Inhibitory effects of plant extracts on growth, development and α-amylase activity in the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae)

Abstract

abstract. The bioinsecticidal effects of methanolic extracts of the leaves of castor bean, Ricinus communis, and papaya, Carica papaya, on the red flour beetle, Tribolium castaneum, were studied. More specifically, larval weight, larval mortality, percentage pupation, percentage adult emergence and F1 progeny production were recorded. We also studied the effects of the extracts on α-amylase activity and amylase gene expression in T. castaneum. The extracts of R. communis and C. papaya, which were administered in a diet, increased larval mortality and extended the durations of the larval and pupal periods. Feeding them an extract-treated diet also reduced the percentages of larvae that pupated and of adults that emerged and the number of F1 progeny. α-Amylase activity was inhibited and glucose content reduced in the larvae and adults of these insects. This inhibition of α-amylase activity by the R. communis and C. papaya extracts was concentration dependent in vitro. In addition, amylase gene expression was reduced in insects fed a diet containing C. papaya, but not R. communis extract. These results indicate that the bioinsecticidal effects of the leaf extracts are mediated by inhibiting the gene expression and activity of enzymes involved in sugar metabolism.

Aphicidal Activity ofIllicium verumFruit Extracts and Their Effects on the Acetylcholinesterase and Glutathione S-transferases Activities inMyzus persicae(Hemiptera: Aphididae)

“…Determining the inhibitory abilities of exogenous compounds on the activities of enzymes in the insect body is an important method for evaluating insecticidal activities ( Li et al. 2007 , Tatun et al. 2014a ,b).…”

Comparative insecticidal activity of different plant materials from six common plant species against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

“…Plant based compounds, being natural and organic, may provide the starting point for such discoveries. In these regards, recent studies have identified several promising natural extracts of plant exhibiting insecticidal activities in stored grain systems (Tatun et al, 2014, Tripathi et al, 2009). Such botanical extracts may have various modes of action and can help in pest management by repelling the pest away, may act as feeding and oviposition deterrent, and at the same time may act as insecticides (Mohan and Fields, 2002).…”

Effects of 20-hydroxyecdysone on the development and morphology of the red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae)

“…This enzyme converts complex carbohydrates into oligosaccharides, which are hydrolyzed to glucose by α-glucosidases (Terra et al, 1996). The changes in α-amylase activity are related to the feeding behaviour and development in T. castaneum (Tatun et al, 2014). In addition, changes in α-amylase activity are associated with different types of plant diets in Helicoverpa armigera (Kotkar et al, 2009).…”

“…Higher doses induce pupation and adult emergence, but caused deformities in the pupae and adults and a reduction in α-amylase activity. It is reported that changes in amylase gene expression and α-amylase activity in T. castaneum (Tc-Amy) correlate well with developmental profi le, with a high expression of amylase in the larval stage, a very low level in pupae and the highest activity in adults, with in the latter it is about 2-fold higher than that in larval stage (Tatun et al, 2014). Thus, further investigations are needed to reveal the relationship between Tc-Amy and ecdysteroid in the red fl our beetle.…”