Zombie fire ant workers: behavior controlled by decapitating fly parasitoids

Abstract

Laboratory observations were conducted on four separate red imported fire ant, Solenopsis invicta, colonies that contained workers parasitized by the decapitating fly, Pseudacteon tricuspis. Parasitized S. invicta workers remained inside the nest during parasitoid larval development and left the nest approximately 8 -10 hours before decapitation by the parasitoid. When parasitized ants left the nest, they were highly mobile, were responsive to tactile stimuli, and showed minimal defensive behavior. Ants ultimately entered into a grass thatch layer, where they were decapitated and the fly maggots pupariated. This study reveals that parasitized ants exhibit behaviors that are consistent with host manipulation to benefit survival of the parasitoid.

Behavior and Development of <I>Pseudacteon curvatus</I> (Diptera: Phoridae) Varies According to the Social Form of Its Host <I>Solenopsis invicta</I> (Hymenoptera: Formicidae) in Its Native Range

“…The impact of Pseudacteon on foraging workers (Feener and Brown 1992;Orr et al 1995Orr et al , 1997Morrison et al 1997;Morrison 1999;Wuellner et al 2002) and on postinfection host behavior (Henne and Johnson 2007) has been analyzed, but without regard to which subcastes are affected. Folgarait and Gilbert (1999) found that when Pseudacteon parasitoids attacked Solenopsis richteri Forel along foraging trails, the relative frequency of smaller workers increased at the expense of larger worker sizes.…”

Evidence for convergent evolution of host parasitic manipulation in response to environmental conditions

“…For a parasite that manipulates the host to bite leaves before using the host cadaver as a platform for transmission, the permanence of a leaf as a platform may impact its fitness. Although there are other parasites that manipulate ant behavior, including other fungi (Boer 2008), cestodes (Beros et al 2015), nematodes (Poinar and Yanoviak 2008), trematodes (Krull and Mapes 1952;Carney 1969), and flies (Henne and Johnson 2007), none of them have been as extensively studied as the zombie ants. This deeper understanding of the biology implies the zombie ant system may be a more suitable model for studying how environmental variation affects the behavioral manipulation of hosts by parasites.…”

Seasonal cues mediate host behaviour modification and cocoon polymorphism in Microplitis mediator (Hymenoptera: Braconidae)

“…These include altered patterns of web spinning in spiders (Eberhard, 2001) Roitberg, 1987;Biron et al, 2005), induced defensive behaviours (Ponton et al, 2006;Grosman et al, 2008), use of the host body as a defensive shield (Brodeur & Vet, 1994) and orientation to safe pupation sites (Brodeur & McNeil, 1992;Eberhard, 2000;Henne & Johnson, 2007). Work has also begun to elaborate the neuronal basis for certain aspects of host manipulation (Libersat et al, 2009).…”