Common Fig Tree Pests – What To Do About Pests On Fig Trees
Figs(Ficus carica) belong to the family Moraceae, which includes over 1,000 species. They have been cultivated for thousands of years with remnants having been found in Neolithic excavations dating back to 5,000 B.C. Despite their ancient history, they are not without many of the same fig tree insect pests that plague the tree today. The key to fig tree pest control is learning how to identify common fig tree pests.
Common Fig Tree Insect Pests
The common fig is a deciduous tree to shrub cultivated for its delicious “fruit.” Fig fruit is not actually a fruit but rather a syconium, or a fleshy hollow area with tiny flowers on its interior walls. Hailing from Western Asia, figs, depending upon conditions, can live for 50-75 years with reliable production.
A condition that might impede their longevity is pest infestation on fig trees. One of the more common pests is the nematode, specifically the root knot nematode and the dagger nematode. They reduce tree growth and yield. In the tropics, nematodes are battled by planting the fig close to a wall or building to allow the roots to grow beneath the edifice, thwarting nematode damage. In lieu of planting near a structure, heavy mulch can deter nematodes as can the proper application of nematicides. Adding marigolds around the tree should help too.
Other pests found on fig trees include:
- Carpenter worm
- Darkling ground beetle
- Dried fruit beetle
- Freeman sap beetle
- Confused sap beetle
- Fig beetle
- Fig mite
- Fig scale
- Fig tree borer
- Navel orangeworm
Fig Tree Pest Control
There are several plans of attack when treating bugs on figs. Not every pest is controllable, however. For instance, the fig tree borer lays its eggs near the base of a branch and then the resulting larvae hatch and tunnel into the tree. Once the larvae are in the tree, control is extremely difficult. Insecticide can be squirted into the tunnels with a syringe, which is time consuming and exacting.
The best defense against borers is a good offense. Enclose the lower portion of the tree in netting to prevent the females from laying their eggs in the bark. Also, cover the top of the netting with foil coated with Vaseline.
Treating bugs, such as dried fruit beetles or spider mites on figs, may require spraying. Dried fruit beetles or sap beetles include related species such as the Freeman and Confused sap beetle. They are small black to brown beetles, about 1/10 to 1/5 inch (2.5 to 5 mm.) long, that may or may not have spotted wings. When they feed on the figs, the fruit spoils and is rendered more attractive to other pests. It is also often infected with Aspergillus niger, a fungal disease that can affect ripening fruit.
To combat these beetle pests, set bait traps prior to figs ripening. When the traps have done most of the work of ridding the tree of beetles, spray the tree with an insecticide containing malathion in a sugar/water solution according to the manufacturer’s instructions. Stay clear of the sprayed area for at least 12 hours and do not harvest any figs for three days.
Both the Pacific spider mite and two-spotted spider mite may afflict a fig tree. They are both yellowish green with black spots. They feed on the underside of the fig leaves, which causes them to brown and drop. Spider mites do have some predatory insects, such as predaceous mites and six-spotted thrips, that will kill them; otherwise, smother them with a horticultural oil mixed with water or a pesticide that has bifenazate in it. If you use a spray with bifenazate, be warned that you should not eat the figs for an entire year.
Earwigs don’t really pose a threat to fig trees but they will eat the fruit. An insecticide that contains spinosad will most likely kill them.
The larva of the carpenter worm burrows under the bark of the fig and can kill entire branches. The larvae are easily recognizable as 2-inch (5 cm.) cream-colored grubs that exude sap and sawdust as they feed. A parasitic nematode, Steinernema feltiae, will help to control them.
Unfortunately, in the case of the darkling ground beetle, there is no biological or chemical control. These ¼ inch (6 mm.), dull black beetles and their larvae feed on decaying detritus at the base of the tree and in the surrounding soil. The best defense in this case is sanitation; keep the area around the tree free from weeds and harvest ripe figs immediately.
Treating an Infected Fig Tree
Having an infected fig tree is not an uncommon occurrence. Treating the tree is not always easy, and if the infection has gone too far, it's almost always impossible to cure. Nematodes like to invade the fig tree root and will make a home there if they can find one. Fig rust and root mosaic are also common diseases known to the fig tree.
Is There a Treatment?
Fig rust is the only one of the three that has treatment available. Fig rust can be treated with a copper spray each season until the tree improves. You might see a loss in harvesting when the rust is present.
Avoidance Is Key
The root nematodes and the fig mosaic are more of an avoidance treatment than anything else. Before you choose the wood for propagation, make sure that the fig piece is free from the fig mosaic. It will pass from tree to tree until you stop spreading the infected wood. Root nematodes are a worm that will take hold inside of a fig trees root. They will sap up all of the nutrients for themselves and eventually starve the tree. Check for nematodes when purchasing your tree, or you won't be able to get rid of them.
By being aware of what to look for when you propagate or purchase a fig tree, you can avoid some of the major fig tree infections.
Fig (Ficus carica)-Fruit Rot
Cause The fungus Botrytis sp. has been reported in Washington and found by the OSU Plant Clinic. Alternaria alternata has been a problem on ripe fruit in California. Rain or dew when figs are ripening will result in surface spotting. These spots are up to 0.2 inch in diameter, are light-brown to-black in color, sunken, and distributed over the entire surface of the fruit. Many of these fungi can be found in the environment, on fruit surfaces, and can colonize damaged tissue.
Surface mold caused by Cladosporium herbarum occurs in California on both green and ripe fruit, but tends to be more common on green fruit. The lesions usually occur in areas of fruit contact.
Symptoms Botrytis fruit rot is first seen as water-soaked area on the fruit. Fruit begin to wilt and collapse followed by the production of masses of closely appressed, buff-colored spores in the necrotic areas.
Surface mold is initially seen as small, olive-green specks but as they enlarge the infected area turns yellowish olive and becomes sunken.
Alternaria fruit rot - water-soaked areas develop on the surface where two or three figs touch but lesions are soon covered with dark green spores.
- Harvest fruit before it is overripe and/or before rainfall events.
Where are fig beetles commonly found?
Fig beetles are native to the southwestern United States and Mexico. Originally, they were limited to Arizona, New Mexico, Texas, and Northern Mexico, but by the 1960s they’d increased their range and began appearing in coastal Southern California.
Today, their populations extend farther up the coast of Central California and into the Central Valley.
It’s believed that fig beetles have increased along with the spread of home gardens, which offer an abundance of food for adult beetles, as well as compost and mulch piles that feed and shelter beetle larvae.