and especially Hynes 1948 ; figures of head, mandi- ble and maxilla are given in lilies 1964), although those of Macrogynoplax have been briefly charac-.
Annîs
Limnol.
20 (1-2) 1984 : 43-48
Brazilian Plecoptera 4. Nymphs of perlid genera from southeastern Brazil
C.G. F r o e h l i c h '
Nymphs ot the three perlid genera known from southeastern Brazil, Anacroneuria, Kempnyia and Macrogynoplax, are distinguished morphogically and a key is provided for their determination.
P l é c o p t è r e s b r é s i l i e n s 4. L e s l a r v e s des g e n r e s de P e r l i d a e d u S u d - E s t d u B r é s i l .
L'auteur précise les caractères morphologiques propres à chacun des trois genres de Perlidae du Sud-Est du Brésil. Anacroneuria, Kempnyia et Macrogynoplax, et il propose une clef de détermination de ces larves.
In southeastern Brazil three well-defined genera of the subfamily A c r o n e u r i i n a e (the only N e o t r o p i cal P e r l i d a e ) o c c u r , viz., Anacroneuria Klap., Kempnyia K l a p . and Macrogynoplax End. T h e only nymphs to have been described and figured are those of Anacroneuria ( N e e d h a m & Broughton 1927, and especially H y n e s 1948 ; figures o f head, mandible and maxilla are given in lilies 1964), although those of Macrogynoplax have been b r i e f l y characterized by Froehlich (1984). In the present paper a comparative discussion of some nymphal characters is presented, based on a study of late instar nymphs of three species of Anacroneuria, five species of Kempnyia (of w h i c h only K. gracilenta (End.) has been d e t e r m i n e d to species), and o n e species of Macrogynoplax (M. veneranda F r o e h l i c h ) . All nymphs c o m e f r o m stony streams of the coastal range of the State of Sâo P a u l o . T h e general shape of the b o d y is perlid-like and similar in the three genera (for Anacroneuria see H y n e s , I.e., Fig. 1 A ) . T h e b o d y is clothed w i t h dark hairs but the clothing hairs of the head may be thinner and lighter in c o l o u r in some species o f Anacroneuria and Kempnyia, and in Macrogynoplax. Ana-
1. Departamento de Biologia, FFCLRP, Universidade de Sâo Paulo, 14100 Ribeirào Preto, SP, Brasil.
cronettria (Fig. 1) and Macrogynoplax possess t w o ocelli ; in the latter genus they a r e nearer to each other in the nymphs than in adults (Fig. 3). Kempnyia has three o c e l l i , the median one being s m a l l e r than the others (Fig. 2) ; p r o b a b l y in s o m e species, as in the adults, the median ocellus m a y sometimes b e minute o r absent. T h e r e is no occipital r i d g e . T h e mouth p a r t s are, on the whole, rather uniform. Macrogynoplax d i f f e r s f r o m the o t h e r t w o genera by the long, thin maxillary and labial palpi (Figs. 6 and 7), and by the m o r e protruding basal teeth, and by the w i d e angle between the mesial brush and the ventral r o w of bristles of the mandibles (Fig. 5). F o r comparison, a mandible, a maxilla and the labium of a Kempnyia a r e shown in Figs. 8-10. The front legs, which are unmodified in Anacroneuria and Kempnyia, f o r m in Macrogynoplax a pair of raptorial structures (Fig. 4). T h e femora a r e thickened and bear anteriorly a receiving groove for the tibiae. T h e g r o o v e is c l o t h e d w i t h thickly set short hairs and is g a r d e d in the basal half by t w o r o w s of bristles. T h e tibiae are c u r v e d t o w a r d s the femora, and clothed w i t h thickly set short hairs on the side that fits into the femoral groove. T h e posterior fringe of long hairs is moderately d e n s e on the femora, thinner and with s h o r t e r hairs on the tibiae.
Article available at http://www.limnology-journal.org or http://dx.doi.org/10.1051/limn/1984018
Fig. î -3. Outlines of head and prothorax ; Î , Anacroneuria sp. ; 2, Kempnyia sp. ; 3, Macrogynoplax Fig. 4. Macrogynoplax
veneranda, fore leg, dorsal view.
veneranda.
Fig. 5-7. Macrogynoplax veneranda, mouth parts, ventral view ; 5, right mandible ; 6, lacinia, galea and pal pus of right maxilla ; 7. labium. Fig. 8-10, Kempnyia sp., mouth parts, ventral view ; 8, right mandible ; 9, lacinia, galea and palpus of right maxilla; 10, labium,
C.G. FROEHLICH
46 Kempnyia
( F i g . 11) and Macrogynoplax
have, on
e a c h side, t w o tufts o f supra-coxal gills on the pro as w e l l as o n the m e s o t h o r a x (gills C] and Cj o f H y n e s 1941), and o n e pair o f p l e u r a l ( s u b s t i g m a l ) g i l l s , each gill w i t h three main branches, b e t w e e n
(4)
2 — T h o r a c i c gills C j , C and C 2
3
present.
Usually with three ocelli and anal gills
Kempnyia
— T h o r a c i c gills C and C , and anal 2
gills absent. T w o ocelli
3
Anacroneuria
the pro- and the mesothorax, and between the mesoa n d the m e t a t h o r a x (gills I and I I of H y n e s ) . A b o v e a n d p o s t e r i o r to the m e t a t h o r a c i c legs there a r e
Literature cited
t h r e e gill tufts, o f w h i c h t w o are p r o b a b l y gills C 3 , and the third, a d i s p l a c e d , single-branched gill I I I . A p a i r o f anal gills is present, e x c e p t in o n e species of Kempnviu.
T h e three species o f
Anacroneuria
have gills as d e s c r i b e d by Hynes 1948. Gills I, I I and I I I h a v e three m a i n branches each, while gill C] is r e p r e s e n t e d by t w o tufts (Fig. 12). Gills C and C 3 , 2
a n d the anal gills a r e absent. A p r a c t i c a l key f o r the d e t e r m i n a t i o n o f late instar n y m p h s of the three genera f o l l o w s : 1 — Front legs raptorial F r o n t legs not m o d i f i e d
Macrogynoplax 2
Froehlich (C.G.). 1984. — Brazilian Plecoptera 3. Macrogynoplax veneranda sp. n. (Perlidae Acroneuriinae). Annls Limnol. 20 : 3942. Hynes (H.B.N.). 1941. — The taxonomy and ecology of the nymphs of British Plecoptera with notes on the adults and eggs. Trans. R. en!. Sue. Land.. 91 : 459-557. Hynes (H.B.N.). 1948. — The nymph of Anacroneuria aroucana Kimmins (Plecoptera, Perlidae). Proc. R. ent. Soc. Lond., (A) 23 (10-12): 105-110. lilies (J.). 1964. — SCidamerikanische Perlidae (Plecoptera). besonders aus Chile und Argentinien. Beitr. Neotrop. Fauna, 3 (3): 207-233. Needham (J.G.) & Broughton (E.). 1927. — Central American sto neflies with descriptions of new species (Plecoptera). /. New York ent. Soc, 35: 109-121.
Fig. 11-12. Ventral view of thorax showing the gills, legs removed from the left side ; 11, Kempnyia sp. ; 12, Ana croneuria s p .
