cite this version: Maria Villa, Sónia A. P. Santos, António Mexia, Albino Bento, José Alberto Pereira. Wild flower resources and insect honeydew are potential food items for Elasmus flabellatus. Agronomy for Sus- tainable Development, Springer Verlag/EDP Sciences/INRA, 2017, 37 (3), pp.15. 10.1007/s13593- 017-0423-0. hal-02967743 HAL Id: hal-02967743 https://hal.archives-ouvertes.fr/hal-02967743 Submitted on 15 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Agron. Sustain. Dev. (2017) 37: 15 DOI 10.1007/s13593-017-0423-0 RESEARCH ARTICLE Wild flower resources and insect honeydew are potential food items for Elasmus flabellatus Maria Villa1 & Sónia A. P. Santos1,2 & António Mexia 3 & Albino Bento1 & José Alberto Pereira1 Accepted: 13 April 2017 /Published online: 8 May 2017 # INRA and Springer-Verlag France 2017 Abstract Adult parasitoids need non-host food such as nectar E. flabellatus females did not consume pollen and did not or honeydew for survival and reproduction. In a conservation produce eggs, suggesting that the species is synovigenic and biological control strategy, the knowledge about non-host requires additional foods for egg production. In sustainable feeding of parasitoid species is a key factor to successfully pest control programs, this novel knowledge is a promising increase their action. The nutritional behavior of Elasmus opportunity for improving suitable food resources of flabellatus (Fonscolombe) (Hymenoptera: Eulophidae), a ma- E. flabellatus in the field. jor parasitoid of the olive moth, Prays oleae (Bernard) (Lepidoptera: Praydidae), is completely unknown. Survival Keywords Nutritional ecology . Survival analysis . Cox experiments were performed on two secondary olive pest hon- proportional hazard model . Parasitoids . Prays oleae . Olive eydews and eight common flowering plant species in order to orchard analyze their suitability as potential food sources for E. flabellatus females. Abdomen and gut dissections were carried out to verify the pollen consumption and the egg pro- 1 Introduction duction. Floral architecture and insect morphology were de- scribed. Cox’s proportional hazard regression models were Insect feeding is determined by several aspects such as avail- used to analyze the differences between parasitoid survivals. ability, detectability, accessibility, and nutritional suitability of Honeydews secreted by Saissetia oleae (Olivier) (Hemiptera: foods (Wäckers 2005). Adult parasitoid wasps need energy Coccidae) and Euphyllura olivina (Costa) (Hemiptera: for maintenance, locomotion, and reproduction that is provid- Psyllidae) resulted in the best performance followed by the ed by non-host foods (Jervis et al. 2008). Several studies have flowers of Malva sylvestris L. (Malvaceae), Daucus carota been conducted to determine the influence of non-host re- L. (Apiaceae), and the Cichorioideae Tolpis barbata (L.) and sources (such as nectar, insect honeydews, and sugar solu- Andryala integrifolia L. Theoretical flower resources accessi- tions) on various parasitoid species. Different traits related to bility were assessed and related with the survival results. survival and reproduction were evaluated under laboratory and field conditions (e.g., Balzan and Wäckers 2013; Lavandero et al. 2006; Wäckers et al. 2008). In all these stud- * José Alberto Pereira ies, parasitoids fed on sugary liquids. Pollen feeding by para- [email protected] sitoids has been studied less frequently than sugar feeding (Lundgren 2009 and references therein), and according to 1 Mountain Research Centre (CIMO), School of Agriculture, Polytechnic Institute of Bragança, Campus de Santa Apolónia, Jervis et al. (2008), only few groups feed on pollen (e.g., 5300-253 Bragança, Portugal Mutillidae, Scoliidae, and some Bombyliidae). However, 2 Present address: Barreiro School of Technology, Polytechnic Institute Patt et al. (1997) found that when crawling on the disc flowers, of Setúbal, Rua Américo da Silva Marinho, the Eulophidae Edovum puttleri Grissell and Pediobius 2839-001 Lavradio, Portugal foveolatus Crawford accumulated pollen on their bodies and 3 School of Agriculture, University of Lisbon, Tapada da Ajuda, they fed on that pollen. In other cases, parasitoids such as 1349-017 Lisbon, Portugal Trichogramma brassicae Bezdenko (Trichogrammatidae) 15 Page 2 of 8 Agron. Sustain. Dev. (2017) 37: 15 benefited from pollen feeding, which increased its longevity anthophagous generation is therefore crucial to its success and fecundity when fed on corn pollen (Zhang et al. 2004). and additional studies are needed in order to elucidate which Gut dissection can be used to analyze pollen consumption by food resources could contribute to enhance E. flabellatus in insects, although few studies have been performed with para- the olive grove during that period. sitoid wasps (Jervis et al. 1993;Lundgren2009). Moreover, honeydews produced by some olive tree sec- The olive tree (Olea europaea L.) is among the oldest and ondary pests, such as the black scale Saissetia oleae most widespread crops in the Mediterranean region. (Olivier) (Hemiptera: Coccidae) and the olive psyllid Nowadays, it is cultivated in several regions of the world with Euphyllura olivina (Costa) (Hemiptera: Psyllidae), are mainly climatic conditions that allow its establishment. The olive present during the anthophagous generation (Pereira 2004; moth Prays oleae (Bernard) (Lepidoptera: Praydidae) is one Tzanakakis 2003 and references therein) and could have a of the most important pests in the olive grove agroecosystem. final positive effect by nourishing parasitoids and improving It has three generations a year, the phyllophagous (feeding on their performance. leaves), the anthophagous (feeding on flowers), and the In this context, this work aims at (1) studying the survival carpophagous generation (feeding on fruit). This pest is para- of E. flabellatus females fed on honeydews secreted by sitized by several hymenopteran species (Villa et al. 2016b); S. oleae and E. olivina and eight spontaneous plant species: however, the information about the type of food resources the Apiaceae Daucus carota L., the Asteraceae Anthemis exploited by them is scarce. arvensis L. and Coleostephus myconis (L.) Rchb.f. (subfamily Species of the genus Elasmus Westwood occur in all the Asteroideae), Andryala integrifolia L. and Tolpis barbata (L.) zoogeographical regions. Elasmus flabellatus (Fonscolombe) (subfamily Cichorioideae), the Boraginaceae Echium (Hymenoptera: Eulophidae) is an ectophagous and gregarious plantagineum L., the Hypericaceae Hypericum perforatum parasitoid, which attacks larvae and pupae of Lepidoptera or- L., and the Malvaceae Malva sylvestris L., (2) analyzing the der (e.g., Gelechiidae, Tortricidae, Noctuidae, parasitoid accessibility to flower resources and the pollen con- Yponomeutidae, Heliozelidae, Plutellidae, Psychidae, and sumption, and (3) determining its type of ovigeny. Pyralidae families) and larvae of Hymenoptera (e.g., Cephidae, Bethylidae, Braconidae, and Ichneumonidae fami- lies) (Yefremova and Strakhova 2010 and references therein). 2 Materials and methods This is an idiobiont parasitoid, i.e., females stop the develop- ment of P. oleae last instar larva, lay their eggs, and develop 2.1 Parasitoids outside of it (Bento et al. 2007). To our knowledge, there is no information about the type of ovigeny of this species. It acts as E. flabellatus adults were obtained from parasitized olive a facultative hyperparasitoid of other P. oleae parasitoids, and moth larvae of the anthophagous generation collected in olive the levels of parasitism on this pest were found to vary from orchards from the Trás-os-Montes region (northeastern 10% for the phyllophagous generation (Bento et al. 2007 and Portugal) at the end of the spring of 2013. In the laboratory, reference therein) to 15.2% for the anthophagous generation P.oleae larvae were transferred individually into tubes (1.7 cm (Villa et al. 2016b). Despite its hyperparasitoid behavior and in diameter and 12 cm length), closed with Parafilm®, and parasitism rates, in some conditions, E. flabellatus can be placed in a climate chamber at 21 ± 2 °C, 70 ± 5% RH, and a considered an important P. oleae biocontrol agent. For photoperiod of 16:8 h (L/D) until the emergence of instance, Villa et al. (2016b) found that in olive groves with E. flabellatus adults used in experiments described in herbicide application, after an extremely dry year and extraor- Sections 2.3 and 2.5. dinary low pest levels, E. flabellatus reached around the half of the overall parasitism with 10% of parasitism levels. 2.2 Selected foods Usually, E. flabellatus attacks the phyllophagous and the anthophagous generations but not the carpophagous (e.g., Selected plants were A. arvensis, A. integrifolia, C. myconis, Bento et al. 2007 and references therein). Increasing numbers