Abstract
The soil-dwelling nematodes Steinernema carpocapsae, S. scapterisci, S.
feltiae, S. glaseri, Heterorhabditis bacteriophora, H. megidis,
Phasmarhabditis hermaphrodita and Caenorhabditis elegans were placed on agar
plates each containing four substrates (peat, sand, sandy loam and leaf
litter). The body-waving behaviour of infective juveniles was recorded over
a 10-day period in the presence or absence of an insect, Galleria
mellonella, a susceptible host of some species. Body-waving behaviour
differed amongst species and varied significantly in relation to substrate,
time and the presence of G. mellonella. Steinernema carpocapsae showed
body-waving behaviour more than other species and this tendency increased
significantly with time. More S. carpocapsae were seen body waving on peat
and leaf litter than on either sandy loam or sand. Conversely, sand promoted
body waving in S. scapterisci. Body waving by C. elegans was more common on
peat than on any of the other substrates. Heterorhabditis megidis, not
previously known to body wave, did so in low numbers on peat and sandy loam.
The remaining four species did not body wave. Previous work has shown that
the presence of S. glaseri increases body waving by S. carpocapsae. We
investigated whether substrate influenced this interaction and also included
S. scapterisci in the study. The presence of S. glaseri significantly
altered rates of body waving in S. carpocapsae and S. scapterisci in a way
that was substrate-dependent. Our data suggest that body-waving behaviour is
determined by substrate quality and differing body-waving behaviours may be
a mechanism by which nematodes avoid competition.
Influence of Substrate Quality and Moisture Availability on Microbial Communities and Litter Decomposition
