The Larva and Pupa of Lytrosis Permagnaria Pack. (Geometridae)
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Journal of the Lepidopterists' Society 57(2),2003, 107-112 THE LARVA AND PUPA OF LYTROSIS PERMAGNARIA PACK. (GEOMETRIDAE) DAVID L. WAGNER DepaJiment of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269, US A. E-mail: [email protected] ERIC W HOSSLER Depariment of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269, USA, and Department of Anatomy and Cell Biology, J.I-l. Quillen College of Medicine, East Tennessee State UniverSity, Johnson City, Tennessee 37614, USA AND FRED E. HOSSLER Department of Anatomy and Cell Biology, J.H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37614, USA ABSTRACT, LaJvae of Lytrosis permagnaria were reared to maturity on red oak (Quercus ntbra). The larva and pupa of this rare eastern geometrid are described and illustrated. Diagnoses and photographic images of late instar huvae are provided for three members of the genus: Lytmsis permagnrl'ria, L. sinuosa, and L. l.tnitaria. Additional key words: Lytrosis sinuosa, Lytrosis unitaria, Euchlaena, twig mimicry. Lytrosis perrnagnaria (Pack.) has been regarded as in a solution of sugar and water, began laying pale one of the rarest of eastern macrolepidopterans. At the green eggs aft er two days in captivity. First ins tars time Forbes (1948) completed his work on the wander actively, often covering large distances, before 'Geometridae of New York and Neighboring States,' settling to feed. Captive 1st instar larvae accepted red the species was known only from the holotype (a fe (Quercus rubra), scrub (Q . ilic~folia ), and white (Q. male from Missouri). Up until a few years ago there alba ) oaks as well as hickory (Carya spp.). The follow were only two specimens in the United States National ing larval description is based on two pickled larvae Museum. Rindge (1971) characterized it as being "an (onc pre-overwintering caterpillar preserved 29 No extremely rare species." Ferguson, an authority on the vember 2000 and one mature, post-overwintering North American Geometridae, had never seen this caterpillar preserved 17 May 2001) and 58 larval pho species alive before we arranged for him to visit tographs (of three pre-overwintering caterpillars and Goshen, Virginia, in 1999. But like so many rare or two post-overwintering caterpillars). The pupa was ganisms, in the right localities at the right time, L. per preserved on 27 May 2001. Adult, larval, and pupal rnagnaria can be common. At Goshen we occasionally vouchers and slides (transparencies) are deposited at observed more than a dozen individuals at light on the University of Connecticut. nights in early June. This species is distributed from Cranial and body setae of Lytrosis perrnagnaria are Georgia to eastern Texas north to Missouri, Indiana, very short and inconspicuous. Because we had but two northeastern Tennessee, and central Virginia. Herc we larvae, and a Single last instar, our setal mappings must describe and illustrate the last instar larva and pupa for be regarded as tentative. This is particularly true of the the first time, distinguish the larva from congeners, cranial setae and minute body setae that were some note several morphological similarities in the imma times difficult to locate, ture stages of Lytrosis and Euchlaena, and provide Description. Last Instar Larva. Length: 40 mm (probably at brief observations on the moth's life history. taining lengths of .50 mm; n = 1). Head (Figs . .5-11, 14-16, 23) somewhat quadrate, with dark spot at top and pale band down each side of triangle; third stemma enlarged; all setae short, espeCially P, METHODS AND RESULTS L, and A setae over dorsum of head (MD setae were not observed). Body (Figs. 1- 4, 12, 13). (Note: in our preserved specimens, the Lytrosis perrnagnaria was seen in the vicinity of the posterior balf of each segment is enlarged, espeCially that of AI. ) shale pit, southeast of Lake Merriweather, on the Ground reddish brown in pre-overwintering larvae and smoky gray brown in mature post-overwintering larvae, fading to tan in alcohol; property of the Boy Scouts of America Camp, south trunk with numerous brown spots and shmi undulating, often dou east of Goshen, Rockbridge Co., Virginia. A female, bled stripes and broken lines of varied width; integument rough with collected at light on 9 June 2000, held in a brown pa many shallow pits. Middorsal and subdorsal stripes poorly differen tiated; supraspiracular stripe perhaps most evident of all body per bag with a wet cotton ball that had been immersed stripes, espeCially on A3- A6; midventral and subventral stripes pres- 108 JOURNAL OF THE LEPIDOPTERISTS' SOCIETY ~ , '- DI , "- , \, *' D2 , \ ./ , , , ~ MDI " '-. I r .I I SOl ! , \ SD2' 0 'a' '0 I , , 0 LI '0 '0 ~ lU I " l ~ J ,I " / , L3 , " / I' ~ ~ I " " SV setae \ \ ~ , /' ..... ~ .. , ~t} . " .' ". ! f i 0, T ' V '-. f 2 TI TIl At A2 A6 A7 3 1'I(:s. 1-4. Last ins tar larva of Lytrosis permagnaria. 1, Habitus. 2, Chaetotaxy; setae associated with thoracic legs not shown; SD2 minute and indicated on ly by its pinaculum. 3, Dorsal view, A9- AlO. 4, Lateral view, A7-AlO . ent on abdominal segments. Most conspicuous markings include A8 raised. Anterior face of thoracic legs brown. Crochets: 50-55 on black oblique lines on A7 and All below each spirade and small anterior proleg (Fig. 13), 61 - 66 on anal proleg, mostly of two obliqll" line above spiracle on A8 (which is a continuation of the lengths; intercalated fleshy lobe of Forbes (1948) absent. Hypoproct obliq"" line that starts on A7). Horizontal black lim' across anterior and paraproct large, latter nearly one-half the length of anal plate proleg. Dorsum of A9 and AlO marked with incomplete middorsal and extending well beyond body; hypoproct sllhequal to paraproct, line. Spiracular peritreme thinned dorsad and ventrad; Tl and pOinted (Figs. 3, 4, 21). Chaetotaxy (Figs. 2- 4); setae brown, short, A6-AS spiracles enlarged, those on A6 and A7 lowered, and that of often less than one-half the height of spiracle on TI. Two SD and VOLUME 57, NUMBER 2 109 FIGS. 5- 13. SEM images of Lytrosis permagnaria. 5, Head, lateral (scale = 500 ~m). 6, Head, dorsofrontal (scale = 500 ~m). 7, Head, ven tral, prolegs removed (scale = 0500 ~m ) . 8, \1axillolahial complex (scale = 0500 ~m). 9, Maxilla (scale = 100 ~lrn). 10, Maxillary palpus (scale = 100 ~m). 11, Antenna (scale = 100 ~m). 12, Mesothoracic claw (scale = 200 ~m ) . 13, Crochets on A6 proleg (scale = ,500 ~m ) . 15 FIGs. 14-16. Lytrosis perrnagnaria head. 14, Dorsofrontal. 15, Lateral. 16, Mandibles. llO JOURNAL OF THE LEPIDOPTERISTS' SOCIETY '. .,~,;~?< :2~'~' ~~ _: . ;. 20 Flt;s. 17-20. Pupa of Lytmsis pemwgnaria. 17, Ventral. 18, Lateral. 19, AS-AlO, ventral. 20, AS-lO, dorsal. two L setae closely situated on T1. 01 from small wart on AI-AS; DISCUSSION 02 on Al and A.5 from small , often yellowed warts (in living individ uals ). S02 minute. LI behind spiracle on Al-AS, but displaced All Lytrosis caterpillars are twig mimics (Figs. downward on An; L2 below and cephalad on AI-AS; L3 grouped 21-26). This is most apparent in Lytrosis sinuosa with SV setae on AI- A2. An with five SV setae. SV setae on A7-A9 and all setae on AlO lengthcncd and paler. L3 and SV setae arising whose texture, coloration, and patterning closely re frol\l raised swellings on A7 and AS; A9 with Land SV setae arising sembles that of a Quercus (especially a white oak) twig from large fl eshy warts, SD2 and V extremely reduced. Anal platc (Figs. 24-25; Wagner et al. 2002). It is believed that with fo ur pairs of setae (Figs. 3, 4). Pupa, Length 20 mm, width .5 ..5 mm (n = 1; Figs. 17-20). middle ins tar Lytrosis larvae spend the winter exposed Fusiform, very dark and shiny, deeply rugous over anterior Y:J of on bark-two of three Lytrosis permagnaria that we wings and dorsum of thorax and head. Labrum hemispherical, sleeved on Quercus rubra in October 2000, survived length 0.64 of width. Labial palpus short, tonguelike, nearly as long as wide. Probosds extending just beyond prothoracic leg. Protho the winter in eastern Tennessee (Johnston City). racie femur not visible. Mesothoracic leg reaching just beyond an McGuffin (1981) stated that Lytrosis unitaria over tenna. Metathoracic leg exceeding mesothoracic leg and wing, winters as a 5th instar. In the same work, McGuffin re reaching antelior margin of A.5. Mesothoradc spiracle raised, elon gate, undercut posteriad. Length of TIll and A1 slIbequal. TI-TIII ported that L. unitaria has up to 9 instars- the largest with 2 setae; Al with 1 seta; A2-A3 with 2; A4 with 3; A.5-A6 with 4, number for any geometrid of which we are aware. SV on prononnced swelling; A7 -AS with :3 setae; A9 with 2 setae and There are four species of Lytrusis in eastern United dark pit cephalad of L seta. AlO cremaster consisting of 4 thickened, recurved pairs of setae and one enlarged pair of caudal hooks (Figs. States (Rindge 1971, Ferguson 1983), only one of 19- 20). which, Lytrosis unitaria (H.-S.) is widespread and com- VOLUME 57, NUMBER 2 III FIGS. 21-26. Larvae of Lytrosis. 21, Lytrosis pennagnaria, overwintering larva. 22, Lytrosis permagnaria, mature larva. 23, Lytrosis per magnana, mature larva, head. 24, Lytrosis sint/osa , overwintering larva. 25, Lytrosis sinuosa, mature larva. 26, Lytrosis "nitaria, mature lalva. man. The three others are scarce or only locally com larged subdorsal swellings on Al and enormous subdor mon. Two of the four, Lytrosis heitzmanomm Rindge sal swellings on A5; in addition there are subventral and L. sinuosa Rindge, were not desclibed until 1971- swellings on A2.