Cereal-crops
Guides
Cephus pygmaeus
European wheat stem sawfly, wheat stem sawfly
Cephus pygmaeus is a stem sawfly in the family Cephidae, widely distributed across Europe, western Asia, and North Africa, with introduced populations in North America. Adults are small, wasp-like insects that emerge in early spring and are active during wheat stem elongation. Larvae develop inside wheat stems, causing significant agricultural damage by tunneling and cutting stems. The species is a major pest of wheat and other cereal crops, with infestations reaching over 50% in some regions.
Diaeretiella
Diaeretiella is a monotypic genus of parasitoid wasps in the family Braconidae, subfamily Aphidiinae. The sole species, Diaeretiella rapae, is a cosmopolitan koinobiont endoparasitoid of aphids with documented occurrence in 87 countries. It has been recorded parasitizing approximately 98 aphid species across more than 180 plant species in 43 plant families, with particular association to cabbage aphid (Brevicoryne brassicae) on cruciferous crops. The genus is recognized as an important biological control agent in integrated pest management systems.
Malachius aeneus
Scarlet Malachite Beetle
Malachius aeneus, commonly known as the scarlet malachite beetle, is a species of soft-winged flower beetle in the family Melyridae. It was introduced to North America in 1852 and has since become widespread across the continent. The species is notable for its larvae being predators of the pollen beetle Brassicogethes aeneus in Great Britain.
Meromyza americana
Wheat Stem Maggot
Meromyza americana, commonly known as the Wheat Stem Maggot, is a chloropid fly species whose larvae are significant pests of small grain cereals. The species completes a second generation in spring, with adults emerging to lay eggs on barley, oats, rye, wheat, and other grass hosts. Larval feeding occurs within stems, causing characteristic whitehead symptoms in infested tillers. Despite its pest status, infestations rarely exceed 1% of tillers, making insecticide treatments generally unnecessary.
Oulema
Cereal leaf beetles
Oulema is a genus of leaf beetles in the family Chrysomelidae, subfamily Criocerinae. The genus contains approximately 100 species distributed primarily in temperate to tropical regions. Several species are economically important agricultural pests, most notably Oulema melanopus (cereal leaf beetle), which has been introduced to North America and causes significant damage to wheat and other small grain crops. The genus can be distinguished from the closely related Lema by pronotum shape and the converging angle of frontal grooves.
Oulema melanopus
cereal leaf beetle
Oulema melanopus is a leaf beetle native to Eurasia that was introduced to North America in 1962, where it has since become a significant economic pest of small grain crops. The species is particularly damaging to spring wheat and oats, with outbreaks that are sporadic and difficult to predict. Larval feeding causes the most damage by skeletonizing leaves. Management relies on insecticides, though biological control using introduced parasitoids and host plant resistance breeding programs offer promising alternatives.
Platypalpus
dance fly, hybotid dance fly
Platypalpus is a large genus of hybotid dance flies comprising at least 580 described species worldwide, with over 200 species in Europe alone. These small predatory flies are characterized by their compact bodies, enlarged compound eyes that occupy most of the head, and raptorial front legs adapted for seizing prey. Adults are active predators that feed on small insects, while larvae occupy diverse microhabitats including leaf litter, soil, and aquatic environments. The genus has been documented in agricultural ecosystems, particularly cereal crops and greenhouses, where they may contribute to pest regulation.
Rhopalosiphum maidis
Corn Leaf Aphid, Corn Aphid
Rhopalosiphum maidis is a globally distributed aphid species and the most economically damaging aphid pest of maize (Zea mays), particularly in tropical and warmer temperate regions. It feeds on phloem sap and causes direct damage through photoassimilate removal. Dense populations can deposit large amounts of honeydew on maize tassels, preventing pollen shed and reducing yield by up to 90%. The species transmits several destructive plant viruses including Maize yellow dwarf virus, Barley yellow dwarf virus, Sugarcane mosaic virus, and Cucumber mosaic virus. Most populations reproduce parthenogenetically (anholocyclic), though sexual reproduction has been reported in Pakistan and Korea with Prunus species as primary hosts.