Electresia zalesskii Kusnezov, 1941

Heikkilä, Maria, Brown, John W., Baixeras, Joaquin, Mey, Wolfram & Kozlov, Mikhail V., 2018, Re-examining the rare and the lost: a review of fossil Tortricidae (Lepidoptera), Zootaxa 4394 (1), pp. 41-60 : 50-51

Electresia zalesskii Kusnezov, 1941

Figs 3 a–c.

Excavation locality and depository: Formerly, the fossil was in the private collection of B. V. Miloradovitsch, Russia, but it is currently in the collection of the PIRAS Moscow (Holotype: no. 20). In the original description the inclusion is reported to be in Baltic amber (Baltic Region, Prussian Fm./Lutetian, Middle Eocene), but Prof. A. Rasnitsyn has examined the specimen and concluded it is copal (pers. comm.). The surface of this specimen, as that of the fossil pyraloid Glendotricha olgae Kusnezov, 1941 , show greater deterioration than the other amber specimens dealt with in the same paper by Kusnezov (1941) and deposited at the PIRAS. In addition, solubility tests were conducted on small, detached pieces of Glendotricha olgae . In less than an hour in 95% alcohol, these particles turned into an opaque jelly-like mass, a reaction typical to copal but which never occurs when alcohol is applied to real Baltic amber (a succinite). Copal is younger than amber ( Poinar 1992; Labandeira 2014), but a more precise age and origin of Electresia zalesskii are currently not known. The re-assessment of the fossil moth is based on the information and illustrations found in the original publication by Kusnezov (1941) and the examination of the specimen at the PIRAS (MH).

Published illustrations: Kusnezov 1941: 63, figs 50–52 (drawings) and reproduction in Carpenter 1992: 374, fig. 2 (drawing).

Condition: The irregularly shaped copal piece (21 × 23 × 8 mm) shows signs of physical degradation. The surface has a dense network of small cracks making it very difficult to examine the moth (forewing length 4.2 mm) within it ( Fig. 3 ). The sex of the moth cannot be determined with certainty, but based on the absence of sensory setae on the flagellomeres of the antenna, it is likely a female. The wings are folded roof-like over the abdomen, so only the forewing venation can be observed; the legs are partly visible.

Comments: Kusnezov (1941) assigned this fossil to “ Eucosmidae ” (now considered a tribe of Olethreutinae), indicating that it is closely allied to the genus Laspeyresia Hübner, 1825 (now Cydia in the tribe Grapholitini). This placement was based on a variety of morphological characteristics, including the following: length of the antennae (slightly longer than half the forewing length); configuration of the labial palpi (a short basal segment, a longer second segment, and a short, obtuse third segment); the absence of (or inconspicuous) maxillary palpi; the overall forewing shape (trapezoidal, 2.5 times long as wide, with apex rounded and obtuse, and termen slightly incurved at M 1) and venation (all veins present and separate beyond the discal cell, with well-developed chorda and M stem). The chaetosemata are not mentioned, and cannot be observed in this fossil. The scaling of the antennae is difficult to see, but it appears that there is only one row of scales. All of these features are highly consistent with the assignment of the specimen to Tortricidae , and the slightly undulate termen in forewings is certainly similar to that of many recent Olethreutinae (e.g. Irianassa Meyrick, 1905 , Periphoeba Bradley, 1957 ).

The monophyly of Olethreutinae is strongly supported by morphological (e.g. Horak 1998) and molecular data (e.g. Regier et al. 2012; Fagua et al. 2017). Horak (1998) stated that Olethreutinae differ from Tortricinae in the retention of the M-stem and the chorda in the forewing discal cell, but these plesiomorphic features are also present in some Chlidanotinae ( Polyorthini and Hilarographini ). Regardless of its tribal and/or subfamilial assignment, we conclude that this fossil belongs to Tortricidae .

Figures

FIGURE 3. Electresia zalesskii Kusnezov, 1941. PIRAS (HT: no. 20). a. Crazing on the surface of the copal piece. b. Dorsal view. Length of forewing 4.2 mm. c. Ventral view. Photos: Maria Heikkilä.