Activités enzymatiques du tube digestif du prédateurPodisus maculiventris (Hem.: Pentatomidae)

Digestive proteolytic activity in the gut and salivary glands of the predatory bug Podisus maculiventris (Heteroptera: Pentatomidae); effect of proteinase inhibitors

“…Of the predatory Heteroptera, P. maculiventris is one of the most widely investigated and is currently used as a biological control agent in North America and Europe, primarily for the control of lepidopteran and coleopteran pests (De Clercq, 2000). Although, the proteolytic processes of P. maculiventris have received some attention previously (Stamopoulos et al, 1993;Cohen, 1995), there is little information available on the potential impact of PIs within the diet of this predator on either gut or salivary proteolytic activity. The effects of PIs in the diets of other predatory insect species have, however, been more fully elucidated.…”

Zoophytophagy in predatory Hemiptera

“…Enzymatic adaptation can also be according to the developmental stage. For example, in the second and third instars of P. maculiventris, the enzyme activity of the midgut is centered on amylase, esterase-lipase, phosphatase, α-glucosidase, leucine arylamidase and N-acetyl-β-glucosaminidases, while fifth instar and adults midgut cells secrete a complex of 19 enzymes, with high activity found for at least 14 of them (Stamopoulos et al, 1993). After the 3rd instar, P. maculiventris shows high midgut activities of β-glucosidase and amylase, indicating their ability to use β-glucosides such as salicine, amygdaline, arbutine, and gentibiose, among others from plant starch digestion (Stamopoulos et al, 1993).…”

“…For example, in the second and third instars of P. maculiventris, the enzyme activity of the midgut is centered on amylase, esterase-lipase, phosphatase, α-glucosidase, leucine arylamidase and N-acetyl-β-glucosaminidases, while fifth instar and adults midgut cells secrete a complex of 19 enzymes, with high activity found for at least 14 of them (Stamopoulos et al, 1993). After the 3rd instar, P. maculiventris shows high midgut activities of β-glucosidase and amylase, indicating their ability to use β-glucosides such as salicine, amygdaline, arbutine, and gentibiose, among others from plant starch digestion (Stamopoulos et al, 1993). The high amylase activity not only indicates its potential to digest the starch, the major glycoside reserve found in plants, but also other polysaccharides and dextrines from glycogen, the major animal cell glycoside reservoir (Cohen, 1990;Stamopoulos et al, 1993) what correlates with amylase presence in neotropic Asopinae species Podisus nigrispinus and Brontocoris tabidus (Oliveira et al, 2006;Azevedo et al, 2007).…”

“…After the 3rd instar, P. maculiventris shows high midgut activities of β-glucosidase and amylase, indicating their ability to use β-glucosides such as salicine, amygdaline, arbutine, and gentibiose, among others from plant starch digestion (Stamopoulos et al, 1993). The high amylase activity not only indicates its potential to digest the starch, the major glycoside reserve found in plants, but also other polysaccharides and dextrines from glycogen, the major animal cell glycoside reservoir (Cohen, 1990;Stamopoulos et al, 1993) what correlates with amylase presence in neotropic Asopinae species Podisus nigrispinus and Brontocoris tabidus (Oliveira et al, 2006;Azevedo et al, 2007). Lygus hesperus is a good example of a phytophagous species with a propensity to switch the feeding between the plant and animal.…”

Efeitos de Metarhizium anisopliae (Metsch.) Sorok. e Beauveria bassiana (Bals.) Vuill. sobre o percevejo predador Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae)

“…No entanto, a reação alcalina ou ácida do conteúdo intestinal dos insetos pode ser uma das causas de eliminação de muitos microrganismos potencialmente patogênicos (Alves 1998), o que poderá ter minimizado a ação desses fungos sobre parâmetros considerados. Além disso, percevejos predadores possuem digestão extra-oral e usam um complexo enzimático para digerir os tecidos e órgãos das presas para posterior ingestão na forma semilíquida (Cohen 1990, Stamopoulos et al 1993, Cohen 2000, possivelmente reduzindo a viabilidade do fungo antes mesmo de sua ingestão, o que precisa ser investigado.…”