Action of Bacillus thuringiensis (Bacillales: Bacillaceae) in the midgut of the sugarcane borer Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae)

Bioactivity of Bacillus thuringiensis (Bacillales: Bacillaceae) on Diatraea saccharalis (Lepidoptera: Crambidae) eggs

“…We observed vacuolization and degeneration in the intestinal epithelium of the D. saccharalis embryo, which is in agreement with the results of previous studies on neonatal larvae of D. saccharalis 23 . These impairments might be associated with the stimulation of the insect's immune system, such as by microbial infection and toxins 86,87 ; similar results have been observed in other lepidopterans 29,88,89 …”

“…We observed that eggs treated with Bta demonstrated gradual alteration of color, changing from an initial yellowish hue to brown and black after unsuccessful embryonic development. The color changes observed in the treated eggs were similar to the changes observed in the larval integumentary region of Urbanus acawaios treated with B. thuringiensis serovar kurstaki (Btk) 29 and of D. saccharalis treated with Bta 23 …”

“…The color changes observed in the treated eggs were similar to the changes observed in the larval integumentary region of Urbanus acawaios treated with B. thuringiensis serovar kurstaki (Btk) 29 and of D. saccharalis treated with Bta. 23 To the best of our knowledge, information regarding the toxicological effects of Bta on insect eggs is limited. Previous studies have analyzed the potential biocontrol activity of other Bt varieties on the eggs of lepidopteran pests, such as Plutella xylostella, 22,30 Spodoptera litura and Pieris rapae, 22 and in the nematodes Meloidogyne incognita 31 and Trichostrongylus colubriformis.…”

“…14,21 The application of Bt to insect eggs may lead to mortality; however, this phenomenon has not been studied extensively. 22 Considering that D. saccharalis is one of the major pests affecting sugarcane cultivation, 23 utilizing Bt to target eggs in addition to larvae, may be useful in obtaining enhanced control of this insect pest. Here, our objectives were to evaluate the bioactivity of Bacillus thuringiensis serovar Aizawai GC-91 (Bta) in D. saccharalis eggs and analyze its possible effects on viability and embryonic development.…”

Olimpíadas De Caxiuanã: Uma Ferramenta Para O Ensino De Entomologia Nas Escolas De Ensino Fundamental Da Floresta Nacional De Caxiuanã, Melgaço-Pa

“…processos fisiológicos nos insetos tais como absorção, excreção e detoxificação de compostos químicos. O mesêntero, por ser considerado um dos primeiros locais a entrar em contato quando analisado os efeitos da ingestão de pesticidas, tem se tornado um importante órgão alvo nos estudos ecotoxicológicos em insetos(DAQUILA e CONTE, 2019;. A detecção de alterações morfológicas neste órgão tem sido útil nos ensaios de toxicidade, evidenciando de…”