Egg (Fig. 6): The eggs were laid on the needles of Larix gmelini. Shortly after laying they were whitish grey, but fertile eggs darkened in two days. The micropyle area became dark reddish brown, and the narrow zone around the micropyle was reddish brown

Morphology of full-grown larva (Figs 1–5): Spinneret flat, 2.5× as long as wide, ventral lip straight, dorsal lip short-fringed, longitudinal grooves present on dorsal surface. Base segment of labial palp (Lps1) about 2× as long as wide, second segment (Lps2) 1/5 as long as Lps1, labial palp seta Lp1 slightly longer than Lps2, seta Lp2 shorter than Lps1 (3/5) and 2× as long as Lp1. Hypopharynx with long spines on anterior surface above spinneret, distolateral spines slightly longer and stouter than distomedian spines, spines on lateroposterior part forming row of 8–10 differentiated, triangular teeth, lateral surface above this row densely covered with tiny spinules, posterior area of medial part bare. Stipular setae below spinneret shorter than seta Lp2 of labial palp, situated in front of prementum. Mandible with two setae on outer surface, six teeth on cutting margin, three ridges on inner surface terminating in low protuberances before cutting margin and triangular tooth on first ridge. Maxillary palp three-segmented, second segment longer than galeal lobe, sensillum styloconicum of galeal lobe as long as end segment of maxillary palp, three sensilla trichodea present. Labrum with low, rounded notch. Epicranial suture slightly shorter than height of frons. Six stemmata present, distance between second (Oc2) and third (Oc3) stemma greater than those between Oc1–Oc2 or Oc3–Oc4, distance Oc1–Oc2 greater than Oc3–Oc4. Abdominal prolegs on abdominal segments 3– 6 (Ab3–6) equal in size, crochets uniordinal, 17–20 on Ab3, 22–24 on Ab6 and 26–28 in Ab10. Body without warts or other protuberances.

Figures 1–5. 

X. brunneopicta, morphology of larval mouth parts. 1. A. Scheme of spines of hypopharynx, from left: distoanterior, distomedial, distoposterior, distolateral, lateral tooth, posterior dorsolateral, posterior medial and lateroposterior spines. B. Spinneret and labial palpi in dorsal view. C. Stipular setae in frontal view. 2. Hypopharynx in dorsal view. 3. Left maxilla in dorsal view. 4. Left mandible in oral face. 5. Labrum in dorsal view. Scale 0.1 mm.

Chaetotaxy resembling that of other members of Pachnobia: Setae of head and body rather long when compared to the height of the spiracle on Ab8: P1 on head 3.1–3.3×, D2 on Ab2 1.6–1.9×, D2 on Ab7 1.3–1.5× and D2 on Ab8 2.1–2.2× height of spiracle 8. Seta SD1 hair-like on thorax and Ab9, tonofibrillary platelet present below seta SD1 on meso- and metathorax and two SV setae on Ab1. Relevant larval setal distances are presented in Table 1.

First instar larva: Length about 2 mm. Head pale brown, body pale greenish grey with small dark- brown setal bases. Prolegs on Ab3–6 well developed, those on Ab3–4 much smaller (Fig. 7).

Figures 6–8. 

Egg and small larvae of X. brunneopicta. 6. Egg on needle of Larix gmelini (Photo: M. Ahola). 7. The 1^st instar larva on needle of Larix sibirica (Photo: M. Ahola). 8. The 2^nd instar larva on needle of Larix sibirica (Photo: M. Ahola).

Second instar larva: Length about 4 mm. Head brown. Dorsal region greenish, ventral region pale yellowish green, setal bases dark brown. Narrow, whitish dorsal and subdorsal lines present, shields on thoracic segments 1 (Th1) and Ab10 pale brown (Fig. 8).

Third instar larva: Length about 7–9 mm. Head brown, stripes visible but weak. Shields pale brown, dorsal lines yellowish, not sharp-edged on shields. Dorsal zone green with white, narrow, middorsal and subdorsal lines without darker margins, setal bases small, pale green. Subdorsal zone dark olive green, spiracular line yellowish white, broad. Pleural and ventral zones pale green (Fig. 9).

Figures 9–12. 

X. brunneopicta larvae. 9. The 3^rd instar larva on Andromeda polifolia L. (Photo: K. Silvonen). 10. The 4^th instar larva on Larix decidua Miller (Pinaceae) (Photo: K. Silvonen). 11. Last instar larva with darker brown head (Photo K. Silvonen). 12. Mature larva on Salix phylicifolia. (Photo: P. Puntila).

Fourth instar larva (Fig. 10): Length 14–18 mm: Head brown, netfields visible but translucent, frons and anterior zone green, brown setal points on brown bases. Thoracic and anal shields pale brown, dorsal and subdorsal lines present as yellowish white flecks on prothoracic shield but absent on anal shield. Body green on dorsal region with pale green or with whitish elements, yellowish green between abdominal segments, dark green on ventral subdorsal zone. Middorsal line nearly white, broad, continuous, subdorsal line slightly narrower, broken into spots. Spiracular line broad, yellowish white, sharply bordered above dark green ventral subdorsal zone. Ventral region pale green. Setal points black on dorsal region with dark green dorsal/whitish ventral bases.

Penultimate and last instar (Figs 11–12): Length of last instar larva 35–40 mm. Head brown, stripes brown, reticulate structure with brown bands and pale brown, weakly visible netfields. Frons and anterior zone greenish, adfrons brown, ocellar zone pale yellowish brown, setal points dark brown. Prothoracic shield darker green than body, with narrow pale grey middorsal line, subdorsal line not visible, shield caudally bordered with narrow, blackish grey colour. Anal shield greenish brown, lines not visible, sutures brown, setal points blackish brown. Dorsal and ventral regions of body green, middorsal and subdorsal lines white, narrow, short and broken, not visible on Ab9–10, both lines with dark-green margins. Dorsal part of spiracular line visible, white, narrow, dorsally dark violet-green border, ventrally no border. Dorsal and subdorsal zones mottled by small, white elements and longitudinal violet-green colour elements; dorsal zone with diffuse wedge-shaped diamond figures; setal points of D1 and D2 black with small white bases, microsetae MD1 and MD2 on common large and white base on metathorax, other MD1 bases also white but small. Spiracles yellowish with black edges. Thoracic legs with green coxae and pale brown tibiae, prolegs green.

Pupa (Figs 13–14): Dark brown. Frons without tubercles or projections, labium and labial palpi visible, proboscis exceeding caudal margin of Ab4, prothoracic femora visible, thoracic legs adjacent to antennae. Abdominal spiracles narrow, Ab5–7 without elevated transverse ridge in front of spiracles, without transverse row of spines or lateral spines; punctuation present close to bases of Ab4–7. Cremaster short, flat, quadrangular, with transverse dorsal and ventral furrows and three pairs of setae, D2 close together, short and hook-like, D1 longer than D2, stout, L1 short and stout, situated beside D2 on caudal margin of cremaster. Pupation after hibernation without feeding in flimsy weak cocoon.

Figures 13–14. 

X. brunneopicta pupae. 13. Pupa in ventral view. 14. Cremaster of pupa in dorsal view (Photos: M. Ahola).

Larvae hatched on July 20 and 21. They were in a plastic jar where they could choose between plants Larix sibirica Maxim. (Pinaceae), Vaccinium myrtillus L. (Ericaceae) and Polygonum aviculare L. (Polygonaceae). About 40 of the 60 larvae chose L. sibirica or V. myrtillus and the rest chose P. aviculare. Five larvae died during the first week for unknown reasons. After about a week the group of larvae was divided amongst four Finnish lepidopterists. It appeared later that young larvae could feed also on Poa annua L. (Poaceae) and Salix phylicifolia L. (Salicaceae). Full-grown larvae were rather polyphagous in laboratory conditions, feeding also on Rubus idaeus L. (Rosaceae), Alnus incana (L.) Moench (Betulaceae), Salix sp. (Salicaceae) and Lonicera xylosteum L. (Caprifoliaceae). Larvae were mostly reared under a lamp.

The collecting site of the female in Chara Sands is a peculiar dune habitat with occasional springs, bogs and coniferous tree patches. It does not represent the typical habitat of the species. During the trip (3–12 July) other localities near Chara were investigated, for which another article on the results of the expedition is under preparation (Saarenmaa et al., in prep.). X. brunneopicta was common across all sites, but it seemed to be more frequent in the lowlands than in the mountain valleys. Typical habitat for the species is forested bog with Larix gmelini (Fig. 15). However, it was most numerous in low Salix and Alnus vegetation on the banks of the Chara River. Other species typical for these localities include several other Xestia (Pachnobia) species such as X. atrata (Morrison, 1874), and also Polia altaica (Lederer, 1853), P. conspicua (A. Bang-Haas, 1912), P. vespertilio (Draudt, 1934), P. vesperugo Eversmann, 1856, and the arctiine Borearctia menetriesii Eversmann, 1846.

Figure 15. 

Typical habitat of X. brunneopicta and the other species mentioned in the article. Chara River with richer vegetation on its banks is 100 meters to the left (Photo: H. Saarenmaa).

Larvae of the subgenus Pachnobia differ from subgenera Megasema and Xestia in chaetotaxy and morphology. Dorsal setae are long in Pachnobia, seta D2 on Ab8 is more than twice as long as height of spiracle of same segment, whereas it is about as long as height of spiracle in subgenera Megasema and Xestia. Also, setal distances P1–P2 (head) and V1–V1 (Ab7) differ on average (Table 2). Spinneret of larvae in subgenus Pachnobia is long, about 1.5–5.0× as long as wide, flat (except X. liquidaria), dorsal margin with short fringes (without fringes in X. liquidaria) and ventral margin straight. Megasema and Xestia larvae have a short spinneret, 1.0–1.5× as long as wide (except 2–3× in X. collina, castanea and agathina), dorsal margin with longer fringes and ventral margin more or less bilobed. Body colour and pattern vary a lot. Larva of X. liquidaria is peculiar with a tubular spinneret but long dorsal setae as in subgenus Pachnobia.

Larvae of European species of Xestia (Pachnobia) albonigra (Kononenko, 1981) and X. (Pachnobia) thula Lafontaine & Kononenko, 1983 are still unknown, and are not included in the following key.