Ips perroti, male frons
Ips perroti, female frons
Ips perroti, antenna
Ips perroti, male declivity

Ips perroti, female declivity

 

Ips perroti, male lateral habitus

Scientific Name

Ips perroti Swaine, 1915

Diagnostic notes

-Has four spines on the elytral declivity and the sutures of the antennal club are nearly straight. 
-Most I. perroti specimens are smaller (2.7 to 3.5 mm) than I. amitinus (3.5 to 4.8 mm). 
-Ips perroti can also be confused with some males of I. borealis. Here it is useful to examine series from a single galery containing males and females. 
-Genitalic dissection may be required to determine sex.

Morphological Summary

females
Body. 2.7-3.5 mm long, 2.6-2.8 times longer than wide; pronotum 1.1-1.2 times longer than wide.
Head. Epistomal margin with uniseriate row of tubercles absent or present with gap at midline. Frons outline convex in lateral view; vestiture fine (not hiding part of integument); surface sculpture near epistoma with isolated tubercles; central carina absent; central tubercle absent or present and single, separated from base of epistomal setae by 0-3 tubercle diameters, without pair of circular tubercles on either side of midline; transverse carina absent or present; frons central fovea absent; circular tubercles above top of eyes absent or present - up to one third of all tubercles. Vertex and pronotum without stridulatory apparatus (pars stridens). Antennal club sutures straight.
Prothorax. Protibiae with three socketed teeth on apical half (does not include apical spine).
Elytra. Interstriae punctate (observed on interstriae 2 and 3 on middle third of elytral disc), punctures (0.4-)0.5(-0.6) times diameter of adjacent strial punctures (punctures and striae measured at steepest part of puncture wall), interstrial setae longer than width of scutellar shield, interstriae 3(-4) times as wide as adjacent striae. Elytral declivity with four spines per side, spine 2 or 3 largest; spine 1 (largest on 2nd interstria) closer to suture than spine 2; spines 1 and 2 separated at base by distance greater than height of spine 1; spine 2 closer to spine 3 than spine 1; spine 3 tapered, apex acute or right-angled, with apical half symmetrical in lateral view; spines 2 and 3 on shared tumescence, in or not in line with spines 1 and 4 (posterodorsal view); declivital integument shiny.

males
Body. 2.7-3.5 mm long, 2.6-2.8 times longer than wide; pronotum 1.1-1.2 times longer than wide.
Head. Epistomal margin with uniseriate row of tubercles with gap at midline. Frons outline convex in lateral view; vestiture fine (not hiding part of integument); surface sculpture near epistoma densely tuberculate-punctate or with isolated tubercles; central carina absent; central tubercle present and single, separated from base of epistomal setae by 0-2 tubercle diameters, without pair of circular tubercles on either side of midline; transverse carina absent or present; frons central fovea absent; circular tubercles above top of eyes absent or present - up to one third of all tubercles. Vertex and pronotum without stridulatory apparatus (pars stridens). Antennal club sutures straight.
Prothorax. Protibiae with three socketed teeth on apical half (does not include apical spine).
Elytra. Interstriae punctate (observed on interstriae 2 and 3 on middle third of elytral disc), punctures (0.4-)0.5(-0.6) times diameter of adjacent strial punctures (punctures and striae measured at steepest part of puncture wall), interstrial setae longer than width of scutellar shield, interstriae 3(-4) times as wide as adjacent striae. Elytral declivity with four spines per side, spine 3 largest; spine 1 (largest on 2nd interstria) closer to suture than spine 2; spines 1 and 2 separated at base by distance greater than height of spine 1; spine 2 closer to spine 3 than spine 1; spine 3 straight sided with tapered apex or pedunculate (capitate), apex acute, with apical half symmetrical or asymmetrical in lateral view; spines 2 and 3 on shared tumescence, in or not in line with spines 1 and 4 (posterodorsal view); declivital integument shiny.

Geographic Distribution

Canada (Alberta, Manitoba, New Brunswick, Ontario, Quebec); USA (Michigan, Minnesota).

Hosts

Pinus spp. Principally P. banksiana and P. resinosa.

Notes

Clade formed by (((I. longifolia + I. stebbingi) + I. schmutzenhoferi) + I. perroti), see Cognato and Sun (2007).

References

Cognato, A.I.2015. Biology, systematics, and evolution of Ips. In Bark beetles: biology and ecology of native and invasive species. Edited by F.E. Vega and R.W. Hofstetter. Elsevier, San Diego, California. Pp. 351–370.

Cognato, A.I. and Sun, J.H. 2007. DNA based cladograms augment the discovery of a new Ips species from China (Coleoptera: Curculionidae: Scolytinae). Cladistics, 23: 539–551.

Wood, S.L. 1982. The bark and ambrosia beetles of North and Central America (Coleoptera: Scolytidae), a taxonomic monograph. Great Basin Naturalist Memoirs, 6: 1–1359.

Internet resources

https://www.barkbeetles.info/regional_chklist_target_species.php?lookUp=1719