It’s believed that there are thousands of types of naturally occurring mold in the world. Some can be beneficial while others can be harmful to your health. One type of mold that you might encounter in your home is commonly referred to as “Cobweb Mold.”
In general, it isn’t just one species of mold. It is more like a closely related group of mold species that tend to cause cobweb disease in mushrooms. Each species of cobweb mold is so similar to its brethren that only careful genetic testing can tell them apart.
Over the years they have been reclassified which has sparked debate between mycologists around the globe. The two species Dactylium and Dactylium Dendroides are most often referred to as the causative agents of cobweb mold in the United States. Yet Cladobotryum is more often found in eastern countries. Other species that have been heaped into this group include Hypomyces or Hypomyces Rosellus.
Where Is Cobweb Mold Found?
Cobweb mold is most commonly found growing on mushrooms and their casing layers. However, this isn’t the only place you might find it. Theoretically, cobweb mold can potentially develop on any uncolonized substrate, as long as there is a suitable host present. At the same time, there have been experiments that found spores no mycelium fragments that were added to spawn resulted in cobweb disease on other types of fungus. This suggests that cobweb mold has several variables that can promote or dissuade it from developing.
One thing that is very clear is that once it is established cobweb mold has the ability to spread quickly. This trait means it can fragment and develop from one fungal substrate to the surrounding environment in a short amount of time. It also means that it can spread to multiple points from a single colony.
You should also bear in mind that the growth rate is directly linked to the environmental conditions the mold it is growing in. This also means that changing the conditions can quickly help deal with an outbreak. Sometimes something as simple as lowering the ambient temperature or altering the RH can slow the growth of cobweb mold. It might even be able to completely inhibit it.
Cobweb mold most often develops in later flushes, which is important in correctly identifying it as well as determining the initial source of the contamination. Like most species of mold, it proliferates by means of spore. In some cases, a small amount of spore may have been present in the past, waiting for the right conditions to activate it.
This means that the appearance of cobweb mold in earlier flushes could be the result of mycelium fragmentation and that it could be present in some other nearby source. This could even be something as simple as spoiled fruit in the same room.
Of course, one of the most common points of origin is an older mushroom stump. It’s important to note that this has little or nothing to do with the rotting in the stumps. A mushroom infected with cobweb mold might simply have left behind a cobweb infected stump.
Cobweb Mold And Aborts
Another common point of origin for cobweb mold is aborts. Now, this doesn’t necessarily mean that all aborts need to be immediately picked. However, you should make a conscious effort to remove all aborts any time you are harvesting your other mushrooms, which can be painstaking if you have a large number of aborts present in the batch in question.
There is a lot of wiggle room in how you could interpret this and ultimately take action on it. Certainly, there is a clear a correlation between the development of cobweb disease and the presence aborts. Yet it is also hard to say that the aborts are the direct cause of cobweb mold or even if the cobweb mold was the underlying cause of the aborts!
Identifying Cobweb Mold Correctly
It’s also important to keep in mind that there are other types of mold that you might encounter that might look very much like cobweb mold, yet they are not actually some other type of mold species. There have been many people misidentify low-density grey mold as cobweb mold. Also, there are types of pinhead mold, with tiny black pinheads which is also commonly misidentified as cobweb mold.
Cobweb mold is more likely to develop in the casing layers, whereas pin molds are more common contaminants found in spawn as well as in various bulk substrates. The growth rate of these molds, in ideal conditions, can match or even potentially surpass the inherent growth rate of cobweb mold. While they may have a very similar appearance the other types of mold are much more difficult to treat. Misidentification adds to this as it has left many people with the perception that true cobweb mold is difficult to treat.
In reality, cobweb mold is very easily treated. One of the more common misconceptions is that hydrogen peroxide will only affect cobweb mold. The reality is that this highly oxygenated solution will react aggressively with just about every type of fungus, and even has the ability to affect mushroom mycelium!
Treating Cobweb Mold
The most common reaction you see when hydrogen peroxide is introduced to fungi is this sort of aggressive fizzing. This is directly caused by the fast conversion of the h202 into its constituent parts, water, and oxygen. Really, the most effective way of identifying cobweb mold in semi-controlled conditions is to look on the casing surface. This will help with correct identification, which of course is the first step toward effective remediation.
In cases where cobweb mold disease is indeed present it is often most easily controlled by carefully placing a damp paper towel over the growth to contain any spores that have not yet released. You can then pour salt over the paper towel before gently removing any mushrooms that show symptoms of spotting. While this might seem difficult, it’s important to note that your overarching goal is to eliminate the cobweb mold presence in the casing layer. In the case of modest contamination, many of the healthy mushrooms may indeed live and even thrive afterward!