This is the first record on the invasion of the Neotropical brown stink bug, Euschistus heros (F.) in Paraná County (latitude 31º 51' 9.6" S, longitude 60º 32' 11.2" W), Entre Ríos province, Argentina. Five adults were intercepted in 2009/2010, one in crop residues and four on soybean fields. The expanding range in the distribution of E. heros in the Southern Hemisphere is believed to be due to the increased commercial trade among countries, increase in the area cultivated with soybean, and the adoption of no-tillage cropping systems.

Laboratory studies were conducted to compare duration of feeding and superficial and in-depth damage to soybean (Glycine max) seeds by the Southern green stink bug, Nezara viridula (L.), the Neotropical brown stink bug, Euschistus heros (F.), the red-banded stink bug, Piezodorus guildinii (Westwood), and the green-belly stink bug, Dichelops melacanthus (Dallas). Results indicated that feeding time was significantly longer for N. viridula (≈ 133 min) compared to E. heros and D. melacanthus (≈ 70 min), but not different from P. guildinii (≈ 103 min). There was a positive correlation between feeding time and the resulting damage for E. heros, N. viridula and P. guildinii (R² > 0.80, P < 0.0001), but not for D. melacanthus (R² = 0.1011, P = 0.1493). The deepest seed damage (2.0 mm) was made by P. guildinii and the shallowest (0.5 mm) by D. melacanthus. The depth of the seed damage by E. heros and N. viridula (0.8, 1.2 mm, respectively) was intermediate in comparison to the other species studied. Feeding damage to the seed endosperm caused variable cell disruption and protein body dissolution, particularly when P. guildinii fed on seeds, suggesting that the deleterious action of salivary enzymes was greater for this bug compared to the others.

Survivorship and reproductive performance of the pentatomids Euschistus heros (F.) (EH), Nezara viridula (L.) (NV), and Dichelops melacanthus (Dallas) (DM) were tested in the laboratory. A mixture of natural foods (pods of green beans, Phaseolus vulgaris, raw shelled peanuts, Arachis hypogaea, and fruits of privet, Ligustrum lucidum, and 50 pairs/box (25 x 20 x 20 cm) were used, observed for 30 days, and replicated three times. Thirty days after emergence, mean female survivorship was 91% (EH), 60% (NV), and 30% (DM). More egg masses were deposited during 11-20 days after emergence, with mean number of 45.1 (EH), 5.3 (NV), and 11.8 (DM). These values were smaller during the first 10 days (25.5, 2.1, and 4.7) and last 10 days (21-30 days) (39.4, 3.9, and 4.9), respectively. Mean maximum number of eggs/day was 489 (EH) on day 29, 474 (NV) on day 11, and 153 (DM) on day 14. Mean monthly fecundity (egg masses/box) was 985 (EH), 92 (NV), and 193 (DM), and mean number of eggs/box was 8,480; 5,147, and 2,042.7, respectively.