The Nigerian pest calendar

Why a calendar beats a reaction

Almost everybody treats a pest problem after it has arrived. That is understandable and it is also the expensive way to do it, because by then a population has had weeks to establish.

The pattern in Nigeria is reasonably predictable. The rains bring standing water and mosquitoes. Harmattan pushes insects and rodents indoors looking for warmth and moisture. Harvest and bulk buying bring storage pests into the house inside the food.

None of that is precise to the week, and the north and the south run to different schedules. Used as a rough guide, though, it tells you what to prepare for rather than what to chase.

April to October, the wet months

The rains are the mosquito season, and the reason is simple. Any container that holds water for about a week can produce adults, which makes buckets, drums, blocked gutters, tyres, plant saucers and bottle caps the real breeding sites rather than the bush.

Flies rise with the same weather, because heat and moisture speed up everything that decomposes. Bins, drains and animal waste are where they multiply.

The useful habit in these months is a weekly walk around the compound to tip out anything holding water and clear the gutter. It takes ten minutes and it removes the sites rather than the adults.

Ants also move indoors during heavy rain, following walls and skirting into the kitchen. That is a flooding response, not a hygiene failure.

November to February, harmattan

The dry, dusty months move the problem indoors. Cockroaches concentrate around the few reliable sources of water left in the house, which is usually the kitchen sink, the bathroom and the space behind the fridge.

Rodents come in for the same reason, and this is the season when sealing gaps earns the most. A hole closed in November saves a great deal of work in January.

Mosquito numbers fall but they do not disappear, because tanks, drums and stored water carry through the dry season.

This is the right window for the slow work. Fill the holes around pipework, fit the door brush, clear the cardboard out of the store.

Harvest and the storage months

Grain bought in quantity after harvest is the main way pantry moths and grain beetles enter a Nigerian home, and they arrive inside the bag rather than through the window.

Check a handful from the middle of a sack before it joins the store. Fine webbing, clumped grains and dust at the bottom of the bag are the signs worth knowing.

Decant into rigid sealed containers rather than leaving food in paper or thin plastic, and rotate the store so nothing sits untouched for months.

Getting this right once, at the point of purchase, prevents most of what would otherwise become a shelf-wide problem by the middle of the year.

March, the turn

The weeks before the rains return are the most valuable and the most commonly wasted. Clearing gutters, tipping out containers and covering water storage in March removes the breeding sites before the first generation of the season uses them.

The same weeks are a sensible time to check screens and netting for tears, and to replace what has perished in the dry.

Working a season ahead is the whole idea of a calendar. Everything else on this page is a description of what happens when you do not.