Phanoperla sp.

Mason, Denise & Stark, Bill P., 2015, Notes On The Genus Phanoperla Banks From Sri Lanka And India (Plecoptera: Perlidae), Illiesia 11 (4), pp. 29-40 : 32

Phanoperla sp. Sl-D

( Figs. 1-6 )

Material examined. SRI LANKA: Kandy District , Kabargala, Nillomalai, 22-23 March 1975, S. Korunaratne, P.B. Korunaratne, 1♀ ( USNM) .

Egg. Spindle shaped ( Fig. 1 ). Length ca. 300-330 μm, equatorial width ca. 248-267 μm. Collar ca. 12- 15 μm long and ca. 60-73 μm wide, margin relatively smooth, not flanged, sides with short, smooth struts ( Fig. 2 ). Chorion ornate over almost entire surface ( Fig. 1 ); ca. first 40-50 μm adjacent to collar covered with follicle cell impressions (FCIs), most with punctate floors; apical row of FCIs much longer than 2 nd and 3 rd rows ( Figs. 2-3 ). Beyond the FCI zone, the chorion becomes rather uniformly, coarsely punctate almost to the subequatorial micropylar zone ( Figs. 1, 4 ), however the pores become smaller for a short distance and then disappear for a section in which the chorion is relatively smooth. On the lid, obscure FCIs reappear with coarsely punctate floors extending over the anterior pole ( Fig. 4 ). Micropyles with short sperm guide canals occur in a subequatorial row ( Figs. 1, 4, 6 ).

Comments. In addition to the seven Phanoperla species formally recognized by Zwick (1982a) from Sri Lanka, there are also descriptions for females and eggs of two Sri Lankan species under informal designation ( Table 1 ). The current specimen may represent an unassociated female of a species distinct from any of those considered by Zwick (1982a), or it may be the female of one of the two named Sri Lankan species ( P. ceylonica Kawai 1975 ; P. srilanka Zwick 1982a ) for which the female and egg are unknown. The chorionic detail of the current species is similar to that of P. sp. A ( Zwick 1982a) in having distinct follicle cell impressions limited to the collar area, and in having punctations over much of the remaining chorion. However, as Zwick (1982a) noted in regard to the egg of P. sp. A, the “…upper half of egg unsculptured.” The “upper half” refers to the end of the egg opposite the collar, which in the current specimen has conspicuous sculpturing on the lid ( Figs. 1, 3 ). The egg of the current specimen is also similar to that of P. nuwara Kawai 1975 and P. testacea ( Hagen 1858) in zonation of chorionic detail, however the image for P. nuwara [( Fig. 24e ) in Zwick (1982a)], shows an egg with apparent, less prominent follicle cell impressions on both ends, but particularly so near the collar, and the image for P. testacea [( Fig. 24d ) in Zwick (1982a)], shows an egg with a linear arrangement of punctations over much of the chorion. In addition, the eggs from our specimen appear to have more densely packed punctations in the equatorial zone. Unfortunately, we returned this single female specimen to the USNM before the subgenital plate was drawn and the specimen may need to be examined later.

Figures

Figs. 1-6. Phanoperla sp. Sl-D egg. 1. Lateral aspect. 2. Collar end (a = anchor; c = collar; fci = follicle cell impression; p = punctation). 3. Collar end with most of anchor intact. 4. Lid and micropylar zone. 5. Collar and damaged anchor, apical aspect. 6. Micropyles (m = micropyle).

Figs. 22-27. Phanoperla wedda egg. 22. Lateral aspect. 23. Collar end (s = stria). 24. Anchor and collar (at = anchor tentacle). 25. Lid and micropylar zone. 26. Anchor and collar, apical aspect. 27. Micropyles (m = micropyle).