Figure 5.
Predation of M. sexta larvae and eggs by Geocoris spp. (A) Examples of predated M. sexta larva (left panel) and egg (right panel). Left, the carcass of a predated first-instar M. sexta larva and typical feeding damage from early-instar Manduca spp. larvae. Right, an intact (lower left) and a predated (upper right) Manduca spp. egg. In this case, the predated egg collapsed during predation. (B) Total predation of M. sexta larvae per trial over two trials during infestation M2. GLVs were supplemented externally by placing cotton swabs next to Manduca-infested leaves (1 per plant). Cotton swabs next to irLOX2 and hemi-irLOX2 plants received 20 μL of a GLV mixture in lanolin paste (Table 1); those next to WT and irPI plants received lanolin with hexane as a control because hexane was used to dissolve GLVs before mixing with lanolin. N=59–60 larvae on May 5–6 and 92–100 larvae on May 13–15. Geocoris spp. tended to predate more larvae from GLV-supplemented plants (Fisher's exact tests, 35–37% vs 22–27% May 5–6, p=0.066; 17–21% vs 12% May 13–15, p=0.069; combined trials, Bonferroni-corrected p=0.0063). (C) Total percentage of M. sexta larvae (left panel, N=30 larvae) and eggs (right panel, N=88 eggs) predated in two separate trials during infestation M3 in 2011 (Figure 4). There was no predation of larvae or eggs by Geocoris spp. in 2010. Raw data for (B) and (C) is in F5BC_SchumanBarthelBaldwin2012predation.xlsx (Dryad: Schuman et al., 2012). Pictures are of a G. pallens adult predating a first-instar Manduca spp. larva (left) and a fifth-instar G. pallens nymph predating a Manduca spp. egg (right picture, S. Allmann). *p<0.05, ***p<0.001 in Fisher's exact tests against WT (irLOX2) or irPI (hemi-irLOX2, which also contains the irPI construct).