Composition and structure of the fig wasp community in Amazonia
Recent studies have shown that fig trees, wasps and orangutans have had a mutually beneficial relationship for thousands of years in In intelligence tests of the three great apes (gorillas, chimpanzees and orangutans) and. If, like me, you think of the year in relation to the fruits that are ripe at various times, you know that we just passed peach and plum time and that. Magnified view inside syconium of Ficus rubiginosa showing two male and two female fig wasps (Pleistodontes imperialis), similar to Pegoscapus spp.
In the absence of any quantitative studies, it has not been possible until now to evaluate the effect of non-pollinating wasps on seed and pollinator production among Amazonian fig trees.
Are figs really full of baby wasps?
There are cases of fig trees being exploited by six Conchou et al. Monoecious species, for example, possess a greater diversity of wasps because they provide a larger number of niches flowers - of at least four types heterostyly - on which non-pollinating wasps may oviposit, while the pollinating wasps associated with the dioecious species are limited to just one type of flower longer-styled flowers.
It can also be seen that, at least among monoecious species, the diversity of non-pollinating wasps varies in relation to fig diameter. Figs diameter normally varies between 4,0 mm and 60 mm, and with 10 to 10, flowers respectively Herre ; Berg and Wiebes ; Cook and Rasplus This potentially leads us to conclude that large-diameter figs will have the largest number of flowers and consequently a greater availability of locations for oviposition than figs of a smaller diameter.
However, although this hypothesis has been proposed by Cook and Segarthere are as yet no studies to corroborate the relationship. In the present study, we describe the composition and structure of the wasps community associated with four monoecious species of Ficus in the municipal area of Manaus, Amazonas, Brazil. The climate is equatorial humid, with a mean annual temperature of The year has two distinct seasons: Seven areas districts were selected for the study: Four taxa were selected: The latter two taxa according to the latest version of Berg All species and subspecies belonging to section Americana are pollinated exclusively by wasps of the genus Pegoscapus.
It was not possible to select individuals within ecological reserves or undisturbed areas, because the height of individuals in these environments above 25m made it difficult to gather syconia from these trees. Six hundred syconia were collected at random from four individuals syconia from each fig tree between July and October We selected figs that we judged to be in male phase D stage sensu Galil and Eisikowitchbut which did not yet have wasp exit holes.
Such figs are relatively large and are often slightly soft when pressed between thumb and forefinger. The syconia were separated in plastic flasks covered with a voile type cloth, and kept for 48 hours to collect all the wasps. The largest diameter of syconia 30 per fig tree was measured using digital callipers.Are There Dead Wasps In Figs? - Gross Science
These syconia were dissected with the aid of a dissecting knife and stereoscopic magnifier in order to count the galls. Syconia of the species F.
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The quantitative distribution of fig wasp species for each host was calculated using the formula proposed by Bush et al. To analyse the relationship between fig wasp diversity and syconium diameter, Bioestat 5. To define the type of statistic used - parametric or non-parametric - a normality test was performed a priori.
To evaluate the relationship between syconium diameter and gall quantity, the Kruskal-Wallis Test was used, followed by the Dunn post-test. Spearman's correlation was used to examine the association between syconium diameter and gall quantity, as well as to estimate non-pollinating wasp species male and female richness and abundance in relation to syconium diameter.
To analyse the effect of the non-pollinating wasp species on the numbers of Pegoscapus and seeds, a simple linear regression was used with the number of individual wasps by genus for each host. The non-pollinating wasps were divided in two groups: This division was done on the basis that the size of the galls of non-pollinating large-bodied wasps reduces the available space in the lumen of the syconia Conchou et al.
Twenty nine morphospecies were encountered in F. The 43 morphospecies of fig wasp belong to three families and seven genera, with Aepocerus and Physothorax being those with the largest number of morphospecies Table 1. The genus Idarnes was notable for having the greatest abundance and the largest number of infested syconia Table 2. Summary of the number of morphospecies, total individuals, and infested syconia for each wasp genus associated with species Ficus in the urban area of Manaus, Amazonas, Brazil.
Quantitative distribution of fig wasp species in syconia present in four species of Ficus in the urban area of Manaus, Amazonas, Brazil.
The numbers of figs collected are in parentheses under the plant taxon column. The distribution index of the fig wasps in the syconia showed that Pegoscapus was the most prevalent genus in all the fig trees. Regarding the diversity of non-pollinating wasps in relation to fig diameter in millimetersa significant difference was observed among the four fig species.
Ficus americana subspecies guianensis form mathewsii and F.
It was also found that species richness of wasps is not correlated with fig diameter in F. Americana subspecies guianensis form mathewsii and F. Syconium diameter mmnumber of galls, richness and abundance of non-pollinating fig wasps, and Shannon diversity index for different species of Ficus in the urban areas of Manaus, Amazonas, Brazil.
Forms belonging to 1 F.
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In relation to the effect of non-pollinating wasps on the number of pollinating wasps and seeds, in F. Among large-bodied non-pollinating species, Aepocerus was the most abundant with For these three species of Ficus, the total number of non-pollinating wasps did not correlate negatively with either the number of Pegoscapus or the number of seeds Figures 1 - 3 A, B.
Number of non-pollinating fig wasps as a function of the number of Pegoscapus sp. Due to the low number of non-pollinating large-bodied wasps, simple regression analysis was performed only for wasps of the genus Idarnes. The results showed that the total number of non-pollinating wasp correlated negatively and significantly with both the number of Pegoscapus sp.
In comparison with studies in the southeast and centre-west of Brazil, it was found that the wasp fauna associated with Amazonian fig trees is more diverse. The wasp community in F. The same was confirmed for F.
This is the first study, in which such a large number of non-pollinating wasp species has been registered, and given the diversity of fig trees in the neotropics species it is likely that there are many more species of fig wasp in the Amazon yet to be described. The results showed that the morphospecies Pegoscapus and Idarnes carme group were the most frequently occurring and abundant. Among the non-pollinating wasps, Idarnes is commonly regarded as the most abundant and diverse in Central and South America West and Herre ; Elias et al.
In the case of Idarnes carme group cleptoparasitessuccess in exploiting the mutualism is evidenced partly by the fact that the species in this group oviposits during phase C - the plant's interfloral phase Murussich and Machado ; Elias et al. This phase, being the longest 18 to 20 days depending on the species of Ficusgives an advantage to wasps from the carme group in ovipositing in a larger number of galls. In addition, the larvae of the males of this group have been observed feeding on the seeds, which broadens the spectrum of alimentary resources and the chances of increasing the progeny Pereira et al.
As they oviposit a little before or at the same time as the pollinators Elias et al. The same may be happening with morphospecies of the genus Aepocerus and Heterandrium gall inducerswhich oviposit approximately seven to twelve days prior to pollination Rasplus and Soldati The genera Physothorax Hanson and Eurytoma, Burks are the last to colonise the syconia and are parasites of the larvae of the phytophagous species West et al.
In relation to fig wasp species diversity, F. Consequently, our data failed to support the hypothesis postulated by Cook and Segar which predicted that larger diameter syconia would have a greater range of niches and the greatest wasp species richness. However, the timing difference in fig production the interval between harvests among species observed during our fieldwork, allows us to suggest that phenological aspects may be, in part, influencing normal fig wasp diversity.
Twice yearly fig production for F. In the same way, Cerezini et al. Considering that the greater the frequency of availability of the flowers, the greater the probability of an available niche suitable for reproduction, it appears that F. The limited period of time available for wasps to identify figs in which to lay eggs, the impact of adverse weather conditions and the effects of predation on the chances of successful reproduction Kjellberg et al.
In addition, even though there is a certain degree of specificity between non-pollinating wasps and host plants Cook and Rasplusthe wasps will select the fig species that are available in the period when they are ready for laying.
For this to occur, it is necessary that the figs have at least some similar morphological characteristics. Phenoptic diversity with respect to syconium size indirectly causes the restriction of a considerable number of non-pollinating wasps, since large figs have a thicker receptacle wall which does not allow some species to reach the flower ovules during oviposition Dunn et al. With respect to the negative effect of the non-pollinating wasps on the numbers of Pegoscapus sp.
According to Conchou et al. Based on this premise, it is suggested that the presence of a smaller number of large-body non-pollinating wasps in F.
This is because the absence of large galls makes viable not only the production of a larger number of small galls, but also of seeds, which are the two resources used in gall development in Idarnes carme group.
Are there really dead wasps in your figs? | MNN - Mother Nature Network
However, caution is necessary in accepting this relationship since the effects on mutualism vary according to the ecology and biology of each one of the non-pollinating wasps involved Bronstein It has also shown that non-pollinating fig wasp diversity varies in relation to fig diameter, but that figs of a large diameter are not necessarily those which host the greatest wasp diversity.
For this to happen, a fig plant needs to share its genetic material in the form of pollen with another of its kind, and the fig wasp needs a place where its larva can grow and feed.
Think of the fig wasp as a tenant, and the fig plant as a landlord who takes payment in the form of pollen. What we call a fig a structure called the syconium is more inverted flower than fruit, with all its reproductive parts located inside.
After a female fig wasp flies over from the fig plant she emerged from, she must travel to the center of the syconium to lay her eggs. To get there, she climbs down through a narrow passage called the ostiole. The passage is so cramped that the tiny fig wasp loses her wings and antenna during her claustrophobic trek. Once inside, there's no getting back out and flying to another plant -- but is she in the right place?
This content is not compatible on this device. Fig plants boast two kinds of figs: If a female wasp enters a caprifig, she'll find male flower parts that are perfectly shaped to hold the eggs she'll eventually lay. The eggs will grow into larvae, which will develop into male and female wasps.