How Do Spider Mites Pierce Leaf Cells to Feed?

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How do spider mites pierce leaf cells to feed? They push a single retractable stylet into the leaf, either between epidermal cells or through an open stomatal pore, and then draw nutrients from a mesophyll cell lying beneath the surface. The mite studied most closely is the two-spotted spider mite, Tetranychus urticae, which is one of the most polyphagous herbivores known. Recent research has followed the stylet step by step through leaf tissue, so the mechanism is now described in some detail. This explainer answers the question directly, then covers the mouthpart, the entry route, what happens inside the cell, and why the leaf stomata matter for the plant’s defense.

Quick answer

• Spider mites have a stylet, a tube made from two interlocking cheliceral digits, and they push it into the leaf to reach the cell contents.
• The stylet usually goes in between epidermal pavement cells or through a stomatal opening, so the outer epidermal layer is left intact.
• A single feeding event usually kills one mesophyll cell, and the feeding can last from several minutes to more than half an hour.
• Abscisic acid-driven stomatal closure hinders mite feeding in the Arabidopsis study, which shows that the stomatal route matters to both the mite and the plant.

The mouthpart that does the piercing

Spider mites belong to the chelicerates, a group that also includes horseshoe crabs, scorpions, spiders and ticks. Their feeding apparatus is built around an elongated cheliceral stylet. Within the family Tetranychidae, the mites have a single, long and retractable stylet, which differs from the several non-retractable stylets found in eriophyoid mites. In the two-spotted spider mite, each cheliceral digit is attached dorsally to a retractable and extrudable stylophore. When the mite feeds, the protracted digits slide into grooves formed by the rostral gutter, where they interlock and form a hollow tube at the level of the buccal cavity.

The result is a narrow tool. The stylet is a tube formed by the interlocking of two cheliceral digits with a single canal of about 2 micrometers in diameter. That small diameter is one reason the damage from each insertion stays limited. The feeding research also points out where the mite is working. In contrast to phloem-feeding herbivores that suck the sap from a plant’s vascular system, spider mites feed on cells within the leaf mesophyll. The stylet has to pass through the outer leaf layers to get there.

The entry route: stomata or the gaps between cells

A leaf has a surface layer of epidermal cells, and the epidermis is the first barrier any stylet has to pass. The research describes two ways through it. The stylet can enter through a natural opening, the stomatal pore, which is formed between two guard cells. Or it can slip in between neighboring epidermal pavement cells. By following the stylet path within the plant tissue, the researchers found that the stylet penetrates the leaf either in between epidermal pavement cells or through a stomatal opening, without damaging the epidermal cellular layer.

The stomatal route is the easier of the two for the mite. The ABA-driven defense paper explains that open stomata are natural apertures where piercing-sucking herbivores like aphids and mites insert their stylets to access nutrient-rich subepidermal cells. It also says that although stylets can also be inserted between epidermal cells, feeding via opening stomata is potentially faster and avoids the damage of cell walls, which can trigger rapid plant defenses. A mite that uses an open pore therefore avoids breaking cell walls on the way in, and broken cell walls are one of the triggers for rapid plant defenses.

The gap route still works, but it is less favored. The paper states that the closure of stomata likely hindered mite feeding through the natural openings on the leaf, compelling them to utilize their stylets for penetrating closed stomata or between the epidermal pavement cells. The same paper notes that mites try to avoid epidermal cell damage, so the stomatal pore is the preferred path when it is open.

What happens inside the cell

Once the stylet reaches the mesophyll, the mite takes the cell contents, and the feeding is limited in scope. In the cellular study, mites consumed a single mesophyll cell in a pattern that was common to both bean and Arabidopsis plant hosts. The damage was also concentrated. The dead cells were most often in the layer just beneath the surface the mites fed from, the spongy parenchyma. The study summarizes this as a feeding event that usually results in the death of a single cell.

The time per insertion is longer than many people would expect. The research reports that the duration of a single mite feeding event is longer than previously estimated, ranging from several minutes to more than half an hour. The same study revises an older count of cells consumed. Earlier work had proposed that mites consume ~20 plant cells per minute, while the newer measurements show that the consumption rate of plant cells is much lower than previously estimated.

The exact way the fluid moves up the stylet is still a question. One older idea is that the nutritive fluid from mesophyll cells is proposed to be extruded to the surface by putative capillary action. The newer study considered that path and judged it improbable, favoring the possibility that mites use their stylet to suck the nutritive fluid in situ. The authors also note that if sap is sucked through the stylet, then some form of pre-oral digestion likely takes place within the feeding cell.

The cell damage also has a visible limit on the leaf. The study tested whether feeding produces the pale spots that often show on a damaged leaf. It found that chlorotic spots that form on damaged leaves are not an immediate consequence of mite feeding. The spots therefore reflect damage that has accumulated over time, not a single feeding event.

Why the stomata matter for the plant

The plant is not passive during an attack. The ABA-driven study shows that Arabidopsis thaliana employs abscisic acid-induced stomatal closure as an effective defense mechanism against Tetranychus urticae infestation. Abscisic acid is the key hormone regulating stomatal aperture, which gates gas exchange for transpiration, photosynthesis and responses to abiotic stimuli. When the plant closes its stomata, the open pore route is closed as well, and the mite has to push through closed stomata or between epidermal cells instead.

The paper reports that mite infestation induced a striking stomatal closure. The researchers used genetic and pharmacological interventions targeting ABA levels, ABA signaling, stomatal aperture, and density. From those tests the paper concludes that ABA-triggered stomatal closure effectively hinders mite feeding and minimizes leaf cell damage. The result links the mite’s feeding route with the plant’s water balance, because the same stomata control transpiration.

The study frames this as a case where biotic and abiotic stress overlap. The paper notes that both chewing and piercing-sucking arthropod pests provoke loss of water, an increase in transpiration, and a reduction in stomata conductance. Those changes are associated with water stress-induced accumulation of ABA and subsequent stomatal closure, so the defense and the drought response share the same hormone. For the watering side of that story, see how to deep water plants.

How we chose

The two sources were picked because each one addresses the feeding question directly. One is a cellular study of where the stylet goes inside the leaf, and the other is a study of how the plant’s stomata respond to the mites. Both are open-access papers on PubMed Central, and both were opened and read for this article on 2026-10-28. Each claim below is tied to a passage in one of those two papers.

What we could not verify

Both sources work with controlled plant hosts, bean and Arabidopsis, and both describe the two-spotted spider mite. The claims in this article stay with what those papers measured. They describe mites on leaves in research settings, not a field guide to every species of spider mite.

What the sources do not say

The sources do not describe how the stylet is driven into the leaf at the level of muscles, so this article does not describe that step. They also do not give a control method for gardens, and they do not compare feeding across many crops beyond the two hosts. Nothing here should be read as advice on managing an infestation. For general soil care in containers, see how to amend garden soil for containers.

Frequently asked questions

Do spider mites bite leaves or suck cell contents?

They suck cell contents. The mouthpart is a stylet that pierces the leaf and draws fluid from a mesophyll cell. The research describes the mite as piercing individual parenchymatic cells with stylets specialized for sucking their content, rather than chewing the leaf.

Can a spider mite feed without breaking the leaf surface?

The studies describe the stylet passing either between epidermal pavement cells or through a stomatal opening, without damaging the epidermal cellular layer. The outer layer can therefore stay intact while the mesophyll cell beneath it is consumed.

Why do leaves get spots from spider mites?

Spots reflect damage that accumulates over time. The cellular study found that chlorotic spots that form on damaged leaves are not an immediate consequence of mite feeding, and that a feeding event usually results in the death of a single cell.

Do stomata help the plant defend against spider mites?

The Arabidopsis study says they do. Abscisic acid-induced stomatal closure is described as an effective defense mechanism against Tetranychus urticae infestation, and the same work reports that ABA-triggered closure effectively hinders mite feeding.

How long does one spider mite feeding event last?

The cellular study says that the duration of the feeding event ranges from several minutes to more than half an hour, and that this is longer than earlier estimates. The same work found that the consumption rate of plant cells is much lower than earlier estimates had suggested.

Sources

• Spider mite herbivory induces an ABA-driven stomatal defense. https://pmc.ncbi.nlm.nih.gov/articles/PMC11288753/
• Plant-Herbivore Interaction: Dissection of the Cellular Pattern of Tetranychus urticae Feeding on the Host Plant. https://pmc.ncbi.nlm.nih.gov/articles/PMC4961969/