Among females with longer tarsi (metatarsomere 2 about 5.0 times as long as high) [longicauda] those of S. areolatus are recognized by their completely black legs. Males are recognized by their completely black legs.
Color. Body, legs, palps and antenna black with dark blue metallic reflections. Fore wing darkly to lightly tinted.
Head. Gena with pits 1.0-5.0 pit diameters apart; vertex with pits 1.0-2.0 pit diameters apart, and each pit diameter about 0.25 times lateral ocellus.
Thorax. Mesoscutum with quite dense pits and numerous transverse ridges in median area. Metatarsomere 2 in lateral view about 5.0 times as long as high (Fig. B2.3); tarsal pad 0.35-0.5 times as long as ventral length of tarsomere. Wings. Fore wing vein 3A present and extending along posterior margin of wing.
Abdomen. Median basin of tergum 9 with basal width 0.6-1.1 times as long as median length, maximum width about 0.9-1.3 times as long as median length, and median length about 0.55-0.7 times as long as cornus length. Cornus in dorsal view long, attenuated in apical 0.25-0.3, and edges not angular midway; median length 1.2-1.5 times as long as maximum width of abdomen at junction of terga 9 and 10. Sheath. Length 0.95-1.2 times fore wing length; basal section 0.5-0.8 times as long as apical section (Fig. B2.5). Ovipositor. Lancet with 39-46 annuli (basal annuli clearly outlined); junction of basal and apical sections of sheath aligned between 10th and 11th to 12th and 13th annuli, with 35-41 pits beginning with annulus 2 (Fig. B2.12). Pits near middle annuli or area apical section of sheath about 0.15 times as long as an annulus (pits gradually decreasing in size toward base), about 0.3 times as high as lancet height in lateral view, and 1.0-1.2 times as long as high; annulus 10 length/ovipositor diameter (lance + lancet) not measured. Last two annuli before teeth annuli with ridge on ventral edge of pit. Edge of apical 5-7 annuli before teeth annuli extending as ridge to ventral edge of lancet (Fig. B2.10).
Color. Head, thorax, antenna, palps, abdominal segments 1, 2, 8, sterna 2 and 3 at side, and 8 black with dark blue metallic reflections; abdominal segments 3-7 mostly light reddish brown. Coxae and femora black (Fig. B2.93). Fore wing clear.
Thorax. Metatibia in lateral view 3.9-4.2 times as long as maximum width. Metatarsomere 1 2.8-3.1 times as long as maximum height.
Sirex apicalis Kirby was not examined, but the description, especially the leg color pattern, perfectly matches this species.
Essig (1926) described adults and pupa as well as the microhabitats of the larvae and pupae. Chamberlin (1949) described pupae both in a stump and in adjacent soil.
The host range of S. areolatus is very wide (Flanders 1925, Essig 1926, Middlekauff 1960, Cameron 1965, Westcott 1971). Based on 76 reared and confirmed specimens, the main hosts are Cupressaceae: Cupressus macrocarpa (49), Juniperus occidentalis (20) (from scorched trees (Westcott 1998)), Calocedrus decurrens (2), Sequoia sempervirens (first recorded by Baumberger (1915), and also from fresh cut burnt trees by De Leon (1952)), and Taxodium distichum (5). They are less often recorded from Pinaceae: Pinus contorta, P. jeffreyi, P. lambertiana, P. radiata, and Pseudotsuga menziesii (Chamberlin 1949).
Based on 44 field-collected specimens, the earliest and latest capture dates are late June and late November. The main flight period is from early September to early October.
CANADA: BC, NS. USA: AR, AL, AZ, CA (Middlekauff 1960), CO, ID, FL, HA, NM, OR, UT, VA, WA. Sirex areolatus is mainly a western North American species known from British Columbia to California and New Mexico (Fig. C5.3). It is adventive in eastern North America (FL, AR, AL, NS, VA) and Hawaii (Burks, 1967) and is probably not established. The species was also intercepted in England (Benson 1940), and we have seen one female from New Zealand (PANZ). However, Smith and Schiff (2002) think that the Virginia record may suggest an establishment in wild habitats.
Specimens studied and included for range map: 50 females and 84 males from BYUC, CNC, FSCA, OSAC, PFRC, UAIC, UCRC, and USNM.
Specimens for molecular studies: 15 specimens. See Fig. E2.5a.
CANADA. British Columbia: 2008, CNCS 1042, 601; 2007, CNCS 1043, 532; 2007, CNCS 1044, 601; 2007, CNCS 1045, 607. USA. California: 1997, CBHR 6, 658; 1999, CBHR 101, 658; 2006, CBHR 377, 658; 2006, CBHR 657, 658; 2006, CBHR 658, 658; 2006, CBHR 659, 658; 2006, CBHR 660, 658; 2006, CBHR 661, 658; 2006, CBHR 662, 658; 2006, CBHR 663, 658; 2006, CBHR 668, 658.