Mites living in the community on wind cockroaches can reduce the risk of allergies

According to a recent study, tiny surface live ticks of Madagascan wind cockroaches help reduce the presence of mold, thereby reducing allergic reactions in those who feed on these insects.

Scientists cultured and determined the amount of mold that lived on the surface of the cockroach body in two cases with and without the symbiosis, thereby finding that the presence of these ticks reduce the amount of mold by at least 50%.

These same scientists reported a year ago that there are 14 types of mold that live on or around this cockroach, including some allergy-related species and vectors if they are invasive. into the lungs or open mouth wounds.

The living mites feed on saliva and organic debris collected between the legs of the cockroach, losing the food source of the species on the cockroach body.Mites do not directly eat mold.

'We have not yet proven that this helps the cockroach body, but generally reducing mold on the surface of their bodies is a good thing,' Joshua Benoit, a postdoctoral fellow in insectology. Ohio, one of the authors of the study, said.

'With the ability to kill mold, mites have a certain role in reducing allergic reactions on cockroaches.'

The study is presented on the latest edition of Symbiosis.

The Madagascan wind cockroach species also has the scientific name Gromphadorhina portentosa. Their adult bodies are 2-3 inches in length, 1 inch in width (1 inch = 2.54 cm). They emit a whistling sound when another object touches or feels threatened. The gentle nature, large size, strange cry and little effort required to make this species become a popular pet and have been widely used in teaching for many years.

When Benoit and colleagues discovered the mold on the cockroach's surface in a previous study, they recommended that people wash their hands after touching cockroaches, and stressed the importance of keeping the cage always clean.And because mites do not completely disappear from mold, researchers continue to recommend that people sensitive to mold need to be cautious when dealing with Madagascar's wind cockroach species.

Not all Madagascan cockroach flocks carry mites on them, Gromphadorholaelaps schaeferi is an example. The reason why is still a secret for researchers. But what they are certain is that cockroaches with ticks on them will have less mold.

In the study, female cockroaches where live mites had 64% less mold than the body without ticks. This figure is 31% for male cockroaches; in larvae and young cockroach body is 24%.

To test the conclusion, the researchers did experiments on cockroaches with and without live ticks, and removed ticks from the flocks they were living in, as well as putting ticks on the cockroaches. Initially no ticks. In all cases, the presence of ticks reduces mold density.

 

These mites are only 1 millimeter in size;they live on the body of Madagascar's wind cockroaches.(Photo: Ohio State University)

The most common types of molds found on Madagascar's wind cockroaches are Rhizopus, Penicillium, Mucor, Trichoderma and Alternaria, some of which have been listed on the Centers for Disease Control and Prevention (CDC). mold living in the house.

'The presence of ticks reduces the number of not only a few, but all types of mold on the body of cockroaches,' said Jay Yoder, a biology lecturer at Wittenberg University, the lead author of the study.

About 20 to 25 ticks live on each adult cockroach. Scientists have tried to add more ticks to the surface of a cockroach body, but this does not work, adding ticks does not reduce mold.

'The number of ticks per cockroach is determined by the amount of food available,' Benoit said.

In captivity, Madagascar wind cockroaches live well thanks to fruits and dog food. Benoit said they tend to spill themselves when eating, leaving saliva and organic debris in the slots along the lower middle of the body - and this is the source of tick food.Mites have a special need for moisture in food, they eat up the water and nutrients that molds need to form and grow.

The mites also get some moisture from the breathing holes of cockroaches. This species cannot live anywhere other than the surface of the Madagascan wind cockroach body. Chemical signals emitted by a growing cockroach larvae will indicate that it is a host large enough for a herd to live.When a cockroach dies, the ticks that once lived on its body will crawl indefinitely on the cockroach until they themselves die.

Whether ticks have direct benefits to cockroaches is not clear. But at least people think they are not harmful.'Mites living on cockroaches do not cause any negative effects. They do not hinder the growth of cockroaches, and do not eat the nutrition of cockroaches, ' says Benoit.

Currently, scientists describe this symbiotic relationship as commensalisms rather than mutualism, in which a species is clearly beneficial, and the other does not suffer any damage.