Insecticidal effect of from three Hypericum species extracts against Rhyzopertha dominica, Sitophilus oryzae and Tribolium confusum

Abstract

The search for new plant natural products with insecticidal properties to control insect pests in agriculture has gained relevance in the past decades. The aim of the study was to investigate the insecticidal activity of extracts derived from flower, leaf, and stem of three Hypericum species (Hypericum heterophyllum, Hypericum perforatum, Hypericum scabrum) against the adults of three important stored grain insect pests namely; Sitophilus oryzae (Curculionidae), Rhyzopertha dominica (Bostrichidae) and Tribolium confusum (Tenebrionidae). The insects were incubated with the food under 10% concentration of Hypericum extracts and the mortality was recorded after 24, 48 and 72 h of exposure. The extracts of the Hypericum species and exposure time were found to have statistically significant effective against the three insect pests. After 72 h exposure, the mortality ranged from 4.3 to 94.1 % for all insects. Among tested insects, R. dominica was more susceptible than T. confusum and S. oryzae. Although desirable insecticidal effect against the insects were recorded from all the three Hypericum species, the leaf extract of H. perforatum was more effective on R. dominica, while the flower and stem of H. scabrum displayed high toxic effect on T. confusum and S. oryzae, respectively. The leaf extracts, of H. perforatum, in particular, may be used as source of new potential botanical insecticides against R. dominica in stored grains.

Contact Toxicity of Hypericum Extracts against Rhyzopertha dominica (Fab.) (Coleoptera: Bostrichidae)

“…When the efficacy of the tested Hypericum species on these insects is examined, H. perforatum (52.2%) was found to be powerful effective than other Hypericum species, but there was no statistical difference between H. perforatum and H. heterophyllum (48.2%) (Table 3). In a recent study, Yaman and Şimşek (2021) investigated the effect of acetone extracts of Hypericum species on R. dominica, and found the highest mortality in H. perforatum as 42.3%. But, in currently study, ethanol extracts of H. heterphyllum displayed the high toxic effect on R. dominica.…”

“…For example, Hernandez Nopsa et al (2015) reported that H. heterophyllum exhibited the stronger inhibition zone against Paenibacillus larvae than other many Hypericum species. Yaman and Şimşek (2021) recorded that H. heterophyllum displayed high toxic effect on stored grain pests. In fact, many scientists have investigated usability in pest control of some Hypericum species.…”

“…Looking at previous studies, many scientists have reported that the leaf part of plants has a superior insecticidal activity compared to other plant parts (Batish et al, 2008;Chauhan et. al., 2015;Alvi et al, 2018;Şimşek et al, 2019;Yaman and Şimşek, 2021).…”

“…When examining the interaction between the Hypericum species and plant part, the leaf part of H. perforatum exhibited the strongest mortality (79.4 %) followed by the leaf part of H. heterophyllum (70.6 %). Yaman and Şimşek (2021) were notified that leaf part of Hypericum species was more effective against R. dominica than their other parts. On the contrary, Dastagir et al (2016) found that different plant parts of H. perforatum had no mortality against R. dominica.…”

Insecticidal activities of long pepper (Piper retrofractum Vahl) fruit extracts against seed beetles (Callosobruchus maculatus Fabricius, Callosobruchus chinensis Linnaeus, and Sitophilus zeamais Motschulsky) and their effects on seed germination

“…The application of film seed coating technology with plant extracts in coating substances was a promising way for insect protection to replace the use of chemical insecticides ( Pumnuan et al., 2021 ). The research of Yaman and Şimşek (2021) showed that Hypericum species extracts had insecticidal potential against various important stored grain insect pests. Gariba et al.…”