Migratory-insect
Guides
Chloropidae
frit flies, grass flies, eye gnats
Chloropidae are a large family of small flies comprising approximately 2000 described species in over 160 genera, distributed worldwide. Adults are minute to small (1.0–4.0 mm, rarely to 12 mm), typically yellow, black, gray, or greenish, with a shiny appearance due to sparse pubescence. The mesonotum often bears three to five dark longitudinal stripes. Larvae exhibit diverse life histories: most are phytophagous, feeding on grasses and cereal crops, with some species causing significant agricultural damage; others are saprophagous, predatory, parasitic, or kleptoparasitic. A few species in genera Hippelates and Siphunculina are attracted to lachrymal secretions and other body fluids of mammals, earning the name 'eye gnats' and serving as mechanical vectors of bacterial and viral pathogens.
Episyrphus balteatus
marmalade hoverfly, marmalade hover fly
Episyrphus balteatus, commonly known as the marmalade hoverfly, is a small (9–12 mm) syrphid fly native to the Palaearctic region. It is considered the most abundant native hoverfly in Central Europe. Adults are significant pollinators of flowering plants, while larvae are voracious predators of aphids, consuming up to approximately 400 aphids before pupation. The species exhibits partial migratory behavior, with some individuals moving southward in autumn while others overwinter locally.
Eristalis
Drone Flies, Droneflies
Eristalis is a large genus of hoverflies (family Syrphidae) comprising approximately 99 species. Adults are commonly called drone flies due to their resemblance to honeybee drones, a form of Batesian mimicry that provides protection from predators. The larvae, known as rat-tailed maggots, are aquatic and possess an extendable breathing siphon that allows them to inhabit oxygen-depleted environments such as stagnant water, sewage, and decomposing organic matter. Adults are important generalist pollinators, with some species proposed as managed alternatives to honey bees for agricultural pollination.
Oncopeltus fasciatus
Large Milkweed Bug
The large milkweed bug is a medium-sized true bug distributed throughout North America from southern Canada to Costa Rica. It is a specialist feeder on milkweed seeds, sequestering cardiac glycosides from its host plant for chemical defense. The species undergoes annual long-distance migrations, wintering in southern states and Mexico before returning north in spring. Both nymphs and adults display striking orange and black aposematic coloration warning predators of their toxicity.