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Early larval dispersal of gypsy moth (Lymantria dispar L.): Effects of maternal nutrition, provisioning of yolk proteins, and temperature during the egg stage
Abstract
North American gypsy moth disperse as larvae on the wind in a behavior called ballooning prior to feeding for the first time. Resources used in dispersal are therefore limited to those carried over from the egg. I measured levels of two yolk storage proteins, vitellin (Vt) and glycine-rich protein (GRP), using quantitative immunoelectrophoresis, I determined the tendency of larvae to balloon in a wind tunnel. I estimated the length of the window for dispersal from the longevity of unfed neonates. Pre-hatch levels of Vt and GRP had no influence on the tendency of neonates to balloon. Levels of these proteins were positively associated with and accounted for 40-50% of the variation in longevity of neonates from the first-laid and center thirds of egg masses. Longevity was greatest for neonates from the first-laid third which also had the highest pre-hatch levels of Vt and GRP. Nutritionally stressed females compensated to maintain levels of Vt and GRP by reducing the number of eggs produced. This compensation was reflected in similar longevities of offspring of stressed and unstressed females. The tendency of larvae to balloon, however, was greater in offspring of unstressed females. It is possible that traits selected for in nutritionally stressed females may be expressed in offspring as a reduced tendency to disperse. Temperature during the six weeks prior to eclosion had a significant effect on pre-hatch levels of Vt and GRP and on neonate longevity. Eggs held at 7$\sp\circ$C or less had similar pre-hatch levels of both proteins. Eggs held at 10$\sp\circ$C for six weeks, however, were depleted of Vt and GRP suggesting a threshold between 7 and 10$\sp\circ$C for stimulation of protein utilization. Eggs held for alternating weeks at 4 and 10$\sp\circ$C had protein levels similar to eggs held at 4$\sp\circ$C indicating eggs must be exposed to temperatures above the threshold for a period greater than a week before utilization of proteins is increased.
Subject Area
Entomology|Ecology|Forestry
Recommended Citation
Diss, Andrea Lisa, "Early larval dispersal of gypsy moth (Lymantria dispar L.): Effects of maternal nutrition, provisioning of yolk proteins, and temperature during the egg stage" (1996). Doctoral Dissertations Available from Proquest. AAI9619383.
https://scholarworks.umass.edu/dissertations/AAI9619383