Leiopodus abnormis (Jörgensen)

ROZEN, JEROME G., 2003, Eggs, Ovariole Numbers, and Modes of Parasitism of Cleptoparasitic Bees, with Emphasis on Neotropical Species (Hymenoptera: Apoidea), American Museum Novitates 3413, pp. 1-36 : 16

Leiopodus abnormis (Jörgensen)

Rozen and Özbek (2003) pointed out that the chorion of many cleptoparasitic bees is thicker than that of other bees and that the deposition of the chorion over an ovum after it is fully formed may take place over a greater period of time than that of other bees. Consequently, an early mature oocyte of cleptoparasites may have a different appearance than a late mature oocyte. I am almost certain that the great variation in the external appearance of mature oocytes of this species can be attributed to the various stages of chorionic deposition. This is because of the correlation of the size of the opercular tubercles with the extent of containment of the micropyle by the opercular rim, as is more fully explained under Remarks. The following description is based on what I think to be a latestage mature oocyte.

DESCRIPTION OF MATURE OOCYTE (figs. 16– 19): Chorion smooth under stereomicroscopic examination; under SEM examination, chorion at least of anterior part of oocyte (including the operculum) without patterning; opercular rim elevated so that disc recessed except for large paired tubercles that extend well beyond the rim (fig. 16); micropyle with pores tightly clustered and deeply recessed within micropylar aperture of the anterior edge of rim.

REMARKS: Figure 18 is thought to show an early­stage mature oocyte with the paired opercular tubercles just starting to be deposited. The opercular rim is elevated and evinces a polygonal patterning around its inner slope. The multipored micropyle cluster is well exposed (except for some follicular tissue that seems to be, but is not, a bridge of the chorionic opercular rim, fig. 18) and a faint polygonal patterning is apparent on the sides of the oocyte.

Figure 19 is interpreted to be an intermediate stage of chorionic deposition with the paired opercular tubercles partly developed but not extending beyond the elevated rim. The polygonal patterning is clearly visible on both surfaces of the rim, and the micropyle aperture of the rim has enclosed the micropylar cluster.

Figures

Figs. 16–19. SEM micrographs of operculum of mature oocyte of Leiopodus abnormis. 16. Late stage, anterodorsal view. 17. Close­up of micropyle; note opercular rim causing micropyle to be recessed. 18. Early stage mature oocyte, with tubercles starting to be deposited, rim thin, and micropyle exposed (except for follicular debris appearing to divide it) anterodorsal view. 19. Intermediate­stage mature oocyte, with tubercles partly developed and micropyle becoming recessed by rim, posterodorsal view.