What is the Difference Between Fungus Gnats and Fruit Flies

The main difference between fungus gnats and fruit flies is that fungus gnats feature dangling legs and long bodies, making them appear similar to a small mosquito, while fruit flies have a rounded silhouette and resemble a smaller version of the common house fly.

Fungus gnats and fruit flies are two common nuisance household pests. Generally, people misidentify them. Both of them cause the same issues such as transferring germs from one dirty place to another, carrying bacteria like E. coli, Salmonella, etc., causing food poisoning, etc.

Key Areas Covered

1. Fungus Gnats
   • Definition, Characteristics, Importance
2. Fruit Flies
   • Definition, Characteristics, Importance
3. Similarities Between Fungus Gnats and Fruit Flies
   • Outline of Common Features
4. Difference Between Fungus Gnats and Fruit Flies
   • Comparison of Key Differences

Key Terms

Fruit Flies, Fungus Gnats

Fungus Gnats – Definition, Characteristics, Importance

Fungus gnats are small, dark, short-lived gnats that belong to the superfamily Sciaroidea. One of the main features of fungus gnats is the feeding of the larval stage on fungi growing in the soil. This helps in the decomposing of the organic matter. However, some species are predatory, including those in the genus Arachnocampa of the family Keroplatidae – the “glowworms” of Australia and New Zealand. Others can be pollinators or carry mushroom spores. Some fungus gnats like pythium also transmit diseases.

Figure 1: Fungus Gnat

Furthermore, adult fungus gnats are around 2 to 8 mm long. Normally, fungus gnats have antifreeze proteins and hence, they are capable of tolerating cold conditions.

Fruit Flies – Definition, Characteristics, Importance

Fruit flies (Drosophila melanogaster) are a species of fly that belongs to the family Drosophilidae. Other names for the species include common fruit fly and vinegar fly. In general, a fruit fly has a yellow-brown color. The average size of it is 3 mm in length and 2 mm in width. Moreover, they have a segmented body into the head, thorax, and abdomen. In addition, the transverse black rings in the abdomen are the main distinguishing feature of male and female fruit flies. Fruit flies are hexapod insects with typically three pairs of legs in the thorax.

Figure 2: Fruit Fly

Furthermore, these flies walk using a tripod gait in which three of the legs swing together while the other three remain stationary. Besides, the fruit flies belong to the order Diptera, the order of true flies having two wings. They also have five large, brick-red eyes and antennae. Moreover, the proboscis is the feeding organ of a general fly and it is used for both taste cue detection and food ingestion. More importantly, the natural habitat of fruit flies is rotting fruits.

Similarities Between Fungus Gnats and Fruit Flies

• Fungus gnats and fruit flies are two common nuisance household insects.
• They cause the same issues such as transferring germs from one dirty place to another, carrying bacteria like E.coli, Salmonella, etc., causing food poisoning, etc.
• They share similar habitats.
• Moreover, they are tiny pests that measure about one-eighth of an inch.
• These flies belong to the order Diptera.

Difference Between Fungus Gnats and Fruit Flies

Definition

Fungus gnats refer to any of various small dipteran flies (families Mycetophilidae and Sciaridae) resembling mosquitoes and having larvae that feed on fungi and decaying organic matter while fruit flies refer to a small fly that feeds on fruit in both its adult and larval stages.

Shape

Usually, fungus gnats feature dangling legs and long bodies, which make them appear similar to a small mosquito, while fruit flies have a rounded silhouette, like a smaller version of the common house fly.

Color

Fungus gnats are gray or black while fruit flies are tan to black.

Eyes

The eyes of fungus gnats are small and hard to see while the eyes of fruit flies are big and red.

Larval stage

The larval stage feeds on fungi in fungus gnats while the larval stage feeds on fruits same as their adult stage.

Infestation

Fungus gnats nest in the soil of gardens or indoor potted plants to feed on the organic matter while fruit fly adults eat overripe fruits or rotting food in trashcans and fruit fly larvae feed on the slime found in dirty drains.

Effects

Moreover, fungus gnats damage plant roots, while fruit flies may spread diseases through contaminated food.

Taxonomy

Fungus gnats belong to the superfamily Sciaroidea while the fruit flies belong to the family Drosophilidae.

Conclusion

In brief, fungus gnats and fruit flies are common household flies that are frequently misidentified. Generally, fungus gnats are gray or black in color while fruit flies are tan to black in color. Moreover, the eyes of fruit flies are big and red but the eyes of fungus gnats are difficult to see. In addition, fungus gnats belong to the superfamily Sciaroidea while fruit flies belong to the family Drosophilidae. However, the main difference between fungus gnats and fruit flies is their shape of the body: fungus gnats have dangling legs and long bodies, like a small mosquito, while the body of the fruit flies is a rounded silhouette.

References:

1. Wikimedia Foundation. (2022, September 13). Fungus gnat. Wikipedia. Retrieved September 15, 2022.
2. Wikimedia Foundation. (2022, September 9). Drosophila melanogaster. Wikipedia. Retrieved September 15, 2022.

Image Courtesy:

1. “Trauerfliege” By Python (Peter Rühr) – Own work (CC BY 3.0) via Commons Wikimedia
2. “Drosophila melanogaster Proboscis.” By Sanjay Acharya – Own Work (CC BY-SA 4.0) via Commons Wikimedia