Key to the Siricidae of North America

Identification of Siricidae of North America (north of Mexico) Draft XI 2016 – Females Only

James R. LaBonte Oregon Department of Agriculture

Non-Scolytinae Wood Borer Identification Workshop Salem, OR October 24-28, 2016 Introduction: I KEY As a consequence of the detection of the exotic and potentially damaging “European wood wasp”, Sirex noctilio Fabricius, in North America in 2005, the first complete treatment of the Siricidae of North America was published in 2006 (Schiff, N.M, S.A. Valley, J.R. LaBonte, and D.R. Smith. 2006. Guide to the Siricid Woodwasps of North America. FHTET-w006-15, USDA Forest Service, Forest Health Technology Enterprise Team, Morgantown, WV. 102 pp.). At the time this fully illustrated (via extended-depth-of-field images) was produced, the authors knew the state of North American siricid taxonomy was in flux but an identification guide for this family was needed to support survey and research efforts. A definitive treatment of the family for the Western Hemisphere was published in 2012 (Schiff, N.M., H. Goulet, D.R. Smith, C. Boudreault, A.D. Wilson, and B.E. Scheffler. Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere. Canadian Journal of Arthropod Identification 21. 270 pp.) Many taxonomic changes were part of this excellent and scholarly revision of the family. This comprehensive treatment can be challenging for non-taxonomists to use. The following identification aid is in no way intended to replace Schiff et al. 2012. It is merely an effort to provide a key to North American Siricidae that will hopefully be less intimidating to non-taxonomists. Introduction: II This aid includes some exotic target species of Siricidae as well as native species. It is designed to be used by individuals with a wide range of taxonomic expertise. Where possible, images of all character states are provided. In general, the most obvious or reliable characters come first in a couplet half, followed by those that are less so. Where possible and efficient, taxonomic jargon has been kept to a minimum. Unfamiliar terms and character states should be explained via the images and associated labels. The first several slides following this introduction illustrate the basic body parts of Siricidae and the terms applied to them.

This screening aid functions much like traditional dichotomous keys, with couplets. However, buttons linking non-sequential couplets and enabling return to the originating couplet have been utilized. Names of exotic species are followed by the ☹ symbol.

As is true of all insect identification, good illumination is essential. Ring lights are particularly good for assessing punctation, surface texture and features, and vestiture. Many features, especially punctation, are best Introduction: III viewed at an oblique angle or with oblique lighting. It is important to maintain a reference collection of identified specimens (hopefully confirmed by a cooperating taxonomist) to ensure correct understanding of the necessarycharacters. Although the images within this identification aid are of very high quality, there is no substitute for actual specimens. Siricid Morphology: I

Precornal plate

Modified from Schiff et al. 2006 Siricid Morphology: II

occiput

temporal frons spot ocelli (simple eyes)

genal ridge

genae 1

Abdomen with long ovipositor (females) (a)…...... 2 Abdomen without long ovipositor (males) (b)…...... 32* *Nothing available beyond couplet 31 at this time!

a. b. 2 (1): Part I Head with pale temporal spot (a-b); cornus elongate, narrowed at middle (e) or at base (f), precornal plate pentagonal (e-f)...... 3 Completely dark behind each eye, without temporal spot (c) or entirely pale behind each eye (d); cornus broad and triangular (sometimes narrower than shown) (g), precornal plate round or oval…...... 14

a. c.

b. d. 2 (1): Part II e. f. g. 3 (2) Cornus narrowed at base, posterior margin of precornal plate shallowly convex (a); hind tibia with two apical spurs (c)…...... Urocerus 4 Cornus narrowed at middle, posterior margin of precornal plate angulate (b); (b), hind tibia with one apical spur (d)...... Xeris 10

a. b.

d. 4 (3) Antennae bicolored dark and pale (a-b); wings dark, all brown (d) to all black (e)…...... 5 Antennae all pale-dark brown (scape sometimes darker) (c); wings pale: clear with darker areas (f) or all yellow (g)…...... 7 d. f.

a. b. e. g. c. 5 (4) At least posterior half of abdomen pale (a)…....Urocerus cressoni Norton Abdomen black (sometimes with pale lateral markings) (b-c)…...... 6

a. b. c. Urocerus cressoni Norton Urocerus cressoni Norton 6 (5) Cornus black (a); antennae pale in middle (c)…....Urocerus albicornis (Fabricius) Cornus pale (b); antennae pale apically (d)…...... Urocerus taxodii (Ashmead)

a. b. d. Urocerus albicornis (Fabricius) Urocerus albicornis (Fabricius) Urocerus taxodii (Ashmead) Urocerus taxodii (Ashmead) 7 (4) Abdomen without broad pale bands in posterior half, at most only a narrow pale band present (a)...... Urocerus californicus Norton Abdomen with broad pale banding in posterior half (b-c)…...... 8

a. b. c. Urocerus californicus Norton Urocerus californicus Norton 8 (7) Head brown except for pale temporal spots (a); pronotum pale (c); apex of abdomen pale (c)...... Urocerus sah (Mocsary) ☹ (exotic established in SE Canada and NE U.S.) Head black except for pale temporal spots (b); pronotum dark (d); apex of abdomen dark (d)...... 9

b. c. d. Urocerus sah (Mocsary) Urocerus sah (Mocsary) 9 (8) Abdomen with pale posterior bands only on tergum 7 and at most the anterior half of adjoining tergum 8 (a)...... Urocerus flavicornus (Fabricius) Abdomen with pale posterior bands on terga 7-8, posterior half of tergum 9, and on tergum 10 (b)...... Urocerus gigas (Linnaeus) ☹ *Frequently intercepted exotic not known to be established in North America.

7 8

a. 9 7 8 10 9 b. Urocerus flavicornus (Fabricius) Urocerus flavicornus (Fabricius) Urocerus gigas (Linnaeus) Urocerus gigas (Linnaeus) 10 (3): Part I Upper portion of head coarsely and contiguously punctate and with only narrow medial carinae apunctate, genae not extending beyond lateral margins of eyes, genal carinae not visible from front view (a); ovipositor sheath without lateral longitudinal carina (c)...... Xeris tarsalis (Cresson) Upper portion of head with sparse small punctures and with large apunctate areas, genae extending beyond lateral margins of eyes and genal carinae clearly visible from front view (b); ovipositor sheath with lateral longitudinal carina (d)...... 11

a. b. 10 (3): Part II c.

d. Xeris tarsalis (Cresson) Xeris tarsalis (Cresson) 11 (10) Pale temporal spots small (rarely absent), not extending ventrally to contact genal carinae (a)...... Xeris caudatus Cresson and Xeris melancholicus (Westwood) These two species are very difficult to reliably identify except via the CO1 barcode sequence. Confirmed specimens of X. caudatus are from Alberta and South Dakota to the west and confirmed Specimens of X. melancholicus are boreal and eastern from Alberta to the east, but ranges overlap. Pale temporal spots large, extending to contact (or nearly so) genal carinae (b)...12

b. Xeris caudatus Cresson *Xeris melancholicus (Westwood) is very similar in appearance Xeris caudatus Cresson *Xeris melancholicus (Westwood) is very similar in appearance 12 (11): Part I Gena narrow, breadth from posterior margin of eye to genal carina about half of greatest eye breadth (a); femora black (c) (known only from the SW U.S.)…..... …...... Xeris morrisoni (Cresson) Gena narrow, breadth from posterior margin of eye to genal carina at least two- thirds of greatest eye length (b); femora pale (d)…...... 13

a. b. 12 (11): Part II

d. Xeris morrisoni (Cresson) Xeris morrisoni (Cresson) 13 (12) Genae below eyes and genal ridge densely punctate and setae on frons long (a) (known only from Arizona)…...... Xeris chiricahua Smith Genae below eyes and genal ridge with only a few punctures and frons with short setae (b) (throughout much of western North America, including Arizona)…...... Xeris indecisus (MacGillivray)

a. b.

Schiff et al. 2012 Schiff et al. 2012 Xeris chiricahua Smith

Schiff et al. 2012 Xeris indecisus (MacGillivray

Pale form Dark form Xeris indecisus (MacGillivray

Pale form

Dark form 14 (2) Hind tibia with one apical spur (a)...... 15 Hind tibia with two apical spurs (b)…...... Sirex 17

b. 15 (14) Dorsum of abdomen, particularly the posterior segments, with dense, long, pale setae, and precornal impression coarsely punctate and rugose (a)...... Eriotremex formosansus (Matsumura) ☹ (exotic established in southeastern U.S.) Dorsum of abdomen without long setae and precornal impression finely micro- sculptured and without obvious punctures (b)...... Tremex 16

b. Eriotremex formosansus (Matsumura) ☹ Eriotremex formosansus (Matsumura) ☹ 16 (15): Part I Each lateral margin of cornus angulate near base (a); dense setae on frons short and mostly from middle of eyes to bottom thereof, posterior margin of head with dark setae (c); setose punctures on ventrolateral margins of last tergite clearly separate from each other and finely asperate (e)…...... Tremex columba (Linnaeus) Each lateral margin of cornus evenly oblique (b); dense setae on frons long and throughout frons and dorsum of head, posterior margin of head with pale setae (d); setal punctures on ventrolateral margins of last tergite contiguous and coarsely asperate (f)...... Tremex fuscicornis (Fabricius) ☹ *Frequently intercepted exotic not known to be established in North America.

no angulation

a. b. dark setae 16: Part II

pale setae

short setae long setae

c. d. 16: Part III setose punctures on ventrolateral margins of last tergite clearly separate from each other and finely asperate

setal punctures on ventrolateral margins of e. last tergite contiguous and coarsely asperate

f. Tremex columba (Linnaeus) (note: highly variable in color) Tremex columba (Linnaeus) (note: highly variable in color) Tremex fuscicornis (Fabricius) ☹

Schiff et al. 2012 Tremex fuscicornis (Fabricius) ☹

Schiff et al. 2012 17 (14) Abdomen mostly pale brown (at least dorsally) or reddish (a-b)…...... 18 Abdomen dark, black or bluish/greenish black (c-d)…...... 19

a. b. c. d. 18 (17) Wings banded (a); gena behind eye with distinct ridge (c)…...... Sirex behrensii (Cresson) Wings all dark (b); gena behind eye without distinct ridge (b)…...... pale form Sirex nigricornis Fabricius

Schiff et al. 2012

b. d. Sirex behrensii (Cresson) Sirex behrensii (Cresson) Sirex nigricornis Fabricius: Pale form Sirex nigricornis Fabricius: Pale form 19 (18)

Ovipositor length medium or long (a-b)...... 20 Ovipositor length short (c)...... 22

c. 20 (21) Legs all black (a)...... Sirex areolatus (Cresson) Tibiae and tarsi pale (b)...... Sirex longicauda Middlekauff

b. Sirex areolatus (Cresson) Sirex areolatus (Cresson) Sirex longicauda Middlekauf Sirex longicauda Middlekauf 22 (21) Metafemur black (a)…...... 23 Metafemur pale (b)…...... 27

a. Schiff et al. 2012 Schiff et al. 2012 b. 23 (22): Part I Tibiae and tarsi pale (a); metatarsomere 2 with ventral pad slightly shorter than length of tarsomere 2 (c)...... Sirex nitidus (T.W. Harris) w/dark femora Tibiae and tarsi dark (b); metatarsomere 2 with ventral pad about half the length of tarsomere 2 (d)...... 24 a.

Schiff et al. 2012

b. Schiff et al. 2012 23 (22): Part II c. Schiff et al. 2012

d. Schiff et al. 2012 Sirex nitidus (T.W. Harris) w/dark femora

Schiff et al. 2012 24 (23)

Wings clear and slightly yellow tinted (a) (known from CO, UT, MX) ...... Sirex xerophilus Schiff Wings dark (b) or clear with dark bands (c)...... 25

b. a. Schiff et al. 2012

c. Sirex xerophilus Schiff 25 (24): Part I Punctation on upper genae (a) and tempora (c) smaller and more widely dispersed ...... Sirex californicus (Ashmead) with dark legs Punctation on upper genae (b) and tempora (d) larger and denser...... 26

Schiff et al. 2012 Schiff et al. 2012

a. b. 25 (24): Part II

Schiff et al. 2012

c. Schiff et al. 2012

b. c. d. Sirex californicus (Ashmead) with dark legs Sirex californicus (Ashmead) with dark legs 26 (25): Part I Metatarsomere 2 in lateral view 2-2.5 times as long as high (a); mescoscutum (portion of dorsal thorax where wings attached) rugosely, contiguously punctate with puncture margins forming a reticulate pattern (c)...... Sirex nigricornis Fabricius (with black legs) Metatarsomere 2 in lateral view about 1.5 times as long as high (b); mescoscutum with punctures more widely dispersed and with margins at most forming a few irregular transverse carinae (d)...... Sirex obesus Bradley

Schiff et al. 2012

b. 26 (25): Part II

c. Schiff et al. 2012 c. Schiff et al. 2012 Sirex nigricornis Fabricius with black legs Sirex nigricornis Fabricius with black legs Sirex obesus Bradley 27 (25): Part I Dark blue metallic reflections on at least metatibiae and often femora and other tibiae (a) (rare specimens with entirely pale legs can be differentiated from S. noctilio, the most important species to distinguish, by the size and dispersion of the pits on the middle of the ovipositor (c-d))…...... …Sirex varipes Walker Legs entirely pale (b)…...... …28

a. b.

Schiff et al. 2012 Schiff et al. 2012 27 (25): Part II

Schiff et al. 2012 c. Ovipositor of Sirex varipes: length of pits in middle portion about one third the length from the anterior margin of one pit to the anterior margin of the adjacent pit and pits distinctly longer than wide.

Schiff et al. 2012 d. Ovipositor of Sirex noctilio: length of pits in middle portion about half the length from the anterior margin of one pit to the anterior margin of the adjacent pit and pits about as wide as long. Sirex varipes Walker Sirex varipes Walker 28 (27): Part I Mesoscutum with most discal pits mainly round, larger pits with separate and distinct asperities along their posterior margins (a); ovipositor with length of pits in middle portion about half the length from the anterior margin of one pit to the anterior margin of the adjacent pit (c)…...... Sirex noctilio Fabricius ☹ *Exotic species established in NE US and SE Canada. Mesoscutum with most discal pits elongate and with contiguous margins forming a reticulate pattern (b); ovipositor with length of pits in middle portion about 0.1(d) -0.4 (e) the length from the anterior margin of one pit to the anterior margin of the adjacent pit…...... 29

To enable usable image size all diagnostic images are on slides 28: Parts II and III 28 (27): Part II a. Mesoscutum with most discal pits mainly round, larger pits with separate and distinct asperities along their posterior margins

b. Mesoscutum with most discal pits elongate and with contiguous margins forming a reticulate pattern.

Schiff et al. 2012

Schiff et al. 2012 28 (27): Part III

Schiff et al. 2012 c. Ovipositor of Sirex noctilio: length of pits in middle portion about half the length from the anterior margin of one pit to the anterior margin of the adjacent pit.

d. Schiff et al. 2012 Ovipositor with length of pits in middle portion about 0.1(d) -0.4 (e) the length from the anterior margin of one pit to the anterior margin of the adjacent pit. e. Schiff et al. 2012 Sirex noctilio Fabricius ☹ Sirex noctilio Fabricius ☹ 29 (28): Part I

Fore wings clear with dark bands at both middle and apex or completely dark (a); metatarsomere 5 completely black (c); ventral pad of metatarsomere 2 about half as long as tarsomere (f)...... Sirex californicus (Ashmead) with pale legs Fore wings clear with no more than a dark apical band (b); metatarsomere 5 pale (d) or dark in apical half (e); ventral pad of metatarsomere 2 almost as long as tarsomere (g)…...... 30 29 (28): Part II

metatarsomere 5 completely dark

c. Schiff et al. 2012

metatarsomere 5 completely pale

d. metatarsomere 5 partly dark

e. Schiff et al. 2012 29 (28): Part III

ventral pad of tarsomere 2 about half as long as tarsomere

g. c.

ventral pad of tarsomere 2 almost as long as tarsomere Schiff et al. 2012 Sirex californicus (Ashmead) with pale legs 30 (29): Part I Based on Schiff et al. 2012, it appears the following species can only be reliably identified via characters on the ovipositor, distribution, or molecular means. Ovipositor pits near middle 0.15-0.25 as long as annulus and present even on annulus 2 (but much smaller than pits at middle), annulus lines clearly outlined in basal 0.3-0.4 (a)...... Sirex nitidus (T.W. Harris) with pale legs *Range overlaps with both of the following species. Ovipositor pits near middle no more than 0.14 as long as annulus and absent in basal 0.4-0.5, annulus lines in basal 0.3 weakly outlined near dorsal edge or not outlined at all (b)...... 31 To enable usable image size all diagnostic images are on slide 30: Part II 30 (29): Part II a.

Schiff et al. 2012

b. Schiff et al. 2012 Sirex nitidus (T.W. Harris) with pale legs

Schiff et al. 2012 31 (30) Range Western – see map (a)...... Sirex abietinus Goulet, new species Range Eastern – see map (a)...... Sirex cyaneus Fabricius

Based on the Schiff et al. 2012 characters used in Schiff et al. 2012, I do not believe it is possible to reliably discriminate between these species based upon morphology.

a. Sirex abietinus Goulet new species Sirex abietinus Goulet new species Sirex cyaneus Fabricius

Schiff et al. 2012