Diapause and different seasonal morphs of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae) in Northern Paraná State

Abstract

, during one year, to evaluate the diapause incidence and the occurrence of different seasonal morphs. The majority of the insects (ca. 90%) with mature reproductive organs was observed during the summer (December-March), when E. heros was found on soybean or on sunflower; in the beginning of autumn, most insects (87%) showed immature reproductive organs, and they were found on star bristle and under fallen leaves. Bugs with mature reproductive organs had more developed shoulders (3.23 and 3.27 mm, for males and females, respectively) than bugs with immature organs (2.91 and 2.89 mm, for males and females, respectively). Two distinct body colors, dark brown and reddish brown, were observed. Nevertheless, the reddish brown was the predominant color of both mature and immature adults during all year. Adults were parasitized by Hexacladia smithii (Ashmead) (Hymenoptera: Encyrtidae) and Tachinidae mainly Trichopoda giacomellii (Blanchard) (Diptera: Tachinidae) (80% and 40% of parasitism in male and female, respectively) during summer (December), when the bugs colonized sunflower. In soybean, 12% of males and 10% of females were parasitized, whereas in fallen leaves, the parasitism rate was 5% in both sexes.These results showed that in autumn/winter (shorter photoperiod) the majority of the insects were inactive under fallen leaves, showing immature reproductive organs and less developed shoulders, indicating that, at this time, these bugs were in diapause.

Nymphal and Adult Performance of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae), as a Potential Alternative Host for Egg Parasitoids Multiplication

“…Thus that E. heros adults collected in the field in February should be kept in a controlled room for only two weeks is recommended, whereas E. heros adults reared in the laboratory can be kept in cages with 100 couples for the first seven oviposition weeks. E. heros shows diapause and no reproductive activity during the autumn/winter (April -September) in North of Paraná State, as recorded by Panizzi & Vivan (1997) and Mourão & Panizzi (2000). Because of this behavior, the period of colect and use of E. heros population found in the field is extremely important.…”

Characterization of the imaginal reproductive diapause of Oebalus poecilus (Dallas) (Hemiptera: Pentatomidae)

“…Kiritani (1963) utilized these characteristics to determine the diapause in N. viridula, Nilakhe (1976) for O. pugnax, andAner (1991) for T. limbativentris. Mourão & Panizzi (2000 utilized the length of the pronotal spine to characterize the diapause in E. heros. They verified that females with immature reproductive organs usually had shorter pronotal spines when compared to those with mature ones.…”

“…Aner (1991) established different physiological ages for females of Tibraca limbativentris Stal through the characteristics of the reproductive organs, gastric caeca, and the body fat amount. More recently, Mourão & Panizzi (2000 characterized the diapause and the different morphological types of the neotropical brown stink bug Euschistus heros (F.).…”

Natural parasitism of Hexacladia smithii Ashmead (Hymenoptera: Encyrtidae) on Euschistus heros (F.) (Hemiptera: Pentatomidae): new record from Mato Grosso State, Brazil

“…(Hemiptera: Pentatomidae) (Noyes, 2010); Antiteuchus mixtus (F.) [= Antiteuchus variolosus (Westwood)] (Hemiptera: Pentatomidae) (Cuezzo; Fidalgo, 1997); A. albopunctatus Silva, 2010), Edessa sp. (Hemiptera: Pentatomidae) (De Santis, 1980;Noyes, 2010); Edessa meditabunda (F.) (Hemiptera: Pentatomidae) (Cuezzo;Fidalgo, 1997); E. heros (Corrêa-Ferreira et al, 1998;Mourão;Panizzi, 2000) and D. furcatus Silva, 2010); Pachycoris torridus (Scopoli) (Hemiptera: Scutelleridae) (Costa Lima, 1930) and Tetyra pinguis (Germar) (Hemiptera: Scutelleridae) (De Santis, 1979).…”