Spotted Lanternfly Biology and Lifecycle
The name lanternfly is misleading; spotted lanternflies have little in common with any type of fly. Another misconception arises when viewing adults with wings spread, making them look like moths. Spotted lanternflies are planthoppers in the order Hemiptera, or true bugs, and are more closely related to cicadas, brown marmorated stink bugs, aphids, and leafhoppers. All insects in this order have piercing-sucking mouthparts that allow them to drill into the phloem of a plant to feed directly on the sugary sap.
What do spotted lanternflies and their eggs look like?
What times of year are the different spotted lanternfly life stages active?
Identification
What do spotted lanternflies look like?
The first instar nymphs are approximately ¼” long and black with white spots. They are occasionally mistaken for ticks. The second and third instar nymphs are also black with white spots.
Fourth instar nymphs take on a red coloration with white spots and can be up to ¾”.
Adults are about 1" long with black-spotted, pinkish-tan wings folded over their backs.
Both male and female adult spotted lanternflies have yellow abdomens with black stripes. Female spotted lanternflies have a set of red valvifers at the distal end of the abdomen. When gravid (mated), the female abdomen swells to the point where they find it difficult to fly.
Many photos show adults with their wings open but in nature this only occurs when the spotted lanternfly is startled or ready to take flight. Their wingspan is about 2 inches. About half of the length of the hindwings are red with black spots.
Spotted Lanternfly egg mass. Eggs are laid in 1 inch long segmented rows; egg masses may contain up to about 60 eggs. Sometime during winter, the covering begins to crack.
Egg Masses
Females lay one or two egg masses, each containing 30 – 60 eggs laid in rows. She covers them with a creamy-white, putty-like substance that becomes pinkish-gray as it dries. After a few weeks the covering turns a darker tan and starts to crack, resembling a splotch of mud. Depending on the substrate, egg masses can be extremely camouflaged. Spotted lanternflies can lay eggs on any outdoor surface, from trees, to camp chairs, to rusty metal.
Lifecycle: One Generation Per Year
In the current infestations, spotted lanternfly has shown to have one generation per year consisting of four nymphal stages, an adult stage, and overwintering as egg masses. Being true bugs, spotted lanternflies molt to progress between stages. Egg hatch is over an extended time period with the first instar nymphs appearing in May and June. Mating takes place starting in late August with egg-laying taking place in September through November or until the first killing freeze.
May–June: Hatch
Spotted lanternflies begin to hatch in May. The first instar nymphs are active from May until July and are approximately ¼” long and black with white spots. They are occasionally mistaken for ticks.
Hatch and first instar nymphs.
May–July: First, Second, and Third Instar
First, second and third instar nymphs are black with white spots. They are likely to be found from May through July.
First, second and third instar nymphs
July–September: Fourth instar
Fourth instar nymphs take on a red coloration with white spots and can be up to ¾”. This stage is active from July through mid-August; they then molt and become adults.
Fourth instar nymphs
July-December
Adults begin to appear in July and can be found through December.
Adult spotted lanternflies
September–November: Egg Laying
Egg-laying taking place in September through November or until the first killing freeze.
Spotted lanternfly laying eggs.
September–June: Eggs
Eggs can be found on any outdoor surface from September through June.
Egg mass of spotted lanternfly. Egg masses change colors over a few weeks from white, to pinkish, to brown and are about 1 inch long.
Dispersion—How do they get to new places?
Transportation by human activity is the most common form of movement and the main reason SLF populations have not been contained.
Jumping and Flying
All nymphal stages and adult spotted lanternflies can use their powerful hind legs to jump impressive distances; adults are able to fly short distances. On their own, they are able to move 3 to 4 miles by walking, jumping and flying.
Hitchhiking
Transportation by human activity is the most common form of movement and the main reason SLF populations have not been contained. Spotted lanternflies are common hitchhikers at all life stages, but adults and egg masses are the most common.
- Adults will fly into open windows of vehicles, into picking bins, and into the back of trucks while they are being loaded.
- Eggs can be laid on almost any outdoor surface and moved to a new location.
Learn how to stop the spread and reduce the risk of spotted lanternfly hitchhikers.
Find out if you are travelling to an area with a known spotted lanternfly infestation or quarantine.
Host Plants
Spotted lanternfly feeds on more than over 100 different species of herbaceous plants, from vines to large trees.
It has been reported that spotted lanternfly feed on almost anything as they move from one area to another in search of a preferred food source. As an example, populations have been found feeding in corn and soybean fields for short periods of time, and spotted lanternfly nymphs have been found feeding on basil, cucumber, rose, statice flowers and even grass though none are a preferred food source. It is hypothesized they are only feeding to get the energy needed to move on to a more preferred host.
Feeding Behavior Varies by Life Stage
- The beaks of first, second and third instars are not strong enough to penetrate woody tissue so they primarily feed on annual plants or the current year growth in perennial plants.
- Fourth instar nymphs and adults have stronger beaks and are able to penetrate the trunks of trees, cordons, and the older growth of other perennial plants.
- Late-stage adults move from Tree of Heaven to other food sources in the fall, although the reasons for this are not clearly understood.
Turgor pressure or sap flow of the plant appears to play a key role in whether spotted lanternfly finds it a good host because spotted lanternflies do not have strong muscles associated with their pumping mechanism.
Preferred Host - Tree of Heaven (TOH), Ailanthus altissima
Tree of Heaven is the preferred host of fourth instar and adult spotted lanternfly. When spotted lanternfly occurs in a new area the adults are most likely to be found on a Tree of Heaven. However the feeding behavior varies depending on life stage.
- Early instar nymphs have no significant preference for Tree of Heaven a broader host range than adults.
- A strong preference for Tree of Heaven develops some time during the fourth instar through early- to mid-staged adults.
- Many more eggs are laid and the egg laying begins sooner if spotted lanternfly can feed on Tree of Heaven.
Late Season
However late season adults tend to move away from Tree of Heaven to grape vines, silver maple, willow, etc. Reduced sap flow later in the season on Tree of Heaven may contribute to this preference. The proximity of Tree of Heaven to other preferred hosts had no significant effect on how many spotted lanternflies were found per tree.
Other Preferred Hosts
- Grapes
- Black walnut (Tree of Heaven look-a-like)
- Hops
- Maple (late season)
Other Observed Hosts
- Willow
- Apple
- Blueberry
- Mulberry
- Fig
- Stone fruit
- Birch
- Sycamore
- Lilac
- Poplar
- Staghorn sumac (TOH look-a-like)
- Virginia creeper
- Many others
Tree of Heaven is also considered an invasive species which is easily mistaken for staghorn sumac, a native that grows in similar soils and areas.
Tree of Heaven is the preferred host for fourth instar and adult spotted lanternfly until late in the season.
Currently, grapes appear to be the hardest-hit horticultural or agronomic crop.