Fig. 3

Close-ups of sections through the sharpshooter precibarial valve. (a – c), G. atropunctata, all contiguous sections comprising the valve; (d – f), H. vitripennis, three out of six sections comprising the valve. (a) First section housing the valve assembly of G. atropunctata, labelled to show important parts. This section is an enlargement of the black-boxed area in Fig. 2b , hence bolder outline. At the top, the densely-staining cuticular tendon inserts into the attachments to the valve and interlaces at the bottom with the fibers of the muscle. Basin (Bls, basin-like structure); *, location of the pit/ring (Ring) at the mouth of the bell-like invagination (Bli); crib. plate, cribriform plate of the distal (D-) sensilla in the distal enclosure. (b) Second section housing the valve assembly. This is a particularly clear view of the precibarial valve muscle’s tendon bifurcating at the distal end into two tendon tips attached to the right side of the basin cuticle (left tip) and middle of the valve (right tip). The left tendon tip is very narrow and folded over at its attachment to the basin cuticle. (c) Third section housing the valve assembly. Dotted, numbered boxes correspond to the numbered segments described in the narrative and Table 1. (d) Structures of the epipharyngeal precibarium in H. vitripennis are nearly identical to those seen in G. atropunctata (a – c). The primary difference is the triangular appearance of the tendon attachment to the basin cuticle and valve. However, this is likely due to the closely appressed position of the tendon tips because the same area takes on a more bifurcated structure in subsequent sections (e) and (f), similar to that of G. atropunctata. The most striking difference in these images compared with those in a – c is the presence of unknown particles (presumed microbial biofilm) (white m) distal to the valve (to the right of it, in the image) in the distal enclosure, seen in all three sections. See text for more information on putative microbes. For color version: colors are based on those in Fig. 2, that is, red, resilin; yellow, sclerotin; pink; procuticle. For black-and-white version: dark gray, resilin; pale gray, sclerotin; medium gray, procuticle.