INDIVIDUAL BAGGING OF IMMATURE FIGS

To overcome the ineffectiveness of food traps, after testing various control methods without success, I opted for individual bagging of immature figs (using organza bags). This process prevents Silba adipata McAlpine from laying its eggs under the ostiolar scales or in the ostiolar canal, and it requires a completely acceptable implementation time in amateur cultivation. See details in the chapter dedicated to this control method.
 

Immature fig individually bagged against Silba adipata McAlpine (organza bag).

 

FOOD TRAPS

Setting the traps.

Two traps per fig tree. A McPhail trap baited with an aqueous solution of ammonium sulfate (4%, or 40 g/l). Set as soon as the fig tree's vegetation is visibly budding, March 1st in my garden. You should not wait for the figs, because Silba adipata McAlpine is present before the breba figs are clearly visible. And a McPhail trap baited with an aqueous solution of diammonium phosphate (4%), as soon as the Medfly (Ceratitis capitata Wiedemann) appears, June 30th in my garden. I leave the two traps on all the fig trees until the last ripe fig in the garden is harvested. I do not do this, but it is possible to prolong the prophylactic action against Silba adipata McAlpine by leaving the traps baited with ammonium sulfate in place until the end of December (Silba adipata McAlpine is usually still present in the garden until this time, even if the fig trees no longer bear figs or leaves).

Role of the traps.

The two traps on each fig tree have two roles: they allow the capture of a certain number of Silba adipata McAlpine individuals and of a high number of Ceratitis capitata Wiedemann individuals coming to consume on the fig tree; and they provide me with a continuous indication of the pressure level of the two pests in my garden. But they prove to be clearly insufficient to significantly limit the figs crop losses. Note: I am dealing exclusively with the case of my garden, in amateur cultivation. For commercial orchards, from a certain number of hectares, a mass effect occurs which allows the traps to have a better effect on Silba adipata McAlpine (even if it remains partial). This is to be determined with the phytosanitary advisors of professional figs producers.
 

McPhail trap set in a fig tree against Silba adipata McAlpine.

 

Ammonium sulfate: food attractant for Silba adipata McAlpine.

 

PROPHYLACTIC REMOVAL OF INFESTED FIGS

Prophylactic removal of infested figs on the tree must be carried out as soon as possible, before the larvae exit holes appear (daily to weekly inspection). Collecting infested figs on the ground is ineffective: when the attacked fig falls from the tree, the larvae have already abandoned it, with the exception of rare figs in which some of the larvae are still present. When it is done well, this process ensures that no larvae will touch the ground.

It should be noted that when individual bagging of immature figs is used, figs attacked by Silba adipata McAlpine are non-existent. Their possible presence is due to the loss of the bag (wind) on certain figs on which it was not tightened enough, or to an error in placing the bag too late on figs already attacked by Silba adipata McAlpine. If the fig bagging process is correctly applied, these cases are very rare. The prophylactic removal of infested figs is then of little use. But it must be known and rigorously applied  in cases where one has been prevented by life events from putting up the protective bags, or from putting up all or part of them on time.
 

Immature figs infested with Silba adipata McAlpine collected from the tree.