Systematics and evolution of gall formation in the plant‐associated genera of the wasp subfamily Doryctinae (Hymenoptera: Braconidae)

Abstract

Gall formation is a specialised form of phytophagy that consists of abnormal growth of host plant tissue induced by other organisms, principally insects and mites. In the mainly parasitoid wasp subfamily Doryctinae, gall association, represented by gall inducers, inquilines and their parasitoids, is known for species of seven genera. Previous molecular studies recovered few species of six of these genera as monophyletic despite their disparate morphologies. Here, we reconstructed the evolutionary relationships among 47 species belonging to six gall‐associated doryctine genera based on two mitochondrial and two nuclear gene markers. Most of the Bayesian analyses, performed with different levels of incomplete taxa and characters, supported the monophyly of gall‐associated doryctines, with Heterospilus (Heterospilini) as sister group. Percnobracon Kieffer and Jörgensen and Monitoriella Hedqvist were consistently recovered as monophyletic, and the validity of the monotypic Mononeuron was confirmed with respect to Allorhogas Gahan. A nonmonophyletic Allorhogas was recovered, although without significant support. The relationships obtained and the gathered morphological and biological information led us to erect three new genera originally assigned to Psenobolus: Ficobolus gen.n. (F. paniaguai sp.n. and F. jaliscoi sp.n.), Plesiopsenobolus gen.n. (Pl. mesoamericanus sp.n., Pl. plesiomorphus van Achterberg and Marsh comb.n., and Pl. tico sp.n.), and Sabinita gen.n. (S. mexicana sp.n.). The origin of the gall‐associated doryctine clade was estimated to have occurred during the middle Miocene to early Oligocene, 16.33–30.55 Ma. Our results support the origin of true gall induction in the Doryctinae from parasitoidism of other gall‐forming insects. Moreover, adaptations to attack different gall‐forming taxa on various unrelated plant families probably triggered species diversification in the main Allorhogas clade and may also have promoted the independent origin of gall formation on at least three plant groups. Species diversification in the remaining doryctine taxa was probably a result of host shifts within a particular plant taxon and shifts to different plant organs. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:0021F253-4ABA-4EAA-A7A9-FC0AD1932EA3

First record of Rhoptrocentrus piceus Marshall (Hymenoptera, Braconidae, Doryctinae) as parasitoid of Psacothea hilaris hilaris (Pascoe) (Coleoptera, Cerambycidae)

“…Most of the known doryctine species are idiobiont gregarious ectoparasitoids of the larvae of xylophagous or bark-boring Coleoptera, while some species live on Lepidoptera or Hymenoptera-Symphyta (sawfly) larvae. Exceptionally they were reared from adults of Embiopter or living within termites nests and several Neotropical genera behave as phytophagous or gall-associated wasps (Marsh 1997, Belokobylskij et al 2004, Zaldivar-Riveron et al 2014). …”

A new species of Labania Hedqvist (Braconidae, Doryctinae) from Costa Rica, reared from aerial root galls of Ficus obtusifolia Kunth

“…More recently, however, three molecular phylogenetic studies consistently recovered a clade exclusively composed of genera whose species are associated with galls from different plant families, including Labania (Zaldivar-Riveron et al 2007, 2008, 2014. In the most recent of these studies (Zaldívar-Riverón et al 2014), the authors described three new gall-associated doryctine genera whose species with rearing records were all associated with Ficus species. One of them, Ficobolus Belokobylskij & Zaldívar-Riverón, was recovered as sister to Labania; the latter genus was represented in that study by an undescribed species from Costa Rica.…”

“…Galls were frequently grouped together forming a mass that measured up to 6 cm in diameter and 12 cm in length. A photograph of these galls is shown in Zaldívar-Riverón et al (2014;Fig. 1B).…”

“…Holotype: female, "Costa Rica: San Jose, Reserva el Rodeo, root galls on Ficus obtusifolia, IV.2011, Col. Miguel Artavia (IB-UNAM). Paratypes: 30 females (9 in alcohol), 16 males (4 in alcohol), the same label as holotype (IB-UNAM, MZCR, ZISP, NMNH); 1 female, same data as holotype, DNA voucher number CNIN1078 (IB-UNAM), GenBank accession numbers KJ586713 (COI), KJ586690 (wingless) and KJ586780 (28S) (Zaldívar-Riverón et al 2014) (IB-UNAM).…”

Venifurca, a new genus of neotropical Doryctinae (Hymenoptera: Braconidae), and its phylogenetic placement

“…This subfamily was erected over 150 years ago (Forster 1862); however, it is far from being fully known even at the supraspecific level. Proof of this is the considerable number of new doryctine genera that have been described over the last few years (Nunes et al 2012, Marsh et al 2013, 2014, Belokobylskij et al 2015, Gadelha et al 2016, Martínez et al 2016. This emphasizes the necessity of conducting more studies in the New World tropics, where most of its species-richness occurs (Hanson and Gauld 1995, Marsh 2002, Braet et al 2003.…”