Photic Signaling in the Firefly Photinus greeni

What We Already Know

Most male and female fireflies use their flashes to come together for mating purposes. In a field with many other types of fireflies also trying to attract a mate, each species has its own specific flash pattern that allows them to locate and approach only fireflies of the same species. For many members of the genus Photinus, the male gives his flash signal while in flight, repeating the signal at fixed intervals. The female does not flash spontaneously, but only in response to a recognized male pattern. The female flashes from a perch, and almost never flash while in flight. Her flash is emitted at a certain time interval after the male's flash.

Nitric Oxide and the Control of Firefly Flashing

"Bioluminescent flashing is essential for firefly reproduction, yet the specific molecular mechanisms that control light production are not well understood." This study suggests that the chemical nitric oxide (NO) plays an important role in the control of the firefly flash.

Flashes of Photuris Fireflies: Their Value and Use in Recognition

This paper presents Dr. Lloyd's observations that have a bearing on using firefly flashes to recognize firefly species in the genus Photuris. Unlike Photinus fireflies, which seldom flash except for mating, have distinct flashing behavior, and will flash in captivity, Photuris flashing proves rather difficult to measure. The paper discusses some limitations in using Photuris mating signals for species identification, and why it is difficult to both recognize a Photuris mating signal and identify which part of the flash is important in species recognition.

Larval Biology and Ecology of Photuris Fireflies in Northcentral Florida

In north central Florida, at least a dozen species of Photuris fireflies occur in a variety of habitats. Since it is often not possible to identify Photuris species by their physical characteristics, species differentiation is based on the male flash pattern. However, since the flash of Photuris fireflies is more complex than other fireflies, sorting out the taxonomy of Photuris fireflies is unresolved. Identifying the differences in the larval fireflies may help in identifying species and improve our understanding of their biology.

Male Photuris Fireflies Mimic Sexual Signals of Their Female's Prey

Fireflies of the genera Photuris, Photinus, and Pyractomena use flashes of light for sexual communication. Females of the genus Photuris also use flash signals to mimic females of other species to attract males and eat them. Studies in the field show that several male Photuris fireflies can also mimic males Photinus and Pyractomena.

Nuptial Gifts and Sexual Selection in Photinus Fireflies

During courtship and mating, males of many species of insects provide females with a source of nutrition to help ensure reproductive success. This nutrition might include captured prey, nutritional substances produced by the male, or body parts of the male himself. This paper reviews what is known about these gifts — called "nuptial gifts" in Photinus fireflies.

Flight Studies on the Photic Communication by the Firefly Photinus pyralis

The priority of this study was to test a flight simulator that studies male communication in Photinus pyralis. The study includes details on male courtship flight, as well as flashing behavior in flying females.

Degree-Day Prediction of Adult Emergence of Photinus carolinus

The male display of Photinus carolinus, informally known as the synchronous firefly of the Smokies, attracts thousands of visitors to the Great Smoky Mountains National Park. On peak nights, masses of flying males emit their flash signal (4 - 11 flashes repeated every 12 - 13 seconds) and dark interval in synchrony. Activity lasts from 9:30 p.m. to midnight. Within days after peak activity, the population drops rapidly.

Phylogeny of North American Fireflies (Coleoptera:Lampyridae): Implications for the Evolution of Light Signals

More than 2,000 described species of fireflies live around the world, but very little is known of their evolutionary relatedness. Of the approximately 120 species in North America, Dr. James Lloyd at the University of Florida has described three methods of mate attraction: chemical signals (pheromones), glows (continuous light signals), and flashes (short intermittent light signals).

Search Paths of Fireflies in Two Dimensions

In this study, the investigator asks, "How are the flight patterns of fireflies adapted for finding a mate?" The study compares the flight patterns of two closely related fireflies: Photinus collustrans and Photinus tanytoxus, both of which are active in southern Florida from May to November.
In both species, males fly in search of flightless females, who are responsive to the males during only a short period each evening. Both species are found in relatively open habitats and may be found in the same location, but they are distinguished by their activity at different times of the evening.

Biology of the Firefly Pyractomena lucifera

This study details the biology, ecology, and flash behavior of Pyractomena lucifera, a firefly that lives in freshwater marshes throughout the eastern half of the United States. In particular, the firefly is common in the marshes around Lake Alice on the campus of the University of Florida, where the study was conducted. There, the main plants were cattail, sawgrass, and water hyacinths. Researchers also conducted experiments in the lab.
Here, we take a closer look at their findings, through all phases of the P lucifera's life: larvae, pupae, and adulthood.

Firefly 'Femmes Fatales' Acquire Defensive Steroids (Lucibufagins) from their Firefly Prey

Fireflies are known to be unacceptable food to a number of vertebrates. Earlier research has shown that fireflies of the genus Photinus are unpalatable to thrushes due to steroidal compounds called lucibufagins (LBG), which had been found in all species of Photinus under study. Another genus of firefly, the Photuris, was also found to contain LBG, but these fireflies do not produce them on their own. Instead, the female Photuris acquires LBG in its blood by preying on the male Photinus firefly.

Natural History and Flash Repertoire of the Synchronous Firefly Photinus carolinus

A spectacular firefly display, called the "Light Show," occurs on June nights in Elkmont, Tennessee. Thousands of male Photinus carolinus fireflies flash in unison in a flash pattern of 4-8 flashes followed by 6-9 seconds of darkness. Meanwhile, females remain hidden on the ground or on low vegetation, responding to the males with a double flash about 3 seconds after the males' final flash.
This paper describes certain aspects of the natural history of the southern Appalachian population of P. carolinus.

Glow-worm Larvae Bioluminescence Operates as an Aposematic Signal Upon Toads

While adult fireflies are famous for their courtship flashes, the function of the glowing behavior of the larvae is less well understood. Recent studies concluded that birds and wood ants find the larvae of Lampyris noctiluca, a European firefly, to be unpalatable, and that the larvae protect themselves by emitting a repellent odor when disturbed. This study proposes to demonstrate that the glow of the larvae serves to signal their unpalatability to nocturnal, visually guided predators, rendering them less susceptible to attack.

Signals with Glows, Flashes and Pheromones

Firefly communication is one of the more easily accessible wild animal behaviors to study. With simply a penlight and notebook, a careful observer may be able to:

1. distinguish several species by the flashing patterns of the males;
2. learn the flash codes of several species by imitating (with a penlight) the flash patterns of the flying males and noting the female responses;
3. attract males by imitating the female's response flash;
4. find predaceous fireflies that mimic the females of other species;
5. observe the aerial attacks by Photuris females by imitating the flying males of other species;
6. find Photuris species that use two or more distinctive patterns in their search for mates.

A Firefly Symbiont of Ants

Firefly larvae, as well as some female adult fireflies with minimal or no wings, often live underground or under debris, feeding on snails, earthworms, and other invertebrates. Finding larval and adult fireflies with other organisms would presumably be coincidental, resulting from overlapping habitats. However, one firefly species, Pleotomodes needhami, has been found living in the nests of two (possibly three) types of ants—a fungus-growing ant (T. septentrionalis) and a carnivorous ant (O. clarus).
This paper describes observations of ant/firefly interactions, as well as firefly activity, larval foraging behavior, bioluminescence, and mating behavior.

Female Preference for Male Courtship Flashes in Photinus ignitus Fireflies

During mating, male fireflies deliver a nuptial gift to the female.  This nuptial gift contains the sperm that will fertilize her eggs and a protein mass that will nourish them.  Since adult Photinus fireflies do not feed in the wild, this nuptial gift may be the female’s only source of nutrition.  For this reason, females would be expected to show preference for males with larger nuptial gifts.  This study will explore how the females choose their mates, what male traits elicit greater female response, and if there is a correlation between these traits and the size of the male nuptial gift.

Thieves in the Night: Kleptoparasitism by Fireflies in the Genus Photuris

Kleptoparasitism: stealing resources, usually food, from another animal of the same or a different species.
Most fireflies do not feed as adults, but there are exceptions. Certain species of Photuris actively hunt and devour other species of fireflies to acquire defensive compounds that they cannot produce themselves. Researchers have already identified two methods of hunting exhibited by Photuris: mimicking the courtship signals of other fireflies to lure the males within reach, and aerial "hawking"---catching male Photinus fireflies in flight. This paper describes a third method of hunting: kleptoparasitism, or stealing trapped fireflies from the webs of orb web spiders.

Female Monogamy and Male Competition in Photinus collustrans

Female Photinus collustrans live in burrows and stay in close proximity to them throughout their adult life. Females live approximately 10 days and are sexually active for only about 18 minutes each night starting around 20 minutes after sunset. A female's complete mating history can easily be recorded because of the regularity of these habits, the specificity of her location, and this short span of time in which her matings occur.
This study indicates that most females mate only once in their life, which limits male prospects for mating. Competition among males for mating opportunities has led to the development of a series of male tactics to increase female susceptibility to mate more than once.

Phausis reticulata

Phausis reticulata, the Blue Ghost, is a firefly mainly of the southern Appalachian Mountains, but can be found as far west as Texas and Oklahoma. It is one of several types of fireflies known as “glowworm fireflies” because the flightless females resemble the larvae. The females produce a constant glow to attract the male, and the males, unlike most other glowworms, produce light as well.
Blue Ghosts are small fireflies - ranging from 0.2 inches to 0.35 inches in length. Females have a transparent exoskeleton and lack wings. They have two light organs on the underside of the abdomen - one near the thorax and the other at the posterior end, although some females have been observed with an extra pair of light organs at the posterior end. These light organs are only evident when lit. The eyes of the female are very small, while males have large eyes that occupy most of the head. The pronotum of the male covers the head and has two transparent areas located directly over the eyes. Males have two light organs at the posterior end of the abdomen.

Ellychnia corrusca

Ellychnia corrusca fireflies live in forested areas over much of the eastern United States. Based on its physical structure and certain DNA sequences, this firefly is thought to be closely related to Photinus fireflies, but exhibits some remarkable differences. E. corrusca is a daytime firefly and, unlike Photinus, the adults do not have light organs. Light organs are, however, present in the larvae.
This study was conducted to add to existing information on the life history and mating habits of E. corrusca.

About Firefly Research

Despite worldwide curiosity about fireflies, there is little in the way of natural history books, field guides, or websites to teach us more about them. What does exist can be decades old, underscoring how important your work as a member of Firefly Watch is to updating our knowledge base.
Papers written by scientists are often the best source for learning about these fascinating insects. However, they are not always easy to find, and are often even harder to understand since they were written by and for scientists.
To help you learn more about fireflies and enjoy your Firefly Watch experience, we feature a different research paper every two months with a helpful summary and link to the full article.

Firefly or Fireflies

Fireflies

Visiting a firefly meadow on a summer evening is a memorable experience, but what exactly do you see? How many different types of fireflies are among the flashing lights? Can you tell if they are male or female? Why are they flashing? What is a firefly, anyway?