Biological control of insect pest

Biological control of insect pests is evolving through the integration of molecular genetics, such as CRISPR-Cas9 and RNA interference (RNAi), with advanced monitoring technologies like artificial intelligence (AI) and computer vision. These strategies enhance precision in pest identification, enable rapid population suppression through gene drives, and optimize the deployment of natural enemies across varying landscapes.

Molecular Mechanisms of Insect Control

The fundamental molecular mechanisms in modern biocontrol involve targeted gene disruption, silencing, and the regulation of physiological pathways.

• CRISPR-Cas9 Genome Editing: This system utilizes the Cas9 nuclease guided by synthetic RNA to create double-strand breaks at specific DNA sequences (Direct, High; DOI: 10.55446/ije.2025.2839). Repair occurs via non-homologous end joining (NHEJ), which often introduces gene-disrupting mutations, or homology-directed repair (HDR), which allows for precise gene insertion or "homing" (Direct, High; PMID: 30247490, PMID: 26641531).
• RNA Interference (RNAi): RNAi achieves gene silencing through the introduction of double-stranded RNA (dsRNA), which is cleaved by Dicer enzymes into small interfering RNAs (siRNAs) (Direct, High; DOI: 10.1080/AIBM.2017.05.555666). These siRNAs guide the RNA-induced silencing complex (RISC) to degrade complementary messenger RNA (mRNA), suppressing the expression of genes essential for development, reproduction, or survival (Direct, High; DOI: 10.1080/AIBM.2017.05.555666).
• Homing and Toxin-Antidote Systems: Synthetic gene drives like "Medea" utilize a maternal-toxin/zygotic-antidote system to ensure the drive allele is preferentially inherited by offspring (Direct, Medium; DOI: 10.1080/AIBM.2017.05.555666). Homing drives specifically target and substitute sequences in the genome to spread engineered traits rapidly through populations (Direct, High; PMID: 25035423).
• Signal Transduction and Immunity: Phosphatases like calcineurin (CAN) act as immune activators; suppressing HaCAN in Helicoverpa armigera has been shown to enhance the toxicity of Bacillus thuringiensis (Bt) Cry1Ac proteins (Direct, High; PMID: 33643268). Similarly, testis-specific serine/threonine protein kinases (TSSK) are critical for spermatogenesis and male fertility in invasive moths like Cydia pomonella (Direct, High; PMID: 39363033).

Strategic Applications in Biological Control

Biocontrol strategies are categorized by their method of implementation and the ecological niche they address.

• Classical Biological Control: This involves the introduction of exotic natural enemies from a pest's region of origin to establish a permanent, self-sustaining population for long-term suppression (Direct, High; DOI: 10.1007/s10526-011-9395-1).
• Augmentative Biological Control: This strategy relies on the periodical release of mass-reared natural enemies for immediate pest control. It includes inundative releases for rapid suppression and inoculative releases where the progeny of released enemies provide ongoing control (Direct, High; DOI: 10.1007/s10526-011-9395-1). Effectiveness often depends on landscape complexity; for instance, augmentation may be more successful in complex landscapes with higher habitat heterogeneity (Direct, High; PMID: 31209256).
• Conservation Biological Control: This approach focuses on human actions that protect and stimulate existing natural enemy populations, such as maintaining semi-natural vegetation or reducing chemical pesticide use (Direct, High; DOI: 10.1007/s10526-011-9395-1, DOI: 10.33545/2618060x.2024.v7.i11a.1912).

Emerging Technological Integrations

Recent advancements integrate biological methods with digital and automated systems.

• Artificial Intelligence (AI) and Machine Learning: AI provides solutions for automated pest identification and classification using convolutional neural networks (CNNs) (Direct, High; PMID: 37538063). Hybrid models, such as Hybrid Vision Graph Neural Networks (HV-GNN), combine convolutional feature extraction with relational modeling to detect pests in complex environments like coffee plantations (Direct, High; PMID: 40189644).
• Precision Agriculture: Integration of the Internet of Things (IoT) and smart sensors allows for real-time monitoring of pest populations and automated decision-making (Direct, High; DOI: 10.31018/jans.v17i3.6710). Unmanned aerial vehicles (UAVs) are increasingly used for precision pesticide application and natural enemy release (Direct, High; PMID: 38535387).
• CRISPR-Based Population Suppression: Gene drives targeting sex determination genes, such as doublesex (dsx), can cause complete population collapse in caged Anopheles gambiae mosquitoes by producing sterile or intersex females (Direct, High; PMID: 30247490). Multiplexing multiple guide RNAs (sgRNAs) is being utilized to reduce the emergence of resistance alleles in species like Aedes aegypti (Direct, High; PMID: 38272895).

Evidence consistently supports the high efficacy of these molecular and digital tools in controlled settings, although ecological factors such as density-dependent feedbacks (PMID: 40059885) and landscape interactions remain critical variables for field success (Derived, Medium; PMID: 31209256).

Unverified Citations

The following sources failed to support their assigned claims after 3 verification rounds designed to ensure only high-confidence, relevant references are retained:

• PMID:38136999 — to degrade complementary messenger RNA (mRNA), suppressing the expression of genes essential for development, reproducti...
  Failed: mechanism,conclusion — The paper discusses CRISPR-Cas9 DNA cleavage at the genomic level for gene drives, not RNA interference (RNAi) to degrade messenger RNA (mRNA) as stated in the claim.
  Possible alternatives (unverified): PMID:39363033 (89% topic match)
• PMID:40059885 — and landscape simplified interactions remain critical variables for field success
  Failed: disease,conclusion — The paper focuses on density-dependent biological feedbacks in gene drives, but does not provide data or analysis regarding 'landscape simplified interactions'.