Goldenrod and gall fly research

Ecology and Evolution "A parent struggling to stay awake for the 2:

Goldenrod and gall fly research

These relatively common native wildflowers--placed by Linneaus long ago in the genus Solidago--spend all summer making rough green foliage, but when days grow short in September every Goldenrod worth its gene pool bursts into bright yellow hues that provide its common name.

Gall biology and research

The one excused exception to this golden extravaganza is S. A few are found in shady wooded spots, but the majority grow in sun-loving habitats like old fields and roadsides--places that each fall become works of floristic art that beg NOT to be bush-hogged by farmers or highway workers.

It is then one realizes every Goldenrod flower head is a microcosm unto itself, inhabited by some combination of nectivorous bees and beetles and wasps and flies left that serve the plant as pollinators--but only if they avoid the resident Crab Spiders, praying mantids, or Carolina Anoles that like to snack on busy little bugs.

Galls themselves are very interesting plant structures influenced by various agents, including insects, fungi, viruses, chemicals, and mechanical damage. Such ravenous ingestion of food by grubs or caterpillars invariably leads to excretion of significant amounts of waste, and these metabolic by-products apparently have an effect on the host plant.

In Goldenrod each of the three gall types is caused by a different insect, and all three galls are quite different in shape.

The first of these Goldenrod galls--and the most common around Hilton Pond--is the "apple gall" or "ball gall," named for its spherical shape and Goldenrod and gall fly research red color above. This gall forms when, in late spring, a small fly with spotted wings and the appropriate name of Goldenrod Gall Fly, Eurosta solidaginis, lays her even tinier egg on Goldenrod and gall fly research fast-growing Goldenrod stem.

This stimulates the host plant to create the ball gall, which provides more space right and a lot more succulent Goldenrod cells on which the grub can dine all summer long.

Initially, the ball gall is bright and shiny green like the rest of the stem, but as the runaway gall growth replaces "normal" cell division, once-vibrant leaves near it wither and turn brown, and the gall eventually becomes mottled with purple and looks even more like an apple. Safely sheltered within the gall when winter cold arrives, the now-mature quarter-inch-long fly larva left slows its metabolism and replaces much of its internal water with glycerol, a compound that serves as antifreeze.

In northern states, ice anglers collect Goldenrod ball galls and their chilly inhabitants, cut open the ball, and use the hibernating grubs for fish bait when snow-covered ground makes earthworms hard to come by.

If a gall goes undisturbed by humans or gall-invading predators, the larva inside slumbers until spring when warm days stimulate it to eat a narrow passageway radiating from its feeding chamber.


Adult Goldenrod Gall Flies do not eat and last only about ten days, living only to mate and produce a new generation of gall-causing young. Eurytoma gigantea is a parasitoid wasp that uses its short, pointed ovipositor to penetrate the gall and lay eggs in the gall chamber, while Downy Woodpeckers are known to peck open galls to get the grubs within.

Industrious Goldenrod Gall Fly larva that cause their host plants to make large galls with thick walls can avoid being parasitized by wasps, but woodpeckers preferentially select the biggest galls in a Goldenrod patch--likely because big galls contain bigger grubs.

Thus, in fields with lots of wasps there are more big, thick-walled galls, in areas with many woodpeckers the galls tend to be smaller, and in locations where both wasps and woodpeckers abound the galls tend to be of intermediate size.

Ah, the wonders of natural selection! The second Goldenrod gall we found in a small meadow at Hilton Pond Center is sometimes confused with the ball gall, but a closer look shows it is spindle-shaped above rather than spherical, hence the name "elliptical gall. Gnorimoschema gallaesolidaginis, the Goldenrod Gall Moth.

The moth chooses a lower leaf on a Goldenrod stem and lays an egg that, in turn, overwinters on the leaf. The larva hatches out the following spring and makes its way from the now dead leaf to a newly sprouted Goldenrod, where it eats its way through a bud and into the stem.

In response to this invasion, the Goldenrod forms an elliptical gall around the area where the caterpillar took up residence. The larvae feeds and develops all summer and ultimately tunnels out of its elliptical gall before retreating and plugging the hole with silk and Goldenrod "sawdust.

Interestingly, the exit hole is beveled--wider at its outer rim than at the inner--so the plug is shaped rather like a bathtub stopper; this makes it easy for the newly emerged Goldenrod Gall Moth to pop the plug, but hard for a potential predator to push it in.

The third and least common Goldenrod gall at Hilton Pond Center looks almost as if it is a normal part of the plant. Called a "bunch gall," "rosette gall," or "flower gall," it occurs when the Goldenrod Gall Midge, Rhopalomyia solidaginis--a miniscule fly--lays its egg in a leaf bud.

After the grub hatches, its presence somehow keeps the stem from growing and elongating, even though the Goldenrod continues to produce leaves.

Goldenrod and gall fly research

Although the Goldenrod Gall Midge is the only insect known to cause a bunch gall, the heavily leaved cluster may become home to a diverse assemblage of arthropods, including spiders and other midge species; for this reason, the Goldenrod Gall Midge has been referred to as an "ecosystem engineer.

One other curious factoid about the Goldenrod Gall Midge is that the female demonstrates "monogeny," meaning that throughout her reproductive life she makes either male or female offspring, but never both.

We suppose forming a gall might rob an individual Goldenrod plant of energy that otherwise would be devoted to flower production--thereby decreasing its reproductive potential--but vast fields of Solidago that bloom each fall across the U.

Around Hilton Pond Center, at least, there seems to be a natural balance between gall insects and Goldenrods--even if all those galls ARE divided into three kinds.Biology 18 Spring 1 Lab 1 - Natural Selection in the Goldenrod Gall Fly System: Effects of Predators and Parasites Week 1: What is natural selection and how can we measure it?

The goldenrod gall fly (Eurosta solidaginis), also known as the goldenrod ball gallmaker, is a species of fly native to North America. The species is best known for the characteristic galls it forms on several species in the Solidago, or goldenrod, genus.

Taxonomy[ edit ] Eurosta solidaginis is in the order Diptera and the family Tephritidae.
gall biology and research While they are still alive, the females mate and lay their eggs on top of goldenrod stems. After ten days, the egg hatches, and digs its way inside the plant stem.
Which Way Out--A Study of the Exit Tunnels Made by the Goldenrod Gall Fly, Eurosta solidaginis Spherical gall on Canada goldenrod caused by goldenrod gall fly. Goldenrods are a common wildflower, painting fields, prairies, and meadows yellow in late summer.

The fly’s eggs Class: Insecta. The goldenrod gall fly, Eurosta solidaginis (Fitch) (Diptera, Tephritidae), is widely distributed across North life cycle of this insect is centred on the goldenrod plant (Solidago sp.).Females lay eggs in the growing tips of goldenrod plants in the spring and when they hatch the larvae bore into the center of the stem and start to eat.

A postdoctoral fellow in entomology at Pennsylvania State University, Anjel Helms, and other researchers identified the specific chemical compound emitted by the male goldenrod gall fly Plant's Odor Sensing System Demonstrates Engineered Adaptability | The Institute for Creation Research.

Goldenrod Gall Fly, Eurosta solidagnis Published on October 12, December 17, by Spherical gall on Canada goldenrod caused by goldenrod gall fly. This gall forms when, in late spring, a small fly with spotted wings and the appropriate name of Goldenrod Gall Fly, Eurosta solidaginis, lays her even tinier egg on a fast-growing Goldenrod stem.

After the egg hatches about ten days later, the hungry larva eats its way into .

Goldenrod gall fly | Revolvy