Laricobius rubidus LeConte, 1861

Leschen, Richard A. B., 2011, World review of Laricobius (Coleoptera: Derodontidae), Zootaxa 2908, pp. 1-44 : 24-25

17. Laricobius rubidus LeConte, 1861

(figs 17, 24, 25, 32, 46)

Diagnosis. Body bicolored. Head dark; ocelli present. Prothorax transverse with well-developed lateral carina and sides explanate. Pronotum dark; posterior tooth usually present. Scutellum dark. Surface of elytra incurvate; elytral punctures not confluent. Epipleura at base dark. Ventrites dark. Femora dark. Tibiae dark. Aedeagus without median carina on phallobase; medium lobe subacute; apices of parameres with an internal ridge.

Description. Length 2.03–2.50 mm (x = 2.32, n = 16). Body bicolored, with head, prothorax, scutellum, and ventrites light brown to black, elytra along sides to apex (covering striae 7–10 or 8–10) and suture dark brown to black, or sutural stripes distinct and present only to basal 1/3 or less, with the broad central disc dark tan to deep red brown; antenna light to dark brown with AI and club sometimes darker, rarely the funicle dark brown to black, palpi, and tarsi reddish brown to tan, femora and tibiae light to chocolate brown (tibiae same color as femora). Head with ocelli; u-shaped furrow present but weakly impressed; interocular distance about 4x the width of the eye; macropunctures weakly to strongly impressed, ovate; micropunctures coarse; setation elongate, erect, average length about 2/3 to full width of the eye. Antenna with length of A3 about equal to A4, ratios 1.9:1.7:1.4:1.3:1.4:1.2:1.2:1.0:1.3:1.4:1.8; A11 not strongly asymmetrical. Prothorax transverse and dorsoventrally flattened, widest at middle, sides weakly sinuate or unevenly convex, with margin converging more sharply posteriorly than anteriorly; about 0.75 x as long as wide (pronotal length/greatest pronotal width = 0.67–0.81, x = 0.75); depth = 0.25–0.39 mm (x = 0.30); pronotum laterally broadly explanate, lateral carina with a distinct sharp edge; anterior angle variable from 90º to about 65°, acute but not forming a tooth; posterior angle distinct and marked by a short tooth that may be weakly formed; foveae visible in dorsal view; macropunctures ovate, deep, usually wellseparated but sometimes contiguous; micropunctures coarse; setae erect and elongate, length about 2/3 to full width of eye. Elytra about 3.22 x as long as wide (elytral length/greatest elytral width = 2.75–3.65, x = 3.22) and 3.25 x as long as pronotum (elytral length/pronotal length = 3.00–3.67, x = 3.25); surface strongly to weakly incurvate at basal third; macropunctures not coalescing posteriorly to form grooves (apart from those of striae 1 along the suture at the apical 1/ 3 in some specimens), separated by an average of 1/2 puncture diameter; micropunctures fine; microsculpture visible or not; vestiture mostly consisting of suberect setae with scattered erect setae, elongate and average length about 2/3 to full width of eye. Aedeagus with phallobase transverse (wider than long), about 2/3 the length of the median lobe, median carina absent; median lobe projecting beyond apices of parameres, relatively broad with its greatest width larger than the width of the parameres, gradually tapering apically with apex subacute, median carina or groove absent, ostium subapical; parameres moderately broad, apex angulate, short setae present on apices and absent along inner margin, internal subapical ridge present. Spiculum gastrale apically acute.

Comments. Laricobius rubidus can be distinguished from other bicolored species with ocelli and explanate pronotal margins (especially the similar looking L. erichsonii ) by the dark-colored tibiae which is the same color as the femora, by the punctures on the head shallowly impressed, the anterior angle not forming a tooth, and most easily by the aedeagal characters. The internal subapical ridge on the parameres is shared only with the species L. nigrinus . Preliminary genetic data suggest that L. nigrinus and L. rubidus can successfully reproduce in the field (Havill et al. in press). Host plants and distributions were recently included in the study by Majka (2007).

Hosts. Plants: Abies fraseri (Pursh) Poir. , Abies balsamaea (L.) Mill., Pinus strobus L., Pinus banksiana Lamb. , Tsuga canadensis (L.) Carriére, Picea rubens Sarg. Adelgids : Adelges tsugae , Adelges piceae (Ratzeburg) , Pineus strobi .

Biology. Natural history ( Clark & Brown 1960, Lawrence & Hlavac 1979).

Distribution. Canada: New Brunswick, Nova Scotia, Ontario, Quebec. United States: Connecticut, Georgia, Maine, Maryland, Massachusettes, New Hampshire, New York, North Carolina, Pennsylvania, Rhode Island, Tennessee, Vermont, West Virginia.

Type material examined. Holotype ( MCZ). 1, pointed, D. C/ Laricobius rubidus Lec. (hw)/ erichsonii 2 (hw)/ M.C.Z. Type 32369 (red label, number hw)/ LARICOBIUS RUBIDUS LEC. Det. J. F. Lawrence (bordered det. label, name hw)/ Holotype (red label)/ Jan–Jul 2005 MCZ Image Database (bordered label with camera icon).

Additional material examined. CANADA. New Brunswick: 1 ( CNC). Ontario: 1, Constance B., 16.v 1933, W. J. Brown ( CAS); 2, Ottawa ( CAS); 5, Toronto, R. J. Crew ( CAS); 24 ( CNC). Quebec: 4, Aylmer, Que., 1.V 1933, W. J. Brown / [hw label] Det. 1934 W. J. B. ( CAS); 1, same but 18-v-1934 ( CAS); 1, same but 9.v 1932 ( CAS); 1, same but 1.v 1933 ( CAS); 1, Aylmer, 12.v 1932, W. J. Brown ( CAS); 2, Lanoraie, 13 iii 77, F. Liard, 1992 Acc. Z-18,343 ( FMNH). UNITED STATES. Connecticut: 1, New Haven Co., New Haven, 30 March 1994, Coll.: S. Lyon ( USDA); same but 19 April 1994 ( USDA); 6, New Haven Co, Lake Whitney, 31 X 1997, M. Montgomery, W. Lu ( USDA); 1, same but 14 vii 1993 ( USDA); 1, Hamden, end of Ingram St., Water Co. property, 27 March 2007, Coll.:N. Havill, ex. Tsuga canadensis, Sample : Havill 07–14 ( YPM); 1, Hamden, USDA Forest Service Northern Research Stn., 51 Mill Pond Rd., 17 April 2008, Coll.: N. Havill, A. Serafin, ex. Pinus strobus, Sample 08-57.1 ( YPM). Maryland: 1, Allegany County, Rocky Gap, 3 May 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4397022N, 0699934E, Sample: Havill 06-126 ( YPM). Massachusettes: 1 ( CAS); 1, Holyoke, Mt. Tom State Park, 5 May 2008, Coll.: J. Biroscak, ex. Pinus strobus, Sample 08-71.1 ( YPM). Michigan: 1 ( CAS). Minnesota: 1, on Pinus strobes ( CNC). New Hampshire: 53, ( UNHD). New York: 1 ( CNC). North Carolina: 1, Watauga County, Holloway Gap, 16 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4000032N, 0431471E, Sample: Havill 06-122.3 ( YPM); 1, same but Sample: Havill 06-122.4 ( YPM); 3, Watauga County, Fosco, Holloway Mountain Road, 17 April 2008, Coll.: M.E. Montgomey, R.C. McDonald, ex. Pinus strobus ; 36.14 N: 81.76 W, Sample 08-61 ( YPM); 1, same but Sample 08-61.1 ( YPM); 2, Yancey County, Locust Creek, 16 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 3964523N, 0390540E, Sample: Havill 06-123 ( YPM); 1, same but Sample: Havill 06-124.1 ( YPM). Pennsylvania: 1, Cumberland Co., Hogestown, 12 April 1994, Coll.: S. Lyon ( USDA); 3, Huntingdon Co., Rothrock State Forest, 4 May 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4504040N, 0268595E, Sample: Havill 06-128 ( YPM). Tenessee: 7, Sevier Co., Smokies Nat. Park, Laurel Creek, 9 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab; UTM 3943370N, 0250526E, Sample: Havill 06-125 ( YPM); 1, same but Sample: Havill 06-125.5 ( YPM); 1, same but Sample: Havill 06-125.6 ( YPM). Virginia: 6, Montgomery Co. Blacksburg, 6-30 IV 2001, coll. G. Zilahi-Balogh, Host tree: Tsuga canadensis, Host : Adelges tsugae, Habitat : plantation <10 yr. mixed, w/ Abies fraseri , Pinus strobus ( VTRC); 3, Montgomery Co. Prices Fork, 6–30 IV 2001, G. Zilahi-Balogh, Host: Tsuga canadensis infested w/ Adelges tsugae ( VTRC); 7, Smyth Co., Hurricane Camp, 20 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4064121N; 0456464E, Sample: Havill 06-129 ( YPM); 6, Montgomery Co. Kentland Farm, 28 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4118054N, 0536469E, Sample: Havill 06-132 ( YPM); 1, Bland Co., Lick Creek, 18 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4096147N; 0461976E, Sample: Havill 06-130 ( YPM); 8, Giles Co., North Fork, 15 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4144202N, 0542872E, Sample: Havill 06-133 ( YPM); 1, same but Sample: Havill 06-133.9 ( YPM); 7, Giles Co., Big Stony, 15 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected, reared in lab, UTM 4141138N, 0538027E, Sample: Havill 06-135 ( YPM); 1, Grayson Co., Highland Trail, 24 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected, reared in lab, UTM 4060842N, 0453808E; Sample: Havill 06-134 ( YPM). Vermont: 1 ( CNC). West Virginia: 15, Pocahontas Co., Seneca State Forest, 27 April 2006, Coll.: D. Mausel, ex. Tsuga conadensis, larva collected. reared in lab, UTM 4239369N, 0594329E; Sample: Havill 06-120 ( YPM); 1, Pocahontas Co., Watoga State Park, 27 April 2006, Coll.: D. Mausel, ex. Tsuga canadensis , larva collected. reared in lab, UTM 4217462N, 0579409E, Sample: Havill 06-121.10 ( YPM); 20, but Sample: Havill 06-121 ( YPM). Laboratory reared: 3, Blacksburg, VA; 10 IV 2003 ( VTRC).