Yucca field work at the Pinhorn Grazing Reserve, Aug 23, 2007

Dan Johnson (University of Lethbridge), Joel Nicholson (Alberta Fish and Wildlife) and Dale Eslinger (Alberta Fish and Wildlife).

On Aug 23, at the Pinhorn Grazing Reserve, we found one pod (apparently produced in 2006) that had a mix of healthy seed and seed damaged by larvae of Yucca moth (Tegeticula yuccasella), indicating recent successful pollination at the site. Previous surveys indicate that the Pinhorn site has had no fruit in most years, and no evidence of larvae. Fish and Wildlife reports indicate that several pods were reported in one previous year only.

 

 
Typical upland Yucca distribution at the Pinhorn site
Yucca on slopes at the Pinhorn site
Typical Yucca plant at Pinhorn. There was very little evidence of browsing by deer.

The pod found Aug 23, 2007.

Hundreds of yucca plants were examined.

Seed from the pod. A sample was taken away and the rest was left on the ground.
Evidence of feeding by the larvae of the pollinator
(Location of the Pinhorn Grazing Reserve )
Example photograph; Yucca moth at the Onefour site, in a previous year

Fruit produced on a Yucca plant in a yard in Lethbridge, August, 2007.

Yucca plants are known to have produced fruit in Lethbridge as early as the late 1980's (DJ).
 
All photos: Dan Johnson, Lethbridge