Garden insects

Major pollination, production of honey and propolis.

A major pollinator, capable of buzz pollination, a thoracic vibration that releases the pollen of flowers with poricidal anthers (tomato, blueberry, aubergine). See the Buzz pollination concept.

A specialist of long-tubed flowers (deep corollas) thanks to its long tongue. Pollinates plants inaccessible to other bumblebees.

One of the largest solitary bees in Europe (up to 2.5 cm). Bores its galleries in dead wood, where it raises its young. Solitary but impressive.

An early solitary bee, a pollinator of fruit trees: it emerges in March-April, when apple, pear and plum flower, and can be hosted in orchards (Gruber et al., 2011).

One of the very first spring pollinators, emerging as early as February in a mild climate. Precious for early-flowering fruit trees, such as the almond, which it can pollinate (Bosch, 1994), the plum and the peach.

A species-rich genus of solitary spring bees, some very specialised: Andrena vaga collects pollen only from willows, A. florea only from bryony. An actor of early pollination.

A dual role: ADULT = pollinator, a flower-visitor (nectar and pollen); LARVA = an aphid predator in nearly 250 species, each larva eating about 400 aphids in its lifetime (INRAE, Encyclop'Aphid). Wasp mimicry (but harmless, no sting).

A large butterfly (63-75 mm wingspan according to the LPO), yellow and black with characteristic “tails”. The green caterpillar, striped black with red dots, feeds on Apiaceae: carrot, fennel, dill, parsley (locally rue, around the Mediterranean), easily seen in July-August.

A migratory butterfly familiar in gardens: black, red and white, about 6-7 cm wingspan. The adult is a pollinator; its spine-bristled caterpillars feed mainly on nettles (Urtica dioica), sometimes on pellitory or hop. Conservation: preserving nettles = preserving red admirals.

An emblematic garden butterfly, recognisable by its 4 large coloured “eyes” on the wings, which startle or confuse predators. The adult is a pollinator; the black, spine-bristled caterpillars, almost always on nettles.

A predator of aphids and scale insects. According to Hodek & Honěk (Ecology of Coccinellidae, 1996), an adult consumes 20 to 60 aphids a day; the larvae, more voracious, can consume several hundred over their cycle. The popular figure of “200 aphids a day” is a generalisation.

The adult is soft green with large iridescent wings (“the golden-eyed maiden”), nocturnal, feeding on pollen and nectar. The LARVA = a formidable predator of aphids, and also of mites and whiteflies (McEwen, New & Whittington, 2001). Overwinters as an adult in shelters (barns, under bark).

A nocturnal generalist predator: slugs, snails, chafer grubs, eggs and caterpillars fallen to the ground. Predation of Colorado-beetle larvae stays marginal in Europe (documented mostly for Lebia grandis in North America). Garden species include the golden ground beetle (Carabus auratus) and the leather beetle (C. coriaceus).

Omnivore: a useful beneficial against aphids, but it can also nibble the petals and young leaves of dahlias, clematis and chrysanthemums when populations are high. To be regarded as a “beneficial to watch”. Precious in orchards, where it eats aphids (RHS).

One of the largest insect families, important in biological control (Quicke, 2014). Parasitoids: the female lays her eggs in or on a caterpillar, larva or pupa of a pest; the ichneumon larva devours its host from the inside. They mostly parasitise the larvae and pupae of insects, especially of moths and butterflies.

A tiny parasitoid micro-hymenopteran of the eggs of pest lepidoptera: European corn borer (Ostrinia nubilalis), cabbage white (Pieris brassicae), codling moth (Cydia pomonella). The female lays her egg inside the host egg, which blackens and then yields an adult trichogramma instead of a caterpillar.

A small bug, a generalist predator: mites, thrips, aphids, young caterpillars, pest eggs. Also pollen-feeding as a complement. Used commercially in greenhouse biological control (Orius laevigatus, O. majusculus), notably against thrips (van Lenteren, 2012).

A very large family of beetles, recognisable by their very short elytra that cover only the first abdominal segments. Generalist predators: fly larvae, pupae, eggs and larvae of other insects, small mites. The “devil's coach-horse” (Ocypus olens), a large black beetle nearly 3 cm long, lives in compost heaps and under stones.

The invisible worker of the soil: it aerates, drains, mixes the organic matter and produces casts very rich in nutrients. The meta-analysis by van Groenigen et al. (Scientific Reports, 2014) reports an average +25% yield in trials comparing soils with and without worms (pot and field trials, with residue inputs).

Sucks the sap of plants, weakens growth and transmits many viral diseases. Secretes a sticky honeydew that encourages the appearance of sooty mould (“soot”).

The green-yellow caterpillars quickly devour the leaves of cabbages and other Brassicaceae, sometimes down to the veins.

Butterfly larvae that devour leaves, flowers and fruit. Not all are harmful, but some cause major damage to crops.

A yellow-and-black-striped beetle whose adults and larvae devour the leaves of the potato.

A tiny jumping beetle, a few millimetres long, that riddles leaves with small round holes; devastating on young Brassica seedlings in spring.

Nocturnal molluscs that gnaw young shoots, seedlings and tender leaves. Particularly devastating in spring in moist soil.

Adults grazing on tree leaves; larvae (white grubs) gnawing crop roots over a life cycle of 3 to 4 years (INRAE, Ephytia).

Small white insects that suck the sap under the leaves and deposit a honeydew conducive to sooty mould.

Larvae boring galleries into the roots, making carrots inedible and encouraging rot.

A small nocturnal black weevil. The adults cut half-moon notches in the leaves; the larvae devour the roots and often kill the plant.

The mammals that visit a garden are rarely “all pests”. A useful distinction: rabbits, roe deer, voles and rats cause direct damage to crops and seedlings; foxes and badgers, on the other hand, are mostly opportunistic omnivores, their damage to the vegetable garden is occasional and they consume many small mammals (an indirect beneficial against voles). The squirrel remains an occasional visitor of hazels and walnuts, rarely a problem.

Formidable predators: adults hunt midges, mosquitoes and other flying insects on the wing, up to butterflies; the aquatic larvae eat almost any prey smaller than themselves (British Dragonfly Society).

Small sap-sucking insects fixed on stems, leaves and fruit, protected by a white wax (mealybugs) or a shield (armoured scales). They weaken the plant, deposit sticky honeydew and encourage sooty mould.

Small moth whose pinkish caterpillar bores a tunnel to the pips of apples, pears and sometimes walnuts: it is the “maggot” of maggoty fruit, the number-one pest of apple orchards.

A tiny mite (about half a millimetre) that pierces the leaf cells in hot, dry weather: the foliage becomes speckled, greys and dries out, sometimes under fine webs.

Thread-like insects of 1 to 2 mm that rasp the epidermis of leaves and flowers and suck up the contents: silvery patches dotted with black specks, distorted flowers. Thrips tabaci mainly attacks alliums, the western flower thrips greenhouse crops.

A small fly whose larva tunnels through the leaves and shaft of leek and other alliums. Spotted in France in 2003, in Alsace, it has become one of the main pests of garden alliums.

A grey fly whose white larvae devour the roots and collar of young cabbages and other brassicas: the plants wilt in full sun and pull out of the ground without effort.

A large piercing bug of vegetable and fruit crops. On tomatoes, its punctures leave tiny spots on young fruit, then white to yellow patches over white, spongy flesh on ripe fruit; it also damages bean pods. Probably native to Ethiopia, it has spread through tropical and subtropical regions; in France, it is often found in the wild and under cover.

A polyphagous bug from Asia, detected in Europe in 2004 and in France from 2012. It feeds mainly on flowers and fruit, and its damage appears even at low numbers. In France, the first damage dates from 2018, in kiwi orchards in the South-West, then from 2019 in Savoie; it has affected the whole South-East since 2020. In autumn, the adults sometimes invade houses to overwinter; they are harmless to people and animals.

The yellow, hard, shiny larvae of click beetles, which live for several years in the soil and bore into tubers, roots and young seedlings: the holed potato is the best-known symptom.

Grey, smooth caterpillars of noctuid moths, which live curled up in the soil by day and cut young plants at the collar by night: freshly transplanted lettuces, cabbages and leeks fall as if scythed.

A small vinegar fly from Asia, spotted in France in 2009-2010 (Montpellier, Corsica, Var), able to lay in healthy ripening fruit thanks to its serrated ovipositor: cherries, raspberries, blackberries, blueberries, strawberries and grapes go soft and leak within days.