Trichoderma is a free-living fungus that acts as a biocontrol agent against plant pathogens (plant diseases), while Baculovirus is a virus that attacks insects and other arthropods (insect pests). Memory hook: "Tricho-DERMA guards the plant's skin (roots/soil); Baculo-VIRUS hunts the bugs." Both are eco-friendly replacements for chemical pesticides, which is why NEET repeatedly asks you to group them as biocontrol agents.
Trichoderma (a fungus) controls plant diseases in the root soil, while Baculovirus (genus Nucleopolyhedrovirus, a virus) attacks insect pests and is species-specific, making it ideal for IPM.
Your doubts, answered
Is Trichoderma a fungus or a bacterium?
Trichoderma is a FUNGUS, not a bacterium. NCERT calls it a free-living fungus that is very common in root ecosystems (in the soil around roots). This is a favourite trap: students confuse it with the bacterium Bacillus thuringiensis. Remember: Trichoderma (fungus) vs Bt (bacterium), both biocontrol, different kingdoms.
What exactly does Baculovirus attack?
Baculoviruses are pathogens that attack insects and other arthropods (like insect pests). They do NOT attack plants. So Baculovirus = insect killer, Trichoderma = plant-disease controller. This split (virus for pests, fungus for plant pathogens) is exactly what NEET wants you to know.
Is Baculovirus the same as Nucleopolyhedrovirus?
Not exactly, but for NEET treat them together. Baculovirus is the group (genus family). The majority of baculoviruses used as biological control agents belong to the genus Nucleopolyhedrovirus. So Nucleopolyhedrovirus is the specific type of baculovirus used in pest control.
Does Trichoderma control pests or diseases?
Trichoderma controls plant DISEASES (it acts against plant pathogens). It is used in the treatment of plant disease. It is NOT an insect-killer. Only Baculovirus and Bt kill the insects. Keep this clear: Trichoderma = anti-disease, Baculovirus/Bt = anti-insect.
Why is Baculovirus called an ideal biocontrol agent for IPM?
Baculoviruses (especially Nucleopolyhedrovirus) are species-specific and narrow-spectrum. This means they kill only the target pest and have no negative effect on plants, mammals, birds, fish, or beneficial insects. This selectivity makes them perfect for Integrated Pest Management (IPM), where you want to protect helpful insects. This links to the next concept: integrated-pest-management-ipm.
⚠️ The NEET trap ✗ Trichoderma kills insect pests and Baculovirus cures plant diseases. ✓ Trichoderma (a fungus) controls plant DISEASES/pathogens; Baculovirus (a virus) attacks INSECTS and arthropods. 🧠 Swap-the-target trap: NCERT gives Trichoderma to plant disease and Baculovirus to insects. NTA reverses them. Fix it as 'fungus fights fungus-type plant disease; virus fights the bug.'
Real NEET questions
2019
Select the correct group of biocontrol agents.
A · Bacillus thuringiensis, Tobacco mosaic virus, Aphids
B · Trichoderma, Baculovirus, Bacillus thuringiensis ✓
C · Oscillatoria, Rhizobium, Trichoderma
D · Nostoc, Azospirillium, Nucleopolyhedrovirus
Solution: Trichoderma, Baculovirus and Bacillus thuringiensis (Bt) are all established biocontrol agents: Trichoderma controls plant pathogens, Baculoviruses attack insect pests, and Bt kills caterpillars. Other options mix in biofertilisers (Rhizobium, Nostoc, Azospirillum) or the pest itself (Aphids).
2019
Which of the following can be used as a biocontrol agent in the treatment of plant disease?
A · Trichoderma ✓
B · Chlorella
C · Anabaena
D · Lactobacillus
Solution: Trichoderma species are free-living fungi common in root ecosystems and are effective biocontrol agents against several plant pathogens. Chlorella and Anabaena are algae/cyanobacteria, and Lactobacillus is a household lactic acid bacterium, none of which is used to treat plant disease.
2026
A biocontrol agent to be a part of an integrated pest management should be
A · Species-specific and symbiotic
B · Free living and broad spectrum
C · Narrow spectrum and symbiotic
D · Species-specific and inactive on non-target organisms ✓
Solution: Ideal IPM biocontrol agents like Nucleopolyhedrovirus baculoviruses are species-specific and narrow-spectrum, with no negative impact on non-target plants, mammals, birds, fish or beneficial insects. This selectivity is what makes them desirable.
Solved Microbes in Human Welfare NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Trichoderma is a free-living fungus of root ecosystems used as a biocontrol agent in the treatment of plant diseases (against plant pathogens).
What is the role of Baculovirus?
Baculoviruses are pathogens that attack insects and other arthropods, so they are used as biological control agents against insect pests.
Which genus of Baculovirus is used for biological control?
The majority of baculoviruses used as biological control agents belong to the genus Nucleopolyhedrovirus.
Is Trichoderma a bacterium?
No. Trichoderma is a fungus. Bacillus thuringiensis (Bt) is the bacterial biocontrol agent; do not confuse the two.
Why are Trichoderma and Baculovirus preferred over chemical pesticides?
They are eco-friendly and (for baculovirus) species-specific and narrow-spectrum, so they do not harm plants, humans, birds, fish, or beneficial insects like chemical pesticides do.
