Identifying and treating the five pests you will actually meet

White, cottony specks tucked into leaf joints, under leaves and in the crevices of cacti. They move slowly, and they leave a sticky honeydew that turns into black sooty mould.

Treatment: dab each cluster directly with a cotton bud dipped in rubbing alcohol, which kills on contact. Then spray the whole plant with neem oil weekly for four weeks — mealybug eggs hatch in waves, and a single treatment always fails.

Fine webbing between leaves and stems, and a stippled, dusty, faded look to the leaf surface. The mites themselves are barely visible. Spider mite thrives in hot, dry air, which makes it the defining pest of a Pakistani summer.

Treatment: raise humidity, because dry air is what allows the population to explode. Spray thoroughly with neem oil, paying particular attention to leaf undersides where they live, every five days for three weeks. Isolate the plant — spider mite spreads across a collection fast.

Small, hard, brown or tan bumps on stems and along the midrib, which look like part of the plant and do not move. Adults are protected by their shell, which is why sprays alone often fail.

Treatment: scrape the adults off physically with a fingernail or a blunt blade first, then treat with neem oil weekly for a month to catch the mobile juveniles, which are vulnerable. Scale is slow to clear and requires persistence.

Silvery streaking and distorted, deformed new growth, with tiny black specks of frass on the leaves. Thrips are slim, fast and hard to see, and they do their damage to leaves that have not yet unfurled — so you often see the effect a fortnight after the cause.

Treatment: the hardest of the five. Remove the worst-affected leaves entirely, spray neem oil every five days for a month, and hang blue sticky traps to catch the flying adults. Isolate aggressively; thrips move between plants readily.

Small black flies rising from the soil when you water. The adults are harmless and merely irritating; the larvae in the soil feed on roots and matter more than people assume.

Treatment: they breed only in constantly damp soil, so the real fix is to let the top three centimetres dry out completely between waterings. Add a layer of sand or grit on the soil surface to block egg-laying, and use yellow sticky traps for the adults. Change your watering habit and they disappear within a fortnight.

Mix roughly 5 ml of cold-pressed neem oil and 2 ml of mild liquid soap into one litre of lukewarm water, and shake it constantly while spraying — oil and water separate within a minute and an unshaken sprayer delivers plain water.

Spray in the evening, never in sun, or the oil film will scorch the leaves. Cover both leaf surfaces and the stems until they are dripping. Repeat every five to seven days for at least three cycles, because neem breaks the breeding cycle rather than killing everything at once. Mix fresh each time — the emulsion does not keep.