JoAnn White

Xylem feeding by periodical cicada nymphs on tree roots

Abstract. 1. Histological sections of tree roots on which periodical cicada nymphs of both the 17‐year and the 13‐year race arid various instars had fed showed that salivary sheaths made by the nymphs ended in xylem vessels.

Effects of superabundant food on breeding success and behavior of the red-winged blackbird

SummaryThe effects of food on breeding success and behavior of the red-winged blackbird (Icteridae: Agelaius phoeniceus) were investigated during 3 successive breeding seasons. In the second season, a 4-week pulse of abundant food in the form of a periodical cicada emergence (Homoptera: Cicadidae: Magicicada spp.) occurred in the forest adjacent to the marsh where the birds were breeding.During the cicada period, the bird population showed: 1) an increase in foraging trips to the forest and a decrease in trips per h, 2) increased biomass of nestlings, 3) increased nestling survival caused by decreased starvation, 4) increased fledging success, and 5) bimodal weight distributions of older nestlings (reflective of the sexual dimorphism in this species). These data suggest the temporary removal of food limitations on the breeding population when the pulse of food was available.

17-YEAR CICADAS EMERGING AFTER 18 YEARS: A NEW BROOD?

eight weeks, by their tiny progeny. Originally we assumed that case (1) but not (2) had occurred in northern Kentucky. Periodical cicadas had appeared in 1970 (Brood X) and 1974 (Brood XIV). However, we later received word from friends that there had been a substantial emergence there in 1975. We revisited our study area and found that this was indeed the case. We then chose one of our study sites (Mason) reported in the earlier paper (Lloyd and White, 1976) and made another collection of twigs along the forest edge adjacent to the previous years collection. We have now counted and measured these eggnests and report the results herewith, along with additional data obtained by digging in an area 2 km away, which also had cicadas emerging in all three years. An unexpected finding of interest is that one of the three synchronized speciesMagicicada septendecula-made up a disproportionately large share of the delayed emergence in 1975. This suggests that M. septendecula is a relatively poor competitor, which may be related to the fact that it is usually the rarest of the three species emerging together. Evolution, 33(4), 1979, pp. 1193-1199