Encounters between bombardier beetles and two species of toads (Bufo americanus, B. marinus): Speed of prey-capture does not determine success
- 69 Downloads
Analysis of filmed (64 fps) prey-capture sequences reveals that the rapid tongue flip is preceded by a slower forward lunge of the entire body and followed by a still slower ingestion of retrieved prey (Fig. 1, Table 1). Only the tongue flip, which establishes contact with the prey and retrieves it into the toad's mouth, requires less time than latencies typically reported for invertebrate defensive responses. Ingestion of retrieved prey is not completed until more than 500 ms after initial contact between tongue and prey, giving prey sufficient time to respond with chemical defenses.
Marine toads, the larger of the two species studied, are slower than American toads in all phases of prey-capture up until the beginning of swallowing; however, they complete ingestion as quickly as American toads (Fig. 1, Table 1).
American toads which attack bombardier beetles usually reject the beetles after retrieving them into their mouths (Table 2). Rejection is a dramatic reversal of prey-capture which typically begins within 300 ms of initial contact between tongue and beetle (Figs. 1, 2). After rejecting a bombardier beetle, American toads exhibit behavior that suggests discomfort and display a temporary aversion to striking again at the beetle (Table 3).
Marine toads which attack bombardier beetles usually ingest the beetles without showing discomfort (Table 2). When they do reject bombardier beetles or show other behavioral reactions, the behavior is similar to but less intense than that of American toads. Irrespective of the outcome of a previous encounter, marine toads strike willingly when a second bombardier beetle is offered (Table 3).
An ingested bombardier beetle occasionally causes a toad discomfort but rarely induces the toad to evert its stomach and reject the beetle.
It is concluded that bombardier beetles attacked by a toad must deploy their chemical defense while still in the toad's mouth if they are to survive. When adequately stimulated, the beetles are able to respond in less time than toads require to ingest prey. Nevertheless, toads can overcome this chemical defense by retrieving and swallowing beetles without eliciting defensive discharges.
KeywordsReaction Time Sufficient Time Initial Contact Chemical Defense Entire Body
Unable to display preview. Download preview PDF.
- Aneshansley, D.J., Eisner, T., Widom, J.M., Widom, B.: Biochemistry at 100 °C: Explosive secretory discharge of bombardier beetles(Brachinus). Science165, 61–63 (1969)Google Scholar
- Brower, L.P., Brower, J.V.Z.: Experimental studies of mimicry 6: The reaction of toads(Bufo terrestris) to honeybees(Apis mellifera) and their dronefly mimics(Eristalis venetorum). Am. Nat.96, 297–307 (1962)Google Scholar
- Brower, L.P., Brower, J.V.Z., Westcott, P.W.: Experimental studies of mimicry 5: The reactions of toads(Bufo terrestris) to bumblebees(Bombus americanorum) and their robberfly mimics(Mallophora bomboides), with a discussion of agressive mimicry. Am. Nat.94, 343–355 (1960)Google Scholar
- Camhi, J.M., Tom, W., Volman, S.: The escape behavior of the cockroachPeriplaneta americana. II. Detection of natural predators by air displacement. J. Comp. Physiol.128, 203–212 (1978)Google Scholar
- Clarke, R.D.: Food habits of toads, genusBufo (Amphibia; Bufonidae). Am. Midl. Nat.91, 140–147 (1974)Google Scholar
- Cole, C.J.: Notes on the distribution and food habits ofBufo alvarius at the eastern edge of its range. Herpetologica18, 172–175 (1962)Google Scholar
- Cott, H.B.: The effectiveness of protective adaptation in the hive bee, illustrated by experiments on the feeding reaction, habit formation, and memory of the common toad(Bufo bufo bufo). Proc. Zool. Soc. Lond.1936, 111–133 (1936)Google Scholar
- Darlington, R.B.: Radicals and squares and other statistical procedures for the behavioral sciences. Ithaca, N.Y.: Logan Hill Press 1974Google Scholar
- Dean, J.: Predator-prey interactions between toads and bombardier beetles: A behavioral and neurophysiological study. Ph.D. Thesis, Cornell University, Ithaca, N.Y. (1977)Google Scholar
- Dean, J.: Defensive reaction time of bombardier beetles: An investigation of the speed of a chemical defense. J. Chem. Ecol., (in press) (1979)Google Scholar
- Dean, J.: Effect of thermal and chemical components of bombardier beetle chemical defense: Glossopharyngeal response in two species of toads(Bufo americanus, B. marinus). J. Comp. Physiol.135, 51–59 (1980)Google Scholar
- Eibl-Eibesfeldt, I.: Nährungserwerb und Beuteschema der Erdkröte (Bufo bufo L.). Behavior4, 1–35 (1951)Google Scholar
- Eisner, T.: The protective role of the spray mechanism of the bombardier beetle,Brachynus ballustarius Lec. J. Insect Physiol.2, 215–220 (1958)Google Scholar
- Eisner, T.: Beetle's spray discourages predators. Nat. Hist.75, 42–47 (1966)Google Scholar
- Eisner, T.: Defensive secretions of millipedes. In: Arthropod venoms. Bettini, S. (ed.), pp. 41–72. Berlin, Heidelberg, New York: Springer 1978Google Scholar
- Eisner, T., Dean, J.: Ploy and counterploy in predator-prey interactions: Orb-weaving spiders versus bombardier beetles. Proc. Natl. Acad. Sci. USA73, 1365–1367 (1976)Google Scholar
- Eisner, T., Meinwald, J.: Defensive secretions of arthropods. Science153, 1341–1350 (1966)Google Scholar
- Ewert, J.P.: Neural mechanism of prey-catching and avoidance behavior in toadBufo bufo. Brain Behav. Evol.3, 36–54 (1970)Google Scholar
- Heatwole, H., Heatwole, A.: Motivational aspects of feeding behavior in toads. Copeia1968, 692–698 (1968)Google Scholar
- Hinckley, A.D.: Diet of the giant toad,Bufo marinus (L.), in Fiji. Herpetologica18, 253–259 (1962)Google Scholar
- Kafatos, F.C.: The chemical defense mechanism of millipedes. Honors Thesis, Cornell University, Ithaca, N.Y. (1961)Google Scholar
- Klimstra, W.D., Myers, C.W.: Foods of the toad,Bufo woodhousei fowleri Hinckley. Trans. Ill. State Acad. Sci.58, 11–26 (1965)Google Scholar
- Larochelle, A.: The American toad as champion carabid beetle collector. Pan-Pacific Ent.50, 203–204 (1974)Google Scholar
- Noble, G.K.: The biology of the amphibia. New York: McGraw Hill 1931Google Scholar
- Roeder, K.D.: Nerve cells and insect behavior. Cambridge, Mass.: Belknap Press 1967Google Scholar
- Roth, L.M.: Studies on the gaseous secr etion ofTribolium confusum Duval. I. The odiferous secretion ofTribolium confusum. Ann. Entomol. Soc. Am.36, 397–424 (1943)Google Scholar
- Schildknecht, U., Holoubek, K.: Die Bombardierkäfer und ihre Explosionschemie. V. Mitteilung über Insekten-Abwehrstoffe. Angew. Chem.73, 1–7 (1961)Google Scholar
- Schildknecht, U., Maschwitz, U., Wenneis, W.F.: Neue Stoffe aus dem Wehrsekret der DiplopodengattungGlomeris. Naturwissenschaften54, 196–197 (1967)Google Scholar
- Schneider, D.: Beitrag zu einer Analyse des Beute- und Fluchtverhaltens einheimischer Anuren. Biol. Zentralbl.73, 225–282 (1954)Google Scholar
- Slobodchikoff, C.N.: Experimental studies of tenebrionid beetle predation by skunks. Behavior66, 313–322 (1978)Google Scholar