Ovipara

Since even in one sample of erigeronensis (e.g., Brickellia sp., Rincon Springs, San Diego County, California, leg. R. van den Bosch, no. 61-2-14c), an ovipara has siphunculi of 1.00 mm, but an aptera vivipara of the same size, 0.79 mm, such a discriminant based on length of siphunculi is not very helpful, and thus erigeronella Soliman is considered a synonym of erigeronensis Thomas (cf. escalantii Knowlton, 1928).[…]A third form, resembling typical erigeronensis, with the hind tibiae black in oviparae, but which has a last rostral segment with a total of about 16-22 hairs, is known only as oviparae from Haplopappus acradenius (Garnet, Riverside County, California, January 16, 1964, H.R.L., no. 137).

The ratios of mean eggs laid/mean oviparae produced for the two groups relate to the mean weights of oviparae in those groups (Fig. 32) and a linear relationship is assumed between the points. The number of eggs laid by each ovipara of the heavier group is approximately 80% of its egg complement, using Brown’s (1975) results from dissections of oviparae of similar weight.

Crema (1969) reported that nine short-day photoperiods were required to switch the vetch aphid from virginopara to ovipara production and that the embryos were determined as virginoparae or oviparae on about the fourteenth day of their development, at which time they had fully formed but undetermined germaria.