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Friday Fellow: Golden Wattle

by Piter Kehoma Boll

If you walk through eucalyptus forests in eastern Australia, you may find today’s fellow in its natural environment. Its name is Acacia pycnantha, commonly known as the golden wattle and, as obvious by its scientific name, is a species of acacia.

A golden wattle among eucalyptus trees in southern Australia. Photo by David Muirhead.*

The golden wattle is a peculiar tree. It reaches a height of about 8 m, although most individuals grow only up to 6 m. As common among Australian species of the genus Acacia, the golden wattle does not have true leaves. Instead, it has modified leaf stems, called phyllodes, that are widened to look and function like leaves. The phyllodes have a lanceolate and falcate shape, i.e., they look like a typical leaf that is slightly curved to one side, like a sickle. The outer side of this “sickle” has an extra-floral nectary, a structure that produces nectar and attracts insects and birds that feed on it.

Phyllodes of the golden wattle with the extrafloral nectary seen as a small round protuberance. Photo by Wikimedia user Melburnian.**

The plant produces flower buds all year round but only those produced between November and May will develop further and open between July and November of the next year. The flowers occur in inflorescences and have a strong yellow color and the typical fluffy aspect of acacia flowers caused by the very long stamens.

One inflorescence with several flowers and their very long stamens. Photo by Patrick Kavanagh.***

Despite the huge amount of flowers that a single tree produces, this species is self-incompatible, meaning that it cannot fertilize itself and needs its pollen to be taken to the flowers of another individual of the same species. It has been shown that birds are very important pollinators of the golden wattle and the tree uses the extra-floral nectaries to aid that. When a bird visits the tree, it feeds on the nectar from the extra-floral nectaries and, in the process, brushed against the flowers, becoming covered with pollen. When the birds visit the next tree and brush against its flowers, part of the pollen of the first plant passes to the flowers of the second one.

The bark of the golden wattle produces large quantities of tannins, more than any other Australian acacia, which led to its cultivation for this purpose. When stressed, the trunk exudes a gum (resin) that is similar to the gum arabic produced by African species of acacia.

Gum exuding from the trunk of the golden wattle. Photo by Patrick Kavanagh.***

The golden wattle has been introduced in several other countries, especially in Europe and Africa, for ornamental or economic purposes. In South Africa, its cultivation for tannin production made it spread quickly through the native ecosystems, becoming invasive. And now, as always, we have to deal with the consequences of our irrational acts and run to solve this problem.

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References:

Hoffmann JH, Impson FAC, Moran VC, Donnelly D (2002) Biological control of invasive golden wattle trees (Acacia pycnantha) by a gall wasp, Trichilogaster sp. (Hymenoptera: Pteromalidae), in South Africa. Biological Control 25(1): 64–73. 10.1016/S1049-9644(02)00039-7

Vanstone VA, Paton DC (1988) Extrafloral Nectaries and Pollination of Acacia pycnanthaBenth by Birds. Australian Journal of Botany 36(5): 519–531. doi: 10.1071/BT9880519

Wikipedia. Acacia pycnantha. Available at < https://en.wikipedia.org/wiki/Acacia_pycnantha >. Access on 9 August 2019.

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Friday Fellow: Mottled Caddisfly

by Piter Kehoma Boll

It’s time to introduce a new insect order here and, again, this is a complicated taxon. The order Trichoptera consists of small moth-like insects known as caddisflies. They are closely related to moths and butterflies, the order Lepidoptera, being a sister-group of them. Having 10 times fewer species than the order Lepidoptera, the order Trichoptera is less common and much less popular, so that it is hard to find species that are well studied to present here.

The species I picked is called Glyphotaelius pellucidus and popularly known as the mottled caddisfly or mottled sedge. It lives in middle and northern Europe and has the typical life cycle of any caddisfly.

A mottled caddisfly in Germany. Photo by Wikimedia user Pjt56.*

The larva of the mottled caddisfly inhabits still and slow-running waters that are overgrown by trees, especially alders, oaks and beeches, in areas of lower altitude. As usual among caddisflies, the larva of the mottled caddisfly builds a silk case (a “caddis”) in which it lives and attaches pieces of debris, especially leaf fragments of the trees mentioned above, to make it stronger. In this species, the fragments that are attached make the case very large and characteristic. To the sides of the case, the larva attaches small and irregular leaf fragments, while to the dorsal and ventral sides, it attaches large, circular sections that are much wider than the larva’s body.

A larva inside its case in Germany. Photo by iNaturalist user fuerchtegott.**

The larva lives several months, from about October to April, and feeds on leaf fragments, the same material with which it builds its case. In April, the larva turns into a pupa which, usually during summer (around June or July), turns into an adult. The adult is not aquatic as the larva and the pupa. Thus, the pupa swims to the surface before breaking and releasing the adult. During this moment, the adult is very vulnerable to predators, especially fish. This is why fake adult caddisflies are commonly employed as fishing baits.

Adult mottled caddisfly in the UK. Photo by Philip Mark Osso.**

If the adult menages to leave the water alive, it still has to spend some time waiting for its wings to dry, which is another very vulnerable moment. The color of the adult is brown and the wings have a mottled pattern of dark and light marks that makes it resemble a fragment of dried leaf.

Egg mass on a leaf in the UK. Photo by Martin Cooper.***

Adult caddisflies in general rarely eat and this is not different with the mottled caddisfly. The only purpose of adults is to mate and lay eggs. After mating, the female lays the eggs in a mass on the surface of leaves hanging over a water body. One female may lay up to six egg masses, which decrease in size from the first to the last, and then dies. When the eggs hatch, the larvae fall into the water, restaring the cycle.

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References:

Crichton MI (1987) A study of egg masses of Glyphotaelius pellucidus (Retzius), (Trichoptera: Limnephilidae). In: Bournaud M., Tachet H. (eds) Proceedings of the Fifth International Symposium on Trichoptera. Series Entomologica, vol 39. Springer, Dordrecht. doi: 10.1007/978-94-009-4043-7_30

Gullefors B (2010) Seasonal decline in clutch size of the caddisfly Glyphotaelius pellucidus (Retzius) (Trichoptera: Limnephilidae). Denisia 29: 125–131.

Kiauta B, Lankhorst L (1969) The chromosomes of the caddis-fly, Glyphotaelius pellucidus (Retzius, 1783) (Trichoptera: Limnephilidae, Limnephilinae). Genetica 40: 1–6.

Otto C (1983) Behavioural and Physiological Adaptations to a Variable Habitat in Two Species of Case-Making Caddis Larvae Using Different Food. Oikos 41(2): 188–194. doi: 10.2307/3544262

Rowlands MLJ, Hansell MH (1987) Case design, construction and ontogeny of building in Glyphotaelius pellucidus caddisfly larvae. Journal of Zoology 211(2): 329–356. doi: 10.1111/j.1469-7998.1987.tb01538.x

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Friday Fellow: Strawberry Top Snail

by Piter Kehoma Boll

Look at this thing:

It is so beautifully red like a strawberry that I feel my mouth salivating and an urge to bite it. But instead of a juicy sweet fruit like a strawberry, this is a hard salty seashell belonging to the species Clanculus puniceus that has the appropriate common name of strawberry top shell.

This species is found in the Indian Ocean along the eastern coast of Africa, from the Red Sea to Cape Agulhas, including nearby islands such as Madagascar and the Mascarenes. It belongs to the family Trochidae, commonly known as top shells or top snails because their shell resembles a spinning top.

Strawberry top shell in South Africa. Photo by iNaturalist user jaheymans.*

The shell of the strawberry top snail measures, in the adult, at least 15 mm in diameter, reaching up to 23 mm, and has a beautiful red color, caused by uroporphyrins, that can vary from orange-red to crimson. The spiral of the shell, when seen from above, has a line formed by black dots, caused by melanin, intercalated by two or three white dots. When seen from below, there are two additional lines with this pattern that run side by side near the shell opening.

The shell seen from several angles. Photo by H. Zell.**

As usual among top snails, the strawberry top snail lives in intertidal and subtidal zones and feeds on algae that it scrapes from rocks using its toothed tongue (the radula). They are dioecious, i.e., there are male and female individuals, as in most sea snails, but there is no sexual dimorphism.

Due to its beauty, the shell of the strawberry top snail is highly desired by shell collectors. However, little is known about the natural history of this particular species. I wasn’t even able to find a photograph in which the snail itself is visible.

This was the only photograph I found in which the soft part of the body of a snail in the genus Clanculus is visible. The species, from Taiwan, was not identified. Photograph by Cheng Te Hsu.***

If you work with this species or at least has a photograph of a living specimen showing the snail inside the shell, please share it! We need more available information on the wonderful creatures that share this planet with us.

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More marine snails:

Friday Fellow: Ornate Limpet (on 3 May 2019)

Friday Fellow: Tulip Cone (on 29 December 2017)

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References:

Herbert DG (1993) Revision of the Trochinae, tribe Trochini (Gastropoda: Trochidae) of southern Africa. Annals of the Natal Museum 34(2): 239–308.

Wikipedia. Trochidae. Available at < https://en.wikipedia.org/wiki/Trochidae >. Access on 29 July 2019.

Williams ST, Ito S, Wakamatsu K, Goral T, Edwards NP, Wogelius RA, Henkel T, Oliveira LFC, Maia LF, Strekopytov S, Jeffries T, Speiser DI, Marsden JT (2016) Identification of Shell Colour Pigments in Marine Snails Clanculus pharaonius and Cmargaritarius (Trochoidea; Gastropoda). PLoS ONE 11(7): e0156664. doi: 10.1371/journal.pone.0156664

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Friday Fellow: Portuguese Millipede

by Piter Kehoma Boll

Millipedes, which make up the class Diplopoda, are very cute arthropods in my opinion and include amazing species, such as the animal with the largest number of legs in the world. Many species are not well studied, though. However, one that is very well known is the Portuguese Millipede Ommatoiulus moreleti.

As its common name suggests, the Portuguese millipede is native from Portugal, more precisely from Southern Portugal and nearby areas in Spain, living in the soil of pine and oak forests. Its body, measuring about 4 cm as adults, has the typical cylindrical and elongate shape seen in most millipedes and is very dark, almost black, with legs that have a light color, usually whitish, but sometimes purplish.

A Portuguese millipede in Portugal. Photo by Romulo Arrais.*

Despite its relatively small size, the Portuguese millipede takes more than a year to reach maturity and grow for about three years. The mating period is usually during Autumn, and after having its eggs fertilized, the female lays from 60 to 80 of them in a chamber about 2 cm deep in the soil. When the eggs hatch, the first stage is a small, pupoid legless animal that remains inside a membrane until it molts into a small six-legged larva. During the first year, the juvenile molts about 8 times and the number of legs increases at each new stage. At about stage 10, they are sexually mature, but continue to molt and gaining more legs until reaching about 90 legs at the 14th stage. Males have an interesting reproductive strategy called periodomorphism, in which mature individuals molt into a “castrated” form, with reduced sexual organs, and becomes sexually mature again in the next molt, only to return to the immature form again in the next molt and so on.

The Portuguese millipede became famous after its accidental introduction in southeastern Australia, apparently in the 1950s. It soon became a very abundant species and, as a consequence, a nuisance for humans. As most millipedes, the Portuguese millipede is mainly detritivorous, feeding on dead plant material, such as rotten wood and dead leaves, so its introduction is not that much an ecological catastrophe, although it can have some negative impacts by competing with native millipede species.

A Portuguese millipede in Australia. Photo by iNaturalist user corunastylis.**

The main problems caused by the introduction of the Portuguese millipede in Australia affect mostly humans. They are attracted to weak light sources, such as those emitted by houses at night, and, as a result, end up invading residences, sometimes hundreds of them at a time. When threatened, the Portuguese millipede emits a pungent yellow secretion that can irritate the eyes and, in contact with clothes, mark them with a permanent stain. Addtionally, the Portuguese millipede sometimes can feed on some crops, especially fruits.

In Portugal, the populations of the Portuguese millipede are controlled by native predators, such as the European hedgehog Erinaceus europaeus and the beetle Ocypus olens. Released from these natural enemies, the millipede spread quickly through southeastern Australia. However, about 30 years later, its population in Australia started to decrease. Apparently some nematode parasites that infect native millipedes adapted to parasitize this invasive species as well, helping to contain its population size. Some other native Australian predators have also observed feeding on the Portuguese millipede, including the blue garden flatworm, Caenoplana coerulea.

Other than Australia, the Portuguese millipede was also introduced in several Atlantic Islands, such as the Macaronesian Islands, Bermuda and the UK, as well as in South Africa. However, it does not seem to be that much of a nuisance there.

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More millipedes:

Friday Fellow: Leggiest Millipede (on 12 February 2016)

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References:

Baker GH (1985) Predators of Ommatoiulus moreletii (Lucas) (Diplopoda: Iulidae) in Portugal and Australia. Australian Journal of Entomology 24(4): 247–252. doi: 10.1111/j.1440-6055.1985.tb00237.x

Baker GH (1978) The post-embryonic development and life history of the millipede, Ommatoiulus moreletii (Diplopoda: Iulidae), introduced in south-eastern Australia. Journal of Zoology 186: 209–228. doi: 10.1111/j.1469-7998.1978.tb03366.x

Gregory SJ, Owen C, Jones G, Williams E (2018) Ommatoiulus moreleti (Lucas) and Cylindroiulus pyrenaicus (Brölemann) new to the UK (Diplopoda, Julida: Julidae) and a new host for Rickia laboulbenioides (Laboulsbeniales). Bulletin of the British Myriapod & Isopod Group 30: 48–60.

McKillup SC, Allen PG, Skewes MA (1988) The natural decline of an introduced species following its initial increase in abundance: an explanation for Ommatoiulus moreletii in Australia. Oecologia 77:339–342. doi: 10.1007/BF00378039

Terrace TE, Baker GH (1994) The blue land planarian, Caenoplana coerulea Moseley (Tricladida: Geoplanidae), a predator of Ommatoiulus moreleti (Lucas) (Diplopoda: Julidae) in southern Australia. Australian Journal of Entomology 33(4): 371–372.

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Friday Fellow: Stonewort Seed Shrimp

by Piter Kehoma Boll

It’s time to talk about an ostracode, or seed shrimp, again and, as usual, this is a difficult time due to the little information easily accessible regarding any particular species of this group. But there is, indeed, one that is considerably well studied. Being one of the most common ostracodes in North America and Eurasia, its scientific name is Cypridopsis vidua, to which I coined the common name “stonewort seed shrimp”.

The stonewort seed shrimp is a freshwater crustacean with the typical ostracode appearance, looking like a tiny bivalve measuring about 0.5 mm in length. Its valves have a distinctive light and dark pattern.

A stonewort seed shrimp with a closed shell. Credits to Markus Lindholm, Anders Hobæk/Norsk institutt for vassforsking.*

A relatively mobile species, the stonewort seed shrimp lives at the bottom of water bodies, over the sediment, and is common in areas that are densely vegetated by stoneworts (genus Chara). This association with stoneworts gives the stonewort seed shrimp both protection from predators, which are mostly fish, and a good food source.

The main food of the stonewort seed shrimp are microscopic algae that grow on the stems of stoneworts. While foraging, the stonewort seed shrimp swims from one stonewort stem to another using its first pair of antennae and clings on the stems using the second pair of antennae and the first pair of thoracic legs. Once realocated, it starts to scrape the microscopic algae using its mandibles.

The body of a stonewort seed shrimp as seen when one of the valves (the left one here) is removed. Credits to Paulo Corgosinho.**

The stonewort seed shrimp is one more of those species in which males do not exist, not even in small quantities. During the warm months of summer, females produce the so-called subitaneous eggs, which develop immediately into new females. However, when winter is approaching, they produce another type of eggs, the so-called diapausing eggs, which remain dormant in the substrate during winter. The adult animals all die during this season and, when spring arrives, a new population appears from the hatching eggs. Since not all eggs hatch in the spring, some of them may remain in the substrate for years before hatching, which usually increases the genetic diversity every year, as it not only depends of the daughters of the last generation.

But how does genetic diversity appear if there are no males and, as a result, the daughters are always clones of the mothers? This mystery is not yet fully solved. Genetic recombination during parthenogenesis, by exchanging alleles between chromosomes, does not seem to be very common. It is possible that different populations are genetically different and that they colonize new areas very often, mixing with each other. Since males are known in closely related species, it is still possible that, some day, we will find, somewhere, some hidden males of the stonewort seed shrimp. It is also possible that, somehow, males went all extinct in the recent past, like in the last glaciation, for example. If so, only time can tell what is the destiny of the stonewort seed shrimp.

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More Ostracods:

Friday Fellow: Sharp-Toothed Venus Seed Shrimp (on 22 June 2018)

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References:

Cywinska A, Hebert PDN (2002) Origins of clonal diversity in the hypervariable asexual ostracode Cypridopsis vidua. Journal of Evolutionary Biology 15: 134–145. doi: 10.1046/j.1420-9101.2002.00362.x

Roca JR, Baltanas A, Uiblein F (1993) Adaptive responses in Cypridopsis vidua (Crustacea: Ostracoda) to food and shelter offered by a macrophyte (Chara fragilis). Hydrobiologia 262: 121–131.

Uiblein F, Roca JP, Danielpool DL (1994) Experimental observations on the behavior of the ostracode Cypridopsis vidua. Internationale Vereinigung für Theoretische und Angewandte Limnologie: Verhandlungen 25: 2418–2420.

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Friday Fellow: Luna Moth

by Piter Kehoma Boll

It’s been a very long time since the last time I presented a lepidopteran here, so today I decided to go back to this amazing group of insects. The species I chose for today is quite popular, maybe the most popular moth in the world. Its name is Actias luna, commonly known as the luna moth.

Adult luna moth in the Unites States. Photo by Andy Reago & Chrissy McClarren.*

The luna moth is native from Canada and the United States. It is a quite large moth, with a wingspan of about 8 to 12 cm, although some individuals can be as big as 18 cm. Its wings, covered with scales as usual in lepidopterans, have a light green color. The forewigs have a brown anterior border that connects to two eyespots (one on each wing) by a stalk. The hindwings also have one eyespot each, but they are not connected by a stalk to the border. The hindwings also have a long tail that is characteristic of the genus Actias and somewhat resembles the similar (but shorter) tails in some butterflies, such as those of the family Papilionidae. Males and females are very similar and can be often distinguished by the size of the abdomen, which is much thicker in females.

In colder climates, such as in Canada, the luna moth has one generation per year, but southern populations, in places where the climate is warmer, can have up to three. The females lay eggs on suitable plants to serve as food for the larvae. There are several identified tree species that are used as food, including birches, walnuts, hickories and persimmons. The larvae feeding on a tree never, or very rarely, reach a number that can cause significant damage to the plant.

Third instar larvae. Photo by Wikimedia user Kugamazog~commonswiki.**

The eggs are brown and laid in irregular clusters on the underside of the leaves. They usually hatch one to two weeks after being laid and originate small, green larvae. The larvae are green in all instars and pass through five of them during a period of about 7 weeks. The fifth and final instar then descends the tree in which it lives to reach the ground. There, it starts to spin a silk coccoon and, after finishing it, turns into a pupa. In warmer regions, the pupa takes about two weeks to become an adult, but in colder regions it enters into diapause over winter, taking about nine months to complete the cycle.

A fifth-instar larvae building its coccoon. Credits to Virginia State Parks staff.*

When females become adults, they search for a suitable tree of its preferred species (usually the same species in which it was born) and emits pheromones to attract males. Adults lack mouth parts and, therefore, do not eat, living only enough to mate and lay eggs. The nice long tails on the hindwings, more than just beautiful, seem to decrease the ability of bats to detect them using their echolocation.

Pupa beside an empty coccon. Photo by Wikimedia user Kugamazog~commonswiki.**

The luna moth is one of the most popular insects in North America. In fact, it was the first insect ever to be described from the continent, being named Phalaena plumata caudata by James Petiver in 1700. When Linnaeus started the binomial nomenclature for animals in 1758, he renamed it Phalaena luna as a reference to the Roman goddess of the moon.

Beautiful specimen in Canada. Photo by Alexis Tinker-Tsavalas.***

Although not considered a vulnerable species at the moment, the luna moth faces some threats caused by human interference, such as habitat loss and damage caused by invasive species. Fortunately, due to its popularity, it is likely to have considerable support from the public for its conservation when that time comes.

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References:

Lindroth RL (1989) Chemical ecology of the luna moth: Effects of host plant on detoxification enzyme activity. Journal of Chemical Ecology 15(7): 2019–2029.

Millar JG, Haynes KF, Dossey AT, McElfresh JS, Allison JD (2016) Sex Attractant Pheromone of the Luna Moth, Actias luna (Linnaeus). Journal of Chemical Ecology 42(9): 869–876.

Wikipedia. Luna moth. Available at < https://en.wikipedia.org/wiki/Luna_moth >. Access on 11 July 2019.

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Friday Fellow: Chinese Banyan Wasp

by Piter Kehoma Boll

During the past three weeks, I presented a fig tree, the Chinese Banyan, a thrips that parasitizes it, the Cuban Laurel Thrips, and a mite that parasitizes the thrips, the Cuban-Laurel-Thrips Mite. However, I haven’t wrote yet about one of the most interesting creatures that interacts with a fig tree: its pollinator.

In the case of the Chinese Banyan, its pollinator is the fig wasp Eupristina verticillata, which I named the Chinese Banyan Wasp. As all fig wasps, this species is very small and completely adapted to live with figs. They cannot survive without the exact fig species with which they interact and the fig species cannot reproduce without that exact wasp. How does this works?

Let’s start our story with an adult female Chinese banyan wasp. The females are black and very small, measuring around 1 to 1.2 mm in length only. This female is flying around looking for a young fig which will serve as her nest and her grave.

This is what a female Chinese Banyan wasp loooks like. Photo by Forest & Kim Starr.*

A fig, in case you don’t know, is not a real fruit in the botanical sense. It is actually a special kind of inflorescence called a syconium that is basically a flower-filled sack. The inner walls of a fig have many tiny male and female flowers and the only way to get to them is through a tiny hole at the fig’s appex. And this hole is only open during the initial stages of the fig’s development.

Chinese Banyan figs in their early stage. You can see the hole marked by a darker “areola” around them. That is the place through which a female fig wasp enters the fig. Credits to Wikimedia user Vinayaraj.**

When the female Chinese Banyan fig wasps is flying around, she is looking for a fig that is at this exactly stage of development. Once she finds one, she crawls inside the fig through that tiny hole. She usually loses her wings while doing that because the passage is too narrow. She evens needs to use her especially adapted mandible to help her go through. Once inside the fig, she looks for the female flowers, which are located at the base of the fig, away from the entrance. The male flowers, located right at the entrance, are not mature yet. However, the female wasps arrived with pollen that she gathered elsewhere (you will learn about that soon). When she reaches the female flowers, she introduces her ovopositor (the long structure at the end of her abdomen that is used to lay eggs) inside the female flower and lays one egg inside the flower’s ovary. Her ovopositor needs to have the exact size to reach the ovary to lay the egg. If it is too short, she is unable to complete her task. And while she is moving from flower to flower to lay eggs, she ends up pollinating them. After she has finished, she dies still inside the fig.

The ovaries that received an egg start to grow into a gall (a “plant tumor”) by influence of the insect and serve as food and shelter for the larvae that hatch from the eggs. A larva grows, pupates and turns into an adult inside a single gall. When the wasps have finally reached their adult stage, they leave the gall in which they were born. This happens when the fig reached its mature stage.

Males are the first ones to emerge. They are even smaller than the females and have a yellow to light-brown color. They gnaw their way through the gall and, once outside it (but still inside the fig) they start to look desperately for female wasps to inseminate. They do that by tearing other galls apart and, when a female is found trapped inside, they inseminate her. After that, the males dig a hole through the fig to the outside and die soon after, never experienced the external world.

A male Chinese Banyan wasp (right) compared to a female. Photo by Forest & Kim Starr.*

Female wasps then leave their galls and move towards the hole opened by the male. While doing that, they move over the now mature male flowers and become covered in polen. After leaving the fig, they search for another fig that is in its early stage of development, restarting the cycle.

When a female leaves a mature fruit, she needs to find an immature one soon after that because she will die in a couple of days. In other words, the only way for this to work is if there are figs in the right stage all year around, and that is what happens. Differently from most plant species, which produce flowers in a specific time of the year, fig trees are always flowering. Well, not exactly. One individual fig tree produces figs only in a specific period of the year. All the figs of that tree ripen at the same time, i.e., a fig tree has an intra-individual synchrony of flower maturation. However, other trees of the same species have different moments to produce flowers, i.e., there is an inter-individual asynchrony of flower maturation. This assures that a wasp will always find a fig at the suitable maturation stage when there are enough fig trees around and also assures that a fig tree will not be fertilized by its own pollen.

As I mentioned when I presented the Chinese Banyan, this tree can only produce viable figs when the wasp is present, so that populations introduced outside of their native range will only reproduce if the waps is introduced as well. However, the wasp will be unable to survive if there are not enough fig trees to provide it with figs all year round. It is a delicate relationship between a tiny, fragile and short-lived insect and a huge, resistant and long-lived tree. And they need each other to survive.

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References:

Cook J, Rasplus J-Y (2003) Mutualists with attitude: coevolving fig wasps and figs. TRENDS in Ecology and Evolution 18(5): 241–248.

Kjellberg F, Jousselin E, Hossaert-McKey M, Rasplus J-Y (2005) Biology, Ecology, and Evolution of Fig-pollinating Wasps (Chalcidoidea, Agaonidae). In Raman A, Schaefer CW, Withers TM (Eds.) Biology, ecology and evolution of gall-inducing arthropods. v.2. New Hampshire, Science, p.539-572.

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