Goldenrod is “golden” for pollinators

There are more than 25 different species of Goldenrod found in Ontario with varieties that grow in almost any conditions. They have bright yellow showy flowers from August to September and are prized as ornamentals by European gardeners.

Species found around the Minden Riverwalk include the Rough-stem or Wrinkleleaf Goldenrod, (Solidago rugosa), Canada Goldenrod (Solidago canadensis) and Grass-Leaved Goldenrod (Euthamia graminifolia) found in moist soils and in full sun.

Goldenrod are some of the most important fall blooming native plants for pollinators. Now why would that be? First of all they bloom in the fall when little else is blooming. The bright yellow flowers are attractive and the sweet nectar acts to lure the insect pollinators with the promise of a feast. Along with the fall flowering asters, the Goldenrod provides food for the monarch butterfly in preparation for its long migratory flight south to its winter home in Mexico. The monarch consumes plant nectar and the plant is happy because its pollen gets spread as the butterfly moves from flower to flower. It may be hard to believe, but the Goldenrod is food for over 100 species of moths and butterflies. Some butterflies drink nectar but many do not. You can be sure however, that all caterpillars (which is another stage in the life cycle of butterflies) are voracious eaters. When they hatch out into caterpillars they grow quickly by eating the leaves of the Goldenrod, asters or milkweed plants, whatever is their preferred food. Some of the caterpillars live to pupate into butterflies, but some get picked up by birds and are carried to their nests to feed their babies. This food web is what makes the Goldenrod a “Keystone” species. It’s too aggressive for a little garden but please leave it to grow in other parts of your property.

If you went by Stop 12 by the Serviceberry shrub you may have learned about the Northern Paper Wasp. It’s the black and yellow wasp with a super thin waist. Look carefully on the goldenrod and you might see it going after a butterfly caterpillar or a grasshopper. It eats other insects that might otherwise get out of control and leave little for others to eat. Don’t disturb it and it won’t bother you.

These wasps are a generalist pollinator species, who begin their cycles as carnivores during their larval form and remain as nectar feeders as adults (Buck et al., 2008) The adults are known for hunting caterpillars, which they will butcher and feed to their larvae, as well as grasshopper species (orthoptera), They are incredibly effective at removing pest species from gardens and can enhance plants by removing problematic species. Once the Northern Paper wasp reaches its adult form, the wasp then forages for nectar, making this species effective for plant growth and development through pollination and protecting it from harmful invaders.

Unfortunately, Goldenrod has an undeserved reputation for causing hay fever and allergies. This is NOT CORRECT. The culprit for this is in fact Ragweed which happens to flower at the same time. Ragweed has little inconsequential green flowers that produce pollen that is very light in weight and therefore easily carried by the wind. The pollen from Goldenrod flowers is heavy and sticky so cannot be carried by the wind but is moved by insects. Honey producers make a Goldenrod honey which when consumed may help people to naturally develop resistance to allergies caused by ragweed pollen.

Other plants at this tour stop include:

Heart leaved Aster (Symphyotrichum cordifolium)

White Panicle Aster (Symphyotrichum lanceolatum)

Bog Aster (Oclemena nemoralis)

Reed Canary grass (Phalaris arundinacea)

U-Links Species Profile:

Northern paper wasp, Polistes fuscatus

The northern paper wasp is one of the biggest head scratchers in the taxonomic world, due to its massive range in colour variation and patterning (Buck et al., 2008). The patterns are heavily influenced by their geographical region, with a massive range of colours over different parts of the body, although the abdomen has the most variation within the samples found in Minden. The patterns seen along the Minden Riverwalk include soft yellow/brown spots, yellow bandings across the abdomen, and yellow patterning on their heads. If this isn’t confusing enough, the female wasps can look identical to two other wasp species, Polistes metricus and Polistes bellicous (Buck et al., 2008), and have also been recorded to integrate with these two species, making the boundaries of identification within these three species very difficult. Males however, are easily distinguishable. Workers and queens in colonies have a unique ability of facial recognition within their group, and can remember individual insects by their faces. Remarkable! (Tibbets et al., 2021)

The Northern paper wasp has a four stage cycle of nest creation and colony behaviour. These stages are: founding, worker, reproductive, and intermediate phases (Sumana & Stark, 2004). The most intriguing of the four stages is the founding stage, where females will fly to new locations, preferring wooded areas, or areas around human development, where they will either create a new nest, or take over an abandoned one (Sumana & Stark, 2004). Although there are displays of aggressiveness between two foundress wasps (females starting a new colony) they typically will work together in raising the first generation of workers and have even displayed signs of working together to forage for food to minimize the time the nest is left unguarded. (Gamboa & Stump, 1996).

These insects are generalist pollinator species, who begin their cycles as carnivores during their larval form and remain as nectar feeders as adults (Buck et al., 2008) The adults are known for hunting caterpillars, which they will butcher and feed to their larvae, as well as grasshopper species (orthoptera), They are incredibly effective at removing pest species from gardens and can enhance plants by removing problematic species. Once the Northern Paper wasp reaches its adult form, the wasp then forages for nectar, making this species effective for plant growth and development through pollination and protecting it from harmful invaders.

Researcher: Caleb Brown, Trent University