Macrosiphum pulcherimum Nevsky, 1928

Stekolshchikov, Andrey V., 2024, A contribution to the aphid fauna (Homoptera, Aphidinea) of the Republic of Dagestan (the Russian Federation), with descriptions of three new species, redescription of Macrosiphum pulcherimum Nevsky, 1928, and descriptions of previously unknown morphs of three species, Zootaxa 5545 (1), pp. 1-68 : 55-57

Macrosiphum pulcherimum Nevsky, 1928

( Figs 107–116 , Table 9)

This species was relatively briefly described by Nevsky based on apterous viviparous females that he collected from Lactuca sp. from Samarkand ( Republic of Uzbekistan). Later, this species was found on the territory of Azerbaijan ( Rusanova 1942). Thus, before the discovery of this species in Dagestan, it was known from only two samples.

One of Nevsky’s slide of Macrosiphum pulcherimum is stored in the aphidological collection of ZIN. Undoubtedly this material was used for the description of the species (i.e. these are syntypes). I here designate a lectotype for this species ( Fig. 107 ), and redescribe it based on Nevsky’s material, his published data and my specimens from Dagestan .

Material. Lectotype: apterous viviparous female, No. 11964, specimen No 2 (right specimen in second row), „ Lactuca muralis , stem, base of leav[es], dirty green, siph[unculi], cauda and legs white, Samarkand, 17. V.2[.], al. et apt., Macrosiphum pulcherrimum “ . Paralectotypes: 6 apterous viviparous females, same data as for lectotype. Additional materials: 16 apterous viviparous females, No. 11915, Republic of Dagestan, Kizlyarsky District, Federal State Nature Sanctuary “Agrakhansky”, nearby Staro-Terechnoe Vill., 25.ix.2023, Lactuca tatarica C.A.Mey .

Description. Apterous viviparous female. Body elongate elliptical, 2.0–2.5 (2.1–2.4) times as long as wide. Living specimens greenish white, head and prothorax dorsally orange-brown, mesothorax and metathorax dorsally greenish brown, with a dorsal dark green spot in the central part of abdominal tergites I–III and a wide dark brown band on tergites V–VII including the bases of siphunculi; shiny dorsally and with lightly waxy pulverulence ventraly or with lightly waxy pulverulence on both sides; 1st and 2nd antennal segments brown, 3rd–4th or 3rd–5th segments yellow with dark apices, and 3rd also with dark middle, 5th–6th or only 6th segments dark, legs yellow, apices of femora, tibiae, tarsi and apices of siphunculi dark brown, siphunculi and cauda pale green. Cleared specimens with frons, 1st antennal segment, 3rd antennal segment at the location of rhinaria, apices of 3rd–5th antennal segment, distal half of 6th antennal segment, proceccus terminalis, apices of femora and tibia, tarsi and apices of siphunculi brown; head (except frons) and two last segments of rostrum light-brown; sclerites on dorsal side of body, peritrems on abdomen, anal and subgenital plate very light brown. Dorsal side of thorax and abdomen with very pale almost invisible small sclerites under setae and just as pale marginal sclerites on abdominal segments V, postsiphuncular sclerites and peritrems. Surface of head, dorsal side of thorax and abdominal tergites I–VI smooth, slightly wrinkled; surface of abdominal tergites VII–VIII with long rows of small pointed spinules which on tergite VIII partially fusing and forming scales; surface of ventral side of thorax with scattered small pointed spinules, the same of abdomen with long rows of small pointed spinules sometimes forming strongly stretched reticulate cells. Setae on dorsal side of thorax and abdomen weakly capitate, on ventral side finely pointed. One or two marginal tubercles present on prothorax in 30% of specimens, marginal and spinal tubercles on other segments of body absent. Head without traces of epicranial suture. Frontal tubercles moderately developed, antennal tubercles high, divergent, median tubercle indistinct, almost invisible. Setae on head weakly capitate or rarely blunt. Antennae 6-segmented, 1st–2nd antennal segments slightly wrinkled, almost smooth, 3th–6th segments with large scales which are almost invisible on 3rd segment but well-defined on 5th–6th segments. Third antennal segment with 6–14 (8.3–10.7) secondary rhinaria, 4th and 5th segment without rhinaria; secondary rhinaria 10–32 mμ in diameter, located in the basal half of segment, segment here slightly swollen and sclerotized. Setae on antennae weakly capitate or blunt (on 6th segment). Rostrum reaching mesothorax or II abdominal segment. Ultimate rostral segment elongate wedge-shaped, with slightly convex sides, 2.51–3.00 (2.78) times as long as its basal width. Legs normally developed; setae on tarsi pointed, on tibiae wekly capitate, blunt or pointed, on trochanters and femora wekly capitate or blunt, on coxae blunt, pointed or finely pointed. Chaetotaxy of first tarsal segments 3, 3, 3 (infrequently with only 2 setae on one leg). Arms of mesosternal furca connected by wide base. Spiracles reniform. Siphunculi with conical base, gradually tapering towards apex, more or less curved outwards, with small, indistinct flange and polygonal reticulation on distal 0.11–0.22 (0.16) of length (largest transverse row in reticulate part of siphunculi consisting of 5–8 cells), with imbrication increasing from rare small spinules in basal part to large rough scales near reticulation. Subgenital plate oval, with weakly capitate or blunt setae. Setae on anal plate finely pointed. Cauda triangular in basal third, then finger-shaped after slight constriction, with long finely pointed setae.

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Measurements of the lectotype ( Fig. 107 ). Body—1883×763, antenna—2532: III—610×34 (in middle), IV—477, V—379, VI—182+644; hind femur—753, hind tibia—1604; siphunculus—688×64 (in middle); cauda— 307×165 (at base) ×140 (before base). Additional measurements are given in Table 9.

Distribution. Republic of Uzbekistan (Samarkand) (Nevsky 1928), Republic of Azerbaijan (Baku, Surakhani district, Zig municipality) ( Rusanova 1942), Russian Federation (Republic of Dagestan, Kizlyar district, Federal State Nature Reserve “Agrakhansky”, near the village of Staro-Terechnoye).

Biology. The life cycle is unknown. Aphids live on the stems, base of leaves, lower surfaces of leaves and flower shoots of Lactuca spp. ( L. muralis (L.) Gaertn., L. saligna L., L. tatarica C.A.Mey. ) without ants. The complex coloration of adult apterous viviparous females is apparently mimicry, since it is very similar to the coloration of small unopened flower buds of the host plant.

Figures

FIGURE 107. Apterous viviparous female of Macrosiphum pulcherimum Nevsky, 1928, habitus (Lectotype).

FIGURE 108. Apterous viviparous female of Macrosiphum pulcherimum Nevsky, 1928, habitus (25.ix.2023, Republic of Dagestan, Kizlyarsky District, Federal State Nature Sanctuary “Agrakhansky”, nearby Staro-Terechnoe Vill.).

FIGURES 109–116. Macrosiphum pulcherimum Nevsky, 1928, apterous viviparous female. 109, antennae; 110, 3rd antennal segment; 111, last antennal segment; 112, head; 113, III and ultimate rostral segments; 114, hind tarsus; 115, siphunculus; 116, cauda.