Pest Lexicon – Green Guardia

Pests: Understanding causes & natural prevention

"Pests" is a collective term for various insects, mites, or other small creatures that are considered a nuisance in the home or garden. The most important step is always: identify the species, find the source, and then take targeted action. Here you will get a clear overview of the most common causes and which natural measures really work in most cases.

ⓘCollective term · Home & Garden #Find source · Hygiene · Sealing · Monitoring

What does “pest” actually mean?

The term “pest” often refers to very different creatures – from ants to moths and beetles to mites. Not everything is automatically dangerous or “bad”: some species are actually beneficial (e.g., spiders). The deciding factor is whether there is damage, hygiene problems, or high infestation pressure.

Collective term Identify species Targeted action

Important: If you are not sure what kind of pest it is, it often helps to look at: location (kitchen? bathroom? plants?), time of day, size, flying ability, and “traces” (droppings, webs, feeding damage). This is the only way to choose truly effective measures.

Typical causes (almost always the same)

Food: crumbs, open food supplies, pet food, organic waste
Moisture: bathroom, basement, mold, permanently wet potting soil
Heat: heating air, warm cupboards, appliance areas
Hiding places: cracks, baseboards, cavities, roller shutter boxes
Introduction: purchases, new plants, cardboard boxes, used textiles

First signs – what to look out for

flying insects at the window or near lamps
webs, fine threads, larval skins
feeding damage on food, textiles, or plants
small black dots (droppings) or traces of dust/crumbs
recurring infestation despite “wiping away”

Green Guardia Tip: The most sustainable way to fight pests is not just to remove “the animals,” but the cause: food + moisture + hiding places.

What to do about pests? (Emergency plan)

1. Roughly categorize the species

Kitchen/food supplies: often moths, beetles, ants
Bathroom/basement: often silverfish, paperfish, moisture and mold indicators
Houseplants: often fungus gnats, thrips, spider mites
Textiles/carpets: often carpet beetles, larder beetles

2. Eliminate the source

pack open food supplies and pet food airtight
consistently dispose of infested items (do not “save for checking”)
reduce moisture (ventilate, dry out, check for leaks)
thoroughly clean dust traps and crumb-prone areas

3. Clean thoroughly (cracks are crucial)

vacuum joints, baseboards, corners
clear out and wipe down cupboards
clean trash containers, check drains

4. Reduce entry routes & hiding places

seal cracks (baseboards, pipe passages)
fly screens on windows/doors
check roller shutter boxes and cavities

5. Use monitoring (so you know if it's working)

sticky traps/monitoring in pathways
yellow sticky traps for plants
pheromone traps for moths (only for control/early detection)

Natural solutions: Which beneficial insects fit when?

Beneficial insects are useful when the pest is clearly identified. They are particularly sustainable because they directly target eggs, larvae, or active stages.

Stored product pests (moths & beetles in the kitchen)

Lagererzwespen (parasitic wasps) – parasitize eggs of stored product beetles and reduce the next generation
Lagerpiraten (predatory bugs) – predatory, help supplementally against overlooked larval stages in cracks
Trichogramma wasps – for food moths (target: eggs)

Houseplants (substrate & leaves)

Nematodes – against fungus gnat larvae in the substrate
Predatory mites – against spider mites and, depending on the species, thrips (young stages)
Lacewing larvae – versatile predators for aphids/thrips (depending on the situation)

Note: For some “pest” problems (e.g., silverfish/paperfish, ants in masonry, large cockroach problems), addressing the cause (moisture, hygiene, sealing) is often more important than beneficial insects.

FAQ about “pests”

Why do pests keep coming back?

Usually, the cause remains: moisture, open food, dust traps, or entry routes. Only when these points are resolved will things permanently improve.

What is the most important first measure?

Determine the location and look for the source: Where are the animals most frequent? What could they find there (food/moisture/hiding place)? This saves the most time.

When do beneficial insects make sense?

When the species is clear and you want to specifically target eggs/larvae – e.g., moths/beetles in supplies or fungus gnats/spider mites on plants.

When should you get professional help?

In case of a very heavy infestation, recurring problems despite working on the causes, or if you suspect that the nest/source is located in cavities or structural elements.