The stem girdler, also known as Sthenias grisator, is a beetle that is a serious pest of grapes in many parts of the world, including India. The adults are gray or brown, about 1/2 inch long, and have long antennae. They are most active at night and are attracted to light. The adult beetles girdle the stems of grapevines by chewing through the bark and wood. This damage can kill the vine above the girdle. The females also lay eggs in the girdled area. The eggs hatch into grubs that tunnel into the wood, further damaging the vine.
- Type of Infestation: Pest
- Common Name: Stem Girdler
- Causal Organism: Sthenias grisator
- Affected Parts Of the plant: Stem
Identification:
Adults:
- Medium-sized, measuring around 10-15 mm in length.
- Greyish-brown in color with a slightly flattened body.
- Each wing cover has a distinct white spot near the middle.
- Antennae are elbowed and saw-toothed.
Larvae:
- White and legless, with a curved body and a brown head capsule.
- Possess strong mandibles for chewing through wood.
Eggs:
- Oval-shaped and pearly white in color.
- Laid singly or in small clusters under the bark of grapevines.
Environmental favorable factors for pests/Diseases:
- Temperature: Adult Stem Girdlers are most active in warm weather, with optimal temperatures for development and reproduction ranging from 20-30°C (68-86°F).
- Humidity: High humidity levels can favor fungal growth in the beetle's tunnels, which can weaken the vine and provide additional food for the larvae.
Symptoms of Pest/Disease:
- Wilting and death of leaves above the girdle
- Cracks in the bark
- Sawdust-like frass around the base of the vine
- Small holes in the wood
Measures to control Pests/Diseases:
| Products | Technical Names | Dosages |
| Docter 505 | Chloropyriphos 50 % + cypermethrin 5 % EC | 300 ml per acre |
| CHLORO20 | Chloropyriphos 20 % EC | 500 to 1200 ML Per Ac |
| Chloro 50 | Chlorpyriphos 50% EC | 400 ml per acre |
