Rhipidothrips brunneus Williams, 1913

Rhipidothrips brunneus Williams, 1913 View in CoL

Figs 1–6

MATERIAL EXAMINED. Iran: Kermanshah province, Javanrud , on rangeland plants, 28.VI 2023, 3♀, leg. Arezoo Moradi.

DIAGNOSIS. FEMALE (f. apterous) Body, legs and antennae largely brown; tarsi, apex of mid and hind tibiae, mostly of for tibiae and base of mid and hind femora yellow (Fig. 1); antennal segments I-II brown, apex of II yellow, III-IV yellow (Fig. 4). Head. Antennae 9- segmented, segments VII-IX fused, segments III and IV with transverse sense cone at apex.

Head with less than five pairs of small ante-ocellar setae; more than 6 thick setae on cheeks, behind compound eyes. Thorax. Pronotum with one pair of long posteroangular setae and 2 pairs of posteromarginal setae. Mesonotum without microtrichia on sculpture lines. Metanotum with elongate reticulations, without microtrichia, median setae near at posterior margin. Fore tarsus with strongly recurved denticle. Abdomen. Abdominal tergites with transverse reticulation, trichobothria on last segment about as large as major setal bases. Abdominal sternites III-VI with 2 or 3 pairs of posteromarginal setae; sternite VII with 4 pairs of posteromarginal setae, 2 pairs of supernumerary setae, 3 discal setae laterally. Ovipositor well developed.

FEMALE (f. microptera) (Fig. 2). Similar to apterous morph, with wings lobe shorter than thorax (Fig. 5).

FEMALE (f. macroptera) (Fig. 3). Fore wing pale with posterior margin weakly shaded, with cross veins visible (Fig. 6).

MALE. Abdominal tergite I with paired longitudinal ridges scarcely one third as long as tergite.

Figs 1–6. Rhipidothrips brunneus , female: 1 – f. aptera; 2 – f. microptera; 3 – f. macroptera; 4 – antenna; 5 – fore wing lobe of micropterous form; 6 – fore wing of macropterous form.

REMARKS. Wings may be present or absent in thrips species; and the wings when present are unique among insects because they are narrow, with few or no veins, fringed with long hairs that hence give the order's name. Recently, we collected many thrips specimens on rangeland plants and one of them, R. brunneus was dominant. After the identification of specimens, the wingless form of this species is described for the first time. Because of extensive collecting in both spring and summer, it seems likely that both morphs of the species occur only at the end of spring and early in summer.

DISTRIBUTION. Iran (Golestan, Khuzestan, Hamedan, Azarbaijan-e-Sharghi, Kermanshah, Ilam), China, widespread across Western Europe to Egypt, also Western Australia and USA (California) ( Mirab-balou, 2018) .

Among Thysanoptera , there are three different wing morphs: aptera (wingless), microptera (short-winged), and macroptera (fully winged). Among Terebrantian species, the ecological function of wing reduction is less obvious, despite being widespread in males. Amongst Aeolothripidae View in CoL , the species with wingless or micropterous adults are usually those that live at ground level and exhibit some level of ant-mimicry, such as Aeolothrips albicinctus Haliday View in CoL , Aeolothrips bicolor Hinds View in CoL , and Desmothrips reedi Mound ( Tyagi et al., 2008) View in CoL . In Iran, among aeolothripids, most of species are fully winged, and a few are short-winged such as A. albicinctus View in CoL . Rhipidothrips species are mostly macropterous ( Alavi & Minaei, 2018), and only a micropterous form was found in R. brunneus View in CoL population (zur Strassen, 2003). R. brunneus View in CoL is phytophagous species feeds on flowers of Poaceae View in CoL ( Mound et al., 1976; zur Strassen, 2003) but was also recorded as having predatory tendencies ( Mound et al., 2023).