Left: Spurgia esulae adult.
Right: Spurgia esulae gall.
Photos from slide show: Biological Control of Noxious Weeds, by Reeves Petrof.

Origin: Originally from Italy and introduced into the U.S. in 1985. (1,4)

Life Cycle:
Egg: Newly laid, egg is approximately .35mm (.01in) in length. Lighter in color when it is young and becomes more dark, and chorion (egg cover) is soft and smooth when it is older. (4)
Larva: There are 3 stages that are generally concentrated in gall. (4,3)
Pupal: Most generations of pupation occur in the gall, except for the over wintering generations which pupate and pass the winter burrowed in the soil. (4,2)
Adult: Adults come out of the soil during early April. This species of fly is very delicate, and adult stage is very short lived, a matter of hours!  Mating occurs in calm and cool periods of twilight and dusk. They do not move a whole lot during daylight when it is hot, and the only time they will move during the day is to shaded areas. (3,2)
Over Wintering: The lava burrows and spends the winter in the soil as a pupa. (4)

Host Impact:  Every generation will attack growing tips of leafy spurge plants causing a gall at the top of
the stem that deforms the leaves. This will destroy the shoot's ability to make a flower thus destroying it's ability to produce seeds. Eventually the upper part of the plant will die. Then the plant will grow new stems which will be attacked by the future generations of Spurgia esulae. (2-4)

Favorable and Unfavorable Release Habitats: They favor slopes facing south that are in cooler climates which have dense spurge. The insect survives well between wind breaks and do not live at all near rivers or other bodies of water. They need areas where the wind is blocked so they can rest and mate. (4)

How and Where to Collect, Transport, and Release: Adults can be collected with common sweep nets on hill sides and slopes facing south.  They can also be found down wind from large shrubs or trees in open fields. Release in such areas also, but not near water bodies. However they are very delicate and short lived, so it is better to collect the infected galls. Keep them moist and green (as you would a plant cutting) and rapidly transport. (1,3)

How to redistribute once established: Collect the infected galls. Keep them moist and green (as you would a plant cutting) and rapidly transport to your new release site. Place in a shady area with spurge and let the adults emerge to infect new plants. (1,3)
Where and how to purchase: Spurgia esulae may be available through some weed management agencies in North America and as well as commercial suppliers. (2)

http://apt.allenpress.com/perlserv/?request=get-abstract&doi=10.1614%2F0890-037X(1998)012%5B0367%3ASBAIMO%5D2.3.CO%3B2&ct=1 http://www.usbr.gov/pmts/eco_research/996.html  

By: By: Clayton Helling.   Published By: Ed Raisor.  Updated By: Morgan Shaw  3/14/08.

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