Aphids' Damage To Plants

In temperate regions, aphids are among the most harmful pests to cultivated plants. Many farmers are afraid of them since they can make plants yellow, have mottled leaves, develop slowly, have curled leaves, produce meager yields, or even die.

Aphids, sometimes known as plant lice, are a superfamily of insects that includes approximately 4,000 species of parasitic insects that only affect plants. They have a bulbous abdomen, are a little longer than 4 millimeters, and come in a variety of colors.

Numerous species have names, either common or scientific, that refer to their preferred host plant, either for food or for rearing their young, or to some of their distinguishing traits.

Aphid Damage

One of the most important issues in horticulture and agriculture is aphid damage. A pest aphid species may only harm a small number of crops, a cluster of closely related crop hosts (such as crucifers), or it may be extremely polyphagous both within and across plant families.

Numerous sister species complexes that are physically identical but have different karyotypes are represented by the notoriously polyphagous aphid pests.

These aphid pests typically come in the form of anholocyclic clones, or biotypes, with varying host preferences, disease transmission capacities, or pesticide resistance.

Therefore, for instance, the black peach aphid (Brachycaudus persicae) loves peach, the cotton aphid (Aphis gossypii) prefers cotton, and so on.

Blackman and Eastop estimate that just approximately 100 species provide considerable economic concerns, despite the fact that about 450 species are found on crops, according to Van Emden and Harrington's 2007 book.

The 14 most dangerous agricultural pests are listed and covered in detail. Thirteen of them are members of the largest aphid subfamily, the Aphidinae, which has a huge number of herbaceous plant feeders.

These include Rhopalosiphum maidis, Rhopalosiphum padi, and Schizaphis graminum in the tribe Aphidini, subtribe Rhopalosiphina; Aphis craccivora, Aphis fabae, Aphis gossypii, and Aphis spiraecola; and the tribe Macrosiphini includes the species Acyrthosiphon pisum, Diuraphis noxia, Lipaphis pseudobrassicae (sensu Eastop), Macrosiphum euphorbiae, Myzus persicae, and Sitobion avenae. Therioaphis trifolii, the fourteenth species, is a member of the tribe Myzocallidini of the subfamily Myzocallidinae (=Calaphidinae sensu Eastop), a family that is typically found on trees but from which Therioaphis has diverged to form the herbaceous Fabaceae.

Aphids harm crops and reduce yields in a number of ways. They may gather in large numbers, destroying plant nutrition and possibly harming plants by sucking out enough sap to make them wither and die.

Excrement from aphid honeydew can accumulate on plants to the point that it serves as a growth medium for sooty molds, which hinder photosynthesis and spread other fungi-related diseases if not cleaned off.

It is especially problematic for horticulture when some aphids' salivary secretions are phytotoxic and cause stunting, leaf distortion, and gall formation.

Even if the plant is otherwise asymptomatic, aphid feeding impacts may change host metabolism in their favor and essentially take over the physiological processes of the plant.

The spread of plant viruses is the most important issue faced by aphids. Aphids gain from virus transmission because virus-infected plants frequently exhibit a yellowing that is appealing to aphids and has an increase in free amino acids.

Aphid-specific viruses can be found on the aphid's epidermis and are known as stylet-borne viruses. They are promptly acquired and transmitted when the plant's epidermis is probed rostrally.

When the aphid molts, these non-persistent viruses lose their infectiousness. Contrarily, circulating viruses require an incubation period before they may spread successfully since they are housed in the aphid's gut.

They are tenacious viruses, and an infected aphid serves as a vector for the rest of its life. Circulating viruses have rather precise virus-aphid-plant relationships, and each virus is spread by just one or a small number of aphid species.

Conclusion

Some aphids can spread viruses to plants. Soft fruits like strawberries and raspberries, some vegetables like tomatoes and members of the cucumber/marrow family, as well as some decorative plants like dahlias, lilies, pelargoniums, tulips, and sweet peas, are particularly affected by this issue.

Plants with the virus should be removed and killed to stop the sickness from spreading to other plants.