Notes 7: Poisonous Attractions

For the Love of Insects
Most of Tom Eisner’s quotations were taken from video interviews he gave in 2000 for the Web of Stories project (see Further Explorations), or from this 2003 NPR interview. Others were from personal conversations I had with Tom during a visit to Cornell in 2008.

Eisner, T. (2003) Interviewed by Robert Siegel on All Things Considered, National Public Radio, November 18, 2003.

Lightningbugs for Breakfast? No-No!
In addition to the Web of Stories video, Eisner relates a charming version of the Phogel story in his popular science book, For Love of Insects (Eisner 2003).

Jim Lloyd amassed more than a century’s worth of anecdotal evidence about which creatures do and do not eat fireflies (Lloyd 1973). Knight and colleagues (1999) give detailed case histories about bearded dragons who met gruesome deaths by firefly. The bat study (Moosman 2009) was conducted prior to the 2007 outbreak of white nose syndrome, a disease which has devastated bat populations in the eastern United States.

Chemical Weapons
The chemical defenses called lucibufagins were first identified by Tom Eisner and his colleagues (1978) from adults of three Photinus fireflies, which make these steroidal pyrones in several flavors. They’re also been reported in adults of the diurnal firefly, Lucidota atra (Gronquist et al. 2006) as well as in larvae of Lampyris noctiluca (Tyler et al. 2008). Day (2011) provides a review of firefly defenses.

Gao and colleagues (2011) provide an overview of the therapeutic potential of bufadienolide drugs, and Banuls et al. (2013) discuss the anti-tumor activity of 35 such compounds.

A Multi-faceted Defense Strategy
Reflex bleeding was first described in Photinus pyralis by Blum and Sannasi (1974), and the phenomenon has since been reported from several other firefly genera, including Pyrocoelia, Luciola, and Lucidina. The pop-out defensive glands of firefly larvae were described for Luciola leii by Xinhua Fu and his colleagues (2007), and then again for several additional species in Fu et al. (2009). The dark side of the Smokies Light Show is explored in Lewis et al. (2012).

Evolution of Warning Displays
The many years that Alfred Russel Wallace spent doing fieldwork in the tropics helped him grasp the concept of warning coloration more readily than did Darwin. He described cryptic coloration, warning displays, and mimicry in his 1867 article (quote appears on p. 9). Wallace used the term “danger-flag” in his 1889 book on natural selection (p. 232). The Darwin quote is from a letter written at Down House to A.R. Wallace dated Feb 26 1867 (F. Darwin 1887, p. 94)

De Cock & Mattysen (2001) showed that firefly color patterns act as a warning signal for starlings. Other studies have demonstrated the power of glows to facilitate avoidance learning in toads (De Cock & Mattysen 2003), mice (Underwood et al. 1997), spiders (Long et al. 2012), and bats (Moosman et al. 2009).

Firefly Look-alikes: Tasty or Toxic?
Bates wrote extensively about his travels and natural history observations (see Further Explorations). Quotation is from his 1862 paper on mimicry among Amazonian butterflies (Bates 1862, p. 507).

The photographs of firefly mimics that in Figure 7-3 are (clockwise from upper left): a cockroach (Blattellinae), Pseudomops septentrionalis (photo by John Hartgerink); a blister beetle (Meloidae), Pseudozonitis sp. (photo by Mike Quinn,; a longhorned beetle (Cerambycidae), Hemierana marginata (photo by Patrick Coin), a net-winged beetle (Lycidae), Plateros sp. (photo by Gayle and Jeanell Stickland), a moth (photo by Shirley Sekarajasingham), a soldier beetle (Cantharidae), Rhagonycha lineola (photo by Patrick Coin).

The Vampire Firefly
The aggressive mimicry behavior of Photuris femmes fatales was described by Lloyd (1965, 1975, 1984). Tom Eisner and his colleagues (1997) showed that Photuris females sequester their prey’s toxic lucibufagins, stockpiling them for their own self-protection. While femmes fatales acquire the vast majority of their lucibufagin from prey, these researchers also found tiny amounts of lucibufagin in some lab-reared Photuris that never had access to Photinus prey. Andres González and his colleagues (1999) noted that Photuris larvae have an endogenous defensive chemical, known as betaine, which carries over into adults and affords them some limited protection against predators. They also showed that females endow their eggs with high concentrations of the lucibufagins that they have sequestered from their prey.

Lloyd & Wing (1983) and Woods et al. (2007) describe hawking by Photuris predators, and Faust et al. (2012) describe the kleptoparasitic behavior of these thieves in the night.

Further Exploration

More about Tom Eisner

Web of Stories
This online repository features video interviews with some of the greatest scientists of our time. Tom Eisner is one, and he talks about his life and work in several segments. In Why entomologists eat bugs: A firefly story, Eisner tells how he and Phogel discovered the chemicals that help fireflies defend themselves against predators.

A gifted communicator, Eisner’s 2003 book provides an entertaining account of his many explorations in the land of chemical ecology, vividly illustrated with his own spectacular photographs.

Eisner, T. (2003). For Love of Insects. Belknap Press, Cambridge MA. 464 pp.

Light Snacks: Predation on Fireflies
This short video by the Lewis Lab shows field observations of fireflies under attack by spiders, bugs, and the predatory Photuris femmes fatales, based on research by Sara Lewis, Lynn Faust, and Raphäel De Cock. The Griff Sextet provided the soundtrack, which features scientist and musician Raphäel De Cock on vocals.

More about Warnings and Mimicry
Ruxton and colleagues provide an outstanding and readable explanation, though perhaps a bit technical, of what we know about the evolution of cryptic coloration, warning signals and mimicry in animals.

Ruxton, G.D., T.N. Sherratt, and M.P. Speed (2004). Avoiding Attack: The Evolutionary Ecology of Crypsis, Warning Signals and Mimicry. Oxford University Press, Oxford.

Quite popular when first published in 1863, this 19th century classic chronicles travels through the Amazon basin by Henry William Bates, the British naturalist and insect collector. This wide-ranging and charming account covers natural history, geography, ethnography and more. One admirer, Charles Darwin, called it “the best work of natural history travels ever published in England.” A hundred fifty years down the road, it remains an enviable model of lyrical nature writing.

Bates H.W. (2009). The Naturalist on the River Amazon. Cambridge University Press, Cambridge UK.