Figure 1.
Effect of competitor density on killing in vivo.
Percentage mortality (mean ± S.E.) of first generation adult males and females of the nematode Steinernema longicaudum in cadavers of the wax moth Galleria mellonella, with varying density, classed by number of males found in each cadaver. The number above the bar is the number of cadavers in each class.
Figure 2.
Fighting in Steinernema longicaudum in a drop of insect haemolymph A. A male wrapped around the tail end of another male (the victim). The victim is moving rapidly at this stage, resulting in blurring of the image. B. The same pair ten minutes later. Here, the victim has slowed movement and is paralysed. Scale bar: 1 mm.
Figure 3.
Time course of killing in IJ-derived males.
Percentage of pairs of male Steinernema longicaudum in which one male was either paralysed or dead at various times after the males were placed together; N = 36 pairs. None of the 36 single male controls was paralysed or dead after 24 h.
Figure 4.
Developmental pathway affects killing.
Effect of developmental pathway on fatal fighting in Steinernema longicaudum. Percentage of pairs in which at least one male was paralysed or dead 24 hours after they were placed together. Differences between the IJ and non-IJ pathways significant at P<0.001 (chi-square, 1 d.f. = 41.049 for dead, 61.016 for total affected (paralysed or dead). Numbers on the bars are numbers of pairs. A maximum of 3% of single males suffered paralysis or death, significantly different to pairs for IJ (chi-square = 34.239, 1 d.f., P<0.001), but not for non-IJ (chi-square = 2.064, 1 d.f., P = 0.151)
Table 1.
Mortality (mean ± S.E.) of male S. longicaudum 24 h and 2–4 days after being placed in groups of 1–32.
Table 2.
Mortality (mean ± SE) of S. longicaudum males and females developing together for 4–5 days in hanging drops of insect haemolymph inoculated with infective juveniles.