<p class="Body"><strong>Supplementary descriptions and DNA barcodes of two rarely encountered <em>Trisetacus</em> species (Eriophyoidea, Phytoptidae) associated with Tertiary relict conifers from the Mediterranean region</strong></p>

Abstract

New records and supplementary morphological descriptions of two rarely encountered Trisetacus species from Pinaceae, T. abietis Postner 1968 and T. cedri (Nalepa 1920), are reported. Trisetacus abietis was found in Abkhazia under the needle epidermis of Abies nordmanniana (Steven) Spach, a conifer endemic to the mountainous Asian coast of the Black Sea. Trisetacus cedri was found in buds of introduced Cedrus deodara (Roxb. ex D. Don) G. Don in Abkhazia and South Africa. It is the only member of Trisetacus known from Cedrus spp. For the first time we provide sequences of two genes (COI and D1–D2 28S) of T. abietis (MN022221, MN025333) and T. cedri (MN022222, MN022223, MN025334, MN025335), along with microphotographs of the damage caused by these mites on their coniferous hosts. Sequences of D1–D2 28S of T. cedri from Abkhazian and South African populations are identical; COI sequences from different populations differ by only one synonymous substitution in a codon for asparagine. Females of T. abietis have long asymmetrical 8/7-rayed empodia, whereas males have shorter symmetrical 6/6-rayed empodia and shorter solenidia ω I. Similar sexual dimorphism in tarsal appendages was previously reported in Novophytoptus, representing an endoparasitic lineage of phytoptids on monocots. In T. cedri, a “long form” and a “short form” of both males and females were detected, suggesting a complex life cycle in this species. The evolution of Trisetacus is discussed within the broader context of the molecular phylogenies of Pinaceae and Eriophyoidea, including estimations of divergence times.

Phylogenetic Position of a New Trisetacus Mite Species (Nalepellidae) Destroying Seeds of North American Junipers and New Hypotheses on Basal Divergence of Eriophyoidea

“…A subcuticular globose apodeme, typical for most Trisetacus from Cupressaceae, present near posterior margin of prodorsal shield. Prodorsal shield setae: vi 12 (10-14), directed up and anteriad; sc 51 (46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57), 26 (24)(25)(26)(27) apart, directed up and anterolaterad; distance between tubercles of vi and sc 17 (16)(17)(18). Gnathosoma directed obliquely down and forward; palps 25 (24)(25)(26).…”

“…Prodorsal shield setae: vi 12 (10-14), directed up and anteriad; sc 51 (46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57), 26 (24)(25)(26)(27) apart, directed up and anterolaterad; distance between tubercles of vi and sc 17 (16)(17)(18). Gnathosoma directed obliquely down and forward; palps 25 (24)(25)(26). Gnathosomal setae: seta ν 0.5 (0.5-1); pedipalp genual seta d non-bifurcate, 9 (8-10); pedipalp coxal seta ep 3 (3)(4).…”

“…Suboral plate rounded anteriorly, smooth. Leg I 27 (25)(26)(27)(28)(29)(30), tarsus 6 (4-6), u' 3 (2-3), ft' 13 (11)(12)(13)(14)(15)(16), ft" 25 (21)(22)(23)(24)(25)(26)(27)(28), ω 9 (9-10) with small spherical knob; empodium 9 (8-10), 9/9-rayed, all rays except terminal pair with 4-6 tiny processes each; tibia 5 (4-6), l' 6 (3-6); ϕ 7 (7-9); genu 5 (5-6), l" 26 (22)(23)(24)(25)(26)(27)(28)(29)(30); femur 8 (8-10), bv 14 (12)(13)(14)(15). Leg II 24 (23)(24)(25)(26), tarsus 5 (4-5), u' 3 (2-3), ft' 8 (7-12), ft" 22 (21)(22)(23)(24)(25)(26)(27), ω 9-10 with small spherical knob; empodium 9 (8-10), similar to empodium I; tibia 5 (4-5); genu 5 (4-5), l" 22 (21-28); femur 7 (7-9), bv 12 (11)(12)...…”

“…External genitalia. Genital coverflap distally rounded, smooth, with medioposterior indentation; 7 (7-8) long, 27 (26)(27)(28) wide; setae 3a 18 (16)(17)(18)(19)(20)(21)(22), 17 (17)(18)(19) apart. Internal genitalia (n = 4).…”

“…Along with living in buds, several cryptic species of the complex Trisetacus juniperinus s.l., are also capable of infesting male cones and causing swollen galls on junipers (Figure 2D,E). Two endoparasitic species, T. abietis and T. neoabietis from Abies spp., live in air-cavities under the epidermis, causing necrosis of the parenchyma (Figure 2C) and premature needle fall [25,26]. A unique lineage of Trisetacus, T. pini, has adapted to live in galls, which they induce on young twigs on pines in Europe (Figure 2B).…”