Evaluation of responses of different ant species (Formicidae) to the scavenger deterrent factor associated with the entomopathogenic nematode-bacterium complex

Baris Gulcu,Harry K Kaya,Edwin E Lewis,Selcuk Hazir

doi:10.14411/eje.2018.030

Abstract

According to previous observations, it was hypothesized that the feeding behavior of some ant species would be deterred by a scavenger deterrent factor (SDF), whereas for other species it would not. The effects of the SDF were studied on 11 ant species in three different subfamilies: Dolichoderinae Forel, 1878, Formicinae Latreille, 1809, and Myrmicinae Lepeletier de Saint-Fargeau, 1835. The experiments were conducted from 2014-2015 in Davis, California, United States, Aydin, Turkey, and Duzce, Turkey. Five-day-old Heterorhabditis bacteriophora (Poinar, 1976), (Hb)-killed and freeze-killed Galleria mellonella (Linnaeus, 1758) were exposed to ant colonies in the field for 3 to 4 h. Seven ant species fed significantly less on Hb-killed insects than freeze-killed insect. On the other hand, there was no significant difference in cadaver consumption with five species, but Liometopum occidentale Emery, 1895 did consume a higher rate of Hb-killed insects than freeze-killed insects and was not deterred by SDF. It was also observed that four ant species took Hb-killed insects into the nests, but two Myrmicinae species, Pogonomyrmex subdentatus Mayr, 1870 and Messor meridionalis (Andre, 1883) removed the cadavers after 30 min, whereas two Formicinae species, Cataglyphis nodus (Brulle, 1833) and Formica fusca Linnaeus, 1758, retained the cadavers in the nest. It was assumed that the latter two species consumed both Hb-killed and freeze-killed insects. Further studies are needed to explain why L. occidentale C. nodus and F. fusca are not deterred by SDF.

Highlights

The scavenger deterrent factor (SDF) is an unidentified chemical compound(s) associated with insects killed by the entomopathogenic nematode-bacterium complex
Zhou et al (2002) demonstrated that the deterrent effect on scavenger ants was associated with the mutualistic bacterial genera, Photorhabdus (Boemare et al, 1993) (Enterobacteriaceae) and Xenorhabdus Thomas & Poinar, 1979 (Enterobacteriaceae) of entomopathogenic nematodes (EPNs) and referred to the compound(s) as an
Gulcu et al (2012) reported that ADF deters several ant species and repelled crickets, vespid wasps and calliphorid flies from feeding on nematode-killed insects, and they renamed it SDF because it had a wider effect on different species of scavenger insects

Summary

Introduction

The scavenger deterrent factor (SDF) is an unidentified chemical compound(s) associated with insects killed by the entomopathogenic nematode-bacterium complex. Gulcu et al (2012) reported that ADF deters several ant species and repelled crickets, vespid wasps and calliphorid flies from feeding on nematode-killed insects, and they renamed it SDF because it had a wider effect on different species of scavenger insects. Studies conducted by Baur et al (1998), Zhou et al (2002), Gulcu et al (2012), and Ulug et al (2014) showed that several ant species do not feed on Steinernema- or Heterorhabditis-killed insects that were more than 2-days old and heterorhabditids produce a stronger deterrent factor than steinernematids.

Results

Conclusion