The results of the combined study effects analysis for the insect damage measurements are presented in Supplementary Fig. 2, and the means and standard errors from individual analyses are presented in Table 3. Insect damage evaluations were documented in 5–19 Experimental Phase studies of MON-89Ø34-3 × MON-88Ø17-3 and MON-89Ø34-3 × MON-ØØ6Ø3-6 GM hybrids and the isohybrid conventional control (Table 3). The analysis across regions, sites, and years showed statistically significant differences (p ≤ 0.05) between MON-89Ø34-3 × MON-88Ø17-3 and the conventional control for Diabrotica root damage (0.05 vs. 0.11 rating), corn earworm damage (0.46 vs. 2.40 cm2), and Spodoptera leaf damage (0.20 vs. 1.94 rating) (Table 3 and Supplementary Fig. 2). MON-89Ø34-3 × MON-ØØ6Ø3-6 had statistically significant differences from the conventional control for corn earworm damage (0.31 vs. 1.87 cm2) and Spodoptera leaf damage (0.33 vs. 2.23 rating) (Table 3). As expected, in all cases of significant differences, the level of insect damage was greater for the conventional control using regional best practices for insect pest control than for the GM IR maize hybrids.Table 3Means and standard errors (SE) for insect damage characteristics of MON-89Ø34-3 × MON-88Ø17-3 and MON-89Ø34-3 × MON-ØØ6Ø3-6 GM hybrids and the conventional control in Experimental and Pilot Phase studies in Mexico during 2009–2013Characteristic evaluated (unit)Study typeMON-89Ø34-3 × MON-88Ø17-3MON-89Ø34-3 × MON-ØØ6Ø3-6No. of studiesMean (SE)No. of studiesMean (SE)TestControlTestControlStalk borer (Diatraea spp.) tunnel length (cm)Experimental140.01 (0.01)1.09 (0.57)110.25 (0.24)0.55 (0.31)Pilot240.02 (0.01)0.18 (0.07)*110.00 (0.00)0.17 (0.08)Stalk borer (Diatraea spp.) tunnel numberExperimental160.00 (0.00)0.16 (0.06)120.01 (0.01)0.05 (0.01)Pilot170.00 (0.00)0.04 (0.01)*40.01 (0.01)0.10 (0.07) Diabrotica root damage (0–3 scale)Experimental180.05 (0.01)0.11 (0.02)*50.13 (0.06)0.12 (0.05)Pilot260.01 (0.00)0.02 (0.01)*130.07 (0.04)0.06 (0.04)Corn earworm (Helicoverpa zea or Spodoptera spp.) damage (cm2)Experimental190.46 (0.18)2.40 (0.51)*150.31 (0.10)1.87 (0.48)*Pilot260.19 (0.10)2.08 (0.31)*130.11 (0.05)1.91 (0.37)* Spodoptera leaf damage (0–9 scale)Experimental190.20 (0.09)1.94 (0.34)*150.33 (0.14)2.23 (0.41)*Pilot160.06 (0.03)1.49 (0.35)*130.05 (0.03)1.26 (0.41)Cutworma (Agrotis or Spodoptera spp.) damage (number of seedlings)Experimental––––––Pilot30 (0.00)35.88 (25.45)*30 (0.00)37.11 (24.07)**Statistically significant at the 5 % level of significance aCutworm (Agrotis spp.) was not present in Experimental Phase trials, and was not included in meta-analysis for Pilot Phase trials because of the small number of studies