Black flies with white spots on wings might lead some to think of the invasive spotted lanternfly.
However, it is important to note the key differences between these insects and basic black flies.
The spotted lanternfly, an invasive pest native to China, India, and Vietnam, features gray forewings with black spots and contrasting red and black hind wings, with a white band visible when the wings are open.
On the other hand, typical black flies are generally 5 to 15 mm in size with a black body, large compound eyes, short antennae, and large fan-shaped wings.
Physical Characteristics
Appearance and Size
Black flies are robust insects with an arched thoracic region and can range in size from 5 to 15 mm1.
They possess large compound eyes and short antennae1.
Their body color can vary, with most species being black, but some also exist in yellow and orange1.
- Colors:
- Black (most common)
- Yellow
- Orange
On the other hand, Adult Spotted Lanternflies exhibit a vibrant coloration, featuring a greyish forewing with black spots.
When the wings are open, a bold display of red hindwings with black spots at the tips and a white band is revealed.
The body is yellowish with black bands, and the legs and head are black.
Black lanternflies have large, prominent eyes that are well-adapted for detecting movement and light.
Wing Patterns
Black flies have a pair of large, fan-shaped wings1.
Some species might display white spots on their wings, which can help in identification.
The adult spotted lanternfly, which is about 1 inch long, has grey wings with black spots, and when it opens its wings, it reveals bright red underwings2.
Distribution and Habitat
Geographical Spread
The spotted lanternfly (Lycorma delicatula) is currently found in several states in the United States, including
- Connecticut,
- Delaware,
- Indiana,
- Maryland,
- Massachusetts,
- Michigan,
- New Jersey,
- New York,
- North Carolina,
- Ohio,
- Pennsylvania,
- Rhode Island,
- Virginia, and
- West Virginia.
It was first discovered in Berks County, Pennsylvania, in 2014 and has since spread to other states.
Additionally, suitable habitats for the spotted lanternfly have been identified globally, including parts of Europe, eastern Asia, southern Africa, and Australia.
However, the presence of spotted lanternfly populations in these international regions is not confirmed.
Black flies are distributed widely in all zoogeographical regions and can be found almost everywhere with running water that is suitable as a habitat for their aquatic stages.
They are prevalent in many parts of the United States, Canada, and various other countries around the world.
Black flies inhabit areas ranging from temporary stream trickles to large rivers and are known to be present in diverse environments such as mixed birch and juniper woodlands, pine forests, moorlands, and pastures.
Preferred Conditions
Spotted Lanternfly
Adult spotted lanternflies prefer areas with:
Adult spotted lanternflies have a strong preference for feeding on the Tree of Heaven (Ailanthus altissima), especially during the fourth instar through early to mid-staged adults.
However, they also feed on a wide range of fruit, ornamental, and woody trees.
In the fall, they particularly prefer the Tree of Heaven compared to other host plants.
The feeding behavior of spotted lanternflies can vary depending on their life stage.
When spotted lanternflies occur in a new area, the adults are most likely to be found on a Tree of Heaven.
Black Flies
Black flies (Simuliidae) are typically found in clean, well-oxygenated, flowing freshwater habitats.
They have a preference for running water, and their larvae are commonly found in rivers, streams, and creeks.
The larvae attach themselves to rocks, vegetation, or other substrates in the flowing water, where they filter-feed on organic matter.
Adult black flies are often found near their breeding sites, but they can also travel considerable distances in search of blood meals.
They are attracted to areas with hosts, such as humans, livestock, and wildlife, and are often encountered in wooded areas, near rivers and streams, and around farms and rural communities.
The presence of black flies can be seasonal, with populations typically peaking in the spring and early summer, depending on the geographical location and environmental conditions.
Life Cycle and Reproduction
Developmental Stages
Black flies
- Mating: Adult black flies mate in swarms, usually in the air.
- Offspring: After mating, females lay around 150 to 500 eggs per batch on various water surfaces.
- Eggs: Black flies lay clusters of small, oval-shaped eggs on water surfaces or aquatic plants.
- Larvae: Hatching from the eggs, the aquatic larvae attach themselves to submerged objects and filter-feed on organic materials.
- Pupae: Larvae then transition to the pupal stage inside cocoon-like structures, still remaining submerged in water.
- Adult black flies: Ranging from 5 to 15 mm, most species have a black body, but some may have yellow or orange colors.
Spotted Lanternfly
- Eggs: Spotted lanternflies lay egg masses on various surfaces, such as tree trunks and stones. These egg masses are covered in a protective, mud-like substance and are typically laid in the fall.
- Nymphs: After hatching in late spring, the nymphs of spotted lanternflies undergo four instar stages. They change in appearance with each stage and feed on a wide variety of plants.
- Adults: Adult spotted lanternflies emerge around July. They are approximately 1 inch long and half an inch wide. The adults have distinctive and eye-catching wings; the forewings are grey with black spots, and the hind wings are red with black spots at the front and a white band at the rear.
Comparison Table: Black Fly vs Spotted Lanternfly
| Feature | Black Fly | Spotted Lanternfly |
|---|---|---|
| Adult size | 5 to 15 mm | About 1 inch long and ½ inch wide at rest |
| Body color | Most species have a black body, some have yellow or orange colors | Adults have grey wings with black spots and a bright red underwing |
| Development stages | Eggs, larvae, pupae, and adults | Nymphs (black with white spots, then red with black and white spots), and adults |
| Mating habitat | In swarms, usually in the air | Not specified |
Conclusion
While black flies and spotted lanternflies may share some superficial similarities, such as the presence of spots on their wings, a closer examination reveals distinct differences between the two species.
Originating from different parts of the world, black flies are widespread and prefer aquatic environments, while the invasive spotted lanternfly, native to parts of Asia, has established itself in several US states, favoring host plants like the Tree of Heaven.
The contrasting life cycles, feeding habits, and preferred habitats of these two insects underscore the diversity within the insect world and highlight the importance of accurate identification for effective conservation and management.
Footnotes
- Black Flies | Public Health and Medical Entomology | Purdue | Biology ↩ ↩2 ↩3 ↩4 ↩5
- Spotted Lanternfly Frequently Asked Questions ↩ ↩2
- https://extension.psu.edu/spotted-lanternfly ↩
- https://www.dec.ny.gov/animals/113303.html ↩
- https://extension.entm.purdue.edu/publichealth/insects/blackfly.html ↩
- https://extension.psu.edu/spotted-lanternfly-frequently-asked-questions ↩
- https://extension.psu.edu/spotted-lanternfly-frequently-asked-questions ↩
- https://extension.entm.purdue.edu/publichealth/insects/blackfly.html ↩
- https://www.dec.ny.gov/animals/113303.html ↩
- https://extension.psu.edu/spotted-lanternfly ↩
