United StatesDepartment ofAgriculture

Combined Forest PestResearch andDevelopment Program

Agriculture HandbookNo. 563

Southern PineBeetle Handbook

How to IdentifyCommon InsectAssociatesof the SouthernPine Beetle

1

Contents

Introduction .................................. 3

Using this Handbook.................... 3

Hemiptera ...................................... 4Anthocoridae ............................... 4

Lyctocoris ................................ 4Scoloposcelis .............................. 4Aradidae ...................................... 5

Aradus ..................................... 5Coleoptera..................................... 6

Histeridae .................................... 6Platysoma ................................ 6Plegaderus ............................... 6

Trogositidae ................................ 8Temnochila .............................. 8Tenebroides .............................. 8

Staphylinidae ............................... 9Leptacinus ............................... 9

Cleridae ..................................... 10Thanasimus............................ 10

Cucujidae .................................. 11Silvanus ................................. 11

Colydiidae ................................. 12Aulonium ............................... 12Colydium ............................... 12Lasconotus ............................. 12

Tenebrionidae ............................ 14Corticeus .............................. 14

Curculionidae ............................ 15Cossonus................................ 15

Cerambycidae............................ 16Monochamus ......................... 16Neacanthocinus ..................... 16

Platypodidae .............................. 18Platypus ................................. 18

Scolytidae .................................. 19Xyleborus ............................... 19Dendroctonus ........................ 19Ips .......................................... 20Pityophthorus ........................ 21Crypturgus ............................. 21Gnathotrichus ........................ 21

Diptera ......................................... 22Stratiomyiidae ........................... 22

Zabrachia .............................. 22Dolichopodidae ......................... 23

Medetera................................ 23Sciaridae .................................... 24Lonchaeidae ............................. 25

Lonchaea .............................. 25Hymenoptera .............................. 26

Formicidae ................................ 26Crematogaster ....................... 26

Braconidae ................................ 26Cenocoelius ........................... 26Coeloides ............................... 26Atanycolus ............................. 26Dendrosoter ........................... 28Meteorus ............................... 28Spathius ................................ 28

Pteromalidae ............................. 29Dinotiscus .............................. 29Roptrocerus ........................... 30Heydenia................................ 30

Eurytomidae .............................. 31Eurytoma ............................... 31

Platygastridae ............................ 32Platygaster ............................ 32Leptacis ................................. 32

Acknowledgments....................... 33Selected References...................... 33

2

How to Identify CommonInsect Associates of theSouthern Pine Beetle

by Richard A. Goyer,’ Gerald JLenhard,’ T. Evan Nebeker,2

and Linda D. Jarrard 2

‘Department of Entomology, LouisianaState University, Baton Rouge.2Department of Entomology, MississippiState University, Mississippi State.

3

Introduction

Heavy timber damage by thesouthern pine beetle (Dendroctonusfrontails Zimmermann) (SPB) andrecent intensive research haveresulted in the need to identify thissubcorticular insect and its insectassociates. Associates includeinsects reported to be predaceous orparasitic as well as those merelyusing the same habitat. No extensivereference collections exist that canbe shared by researchers, techni-cians, students, and others con-cerned with such identification. Wedeveloped this handbook to presentsome of the more commonly foundinsect associates of the SPB.

This guide by no means representsall the insects associated with SPB.Our selection was based on a surveyof entomologists and others experi-enced with SPB research: theyindicated which insect associates ofthe beetle would be most representa-tive and helpful in their work. Ofcourse, we made the final selectionsand our biases are reflected herein.It is our belief, however, that the 48species, or species groups, coveredin the handbook comprise theimportant insect associates of theSPB encountered in the southeasternUnited States.

Using this Handbook

To use the handbook, turn to thefirst page listing specimens in theinsect order. Then, compare theunknown species with the descrip-tions and photographs or drawing’given. Although the photographsdepict natural color, preservedspecimens--especially those inalcohol--may not have exactly thesame color as those in the picturesAll sizes given are average length.

The brief written descriptions arenot intended to be taxonomicallycomplete, but to pinpoint thefeatures most useful in distinguish-ing a species or species group.Where minute characteristics arerequired to distinguish species, orwhere taxonomic problems exist, thegenus alone is listed. Some priortraining in entomology is assumed.

4

Hemiptera

Anthocoridae

● Lyctocoris Hahn (fig. 1 A); andScoloposcelis mississippensis(Drake and Harris) (figs. 1B, 2):S. mississippensis (2.8-3.5 mm) hasspines on the front femora, whichLyctocoris (3.8-5.0 mm) does nothave (figs. 1A, 1B).

Figure 2

Figure 1A

Figure 1B

5

Aradidae

● Aradus F. (fig. 3): The mostnoticeable features of Aradus sp.(3.4-4.0 mm) are its dorsoventrallyflattened appearance, its small headand thorax in relation to abdominalsize, and its pebbly appearance.Antenna are four-segmented.

Figure 3

6

Coleoptera

Histeridae: The histerids are black,shiny, hard-bodied beetles withshort elytra. The posterior abdomi-nal segments are exposed dorsallybeyond the elytra.

● Platysoma (Cylistix) cylindrica(Paykull) (figs. 4A, 5): P. cylindrica(4.3 mm) has a spiny front tibia anda pointed prosternum (fig 4A).

● P. (Cylistix) attenuate (LeConte(figs. 4A, 6): P. attenuata is similarto P. cylindrica but is smaller (3.1mm) than P. cylindrica. Also, P.attenuata appears thinner whenviewed dorsally (fig. 6).

Figure 5

Figure 4A

Figure 4B

7

● P. parallelum Say (figs. 4B, 7): P.parallelum (2.7-3.6 mm) can bedistinguished from these first twospecies because it has a roundedprosternum (fig. 4B). In addition,its pronotum is short relative to thelength of the elytra (fig. 7), and itlacks deep pits on the metasternalplate.

● Plegaderus Erichson (fig. 8):Plegaderus is a tiny (1.5 mm),oval, shiny, black beetle.Plegaderus has short elytra and ispunctate with a smooth band onthe prothorax.

Figure 6

Figure 7

Figure 8

8

Trogositidae: Trogositids (formerly,Ostomidae) have large heads andpronota and a narrow unionbetween the pronotum and elytra.They appear somewhat flatteneddorsoventrally.

Temnochila virescens (F.) (figs. 10,adult; 9, larva): This predator islarge and elongate. Its size (10 mm)and its brilliant metallic green colormake it easily recognizable. Larvaeare white, have dark heads,well-developed thoracic legs, andtwo darkened anal projections(urogomphi). They have fusedthoracic shields on the secondsegment.

● Tenebroides collaris (Sturm) (fig.11): T. collaris can be distinguishedfrom T. marginatus (fig. 11)because it is larger (7.2 mm) andhas dark brown to black elytra and areddish brown head. Each specieshas a punctate head and marginedelytra

● T. marginatus (Palisot de Beauvois) (fig. 12): T. marginatus (5.2mm) is more uniformly mediumbrown on the pronotum and elytrathan T. collaris.

Figure 9

Figure 10

Figure 11

Figure 12

9

Staphylinidae

● Nudobius luridipennis (Casey) (fig.13): N. luridipennis (7.5-8.2 mm),like other staphylinids, are slenderand elongate with very short elytra(usually only as long as the elytraare wide). The antennae arebeadlike and medium length. Itshould be noted that there are otherspecies of staphylinids associatedwith the SPB that, although quitecommon, are yet undescribed.

Figure 13

10

Cleridae

● Thanasimus dubius (F.) (figs. 14,15, 16): The checkered beetle, T.dubius (7.5-9.0 mm), has easilydistinguishable black elytra withwhite angulate crossbars. The head,thorax, and base of the elytra arered. The larvae are pink when alive(white if preserved), do not havefused thoracic shields, but areotherwise similar to T. virescenslarvae (see fig. 10).

Figure 14

Figure 15

Figure 16

11

Cucujidae

● Silvanus bidentatus (F.) (fig. 17):Silvanus spp. (3.5-3.9 mm) likeother cucujids, are extremely flat,densely punctate, amber brown, andhave an elongate prothorax andhead. The antennae are beadlike andmedium length. There are two teethon the front angle of the pronotum.

Figure 17

12

Colydiidae

● Aulonium Erichson (figs. 18, 19):Both species presented here areelongate, pale brown, and 3.5-5.0mm long. They have relativelyshort, clubbed antennae. Auloniumspp. are separated from other SPBinsect associates by the strongridges running nearly the length ofthe pronotum.

● A. ferrugineum Zimmermann, hasdistinguishing projections on theanterior pronotum, which extendbeyond the anterior corners (fig18A).

● A. tuberculatum LeConte males(fig. 18B) have distinct pronotaltubercles that are absent in thefemales (fig. 18C).

● Colydium lineola Say (fig. 20): C.Iineola (3.5-5.5 mm) has a ridgedpronotum, but the elytra are muchmore elongate and cylindrical thanthose of other colydiids found withthe southern pine beetle.

● Lasconotus Erichson (fig. 21)Lasconotus spp. also have a ridgedpronotum, but all are considerablysmaller (2.8 mm than Aulonium spp.They are reddish brown, with rough,striated elytra, and clubbed anten-nae.

Figure 18A

Figure 18B

Figure 18C

13

Figure 19

Figure 20

Figure 21

14

Tenebrionidae

● Corticeus Pillar and Mitterpacher(figs. 22, adult; 23, larva): AdultCorticeus spp. (3.0-3.4 mm) havean elongate, cylindrical shape, 1l-segmented antennae, andamber-brown color (fig. 22). Larvaeare laterally striped with alternatinglight and dark bands on the dorsumof each segment (fig. 23).

Figure 22

Figure 23

15

Curculionidae

● Cossonus corticola Say (fig. 24):The weevil most frequently encoun-tered in association with SPBgalleries is C. corticola (4.0-5.0mm). When the insect is viewedlaterally, the stubby snout is themost representative feature. Thebody is black, cylindrical, andelongate with a punctate andstriated elytra. There is a deepgroove between and above the eyes.

Figure 24

16

Cerambycidae: Cerambycids are thelargest insect associates of theSPB. They characteristically havevery long antennae, often longerthan the body. All cerambycidlarvae are cylindrical, fleshy white,and legless (fig. 25). They tapergradually from anterior to poste-rior, and are not C-shaped. Theyhave darkened, strong,well-developed mandibles.Cerambycids taper less abruptlythan buprestid larvae, and do notpossess an inverted “V” on thelarge first segment as do thebuprestids (fig. 26).

● Monochamus Serville (fig. 27):Monochamus spp., or pine sawyers,are 17.5-30.0 mm long as adults,and are mottled gray and brown.The thorax has a stout spine oneither side. The male antennae are 21/2 times body length; femaleantennae are l 1/2, times body length.

● Neacanthocinus obsoletus (Olivier)(fig. 28): N. obsoletus adults aresmaller (7.0-14.0 mm) than othersawyers and have black patterns ona primarily gray elytra. The elytra isdistinctly punctate nearly to theapex. Lateral tubercles are presenton the pronotum, and the legs aresuccessively longer from front torear.

Figure 25

Figure 26

Figure 28

17

Figure 27

18

Platypodidae

Platypus compositus Say (figs.29, male, 30, female): Males havetwo stout spines on the end of theelytra. Females lack the spines,but like the males, have a very

elongate metathorax. Thus, the hindlegs appear to rise from the abdo-men. The abdomen is very shortrelative to overall body length. Thetip of the elytra are squared off inthe middle. Average length for eachsex is 5.0 mm.

Figure 29

Figure 30

19

Scolytidae

● Xyleborus Eichhoff (figs. 31, 32):Xyleborus spp. are small (2.0-3.0mm) and oblong. When viewedfrom above, the prothorax concealsthe head. Like Ips spp., someXyleborus have irregular teeth orspines on the posterior of the elytra.These insects, however, have amore shallow declivity than Ips andno shelf at the base of the elytra(fig. 31). Xyleborus has abellshaped pronotum that is widerthan the anterior portion of theelytra.

● Dendroctonus frontalisZimmermann (fig. 33): D. frontalis,the SPB (2.2-4.0 mm), should beeasily recognized by the users ofthis guide. The head is visible fromabove, with the elevation on eitherside of the medial frontal groovemore pronounced in the male; thefemale has a ridge on the anteriormargin of the pronotum.

● D. terebrans (Olivier) (fig. 34): Itssize (5.0-8.0 mm) makes the blackturpentine beetle easily recogniz-able. It has club-shaped antennaeand no declivity at the posterior ofthe elytra, with the pronotumwidening posteriorly.

Figure 31

Figure 32

Figure 33

Figure 34

20

● Ips De Geer: The pine engravers orIps spp., have spines lining adeclivity on the posterior portion ofthe elytra. Unlike Xyleborus spp.,the engravers have a distinct shelf,or ridge, at the base of the deepdeclivity. They are larger than otherscolytids having a declivity linedwith spines.

● I. avulsus (Eichhoff) (fig. 35):Elytral declivity is moderatelyexcavated, with four teeth on eachside; the second and third teeth areconnected at their base The apicalmargin is slightly elevated. Lengthis 2.1-2.8 mm.

● I. grandicollis (Eichhoff) (fig. 36):Five teeth line the margin of thedeclivity on each elytra. The centertooth is most prominent. The apicalmargin is strongly elevated. Lengthis 3.0-38 mm.

● I. calligraphus (Germar) (fig. 37):There are six teeth on the margin ofthe declivity. The third tooth is stoutand curved downward at the tip.The apical margin is acutelyelevated. Length is 4.0-6.0 mm.

Figure 35

Figure 36

Figure 37

21

● Pityophthorus Eichhoff (fig. 38):The female of this small (1.6 mm)scolytid has long golden hairs onthe front of the head; male hairs areshorter and less numerous. Thehead is covered by the pronotum.There are numerous elevations(asperities) on the pronotum.Antennae are clubbed.

● Crypturgus aleutaceus Schwarz(fig. 39): This is the smallest (0.9mm) insect associate of the SPB.Head is visible from above, and theantennae have three segments, thethird much larger than the others.

● Gnathotrichus materiarius (Fitch)(fig. 40): The prothorax summitswell before the middle of this smallscolytid (3.0 mm). It is dark brownand has slightly pale elytra. Thehead is not visible from above.Antennae are clubbed.

Figure 38

Figure 39

Figure 40

22

Diptera

Stratiomyiidae

● Zabrachia polita Coquillet (figs 41,42): Zabrachia (2.4-2.6 mm has around cell in the middle of the wing(fig. 41A). The antennae have threesegments with an apical arista. Thebody is black with a tiny, pointedabdomen. The thorax has no longspines and the eyes are large andgold. The larva (fig. 41B) hasarmored skin and many longbristles.

Figure 41A

Figure 41B

Figure 42

23

Dolichopodidae

● Medetera Fisher van Waldheim(figs. 43, 44, 45): Medetera (2.8-3.4mm) has a distinguishing wingvenation (fig. 43A); there are noround cells in the middle of thewing and only one cross vein. Theantennae have three segments withan apical arista. Medetera whenalive has red eyes and a green body;when dead it is gray. The malegenitalia is quite conspicuous. Thelarvae (fig. 43B) have an incom-plete head capsule and soft skin.

Figure 44

Figure 45

Figure 43A

Figure 43B

24

● Sciaridae: Sciarids (figs. 46, 47)are small (1.4-1.7 mm), delicateflies and are usually gray to black.Antennae are long andmany-segmented. Eyes are dark andthe abdomen pointed. Wings (fig.46A) have no cells or cross veins inthe middle, but each wing has adistinctly forked vein. The larva(fig. 46B) has a complete headcapsule and soft skin.

Figure 47

Figure 46A

Figure 46B

25

Lonchaeidae

● Lonchaea Fallen (figs. 48, 49):Lonchaea (3.4-4.2 mm) is a black,heavy-bodied fly with a pointedabdomen and red-brown eyes. Theantennae have three segments with asubapical arista; the third segment ismuch more elongate than that ofother flies discussed here. The wing(fig. 48A) is similar to that ofMedetera but has a small cross veinnearer the apical cross vein. Thelarva (fig. 48B) has soft skin andinternal mouthparts.

Figure 49

Figure 48A

Figure 48B

26

Hymenoptera

Formicidae

● Crematogaster ashmeadi Mayer(fig. 50): C. ashmeadi, like all antsfound with SPB, are usuallywingless. They are small (2.1-2.6mm) brown insects with extremelynarrow waists (gaster) and triangu-lar abdomens. There are two spineson the propodeum.

Braconidae

● Cenocoelius nigrisoma (Rohwer)(fig. 51): The male of C. nigrisomais 5.0 mm long; the female is 6.0mm long. Both sexes have a redhead and shiny black body. Thethorax is deeply pitted and rough.The abdomen is narrow andattached high on the thorax (dor-sally).

● Coeloides pissodis (Ashmead) (fig.52): C. pissodis is smaller (3.8-4.6mm) than Cenocoelius nigrisomaand has a smooth red head and anorange abdomen. The thorax ishairy and shiny. There are broadfurrows at the base of the abdomenand petiole The pedicel of theantennae is twice as long as the firstflagellar segment.

● Atanycolus comosifrons Shenefelt(fig. 53): Females are 9.0-11.0 mmlong with an ovipositor 13.0-16.0mm long; males are 9.0 mm long.The face is densely covered withsilver hairs. The pedicel of theantennae is about five times longerthan the first flagellar segment.

Figure 50

27

Figure 52

Figure 51 Figure 53

28

● Dendrosoter sulcatus Muesebeck(fig. 54): D. sulcatus has a deepcleft above the eyes, with swollenareas (tubercles) on each side. Thewings are dusky with a white bandextending across them. The adultsare 2.8-3.5 mm, dark brown, andthe apical half of the abdomen isdarker than the basal half.

● Meteorus hypophloei Cushman(fig. 55): M. hypophloei (2.8-3.8mm) has a thick head, a stout thorax(about 2 1/2 times as long as wide),and coarsely sculptured hind coxae.The females have a slender, slightlydecurved oviposter. Wings are clear.

● Spathius pallidus Ashmead (fig56): The adult s. pallidus is 3.5 mmlong and light brown. The head hasstriations, and the wings appearpatterned. The petiole is striatedand has lateral processes. The firstabdominal segment is almost aslong as the remainder of theabdomen.

Figure 56

Figure 54

Figure 55

29

Pteromalidae: The pteromalids areminute, metallic-bronze insectswith greatly reduced wing venationand triangular-shaped abdomens.

● Dinotiscus dendroctoni (Ashmead)(figs. 57, male; 58, female; 59A):The sexes of D. dendroctoni differmarkedly. Both sexes are metallicgreenblack with clear wings havinggreatly reduced venation. Also, thethorax is densely punctate. Females(3.8 mm) have long, pointedabdomens. Males (2.7 mm) appearsimilar to males of Roptrocerus (fig.59), but have a distinctly rectangu-lar stigma in the forewing (fig.59A).

Figure 58

Figure 57

Figure 59

30

● Roptrocerus Ratzeburg (figs. 59B,60, male; 61, female): Both sexes ofRoptrocerus have a finely punctatethorax. They are usually smallerthan D. dendroctoni; females are3.0 mm, males 1.8 mm long. Malesand females have a rounded stigmain the forewing (fig. 59B). Theirwings have short hairs.

● Heydenia unica Cook and Davis(fig. 62): H. unica adults (2.8-4.2mm) are usually reddish brown andhave large front femora. There is aspot on the forewing. The pronotumis bell-shaped, and gives it a“necklike” appearance.

Figure 61

figure 60

Figure 62

31

Eurytomidae: Female eurytomids aresimilar in abdominal shape to thepteromalids, but they are usuallyblack and have a more coarselypunctate thorax. The antennae havedense, light-colored hairs.

● Eurytoma tomici Ashmead (figs.63, male; 64, female): These areshiny black wasps 3.5-4.0 mm.They have a squarish pronotum,large pits on the thorax, and atriangular abdomen. The males haveasymetric, elbowed antennae.Female eurytomids are similar inabdominal shape to the pteromalids,but they are usually black and havea more coarsely punctate thorax Theantennae have dense, light-coloredhairs.

Figure 63

Figure 64

32

Platygastridae: Platygastrids areminute (1.0-1.3 mm) shiny blackwasps with reduced wing venationmuch like chalcids. The antennaehave 10 segments, and are attachedvery low on the face, next to theclypeus.

● Platygaster Latreille (fig. 65):Platygaster spp. (1.3 mm) haveclear wings without a fringe of hairson the hind margin of the forewing,a trait which distinguishes themfrom Leptacis spp. (fig. 65). Thescutellum is rounded off at the rearmargin.

● Leptacis Foerster (fig. 66):Leptacis spp. are similar toPlatygaster spp., except for thesome what dusky wings with afringe of hairs. Length is 1.0 mm.They have a backward projectilespine on the scutellum.

Figure 65

Figure 66

33

Acknowledgments

Thanks are extended to Dr. H. J.Teskey, Biosystematics ResearchInstitute, Agriculture Canada, Ottawa,for allowing us to reproduce hisfigures of Diptera larvae. Specialgratitude is due to Dr. C. W. Berisford,Department of Entomology, Universityof Georgia Athens, and Dr. F. M.Stephen, Department of Entomology,University of Arkansas, Fayetteville,for review and suggestions. Also, weappreciate the suggestions made byDrs. F. Hain, North Carolina StateUniversity, Raleigh; G. MooreU.S.F.S., Research Triangle Park,North Carolina; J. Moser, U.S.F.S.,Pineville, Louisiana; J. Richerson,Texas A&M University, CollegeStation; and R. Wilkinson, Universityof Florida, Gainesville. Funding wassupplied in part by the MississippiAgricultural and Forestry ExperimentStation and the Louisiana AgriculturalExperiment Station.

Selected Reference

Leng, C. W., A. J. Mutchler, andR. E. Blackwelder. 1920. Catalogueof Coleoptera of America, North ofMexico. John D. Sherman, MountVernon. NY.

Moser, J. C., R. C. Thatcher, andL. S. Pickard. 1971. Relativeabundance of southern pine beetleassociates in East Texas. Ann.Entomol. Soc. Am. 64:72 77.

Muesebeck, C. F. W., et al. 1951.Hymenoptera of America north ofMexico. Synoptic Catalog. U.S.Dep. Agric., Monogr. 2. U.S. DepAgric., Washington, D C.

Overgaard, N. A. 1968. Insectsassociated with the southern pinebeetle in Texas, Louisiana, andMississippi. J. Econ. Entomol. 61:1107-1201.

Stone, A., et al. 1965. A catalog ofthe Diptera of America north ofMexico. Agric. Handbk. No. 276.U.S. Dep. Agric., Agric Res. Serv.,Washington, D.C.

Teskey, H. J. 1976. Diptera larvaeassociated with trees in NorthAmerica. Memoirs Entomol. Soc.Canada. No. 100.