Lacanobia oleracea, Bright-line brown eye above. The common name refers to the adult markings. There is usually one generation a year, but there may be two in the south of the U. K. in good years. As with their foodplants (see below) they can be found in a wide variety of habitats. They are fairly common in the south, becoming less so as you go north, but are found as far north as Shetland, and are widespread throughout Europe.
Eggs are laid in batches on the underside of the foodplant leaves in June, and hatch about a week later.
The caterpillars feed at night from June to October, and rest low down or on the soil during the day, but some can be found basking in the sun. As with many other insects, this may aid digestion. They feed on a wide variety of plants including nettle, willow herb, St. John's wort, elm, hazel, hop and tomatoes. The one above was found in a raised bed on lettuce next to a row of carrots, and is happily munching its way through lettuce as I write this. They grow up to 45 mm long. The main body colour varies from brown to green, but the patterning remains the same. They can cause damage to tomato crops, especially those grown under glass as they bore into the tomato itself.
They overwinter as a pupa in the soil. Pupation is underground in a cocoon starting from late August to October.
Adults emerge in June, and have a forewing length of 14 - 19 mm.
Turnip moth, Agrotis segetum
Above is the caterpillar of the Turnip moth, Agrotis segetum. It is found throughout Europe, is abundant in England, but less common in Scotland. The caterpillar grows up to 47 mm long (the scale above is in 5 mm squares), is glossy with a few hairs growing out of black dots, grey or brown in colour tinged with purple and green, and has a dark brown head. It is found on farm land, gardens and meadows. The foodplants include dock, turnip, parsnip and carrot. It can be considered a pest of root crops.
There is usually one generation a year, although now there can be two in the south. The eggs are laid in groups on plant stems and leaf litter in June. The caterpillars hatch in July and feed at ground level or below ground, boring into plant roots, often causing the death of the plant. Caterpillars feed until October and remain in the soil over winter.
They pupate in the soil in a cocoon in May and the moths emerge in May and June.