PERFORMANCE AND SEASONAL ABUNDANCE OF THE NEOTROPICAL BROWN STINK BUG, EUSCHISTUS-HEROS NYMPHS AND ADULTS ON A NOVEL FOOD PLANT (PIGEONPEA)AND SOYBEAN

Pigeonpea, Cajanus cajan (L.) Millsp. (Leguminosae) was found as a nov el food plant of the neotropical brown stink bug, Euschistus heros (F. ), in Parana State, Brazil. Laboratory studies indicated nymphs perfor ming better when fed on immature pods of soybean, Glycine max (L.) Mer rill (Leguminosae), than on immature pods of pigeonpea. Female nymphs required 1.7 d less to complete development and tended to have a lower mortality on soybean (17.5%) than on pigeonpea (25.0%). At emergence, fresh body weight was greater on soybean than on pigeonpea. Adult E. her-os performed better on soybean than on pigeonpea. After 120 d, app roximate to 35% of adults were alive on soybean and 30% on pigeonpea; 93.3% of females oviposited on soybean, and 73.3% on pigeonpea, with a n oviposition delay of approximate to 17 days on pigeonpea compared to soybean. Fecundity was approximate to 63% greater on soybean than on pigeonpea, and adult body weight gain for females and males at differe nt ages was approximate to 6-36% greater on soybean than on pigeonpea. E. her-os colonized soybean during January-March, from the pod-settin g and filling stages (R3-R6) to maturity (R7-R8), and pigeonpea during April-June. These results indicate that E. her-os has expanded its ho st range to pigeonpea in Brazil; pods of this plant are suitable food, and can support the insect during autumn-early winter, after soybean harvest, and before it enters into partial hibernation.