Glossosomatidae

Introduction

There are three genera 3 genera found in Michigan, Glossosma Curtis (3 species), Agapetus Curtis (2+1 species) and Protoptila Banks (3+1 species). A species key to pupae and larvae (except Glossosoma) is currently unavailable.

Adults (adapted from Leonard and Leonard 1949, Ross 1941, 1944, Schmid (1982, 1998), and Wymer and Morse (2000)

1a	a. Protibiae without spurs (0,4,4 or 0,3,3)	Protoptila Banks, 3
	b .Front and hind wings long and very narrow, venation reduced and faint
	also: phallic apparatus between preanal appendages; male Ab8 sternite platelike, elongated posteriorly; in ventral view, vaginal apparatus with a very long rod
1b	a. Protibiae with two spurs (2,4,4)	2
	b. Front and hind wings fairly evenly elliptical, veneation complete or almost complete
2a(1b)	a. Hind wing with the discoidal cell closed, and the R1 long and ending at the wing margin	Glossosoma Curtis, 9
	b. Dorsum of head with neither pair of warts connected by transverse epicranial sutures
	also: Aedeagus small with its vertical parameres completely concealed in the genital cavity, and a tendon connecting the phallotheca to the preanal appendages
2b	a. Hind wing with the discoidal cell open, and the R1 short, ending at vein R2+3	Agapetus Curtis, 14
	b. Dorsum of head with both pairs of warts connected by transverse epicranial sutures
3a(1a)	Males	4
3b	Females	7
4a(3a)	In ventral view, Ab8 sternite scoop-shaped, large and weakly produced posteriorly, and not produced into a bifid process	Protoptila erotica Ross
4b	In ventral view, Ab8 sternite strongly produced posteriorly and produced into a bifid process	5
5a(4b)	In ventral view, Ab8 sternite with the apicolateral corner produced into a brushy lobe, and with the apex with a large and wide median emargination	Protoptila tenebrosa (Walker)
5b	In ventral view, Ab8 sternite with the apicolateral corner angulate, not produced, and with its apex more slender	6
6a(5b)	Lateral spine (parameres) of aedeagus stout, short, and abruptly angled upward near its apex	Protoptila maculata (Hagen)
6b	Lateral spine (parameres) of aedeagus slender, long, and only gradually curved, abruptly narrowed at its base	Protoptila lega Ross
7a(3b)	a. In ventral view, internal plate of Ab9 tergite with a dorsal, bandlike prolongation which is joined to the base of Ab10 tergite	Protoptila maculata (Hagen), Protoptila lega Ross
	b. apicolateral lobes of Ab8 sternite long, trianguloid
7b	a. In ventral view, internal plate of Ab9 tergite without a dorsal prolongation	8
	b. Apicolateral lobes of Ab8 sternite narrow
8a(7b)	In ventral view, internal sternal "whip" attached to a small, projecting, mesal sclerite	Protoptila tenebrosa (Walker)
	also: Lobes of Ab10 tergite conical
8b	a. In ventral view, internal sternal "whip" attached to a large, rounded plate which spans almost the entire width of the segment	Protoptila erotica Ross
9a(2a)	Males	10
9b	Females	12
10a(9a)	Inferior appendages each single, clavate	Glossosoma intermedium (Klapálek)
10b	Inferior appendages each with two or more branches	11
11a(10b)	a. Inferior appendages each with two branches	Glossosoma nigrior Banks
	b. Preanal appendages each with an irregular incision in the posteroventral margin, and without a dorsal hook
11b	a. Inferior appendages each with three branches	Glossosoma lividum (Hagen)
	b. Preanal appendages not incised posteroventrally, but with a dorsal hook
12a(9b)	a. Ab8 broadly and deeply incised posterodorsally and posteroventrally, and lobed posterolaterally	Glossosoma nigrior Banks
	b. Spermathecal sclerite clavate
12b	a. Ab8 not incised dorsally, and with a quadrate or acute incision posteroventrally	13
	b. Spermathecal sclerite not clavate
13a(12b)	a. Ab8 with a broad, nearly quadrate incision posteroventrally	Glossosoma lividum (Hagen)
	b. Spermathecal sclerite rectangular
13b	a. Ab8 with a deep, narrow cleft posteroventrally	Glossosoma intermedium (Klapálek)
	b. Spermathecal sclerite tapered
[note: description of the female of Agapetus tomus Ross has not been published, but associated female specimens from Michigan have been found and a description is forthcoming]
14a(2b)	Males	15
14b	Females	17
15a(14a)	In lateral view, inferior appendage with its apical (posterior) margin medially emarginate, with the dorsal and ventral corners produced into a sharp but short point	Agapetus tomus Ross
15b	In lateral view, inferior appendage with its apical margin not with largely medially emarginated, but either largely rounded or trilobed	16
16a(15b)	In lateral view, basal portion of the inferior appendage clearly narrower than its apical (posterior) portion, which is largely rounded, and only a low, undulant ridge on its inner face	Agapetus rossi Denning
16b	In lateral view, inferior appendage narrowed in the basal portion, considerably wider at its apical portion which is often more strongly trilobed, and with a hook arising from the inner face	Agapetus hessi Leonard and Leonard
17a(14b)	In lateral view, the lower basal angle of Ab8 forms a large, prominent and convex lobe	Agapetus hessi Leonard and Leonard
17b	In lateral view, the lower half of the basal portion of Ab8 is largely concave, with the ventral basal portion forming an acute point	Agapetus rossi Denning

Pupae (from Ross 1944)

1a	a. Apical inner tooth of mandibles 0.5x long as apical blade and subparallel with it	Protoptila Banks, no species key currently available
	b. Mandibles in repose over-reaching side of head
	c. Body length <4 mm
1b	a. Apical inner tooth of mandibles much shorter	2
	b. Mandibles in repose not reaching side of head
	c. Body length > 5 mm
2a(1b)	a. Apical inner tooth of mandibles only slightly larger than basal one	Agapetus Curtis, no species key currently available
	b. Posterior (apical) abdominal segments only slightly curled ventrad
2b	a. Apical inner tooth of mandibles many times larger than basal one	Glossosoma Curtis, no species key currently available
	b. Posterior (apical) abdominal segments curled ventrad and slightly forward

Larvae (adapted from Wiggins (1996) and Wymer and Morse (2000))

1a	a. Mesonotum without sclerites	Glossosoma Curtis, 3
	b. Head with ventromesal margins of genae thickened, median ventral ecdysial line approximately as long as each divergent branch enclosing ventral apotome
	c. Anal opening bordered on each side by dark, sclerotized line
	also: Pronotum in lateral view about one-third excised anterolaterally to accommodate coxa; venter of Ab8 lacking setae
1b	a. Mesonotum with two or three sclerites	2
	b. Head with ventromental margins of genae not thickened, median ventral ecdysial line approximately 1.5x longer than each divergent branch
	c. Anal opening usually lacking dark, sclerotized line on each side
2a	a. Mesonotum with three sclerites	Protoptila Banks, no species key available
	b. Head with ventral apotome reduced to slender, V-shaped sclerite
	also: Tarsal claws with basal seta long and slender, arising from side of stout process at base of claw
2b	a. Mesonotum with two sclerites	Agapetus Curtis, no species key available
	b. Head with anterior ventral apotome not slender as above
3a	Pronotum without a small black spot above the forecoxa	Glossosoma lividum (Hagen)
3b	Pronotum with a small black spot above the forecoxa	4
4a	Intersegmental fold between thorax and abdomen posterior of each metathoracic epimeron with small sclerite	Glossosoma nigrior Banks
4b	Intersegmental fold between thorax and abdomen posterior of each metathoracic epimeron without small sclerite	Glossosoma intermedium (Klapálek)

References

Leonard JW, Leonard FA. 1949. Noteworthy records of caddis flies from Michigan, with descriptions of new species. Occasional Papers of the Museum of Zoology, University of Michigan 520:1-8, 5 pls.
Ross HH. 1941. Descriptions and records of North American Trichoptera. Transactions of the American Entomological Society 67:35-126, 13 pls.
Ross HH. 1944. The Caddis Flies, or Trichoptera, of Illinois. Bulletin of the Illinois Natural History Survey 23(1):1-326.
Schmid F. 1982. Revision des Trichoptères canadiens. II. Les Glossosomatidae et Philopotamidae (Annulipalpia). Mémoires de la Société entomologique du Canada 122:1-83.
Schmid F. 1998. The Insects and Arachnids of Canada. Part 7. Genera of the Trichoptera of Canada and Adjoining or Adjacent United States. NRC Research press, Ottawa, Ontario, Canada. 319 pp.
Wiggins GB. 1996. Larvae of the North American caddisfly genera (Trichoptera). University of Toronto Press: Toronto, Ontario. 457 pp. + xiii.
Wymer DA, Morse JC. 2000. Larva, pupa, and adults of Glossosoma nigrior (Trichoptera: Glossosomatidae) with a review of the eastern North American species of Glossosoma. Entomological News 111(3):149-158.

Page created: May 12, 2003 (EB)
Page last reviewed: November 25, 2003 (EB)