Galls or stem swellings on citrus trees need to be removed by pruning by the end of August, as very tiny black wasps emerge from the galls in September and October ready to lay a new batch of eggs in citrus stems. Because these wasps are poor fliers, they tend to reproduce on the same tree unless blown by wind to a new host.
Unlike many other wasps that assist pollination or are pest predators, the citrus gall wasp is a true pest. Eggs are laid in young stems of citrus trees, particularly lemon and grapefruit varieties, and the native finger lime. The larvae remain within the stem, stimulating the growth of cells, and causing a gall or swelling to form on the infested stem by early summer. Trees that are repeatedly attacked will become weaker and produce less fruit.
Originally, only coastal gardens of New South Wales and Queensland were affected, however, this wasp is spreading to other areas of Australia.
Do not add galls to the compost heap. Burn them, or dispose of them in a sealed plastic bag. It is very likely that the gall in the photo missed last year’s pruning because it is unusual for galls to reach that size in one season. As you can see, the tree in the photo is also affected by scale, and it is more common for citrus gall wasp to attack stressed trees. After pruning, water the tree thoroughly, and feed it with a complete organic fertiliser and as much compost as you can spare. A drink of seaweed extract tea will help it to resist further pest and disease attack.
Moon Planting Calendar 2019Our 2019 moon planting calendar for Australia and New Zealand is now available for purchase.
GARDEN ADVICEIf you have a gardening problem, I can provide advice on Aussie Organic Gardening. (PLEASE INCLUDE YOUR LOCATION as climates and soils vary greatly in our wide, brown land.) E-mail me at: firstname.lastname@example.org
- Around the farm… (56)
- Frogs (4)
- Chain saw carpentry (4)
- Chooks (1)
- Climate Zones (2)
- Fruits and Vegetables (124)
- Garden projects (13)
- Healthy soil (44)
- Herbs (28)
- Moon Planting diary (26)
- Moon planting explained (10)
- Ornamentals (60)
- Pest-free Gardening (58)
- Recipes (2)
- Saving seed (6)
- Seed suppliers (3)
- Uncategorized (29)
- Weeding between the lines (10)
- Around the farm… (56)
- What to grow in March 2019 March 1, 2019
- What to grow in February 2019 February 5, 2019
- What to grow in January 2019 January 4, 2019
- Tis the season … December 3, 2018
- What to grow in December 2018 December 1, 2018
- Moon planting calendar for 2019 November 30, 2018
- 2019 Moon Planting Calendar November 30, 2018
- What to grow in November 2018 October 30, 2018
- What to grow in October 2018 October 1, 2018
Blogs and other sites