What does a tick look like on cucumbers in a greenhouse? - briefly
A tick on greenhouse‑grown cucumbers is a tiny, dark, oval parasite roughly 2–5 mm in length, attached to the fruit or leaf surface, often near the stem. Its hard, glossy exoskeleton and visible legs set it apart from the plant tissue.
What does a tick look like on cucumbers in a greenhouse? - in detail
Ticks that infest cucumber plants in a controlled environment present a distinct set of visual cues. The adult stage is a small, reddish‑brown arachnid, typically 2–5 mm in length, with a flattened, oval body and eight legs. The dorsal surface may show fine, pale scutes arranged in a pattern unique to each species; for greenhouse cucumbers, the most common culprit is Ixodes ricinus, whose scutes form a subtle checkerboard.
Nymphs are considerably smaller, 0.5–1 mm, and appear darker, often nearly black. Their bodies are less defined, making them harder to discern against the green foliage. Larvae, called seed ticks, measure about 0.2 mm and are translucent, barely visible without magnification.
Key visual indicators on the plants include:
- Attachment sites: Ticks attach to tender leaf veins, tendrils, and the undersides of leaves where humidity is high. Look for tiny, raised points where the mouthparts pierce the tissue.
- Feeding lesions: After attachment, a small, pale, circular area may develop around the bite, sometimes surrounded by a faint yellow halo caused by plant sap loss.
- Movement tracks: Nymphs and larvae often leave a faint trail of silk or excrement, appearing as fine, white lines on the leaf surface.
- Accumulation: In heavily infested vines, clusters of adult ticks can be seen near growing tips, forming a mottled pattern of reddish‑brown specks.
Microscopic examination reveals the characteristic capitulum (mouthparts) extending forward, with a pair of chelicerae used to penetrate plant tissue. The dorsal scutum is hard and may reflect light, aiding identification under a hand lens.
Control measures rely on early detection of these signs, as adult ticks can lay several hundred eggs on the greenhouse substrate, leading to rapid population growth. Regular inspection of leaf undersides and tendrils, combined with environmental monitoring (temperature 22–28 °C, relative humidity 70–80 %), helps maintain a tick‑free cucumber crop.