àpids

àpids, commonly known as aphids or plant lice, are small, soft-bodied sap-sucking insects in the superfamily Aphidoidea within the order Hemiptera. They include thousands of described species distributed worldwide and vary in size from about 1 to 10 millimeters. Aphids are typically pear-shaped with two long cornicles (tail-like organs) at the rear and antennae that can be conspicuously long in some species. They feed on the phloem of a wide range of plants, from wild grasses to agricultural crops and ornamental species.

Aphid life cycles are diverse. Many species reproduce asexually (parthenogenesis) for multiple generations in favorable conditions, giving birth to live, young aphids. This rapid asexual reproduction can lead to swift population buildup. When conditions change or as seasons shift, some species produce winged morphs that disperse to establish new colonies. A holocyclic life cycle, in which aphids alternate between a primary host (often a woody plant) and a secondary host (usually herbaceous plants), occurs in some species. Aphids host symbiotic bacteria, notably Buchnera, which provide essential amino acids.

Ecologically, aphids are important agricultural pests and vectors of plant viruses, transmitting luteoviruses, potyviruses, and other pathogens during feeding. They excrete honeydew, attracting ants and fostering sooty mold on surfaces, which can further affect plant health and photosynthesis. Natural enemies, including lady beetles, lacewings, syrphid flies, and parasitoid wasps (such as Aphidius spp.), play a key role in regulating populations. Integrated pest management combines monitoring, biological control, cultural practices, and, when necessary, selective chemical controls to minimize crop damage.

Distribution of àpids is cosmopolitan, with greatest impact in temperate regions where many crops are grown.