“Fig fly” refers to two different insects that attack fig fruit: the black fig fly and the African fig fly. The black fig fly is the more destructive of the two, capable of ruining unripe fruit from the inside out. The African fig fly is a secondary pest that feeds only on fruit that’s already damaged or overripe. Both are invasive species in the United States, and if you’re growing figs, knowing the difference matters for protecting your harvest.
Black Fig Fly
The black fig fly (Silba adipata) is the one most fig growers worry about. It’s a small, dark-bodied fly that exclusively attacks figs, preferring unripe and unfertilized fruit. The adult female lays her eggs directly into the fig through the ostiole, the small natural opening at the bottom of the fruit. Once inside, the larvae feed on the fig’s interior, causing the fruit to rot and drop prematurely from the tree.
When the larvae finish developing, they either chew their way out of the fruit and drop to the soil to pupate, or in some cases, pupate right inside the fallen fig. Because the damage happens internally, you often won’t realize a fig is infested until it drops or you cut it open. Premature fruit drop during the growing season is the biggest telltale sign of a black fig fly problem.
First reported in the United States in 2022, the black fig fly has been found across Southern California in Los Angeles, Orange, Riverside, Santa Barbara, San Bernardino, San Diego, and Ventura counties. It’s classified as having limited extent in California but is considered already established, meaning eradication isn’t the goal. Management is.
African Fig Fly
The African fig fly (Zaprionus indianus) looks quite different from its black counterpart. It has a light-colored body with bright red eyes and is slightly larger than common fruit flies. Under magnification, you can spot three distinct white stripes bordered in black running along each side of its head and upper body. Females lay around 60 eggs on average, depositing them inside fruit where the larvae develop.
The key difference: the African fig fly has a weak egg-laying organ and cannot pierce intact, undamaged fruit. It can only infest figs that are overripe, split, or already damaged by another pest like spotted wing drosophila. So while it contributes to fruit breakdown and can introduce secondary infections, it’s not the one starting the problem. Its larvae look nearly identical to other small fruit fly maggots, making visual identification of the larval stage unreliable.
Outside the fig industry, the African fig fly hasn’t been shown to cause significant economic damage to other crops. It may build up alongside spotted wing drosophila populations, taking advantage of the entry wounds that pest creates in soft fruit.
How to Spot an Infestation
With the black fig fly, the primary warning sign is fruit dropping before it’s ripe. Since the larvae feed inside the fig, external damage is minimal or absent early on. The fly enters through the ostiole, leaving no obvious puncture wound on the skin. If you’re finding unripe figs on the ground, cut a few open and look for small white larvae or signs of internal decay.
For the African fig fly, the signs are more obvious because the fly targets fruit that’s already compromised. Overripe figs on the tree or ground that seem to be breaking down faster than expected, especially if you notice small flies around them, are likely hosting larvae.
Protecting Your Fig Trees
No pesticide spray can reach black fig fly larvae once they’re inside the fruit, and there are no effective soil treatments for the pupal stage. That makes prevention and sanitation the most practical tools for home growers.
Orchard sanitation is the single most important step. Remove and destroy any fallen or infested fruit promptly. Leaving damaged figs on the ground lets larvae complete their life cycle in the soil, building up the population for the next generation. Placing plastic mulch or a barrier under the tree canopy can also help by preventing larvae that drop from fruit from successfully burrowing into the soil to pupate.
Physical exclusion works well on a small scale. Mesh bags placed over individual developing figs, or a larger mesh cage draped over the entire tree, can block adult flies from reaching the ostiole to lay eggs. This is labor-intensive but effective, particularly for home gardeners with just a few trees.
You can monitor adult black fig fly populations using traps baited with torula yeast. Dissolve four tablets (about 20 grams) in 400 milliliters of water inside a McPhail-style trap and replace the solution every two weeks. This won’t eliminate the flies, but it tells you when they’re active and how heavy the pressure is, so you can time your protective measures.
Researchers are currently testing insecticidal baits for adult black fig fly control, but no products have been specifically labeled or proven effective against this pest yet. For the African fig fly, the best defense is simply harvesting ripe fruit promptly and not letting damaged or overripe figs linger on the tree or ground.
Fig Flies vs. Fig Wasps
If you’ve seen claims online that figs contain insects, you’re probably thinking of fig wasps, not fig flies. Fig wasps are tiny pollinators that enter certain fig varieties to lay eggs and pollinate flowers inside the fruit. The fig produces an enzyme called ficin that completely breaks down any wasp that dies inside, leaving no insect remains in the finished fruit. Fig flies are an entirely different situation: they’re pests, not pollinators, and their larvae actively damage the fruit rather than playing a role in its development. Most commercial fig varieties sold in grocery stores don’t require wasp pollination at all.