We assessed the relative contributions of in situ survival and recolonizati
on to overall recovery of arthropod populations following prescribed fire b
y monitoring arthropod morphospecies richness and abundance in enclosed and
open plots in adjacent burned and unburned units within two remnant Illino
is prairies. Vacuum sampling of arthropods at semimonthly intervals followi
ng spring burns at each site indicated that fire strongly depressed arthrop
od abundance initially, but that abundance and species richness tended to r
ecover toward the end of the summer, mostly due to recolonization from adja
cent unburned refuges. Nevertheless, arthropod groups (taxa or guilds) were
affected differently by fire, and differences in arthropod species composi
tion among burned and unburned plots persisted. Sampled arthropod groups si
gnificantly reduced by fire at one or both study sites included springtails
(Collembola), deltocephaline leafhoppers (Homoptera: Cicadellidae: Deltoce
phalinae), aphids (Homoptera: Aphididae), delphacid planthoppers (Homoptera
: Delphacidae), parasitoid wasps (Hymenoptera), and spiders (Araneae). Only
one group, typhlocybine leafhoppers (Homoptera: Cicadellidae: Typhlocybina
e), exhibited a significant positive response to fire. These results indica
te that in situ populations of many arthropod species are substantially red
uced by prescribed fire. Thus, to preserve native arthropod faunas, land ma
nagers should ensure that unburned refuges are maintained and that the inte
rvals between burns are sufficient to allow recolonization of burned areas
to occur.