Toxicity of isolated phenolic compounds from Acorus calamus L. to control Spodoptera litura (Lepidoptera: Noctuidae) under laboratory conditions

Background Spodoptera litura (Lepidoptera: Noctuidae), the tobacco cutworm, is an prominent agricultural pest. To reduce the use of chemical pesticides that cause health problems and that leave residue in the environment, some botanical pesticides have been developed. Our research aimed to evaluate the insecticidal efficacy of Acorus calamus L. extract for the control of S. litura under laboratory conditions. Results After 24 h of topical application, the A. calamus methanolic crude extract showed toxicity against secondary instar S. litura larvae (LD50 ~ 7.438 µg/larva). Chrysin (5,7-dihydroxy flavone), one of the isolated phenolic compounds, showed optimal control efficiency (LD50 ~ 2.752 µg/larva) and showed a reduction in carboxylesterase activities, which have detoxification reduction roles in larvae. Conclusion Chrysin in the crude extract of A. calamus may be an active compound to control this pest, and it may be applied as an alternative to minimize the usage of chemical insecticides. Graphical Abstract

Adoption of Chemical Pesticides Under Commercial Vegetable Cultivation inSri Ganganagar District of Rajasthan

The study was conducted in Sri Ganganagar district of Rajasthan to assess the extent of use of chemical pesticides under commercial vegetable cultivation. The primary data were collected from 100 farm households across 18 villages from 2016 to 2019. Chemical insecticides were used by all farmers whereas biopesticides and botanical pesticides were used by <5% for insect pest control in vegetables. The average number of chemical pesticide sprays in a crop cycle was 14, 15, 15 and 13 in cauliflower, cabbage, tomato and pea crops respectively. Average quantity of chemical pesticides used was 4.23, 3.87, 5.16 and 3.47 kg active ingredient per hectare in cauliflower, cabbage, tomato and pea crops respectively. The study highlights the overuse and misuse of chemical pesticides in vegetable crops where the economic part is edible unlike cotton where the economic part is nonedible.The direct negative impact of chemical pesticides on health of farm workers is estimated in the paper.

Botanical Pesticides: Use of Plants in pest management

Plants play a vital role in human life since the beginning of life on earth. Plants are not only directly used as a feed and fodder for humans and animals but are also used as drugs, food additives, pesticides, in flavor and fragrances and dye and pigments. The plants produce compounds for their growth and development and also produce secondary metabolites which provide additional properties to plants. These secondary metabolites produced by plant are responsible for these activities. Plants as a whole or in extracts/fractions form have been used as pesticides for protection of plants since thousands of years. Pyrethrum, neem, rotenone are such plants which has been used in many cultures and traditions for crop protection since ages and hold relevance in today’s world as well. The plant extracts contain secondary metabolites which provide protection to plants against pests by either causing mortality of pests or act as repellent to them. They can also impact pests by causing anti-feedancy, toxicity, alters insects behavior during oviposition and mating and inhibition of progeny emergence in pests. Essential oils isolated from the plants have also pesticidal properties. Lemongrass essential oil, Citronella essential oils, Tea tree essential oils and Oregano essential oils are the commonly used essential oils against the pests. In this review, botanical pesticides are discussed and their role in pest management and their advantageous over synthetic pesticides in terms of biodegradability, posing no or low risk to humans, environment and non-target organisms. Also, the future of botanical pesticides is discussed where they can be an alternative to synthetic pesticides if more research is done on their stability, efficacy, safety, modes of action, cost reduction is done.

Use of essential oil for post-harvest pest control.

Since past few decades, application of essential oils (EOs) was explored experimentally for the management of postharvest pests and diseases. However, uses of essential oils face a series of problems, including regulatory obstruction to commercialization (such as cost of toxicological and environmental assessments) or the way that efficiency of essential oils toward pests and diseases is not as evident or clear as that seen with the present available forms. This review highlights several issues extending from EOs chemistry to their bioactivity potential. The mechanism of action of EOs is also discussed to provide better understanding about their functions and improve the scope for the establishment of commercial opportunities in the form of natural biocontrol agents/botanical pesticides.

The potency of Myrtaceae Family from Cibodas Botanic Gardens (Cianjur, Indonesia) as botanical pesticide

Pratiwi RA, Nurlaeni Y. 2021. The potency of Myrtaceae Family from Cibodas Botanic Gardens (Cianjur, Indonesia) as botanical pesticide. Biodiversitas 22: 4648-4664. Cibodas Botanic Gardens (CBG) is a biodiversity reservoir that can be explored for the discovery of new candidates for botanical pesticides. Myrtaceae has been reported to provide biological activity against pests or pathogens due to their essential oil contents. This research was conducted to inventory and categorize Myrtaceae collection in CBG that had the potency to be botanical pesticide. The list of Myrtaceae collection of CBG obtained from Unit Registration and Collection CBG per 2021. Database fulfilling regarding the bactericide/fungicide/herbicide/insecticide potency of the Myrtaceae of CBG’s collection was carried out through digital references search. Our result showed that there were 73 species of Myrtaceae (from 18 genera) that are potential to be botanical pesticide sources. There were 17 species that are considerably had a high potency. Most of them belong to the Eucalyptus and Melaleuca, followed by Backhousia, Leptospermum, Psidium, and Syzygium. The data resulted from this study is expected to serve as baseline information for further research about the formulation, efficacy, and conservation management of botanical pesticides from Myrtaceae for sustainable use. Furthermore, the development of biological pesticides is a step to improve the quality of Indonesian export products so as to increase national competitiveness in the globalization era nowadays.

UJI BEBERAPA KONSENTRASI EKSTRAK UMBI GADUNG (Dioscorea hispida Dennst) TERHADAP HAMA KEONG MAS (Pomacea canaliculata L.)

Riau is one of a lowland rice producing provinces. One of the pests that can reduce rice productivity is the golden snail (Pomacea canaliculata L.). The solution for controlling the golden snail (P. canaliculata L.). Pest uses environmentally friendly control techniques, namely botanical pesticides of gadung tubers. This study aims to obtain a concentration of the extract of gadung tuber flour (Dioscorea hispida Dennst) which is effective in controlled the attack of golden snails (P. canaliculata L.) in lowland rice plants. This research was conducted experimentally using completely randomized design (CRD) consisting of five treatments and four replications, in order to obtain 20 experimental units. The treatments consisted of concentrations of gadung tubers extract, namely 0 g.l-1, 25 g.l-1, 50 g.l-1, 75 g.l-1, and 100 g.l-1. Observations included the initial dst time to snail death, lethal time 50 (LT 50), daily total mortality, and behavior changes in behavior. The results showed that the application of 100 g.l concentration of gadung tuber extract treatment caused the highest total mortality of golden snails (P. canaliculata L.) of 74.99%, but it was not effective yet in controlling the golden snail pest because it was not able to kill the golden snail above 80%.

Biopesticide Evaluation from Lab to Greenhouse Scale of Essential Oils Used against Macrosiphum euphorbiae

Aphids are recognized as a major threat to economically important crops. Their control is predominantly based on synthetic insecticides that are detrimental to human health and the environment. Botanical pesticides based on essential oils (EOs) are a promising alternative. In this study, the entomotoxicity of green anise and fennel EO fumigation was tested on the potato aphid Macrosiphum euphorbiae. Three different settings of increasing scale were considered (leaflet, whole plant and greenhouse) to appraise the consistency of EO impact from controlled laboratory to greenhouse production conditions. LC50 values for green anise and fennel were 6.6 μl L−1air and 12.2 μl L−1air, respectively, based on dose-response curves in leaflet experiments but fennel EO induced phytotoxicity. EO efficiency was confirmed at the whole-plant scale. In the greenhouse experiment, fennel EO exhibited greater efficiency than at the laboratory scale equaling green anise EO efficiency but both EOs showed delayed phytotoxicity, illustrating the importance of long-term monitoring. The present study revealed the ability of both EOs to control M. euphorbiae populations under greenhouse conditions and hinted at the importance of assessing EO efficiency in realistic agronomic conditions (e.g., under the fluctuating environmental conditions usually occurring in greenhouses).

Insecticidal Terpenes From the Essential Oils of Artemisia nakaii and Their Inhibitory Effects on Acetylcholinesterase

Essential oils (EOs) are often the source of insecticidal substances of high efficiency and low toxicity. From gas chromatograph-mass spectrometer, column chromatography, and nuclear magnetic resonance spectra analyses, twenty terpenes were identified from the EOs of Artemisia nakaii. These comprised mostly monoterpenes (49.01%) and sesquiterpenes (50.76%). The terpenes at the highest concentrations in the EOs of A. nakaii were feropodin (200.46 ± 1.42 μg/ml), (+)-camphor (154.93 ± 9.72 μg/ml), β-selinene (57.73 ± 2.48 μg/ml), and 1,8-cineole (17.99 ± 1.06 μg/ml), calculated using area normalization and external standards. The EOs were tested for biological activity and showed strong fumigant toxicity and significant antifeedant activity against the larvae of Spodoptera litura. Furthermore, the monoterpenes 1,8-cineole and (+)-camphor displayed significant fumigant activity against S. litura, with LC50 values of 7.00 ± 0.85 and 18.16 ± 2.31 μl/L, respectively. Antifeedant activity of the sesquiterpenes feropodin and β-selinene was obvious, with EC50 values of 12.23 ± 2.60 and 10.46 ± 0.27 μg/cm2, respectively. The EOs and β-selinene were also found to inhibit acetylcholinesterase, with IC50 values of 37.75 ± 3.59 and 6.88 ± 0.48 μg/ml, respectively. These results suggest that monoterpenes and sesquiterpenes from the EOs of A. nakaii could potentially be applied as a botanical pesticides in the control of S. litura.