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Home > Infestation > Multiple ovipositions in the same fig (Observing the egg-laying females).
Author: François DROUET.
Photographs / videos: F. DROUET
and Bernard PEYRE.
All rights reserved.
Multiple ovipositions in the same fig
(Observing the egg-laying females)
I have highlighted the existence of multiple Black Fig Fly ovipositions in a same fig by three means: direct observation of the egg-laying females on the fig trees (this chapter), examination of the larvae contained in the figs (see chapter), study of the eggs deposited under the ostiolar scales and/or in the ostiolar canal (see chapter).
2020 OBSERVATIONS CAMPAIGN
In June 2020, I carried out an observation campaign of egg-laying Silba adipata McAlpine females on a fig bush (uniferous variety 'Bellone') partially stripped beforehand, which allowed me to observe 182 ovipositions. During this campaign, I was able to note that during its successive ovipositions sequence on the same fig tree (up to twenty figs, see chapter), the female lays eggs in figs in which other females have previously laid eggs . And it also happens that a female lays eggs in a fig in which it has already itself laid eggs a few minutes before, during the same successive ovipositions sequence.
Silba adipata McAlpine: egg-laying under an unripe fig ostiolar scale.
I recorded over time on my daily observation sheets the occurrences of multiple ovipositions in the same fig, using four processes to detect them.
First process: I easily counted multiple ovipositions in figs labeled with an oviposition number. In fact, to study the increase in the immature fig diameter between egg-laying and abscission, I was able to label a control batch of about forty attacked figs (after having located them by breaking the petiole of the leaf closest, immediately after oviposition).
Second process: during the successive ovipositions sequence of certain females, I was able to spot figs in which the female had already laid eggs during the same sequence.
Third process: I detected multiple ovipositions in figs located at positions which had become familiar to me from the observation posts (after several hours of observation...), and for which I remembered from a previous oviposition.
Fourth process : for certain immature figs which were still entirely green, I was able to identify the previous egg-laying infestation by noticing that the ostiole in which the female was laying eggs had the characteristic appearance of an ostiole attacked by ants having detected Black Fig Fly eggs presence. It is an ostiole with a whitish zone in the center, consequence of the reddish surface scales shredding by ants (see photograph below).
Black Fig Fly female laying eggs in a fig ostiole attacked by ants.
(note the whitish color of the ostiole center, which indicates that ants have shredded the uppermost ostiolar scales).
Taking into account traces of purplish red color on the immature fig for which I observed an egg-laying, which would have indicated that the fig was already infested, was not a possible process for detecting multiple ovipositions in the same fig. Indeed, I have noticed that Silba adipata McAlpine does not attacks suchs figs, probably because they release less of latex odor, or even none dependig of their evolution stage, than the unripe figs. And, anyway, the first traces of purplish red color on immature figs infested by Silba adipata McAlpine (that begin to appear, for the crop of an uniferous variety, at least 10 days after the first oviposition in the fig) was really perceptible only after the intense attacks period (phase 1 of the Black Fig Fly general attacks pattern, see chapter).
It is important to note that multiple ovipositions in the same fig constitute an attenuation factor of the Black Fig Fly female individual nuisance: the number of new figs lost for the crop during the female successive ovipositions sequence on the same fig tree is equal to the total number of ovipositions minus the number of ovipositions on figs already infested.
CONFUSION TO AVOID
When observing egg-laying females on the fig tree to detect multiple ovipositions in the same fig, one must not confuse the slight reddish blush at the apex, caused by intense direct sunlight on the immature fig, with the partial but marked reddish discoloration indicating an infestation by Silba adipata McAlpine.
Silba adipata McAlpine: egg-laying under an unripe fig ostiolar scale.
(the slight reddish blush at the fig apex is due to intense direct sunlight; it is not an infestation symptom).
Silba adipata McAlpine: egg-laying under an unripe fig ostiolar scale.
(the slight reddish blush at the fig apex is due to intense direct sunlight; it is not an infestation symptom).
EXCEPTIONAL OBSERVATION
Bernard PEYRE, former fig producer and consultant-trainer for commercial fig cultivation, reported to me of an exceptional observation testifying to Silba adipata McAlpine multiple ovipositions in the same fig.
On September 22, 2020, around 7 p.m., on one of his potted fig trees: two females landed simultaneously on the same immature fig, and began to lay eggs together in its ostiole. The two simultaneous ovipositions lasted about 4 minutes, and the two females were each able to carry out their repetitive sequences of comings and goings above the ostiole and egg deposits.
Silba adipata McAlpine: two females simultaneously laying eggs in the ostiole of a same fig.
Credit: Bernard PEYRE.
For my part, while observing Silba adipata McAlpine egg-laying, I only saw (once) an individual of the species land for 2 seconds near a female laying eggs in the ostiole, then fly away. And, only once also, an individual of the species to make a rebound on the side (in the upper part) of a fig in the ostiole of which a female was laying eggs (by "rebound", I mean: arrival in rapid flight, touch of the legs on the surface of the fig without landing, and immediate removal).
Illustration video.
Silba adipata McAlpine: two females simultaneously laying eggs in the ostiole of a same fig.
Credit: Bernard PEYRE.
Video analysis.
The analysis of the video (duration equivalent to a third of the time counted for the simultaneous ovipositions) makes it possible to appreciate more finely the two females behavior. To facilitate the analysis, it is better to observe separately (therefore successively) the behavior of each of the females. When the video starts, the bottom female is laying eggs in the ostiole, while the top one is outside the ostiole, on the edge of the fig top.
Top female behavior: two egg-laying sequences.
First sequence. The female goes towards the ostiole, crosses it and undertakes a fairly long oviposition under an ostiolar scale. Shortly before the oviposition end, the female moves slightly to the right. It then frees its ovipositor from the ostiole and moves away slightly (end of the first egg-laying sequence). The female then engages in rubbing its hind legs together for a short time.
Second sequence. The female carries out an almost complete reversal on itself (nearly 180°) on its left, and initiates a crossing of the ostiole by placing itself behind the other female, under the wings, as if to push it. It bypasses it to the right to complete its crossing of the ostiole and begin oviposition. During oviposition, it engages in repelling the other female using its second and third legs on the left side (the other female doing the same on its right side). The female then gradually moves to the right without the ovipositor leaving the ostiole. Then it frees its ovipositor from the ostiole (end of the second egg-laying sequence), and moves away slightly. The female then engages in rubbing the hind legs and wings (in progress when the video stops).
Bottom female behavior.
After a few pushes to complete the egg deposit in progress when the video begins, the female moves away from the ostiole by pivoting to its left and moves away slightly. It then carries out a complete reversal on itself (180°) on its right, goes around the other female from behind, crosses the ostiole and undertakes egg-laying. During egg-laying, it pivots slightly to its left without the ovipositor coming out of the ostiole. Then, while continuing egg-laying, it repels the other female by spreading its wings horizontally, or with the help of its legs on the right side. Egg-laying lasts a long time and is still in progress as the video ends, with the female then having its wings open at 45° to prevent the other female from approaching.
Remarks: the decomposition of a female Silba adipata McAlpine oviposition into several repetitive sequences is usual (see chapter). And it is also common for two Silba adipata McAlpine individuals in close proximity to each other to engage in mutual pushback.
ADDITIONAL OBSERVATIONS
Since the publication of his own observation, B. PEYRE has reported the following two other observations of two Silba adipata McAlpine females simultaneously laying eggs in the same fig, published on the Internet.
Arvel HERNANDEZ, a certified naturalist from the University of California, published on the iNaturalist website three Silba adipata McAlpine photographs taken on September 29, 2025, in Alameda, California (San Francisco area). See the page and click on the second photograph.
Mark RENZ, a member of the Facebook group "Growing Figs While Battling the Black Fig Fly," posted five photographs taken by a friend on February 23, 2026, on the border between Santa Clara and Cupertino, California (San Francisco area). See the page and click on the second photograph.
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