Stem-Borrowing Pest

Classification

• These live within the plants stem, often found stunting growth or killing the apical meristem.
• May also infect the roots and leaves
• May be a disease vector

Nematodes

• Stem Nematodes include Ditylenchus and Aphelencoides spp.

Diagram of Ditylenchus Dipsaci



• plant pathogenic nematode that primarily infects onion and garlic. It is commonly known as the stem nematode, the stem and bulb eelworm or onion bloat.
• Live in the roots of the plants to infect their host.
• Symptoms of infection include stunted growth, discoloration of bulbs, and swollen stems.

Coleoptera

Cabbage Stem- Weevil
 

• There's species are more often seen from spring to autumn
• The larvae develops in the stems of the brassicas and then continues its feed from there.
• Widespread throughout England and Wales
• Control used to reduce the amount is by seed treatments of gamma-HCH or Sprays of gamma-HCH, Azinphos-Methyl, Azinphos-methyl + demeton-s-methyl sulphone, chlorpyrifos or triazophos. (GRAHAM and GOULD, 1980)

Diptera

Frit Fly Life Cycle Showing that it is constantly living throughout the seasons

 

• The Frit Fly usually white, yellow and black and are often found in grassy areas.
• They cause damage to new turf by destroying the stems of ryegrass, fescues and bents (use of larvae)
• Adult Flies are attracted to white objects and if a sighting of a large number of these flies could indicate larvae
• Larvae dig tunnels, infect stems and stay through winter
• Fruit Flies can be controlled by chemical sprays

Lepidoptera

Rose Stem Girdler (Species Unknown)

 

• Metallic wood boring beetle
• Flathead larvae is the known youngling of the group they cause the most damage to the rose by borer tunnelling within the pithy centre of the stem.
• Swollen, gall-like area on canes
• Canes with wilted, dried leaves
• Upper portions of canes break off easily during the summer
• Tunnelling in the lower part of the cane
• Boring damage and galleries inside of the cane
• CONTROL; insecticides to kill any larvae and eggs, remove infected plants over the season and over winter  

references;

GRAHAM, C. and GOULD, A. (1980). Cabbage stem weevil (Ceutorhynchus quadridens) on spring oilseed rape in Southern England and its control. Annals of Applied Biology, 95(1), pp.1-10.