Table 2 Key for the Churchill, Manitoba, area Limnephilidae larvae

1)

all gill clusters with a single filament

at least some gills with clusters of 3 or more filaments (Figure 15A)

2)

at least some gill clusters with more than 3 filaments (Figure 15A)

no gill clusters with more than 3 filaments (Figure 15D)

3)

setae present on metonotal membrane between sa2 sclerites (Figure 15B)

metanotal membrane setae absent

4)

2nd and 3rd mesofemur with only 2 major ventral setae (Figure 15C)

2nd and 3rd mesofemur with numerous major ventral setae (Figure 15F)

5)

setae present on metonotal membrane between sa2 sclerites (Figure 15B)

metanotal membrane setae absent

6)

dorsomesal chloride epithelia present (Figure 15D)

dorsomesal chloride epithelia absent

7)

mesofemur with accessory setae on at least one lateral surface (Figure 15C)

mesofemur lacking lateral accessary setae

8)

anterolateral corner of pronotum with scurf of small, stout spicules (Figure 15E)

stout spicule scurf absent

9)

basal trochantal segment with accessory setae (Figure 16A & B)

basal trochantal segment without accessory setae

10)

ventrolateral abdominal gill series extends to 4th segment

ventrolateral abdominal gills extend to 6-7th segment

11)

ventral apotome short, about half the length of ventral ecdysial suture (Figure 16C); metanotal sa1 and sa2 sclerites small or absent

ventral apotome long, nearly reaching posterior margin (Figure 16D); metanotal sclerites large, obvious (Figure16E)

12)

accessory setae present on at least one mesofemur lateral surface (Figure 15C &16B)

mesofemur lateral accessary setae absent

13)

basal segment of mesotrochanter with accessary setae (Figure 16B)

mesotrochanter basal segment without accessory setae

14)

dorsum of head base color pale with a distinct U-shaped dark band (Figure 10C)

base color of head dark (Figure 9I)

15)

anterior of pronotum with transverse, wide dark band (Figure 16E)

anterior of pronotom without wide, transverse dark band

16)

head with three distinct dark bands dorsally against pale background (Figure 9G)

head with dark areas and scattered darker muscle scars, without pale background laterally (Figure 9I)

17)

pale blotches of frontoclypeal area all located within frontoclypeal sutures (Figure 8K)

at least parts of frontoclypeal pale areas located laterad of frontoclypeal sutures (Figure 8J)

18)

the two anterior frontoclypeal pale areas are round (Figure 8J)

the two anterior frontoclypeal pale areas are linear and extend further forward along frontoclypeal suture (Figure 9H)

19)

head with dark background color with darker muscle scars. Any pale areas are small and limited to the frontoclypeal area (Figure 9L)

head with large pale areas not limited to frontoclypeal area (Figure 9A)

20)

head monochromatic brown with little evidence of pale areas in frontoclypeal area (Figure 8L)

head with pale areas in frontoclypeal area (Figure 10B)

21)

anterior ventral apotome about half the length of the ecdysial suture (Figure 16C)

anterior ventral apotome nearly as long as the ecdysial suture (Figure 16D)

22)

frontoclypeal pale blotches extend anteriorly beyond eye (Figure 9K)

frontoclypeal pale blotches do not extend anteriorly beyond eye (Figure 10B)

23)

frontoclypeus without distinct linear dark stripe (Figure 9A)

frontoclypeal stripe distinct (Figure 9D)

24)

medial frontoclypeal band expanded anteriorly with dark coloration reaching anterior frontoclypeal corners (Figure 9C)

medial frontoclypeal band not strongly expanded and without distinct dark coloration in anterior frontoclypeal corners (Figure 9F)

25)

lateral dark bands of head reach posterior margin of head (Figure 9D)

lateral dark bands curved mesad and not reaching posterior margin of head (Figure 9B)

26)

mesonotal sa1 with numerous setae

mesonotal sa1 with only a single seta (Figure 16F)

27)

mesonotal base color dark (Figure 17A)

mesonotal base color pale (Figure 17B)

28)

dark muscle scars broadly scattered across postgenal area (Figure 17C)

postgenal muscle scars coalesced into a band

29)

postgenal band distinct (Figure 17D)

postgenal band indistinct (Figure 17E)