1Department of Food Science, Yuanpei University of Medical Technology, No. 306 Yuanpei Street, Hsinchu 30015, TaiwanFind articles by
1Department of Food Science, Yuanpei University of Medical Technology, No. 306 Yuanpei Street, Hsinchu 30015, TaiwanFind articles by
1Department of Food Science, Yuanpei University of Medical Technology, No. 306 Yuanpei Street, Hsinchu 30015, TaiwanFind articles by
Bacopa caroliniana (BC) is a perennial creeping herb and popular aquarium plant. This plant is easily cultivated; consequently, it has the potential to be a raw material which is readily available for mass production if it contains useful bioactive substances. The information about the functionality of this plant has been very limited. Therefore, the aims of this research were to analyze the composition of the essential oil (EO) of BC and to study its insecticidal effect on rice weevils. Moreover, the interactive effects of active compounds of the EO on this activity were also investigated. A total of 18 volatile compounds was identified, accounting for ca. 94% of the BC-EO in terms of quantity. Of them, α-terpinolene was the largest compound. The impact of individual volatile compounds on the inhibition of acetylcholine esterase and insecticidal activity were determined. α-Terpinolene exhibited the highest activity on these assays. Both additive and synergistic effects existed in terms of the insecticidal activity. Many compounds found in the BC-EO are widely present in other EOs. Thus, the information obtained from this study is useful for EO-related research, applications in selecting EOs or in seeking the best combination of EOs or individual compounds to achieve efficient insecticidal effects.
Many herbs have been used as food or medicine since ancient times because they contain a wide variety of bioactive phytochemicals, which have been reported to reduce the risk of diseases and promote health [1]. Regarding phytochemicals, essential oils (EOs) are mainly responsible for the aroma of aromatic plants and provide plenty of functionality such as antimicrobial, antioxidant, anti-inflammatory, and pesticide repelling or insecticidal activity.
In regard to insect pests, some are a detrimental threat to stored grains, which may cause the physical, nutritional, and quality deterioration of the grains. Of all the coleopteran pests of stored grains, the most damaging species of storage insects are found in the genus Sitophilus. For example, rice weevils (Sitophilus oryzae L.) are an internal feeding insect pest that bores into stored grains, causing damage by consuming the grains [2]. The management of agricultural pests has been largely dependent on the use of synthetic chemical pesticides for the field and post-harvest protection of crops. Nevertheless, the indiscriminate use of synthetic pesticides has caused many serious problems such as toxicity to non-target organisms, development of pest resistance and resurgence, and environmental contamination [3]. EOs and their derivatives are considered to be an alternative means of controlling many harmful insects [4]. Many EOs such as Ruta graveolens [5], Cinnamomum tamala [6], and Cleistanthus collinus [7] have been reported to be effective against rice weevils.
Bacopa caroliniana (Walt.) B.L. Robins. is a perennial creeping herb. The leaves of this plant are relatively thick and succulent, releasing a smell of lemon if crushed. The flowers are blue, with five petals, and it grows to 50–100 cm. It can be used as an aquarium plant due to its ability to grow in water. In the wild, it grows in bogs or semi-submersed conditions, adapting well if flooded and fully submerged [8]. This plant is easily cultivated because only simple conditions are sufficient for growth. Consequently, it has the potential to be a raw material readily which is available for mass production if it contains useful bioactive substances. The information about the functionality of this plant has been very limited. To the best of our knowledge, only the antimicrobial activity of the plant extract has been reported [9]. The composition of essential oil of BC (BC-EO) has not been investigated. In addition, the insecticidal activity has not been studied either.
Concerning research into the functionality of EOs, most studies have used whole EOs or their major compounds for the investigation [10,11]. Relatively few studies have worked on the interactive effects [12,13]. Thus, the information about the effects of interaction among individual compounds on the functionality of EOs has been limited. Therefore, the aims of this research were to analyze the composition of BC-EO and to study its insecticidal activity on rice weevils. Moreover, the interactive effects of active compounds of the EO on this activity were also investigated.
With its beautiful cascading flowers and easy care requirements the bacopa plant is a popular choice for gardens and containers. However like any plant, bacopas can fall victim to various pests that can damage the plant and detract from its beauty. By learning about the most common bacopa pests and how to prevent and control them, you can keep your plant healthy, pest-free, and looking its best.
Identifying Common Bacopa Plant Pests
Some of the most common pests that affect bacopa plants include
Mealybugs
Mealybugs are small, soft-bodied insects that appear as white cottony masses on stems and leaves. They pierce plant tissues and suck out sap. Heavy infestations cause yellowing, wilting, stunted growth, and leaf drop.
Aphids
These tiny, pear-shaped insects come in a variety of colors like green, black, brown, or yellow. They cluster on young stems and undersides of leaves, sucking plant juices. This causes distorted growth, yellowing, and dropping leaves.
Spider Mites
Too small to see with the naked eye, spider mites spin fine webs and cause stippling damage on leaves. They thrive in hot, dry conditions.
Whiteflies
Resembling tiny white moths, these sap-sucking insects cling to the undersides of leaves. They cause yellow speckled leaves and stunted plant growth.
Fungus Gnats
These small black flies have larvae that feed on plant roots, which can cause wilting, stunting, and potentially plant death. Adults are merely a nuisance.
Preventing Pests on Bacopa Plants
An ounce of prevention is truly worth a pound of cure when it comes to bacopa pests. Here are some key tips for prevention:
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Inspect plants regularly for early detection of pests before they spread.
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Remove and destroy severely infested stems and leaves.
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Keep garden areas clean and free of weeds, debris, and dying foliage.
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Avoid overhead watering and promote good air circulation.
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Use sterile potting mix and clean containers.
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Quarantine new plants before introducing to your existing collection.
Safely Controlling Bacopa Pests
If pests do strike, there are several effective organic control methods:
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Insecticidal soap or neem oil – These natural pesticides coat and smother insects. Spray all plant surfaces for full coverage.
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Horticultural oils – These oils dissolve the waxy coating on soft-bodied insects, causing dehydration and death. Coat all plant surfaces.
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Rubbing alcohol – Wipe mealybugs off with a cotton swab dipped in alcohol. Be careful not to damage tender new growth.
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Sticky traps – Yellow, blue, or white traps lure and catch flying pests like fungus gnats, whiteflies, and aphids.
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Beneficial insects – Release ladybugs, lacewings, predatory mites, or parasitic wasps to naturally control pests.
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Blast pests off – Use a strong stream of water to dislodge aphids and whiteflies. Repeat as needed.
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Remove by hand – For minor infestations, simply wipe or pick pests off of plants. Crush or drop in soapy water.
Integrated Pest Management for Bacopa
For the most effective control, utilize an Integrated Pest Management (IPM) approach that combines multiple tactics:
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Monitor plants closely to detect pests early before they spread
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Employ preventive practices like quarantining, disinfecting, and cleaning up debris
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Use mechanical control like blasting off pests with water and hand removal
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Release beneficial insects and apply biorational pesticides like insecticidal soap or neem oil
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Use selective traditional pesticides only when absolutely needed
The combination of vigilance, prevention, mechanical and biological control provides comprehensive protection to keep your bacopa healthy and pest-free while minimizing reliance on harsh chemicals.
While bacopa plants are susceptible to pests like aphids, spider mites, whiteflies, and others, there are many effective organic prevention and control options available. By scouting regularly, utilizing preventive practices, and being ready to take action with gentler biorational and mechanical interventions, you can prevent major pest infestations and keep your bacopa looking lush and beautiful. A little knowledge and vigilance goes a long way in cultivating a thriving, pest-free bacopa plant.
Materials and Methods
The Bacopa caroliniana herb was purchased from a local horticulture market (Taichung, Taiwan). The chemicals α-pinene (≥95%), β-pinene (≥96%), p-cymene (≥90%), sabinene (≥92%), linalool (≥97%), nerolidol (≥95%), α-terpineol (≥90%), 4-terpineol (≥95%), β-caryophyllene (≥85%), β-caryophyllene oxide (≥95%), 1-octen-3-ol (≥95%), 1,8-cineole (≥90%), α-terpinolene (≥92%), were obtained from K. F. Lings Co. (Taoyuan, Taiwan). Citronellol (≥95%) and α-terpinene (≥90%) was acquired from Alfa Aesar. Myrcene (≥90%) and γ-terpinene (≥97%) were purchased from Acros Organics. Limonene (≥95%), acetylthiocholine iodide, and 5,5-dithio-bis (2-nitrobenzoic acid) were purchased from Sigma-Aldrich Co.
Isolation of Essential Oil
The amount of 200 g of BC herb in a fresh state was cut and placed in a glass flask. Double de-ionized water was added into the flask to make the final volume of 1500 mL. The sample was subjected to hydrodistillation using a Clevenger-type apparatus. The vapor mixture of water and EO produced in the flask passed through a condenser, and then the distillate was collected. The EO in the upper layer of the distillate was taken and dried over anhydrous sodium sulfate.
7 Pests You Probably Have In Your Garden (And What To Do)
FAQ
How to care for a bacopa plant?
Can you eat the bacopa plant?
Does bacopa like moist soil?
Can bacopa be grown indoors?
How do you propagate Bacopa?
Bacopa propagates easily from cuttings which can be replanted directly into the ground or in pots with potting soil. Take 2- to 3-inch cuttings from branch tips just below a set of leaves. Remove lower leaves and dip the cutting bottom in rooting hormone to cover one or two leaf nodes.
Is Bacopa a perennial?
Bacopa is a very cute perennial plant that has the advantage of growing and blooming very well in the shade. Basic Bacopa facts Easy to care for, here are the tips for a beautiful and long-lasting blooming bacopa plant. It is recommended to plant your bacopa in spring in a blend of garden soil and flower plant soil mix.
How do you care for a Bacopa plant?
Easy to care for, here are the tips for a beautiful and long-lasting blooming bacopa plant. It is recommended to plant your bacopa in spring in a blend of garden soil and flower plant soil mix. Favor part sun, but ensure that the sweltering noontime sunrays aren’t directed to the plant. For a hanging pot, select special hanging pot soil mix.
Can you cut back a Bacopa plant?
In garden terminology, bacopa is a ‘spiller’, meaning it has a trailing growth habit. It won’t harm the plant to cut it back if it becomes too long or overcrowded in a pot. You can take off several inches and start new plants with the cuttings.