North American Tarnished Plant Bug

• The damage is caused not by the sap it takes but by its saliva, loaded with enzymes that kill the cells around the puncture and make the shoot abort or the fruit grow deformed.
• It overwinters as an adult among the leaf litter and weeds of the field margins and colonises the crop as soon as it sprouts, which makes managing the margins a key measure.
• It is one of the costliest pests of cotton and strawberries in North America.
• It is one of the most polyphagous agricultural pests in North America: it has been recorded on more than three hundred species of cultivated and wild plants.
• Its damage is out of all proportion to its size because it does not feed on just any tissue: it preferentially pierces meristems and flower buds, and injects enzymes that kill developing tissue. One small puncture ruins an entire bud.
• In cotton it causes the flower buds to drop, and in strawberries it deforms the fruit: the so-called cat-faced strawberries are the work of this bug.
• It rose to prominence just as the boll weevil was brought under control: once the blanket treatments against that pest disappeared, this bug became the main cotton pest in the southern United States.
• It has developed resistance to several groups of insecticides, and its control relies more and more on managing the margin vegetation where it shelters between crops.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Herbaceous crops, cotton, orchards and weeds of North America

Size at birth

Newly hatched nymph of about 1 mm; egg of 1 mm inserted into the plant tissue

Sexual maturity

The females start to lay about 10 days after emerging

Gestation / incubation

The eggs hatch between 7 and 12 days depending on the temperature

Litter / clutch size

30 to 120 eggs per female over her lifetime, averaging 96 in optimal conditions

Sources consulted: Universidad de Florida, Featured Creatures · USDA · Snodgrass, trabajos sobre resistencia en Lygus · LSU AgCenter, ficha Lygus lineolaris · Cornell CALS, ficha tecnica · UMass Amherst, guia de insectos, Lygus lineolaris · WSU Tree Fruit, ficha Lygus bugs · UMass Amherst, guia de insectos · Cornell CALS · LSU AgCenter

Best time: Adults active from late April; peak activity from mid-April to late June and very abundant populations in late summer