Protastegopteryx, Stekolshchikov & Novgorodova, 2023

Stekolshchikov, Andrey V. & Novgorodova, Tatiana A., 2023, Review and new data on the aphid fauna (Hemiptera, Aphidoidea) of the Socialist Republic of Vietnam with a description of a new genus and a new species of the family Hormaphididae, Zootaxa 5389 (1), pp. 55-78 : 59-60

Protastegopteryx gen. nov.

Type species. Protastegopteryx vietnamensis sp. nov.

Description. Apterous viviparous female. Body widely rounded at head, more sharply rounded at end of body and slightly convex with almost parallel margins on sides (almost same width in part from metathorax to abdominal segment IV). Body fully sclerotized, light brown or brown; frons with horn-like processes on it and apex of siphuncular cones dark brown; appendages not sclerotized, semitransparent. Head fused with pronotum, with distinct furrow between pro- and mesonotum; abdominal segment VIII free; segments from mesonotum to abdominal segment VII covered with a single sclerotized shield, but with distinct groove and breaks along edges of body between mesonotum and metanotum, metanotum and abdominal segment I, abdominal segments I and II, and to a lesser extent between abdominal segments II and III; abdominal segments from III to VII fused, borders between them almost indiscernible. Surface of body smooth or slightly wrinkled and only on abdominal tergite VIII with long rows of inconspicuous small pointed spinules. Setae on head, dorsal surface of body, antennae, tibia, tarsi, and subgenital plate finely pointed, almost wavy, on horn-like processes on frons and femora pointed or finely pointed, on ventral surface of thorax and abdomen pointed, on anal plate and knob of cauda setae of two types —relatively not long, thin, finely pointed, almost wavy, and also finely pointed at apices, but very long, thick at base and for most of their length. Marginal and spinal tubercles absent. There are three types of wax gland plates on body ( Figs 3 and 4 ): (1) band-like, multi-facet (each facet contains many minute pores) plates located along margins of segments and between eyes and forming a vicious circle of wax filaments around body of aphid with only small gaps between segments; (2) two rows of pleural and one central row of spinal multi-facet cellular-like plates (each facet contains many minute pores) located on thorax and abdominal segments I–VII; pleural rows complement vicious circle of wax filaments around body of aphid, central row creates a low wax crest along center line of body; (3) star-shaped groups of wax pores scattered over all dorsal surface from pronotum to VII abdominal segmet and creating a wax pulverulence on dorsal part of body not covered with wax filaments (names of wax gland plates is after Chen & Qiao 2012). Epicranial suture reduced. Frons rectangular, protruding so that bases of antennae located in lower corners of rectangular frons in front of eyes, and horn-like processes located on upper corners; antennal tubercles absent, medial tubercls small, inconspicuous; horn-like processes cone-shaped, tall, pointed, with setae, which small at top of horn, but relatively longer at its base. Eyes with three ommatidia set on low, heavily sclerotized dark brown tubercles.Antennae 4-segmented, smooth, sometimes weakly wrinkled and only processus terminalis clearly imbricated; processus terminalis very short, shorter than or almost equal to its diameter at base, with four or very rarely three apical setae; secondary rhinaria absent, primary rhinarium on apical part of penultimate segment small, non-ciliated, one at apex of basal part of last segment with ciliated ring. Ultimate rostral segment obtuse, almost square, almost as long as wide, without additional setae. Arms of mesosternal furca very short, widely separated. Legs short, with trochanters and femora fused. Fore and middle first tarsal segments with 2 or 3 setae, hind tarsal segment always with only 2 setae, so chaetotaxy of first tarsal segments varies from 2, 2, 2 to 3, 3, 2; dorsoapical setae of the second tarsal segments with expanded apices. Spiracles small, round or oval, with small non-sclerotized peritremes, present on abdomen only on segments II–VII. Siphunculi in the form of pores located at apex of a small cone, pore is located on tergite V on border with tergite IV, so that siphunculi cone located on both tergites; siphuncular cone with several setae. Subgenital plate small, narrow, almost rectangular, with rows of small spinules and rare scales, non-sclerotized. There are two gonapophyses. Anal plate bilobed. Cauda distinctly knobbed, knob oval, its width is much greater than its length.

Etymology. The generic name Protastegopteryx is feminine gender and derived from the Greek word “prōtos” (πρώτος) meaning “first” and generic name Astegopteryx formed by combining of the Greek prefix “ἀ- “ (a-) meaning “without” and Greek words “στέγω” (stegō), meaning “roof” or “cover”, and “πτέρυξ” (ptéryx), meaning “feather” or “wing”. This name indicates a more primitive state of a number of characters in individuals of the described genus than in representatives of Astegopteryx .

Diagnosis. The combination of such characters as pore-like siphunculi located on low cones, the presence of horn-like processes on frons, and head of apterous females fused with pronotum, but meso- and metanotum not fused with abdominal segments, unambiguously assigns the new genus to the subfamily Cerataphidinae . Protastegopteryx gen. nov. is very close to the genus Astegopteryx Karsch, 1890 , but clearly differs from it by the presence of numerous wax glands on the dorsal surface of the body (species of the genus Astegopteryx have only marginal glands and sometimes glands on the head and tergite VIII), wherein the marginal glands in Protastegopteryx gen. nov. are located along the edge of the body along the entire perimeter, forming an almost continuous row, interrupted only in the intersegmental zones (a row of marginal glands around the body in species of Astegopteryx clearly breaks up into short rows with significant distances between them on each segment, and sometimes glands are completely absent on some segments) and a row of glands on tergite VIII is continuous (a row of glands on tergite VIII in many species of Astegopteryx is broken in the middle). Most species of Astegopteryx have a pear-shaped body, when the maximum width of the body falls on the III–IV abdominal segments, or specific expansion, as in Astegopteryx rappardi Hille Ris Lambers, 1953 , when aphids have an oval shape with a gradual widening of the body towards the middle and its gradual narrowing towards the end of the body, while body of Protastegopteryx gen. nov. is rounded at both ends and has almost the same width in the part from metathorax to abdominal segment IV. The new genus is also similar to Ceratovacuna Zehntner, 1897 , but differs from it in that it has marginal wax glands located in longitudinal lines, abdominal tergite VIII with wax gland in a single row and siphunculi with a cone having setae, whereas species of the genus Ceratovacuna have marginal wax glands located at least in two tiers and sometimes forming plates, abdominal tergite VIII with wax cells arranged in more than one row and siphunculi without a distinct cone and setae. A continuous row of marginal glands is found in species of the genera Aleurodaphis van der Goot, 1917 and Cerataphis Lichtenstein, 1883 , and it is also almost continuous in Ceratoglyphina van der Goot, 1917 and in some species of the genus Tuberaphis Takahashi, 1933 . However, species of the genus Aleurodaphis lack horn-like processes on frons, and the length of the ultimate rostral segment significantly exceeds its width at the base (the length of ultimate rostral segment of Protastegopteryx gen. nov. is less or only slightly, 1.06 times its width at the base). Species of the genus Cerataphis have an almost round body shape, as well as a completely fused head and all three segments of the thorax and all segments of the abdomen except segment VIII, so that the body looks like it consists of three parts—the cephalothorax and abdomen with a groove between them, and a separate abdominal segment VIII. Species of the genus Ceratoglyphina have an entire anal plate and a semicircular cauda, while Protastegopteryx gen. nov. have bilobed anal plate and cauda with a constriction, knobbed. In species of the genus Tuberaphis round wax glands are always absent on the head between the eyes and the head ventrally with two horns which bear one peg-shaped seta on top, or horns are absent, while in Protastegopteryx gen. nov. on the head between the eyes there is a row of round wax glands and horns on frons bearing four or more normal, not peg-shaped setae, which are small at the top of the horn, but at the base of the horn relatively longer. In other genera of Cerataphidinae — Chaitoregma Hille Ris Lambers et Basu, 1966 , Glyphinaphis van der Goot, 1917 , Ktenopteryx Qiao et Zhang, 2003 , Pseudoregma Doncaster, 1966 —there is no distinct row of marginal wax glands surrounding the entire body. In addition, at Chaitoregma frontal horns are cylindrical with rounded tips, while in Protastegopteryx gen. nov. frontal horns are narrowly conical, pointed at apex. The only species from the genus Glyphinaphis lacks frontal horns, while Ktenopteryx has curved blunt-ended frontal and marginal processes, and a single long finger-like process arising from the posterior margin of abdominal tergite VIII, which are absent in the described new genus. Species of the genus Pseudoregma have pronotum with two variable grooves, separated by a median ridge, such a structure is absent in Protastegopteryx gen. nov.

Figures

FIGURES 3–4. Wax glands of Protastegopteryx vietnamensis gen. nov., sp. nov. 3, band-like, multi-facet marginal plates (a) and pleural multi-facet cellular-like plates (b); 4, spinal multi-facet cellular-like plates (c) and star-shaped groups of wax pores (d) some of them with the remains of the threads they secrete (e).