Thrips setosus is a plant pest with a wide host range, including economically important vegetable crops and ornamental plants. It is a voracious feeder that can transmit tomato spotted wilt virus (TSWV or Tospovirus). In fall 2016, a Michigan greenhouse reported the first U.S. detection of Thrips setosus on hostas housed with the facility’s imported material. While this pest can attack many types of plants, it is most often found on Hosta spp. or solanaceous hosts, such as tomato, eggplant, and tobacco. Thrips setosus is found in Indonesia, Japan, the Republic of Korea, and the Netherlands. The pest is most likely spread through cut flowers and plants for planting imports. Suitable habitats in the United States include Plant Hardiness Zones 4-11; the pest prefers protected areas, such as greenhouses. Japanese Flower Thrips (Thrips setosus) Figure 1. Female Thrips setosus feeds on flowers and plant leaves. Most thrips are about 1 mm in length. Males are uniformly yellow, and females are dark brown with some yellow. INSECTS Figure 2. Larvae can be found on the underside of leaves. Figure 3. Second life stage of Thrips setosus.

Japanese Flower Thrips - USDA-APHIS · Japanese Flower Thrips (Thrips setosus) Figure 1. Female Thrips setosus feeds on flowers and plant leaves. Most thrips are about 1 mm in length

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Page 1: Japanese Flower Thrips - USDA-APHIS · Japanese Flower Thrips (Thrips setosus) Figure 1. Female Thrips setosus feeds on flowers and plant leaves. Most thrips are about 1 mm in length

In fall 2016, a Michigan greenhouse reported the first U.S. detection of Thrips setosus on hostas housed with the facility’s imported material. While this pest can attack many types of plants, it is most often found on Hosta spp. or solanaceous hosts, such as tomato, eggplant, and tobacco.

Thrips setosus is found in Indonesia, Japan, the Republic of Korea, and the Netherlands. The pest is most likely spread through cut flowers and plants for planting imports. Suitable habitats in the United States include Plant Hardiness Zones 4-11; the pest prefers protected areas, such as greenhouses.

Japanese Flower Thrips (Thrips setosus)

Figure 1. Female Thrips setosus feeds on flowers and plant leaves. Most thrips are about 1 mm in length. Males are uniformly yellow, and females are dark brown with some yellow.

INSECTS

Figure 2. Larvae can be found on the underside of leaves.

Figure 3. Second life stage of Thrips setosus.

Page 2: Japanese Flower Thrips - USDA-APHIS · Japanese Flower Thrips (Thrips setosus) Figure 1. Female Thrips setosus feeds on flowers and plant leaves. Most thrips are about 1 mm in length

DamageThrips setosus may cause silver or bronze-colored spots on foliage. The pest causes dark punctures when it feeds on leaves.

Thrips setosus can transmit TSWV and may be on infected plants. Once the thrips feeds on a plant and infects it with the TSWV, the plant will show symptoms of the virus. TSWV symptoms vary among hosts, but may include: stunting, yellowing or whitening of normally green plant tissue, and premature leaf death. If you see these symptoms, look for life stages of Thrips setosus.

Report Your FindingsPlease keep in mind that while thrips is a fact of life in most nurseries, it is critical to correctly identify Thrips setosus, as this pest has a wide host range and the potential for serious crop damage.

INSECTS

Figure 5. When Thrips setosus feeds on a leaf, it leaves behind bright shiny spots and black excrement.

Figure 4. Thrips setosus causes leaf damage.

If you suspect Thrips setosus, please contact your local extension office (nifa.usda.gov/LGU-map) or State Plant Health Director (http://www.aphis.usda.gov/planthealth/sphd).

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Photo credit: Dr. Manfred R. Ulitzka

Animal and Plant Health Inspection Service

Issued April 2017PPQ-17-001