Field of Science

Wasps that don't Give to a Fig

The strategies employed by flowering plants to draw in their pollinators are many and varied. Some have entered into exclusive partnerships, contriving methods by which their rewards are shared with a single animal species and hence presumably increasing the likelihood of that species visiting them. Once remarkable example of such a partnership is found among the figs. To the casual observer, fig trees might appear to never produce flowers. However, immature figs are in fact closed inflorescences called syconia with the flowers produced on the inside of the fig, never exposed to the outside world. The only way for pollinators to reach the fig flowers is through a tiny hole or ostiole at the fig's apex. This ostiole is used by the fig's pollinators, tiny female wasps of the chalcidoid family Agaonidae, who enter the fig in search of places to lay their eggs. The wasp herself does not leave the fig again after laying but her eggs and larvae develop within galls inside the fig, feeding on the tissue of the fig itself. After developing into wingless males and winged females, the next generation of fig wasps mates within the syconium; pollination of the fig tree occurs through the young females leaving the fig to find their own laying places and carrying pollen as they do so.

Female Idarnes nr flavicollis, a typical late-laying sycophagine, copyright Sergio Jansen Gonzalez.


The fig benefits by having an exclusive pollinator, the fig wasp benefits by having a ready-made nursery for its offspring. However, all that tasty fig tissue is bound to prove attractive to others who would circumvent the standard contract. Another group of chalcidoid wasps, the subfamily Sycophaginae, includes prime examples of such freeloaders. Like the true pollinating fig wasps, these non-pollinating fig wasps develop in galls within fig syconia. However, instead of entering the fig through the ostiole, most sycophagines use their ovipositor to pierce the fig's outer skin and lay from outside. In some sycophagines, the ovipositor is relatively short and thick; these species lay their eggs when the fig is only just beginning to develop. In others, the ovipositor is longer and slender, longer in fact than the rest of the wasp, and oviposition happens later when the fig has grown to a larger size. In some of these later-arriving forms, the ovipositing female lays into a gall already induced by the fig's actual pollinator (how she finds it from outside the fig, I have no idea), and as well as feeding on the gall, her larva will eventually feed on the pollinator larva. There are also some sycophagines that enter the syconium through the ostiole and oviposit internally; I haven't been able to find whether these species may function as true pollinators.

Female Sycophaga ovipositing on Ficus sur, copyright JMK.


As noted above, pollinating agaonids exhibit strong sexual dimorphism with only the females having wings, and males never escaping the host syconium. The wingless males cannot be easily recognised as belonging to the same species as the females; indeed, if one does not already know what they are, they can barely even be recognised as wasps. In sycophagines, matters are a bit more complicated. In some species, males are wingless and highly modified as in pollinating fig wasps. In others, males are winged and similar in appearance to females. And in still others, wingless and winged males are both present within a single species. I don't know what determines whether a given larva of these species develops wings or not; both forms may develop within the same syconium. It has been suggested that the presence of the two forms is related to conflicting pressures of gene flow vs speed. Winged males that can look for mates outside the parent syconium have a better chance of finding mates outside the pool of their own siblings, thus avoiding the risk of inbreeding. However, wingless males can mate with females immediately after they emerge within the syconium (if not before, as I'll explain shortly), in which case the winged males may simply find themselves too late to the party. Certainly there is a correlation between winglessness and the size of broods. Early-ovipositing species, which tend to produce smaller broods because the younger host syconium offers less space for egg-laying, are more likely to have winged males whereas males of later-ovipositing species are more likely to be wingless (Cruaud et al. 2011).

Male Apocryptophagus, copyright Centre for Biodiversity Genomics.


Males of the genera Sycophaga and Apocryptophagus (which Cruaud et al., 2011, suggested should probably be synonymised) are invariably wingless and have elongate, flattened, extensible gasters. The terminal pair of spiracles on the abdomen have the surrounding peritremes (supporting rings) extended into a pair of long filaments. In the host figs of these genera, the interior of the syconium becomes filled with liquid after being pollinated by its associated agaonids; the liquid is resorbed when the pollinators emerge. Nevertheless, there are advantages for the sycophagines in emerging before the pollinators: not only could the interior of the syconium become rather crowded, males of some agaonid species have enlarged mandibles that they may use to dispatch any interlopers. So instead of waiting for the syconial fluid to drain away, the male Sycophaga cuts a small opening slit in his gall (too narrow for the surrounding fluid to seep in) through which he partially emerges into the central cavity. The peritremal filaments are used to anchor the end of his gaster within his original gall so that he can continue to breathe from the air-pocket inside it while he stretches out in search of another gall containing a female. When he finds one, he will cut into it in the same way that he cut out of his own, then release the end of his gaster from its anchor-point and quickly slip into the gall of his intended. After a brief mating, he can repeat the process, this time using the female's gall as his air-tank (Ramírez 1996–1997). The female presumably emerges once the syconial fluid is gone.

Male Apocryptophagus emerging from a gall containing a female, from Ramírez (1996–1997).


There have been various viewpoints about the relationships of Sycophaginae to other chalcidoids. Some authors have included almost all the fig-associated wasps in the Agaonidae, whether pollinators or not. Others have restricted the Agaonidae to the true pollinators and classified non-pollinating fig wasps such as the Sycophaginae with the poorly defined family Pteromalidae. An analysis of chalcidoid relationships by Heraty et al. (2013) identified Sycophaginae as a sister group to Agaonidae sensu stricto (while placing other groups of non-pollinating fig wasps elsewhere on the tree). This might lead one to consider the possibility that the gall-making habit seen in both Sycophaginae and pollinating Agaonidae pre-dates the evolution of the wasp-fig relationship as pollinators. Perhaps the evolution of the syconium allowed figs to convert gall-makers that had previously been parasites into partners.

REFERENCES

Cruaud, A., R. Jabbour-Zahab, G. Genson, F. Kjellberg, N. Kobmoo, S. van Noort, Yang D.-R., Peng Y.-Q., R. Ubaidillah, P. E. Hanson, O. Santos-Mattos, F. H. A. Farache, R. A. S. Pereira, C. Kerdelhué & J.-Y. Rasplus. 2011. Phylogeny and evolution of life-history strategies in the Sycophaginae non-pollinating fig wasps (Hymenoptera, Chalcidoidea). BMC Evolutionary Biology 11: 178.

Ramírez, W. 1996–1997. Breathing adaptations of males in fig gall flowers (Hymenoptera: Agaonidae). Revista de Biologia Tropical 44 (3)–45 (1): 277–282.

Neostrinatina mixoppia

Dorsum of Neostrinatina mixoppia, from Mahunka (1978).


Time for another oribatid. This is Neostrinatina mixoppia, a species described as the only member of its genus by S. Mahunka in 1978. It was described on the basis of two specimens from near Coban in the highlands of Guatemala. Neostrinatina belongs to the family Oppiidae, a group of often smaller oribatids with moniliform legs, and is a bit over a quarter of a millimetre in length. N. mixoppia noticeably differs from other oppiids in its long pectinate sensillus on either side of the prodorsum. The other dorsal setae are also particularly long and barbed. Other distinctive features of this species, according to Mahunka, are a pair of lateral teeth on the dorsosejugal suture (the junction between the prodorsum and the notogaster, or what one might think of as the 'head' and 'body' regions of the dorsum) that jut towards the sensilli, and an 'enormous, spiniform excrescence' projecting forwards from the anogenital region. I must admit, though, I've been trying to interpret Mahunka's illustration of the ventral region of N. mixoppia and I'm still not entirely sure what this latter feature looks like. Like other oppiids, the prodorsum does not have the projecting lamellae found in many oribatid families; instead, N. mixoppia has a pair of branching costulae (thickened ridges). The legs each end in a single claw.

Venter of Neostrinatina mixoppia, from Mahunka (1978).


Oppiids are currently recognised as the most diverse family of oribatids with over 1000 known species, the greater number of these found in the tropics. Though the ecology of N. mixoppia itself is unknown, other oppiids feed on fungi. The single claws on the legs suggest a terrestrial habitat. As with many (if not most) oribatid groups, the relationships of oppiids are in great need of revision with many genera being arranged on the basis of potentially convergent characters. Mahunka himself recognised this in his description of N. mixoppia, expressing the opinion that it represented '? mixture of at least three present day " genera"'. The number of dorsal setae suggested one genus, the dorsosejugal teeth suggested another. Perhaps one day we'll know which is which.

REFERENCE

Mahunka, S. 1978. Neue und interessante Milben aus dem Genfer Museum XXV. On some oribatids collected by Dr. P. Strinati in Guatemala (Acari: Oribatida). Acarologia 20 (3): 133–142.

Pond Turtles of Asia

In an earlier post on this site, I discussed some members of the tortoise family Testudinidae. In popular depictions, the terrestrial tortoises are commonly associated with arid deserts and Mediterranean climes, where rains are sparse and water bodies few. But tortoises are exceptional in this regard among the order Testudines, members of which are more generally aquatic. As an example, consider the closest relatives of the Testudinidae, the pond turtles of the Geoemydidae.

Southern river terrapin Batagur affinis, copyright Eng Heng Chan.


Members of the Geoemydidae (historically referred to in many publications as the Bataguridae) are commonly referred to as the Asiatic pond turtles and it is in southern and eastern Asia that they are most diverse. However, they are also found in Europe and northern Africa, and a single genus Rhinoclemmys is found in northern South America. About 65 or 70 species are recognised in the family, making them quite diverse as turtles go. Many geoemydids are colorfully patterned and some can reach reasonably large sizes. The northern river terrapin Batagur baska, for instance, may grow up to two feet in length and close to twenty kilograms in weight.

Black-breasted leaf turtle Geoemyda spengleri, copyright Heather Paul.


A phylogenetic analysis of the Geoemydidae by Hirayama in 1984 lead to the suggested division of the geoemydids between two subfamilies, the Geoemydinae and Batagurinae. The two subfamilies were primarily distinguished by the extent of development of the secondary palate and hence the width of their jaws, with the Batagurinae having a more extensive secondary palate and broader jaws than the Geoemydinae. Batagurines were also generally more aquatic and more herbivorous than the semi-terrestrial, more omnivorous geoemydines. Hirayama also suggested that the geoemydines might be paraphyletic to the Testudinidae (Spinks et al. 2004). More recent phylogenetic analyses have supported geoemydid monophyly, placing them as sister rather than ancestral to Testudinidae (Spinks et al. 2004; Guillon et al. 2012). They have also supported a clade including the majority of Hirayama's batagurines, excluding only the genus Siebenrockiella. However, Hirayama's geoemydines have not been supported as monophyletic; instead, the Neotropical Rhinoclemmys represents the sister group of the Old World geoemydids. This is not entirely surprising; comparison with other turtle families indicates that the narrow-jawed 'geoemydine' condition is primitive among turtles. As a result, the Batagurinae is no longer recognised as a distinct subfamily.

Golden coin turtle Cuora trifasciata, copyright Torsten Blanck.


Unfortunately, the Asian species of pond turtle are currently facing a conservational crisis. The majority of species are regarded as endangered, many critically so, due to threats such as habitat loss and hunting for food. Some species, most notably the golden coin turtle Cuora trifasciata, are targeted for use in Chinese medicine because why wouldn't they be? Many geoemydid species have been bred in captivity but this is also not without issues. In the case of the golden coin turtle, there is the all-too-common issue that even when farmed individuals are available they are not seen as being as valuable as wild-caught specimens. Also, because the gender of hatchlings is determined by incubation temperature, farmed clutches are skewed almost entirely towards females, requiring the continued harvesting of wild males. Many geoemydid species hybridise readily. During the period from 1984 to 1997, no less than thirteen new species of geoemydid were described from China, most on the basis of specimens purchased from a single pet dealer in Hong Kong (Parham et al. 2001). Many of these specimens were of uncertain origin. Searches for further specimens in reported localities for some species failed to provide results, and queries to local residents revealed that they had never seen such turtles. At least some of these supposed new species have since been identified as hybrids, probably produced in captivity, and the status of others remains questionable.

REFERENCES

Guillon, J.-M., L. Guéry, V. Hulin & M. Girondot. 2012. A large phylogeny of turtles (Testudines) using molecular data. Contributions to Zoology 81 (3): 147–158.

Parham, J. F., W. B. Simison, K. H. Kozak, C. R. Feldman & H. Shi. 2001. New Chinese turtles: endangered or invalid? A reassessment of two species using mitochondrial DNA, allozyme electrophoresis and known-locality specimens. Animal Conservation 4: 357–367.

Spinks, P. Q., H. B. Shaffer, J. B. Iverson & W. P. McCord. 2004. Phylogenetic hypotheses for the turtle family Geoemydidae. Molecular Phylogenetics and Evolution 32: 164–182.

Mystery Fungus

For this week's semi-random taxon, I drew the fungal genus Trichangium. Unfortunately, there's not much I can say about this one. The single species of this genus, Trichangium vinosum was described by German mycologist Wilhelm Kirchstein in 1935 in a volume of the journal Annales Mycologici to which I don't have access (there are other volumes of this journal available at archive.org but seemingly not this one). The original collection was found growing on bark of a pear tree. Since then, Kirchstein's species seems to have gone largely unrecognised. I could find no further records under this name and recent synopses of ascomycete genera (e.g. Lumbsch & Huhndorf 2010) list it incertae sedis in the order Helotiales. Helotiales are mostly minute fungi with cup-shaped fruiting bodies that most commonly grow as saprobes on organic substrates such as fallen logs or humus.

Fruiting body of Unguiculella robergei, copyright Abel Flahaut.


However, in 1962 the British mycologist Richard Dennis noted that Kirchstein's description of Trichangium vinosum bore a close resemblance to another bark-living fungus, Unguiculella robergei, and suggested that the two might be the same species. Unguiculella robergei is itself a very rare fungus, otherwise only known from a handful of records in France and Scotland, seemingly all in the month of April (see MycoDB). It has been recorded from bark and dead twigs of mistletoe and roses, producing dark red, disk- or cup-shaped fruiting bodies less than a millimetre in diameter. These fruiting bodies are covered with small glassy hairs; the hooked shape of these hairs was presumably the inspiration for the genus name meaning a small claw or nail. It is possible, of course, that this fungus is more common than realised: with something this small, you need to be looking for it.

REFERENCE

Dennis, R. W. G. 1962. New or interesting British Helotiales. Kew Bulletin 16 (2): 317–327.

Lumbsch, H. T., & S. M. Huhndorf. 2010. Myconet volume 14. Part One. Outline of Ascomycota—2009. Part Two. Notes on ascomycete systematics. Nos 4751–5113. Fieldiana: Life and Earth Sciences, N.S. 1: 1–64.

Getting Your Diatoms in a Row

Diatoms are one of the world's primary groups of aquatic unicellular algae. Perhaps only the cyanobacteria rival them for ecological significance. They play a crucial role in the production and fixation of nutrients on which other organisms depend.

Colony of Melosira moniliformis attached to some sort of weed, copyright Frank Fox. The last individual seems to have suffered some unfortunate bisection.


Diatoms live protected in a siliceous test or, to put it another way, they really do live in glass houses. The test is composed of a pair of opposed valves; as noted by Round & Crawford (1990), the arrangement of valves is commonly compared to that of a Petri dish. The valves themselves do not overlap directly in the manner of a Petri dish, but a series of girdle bands around the edge of each valve does overlap. Diatoms come in a range of shapes and structures (artistically minded microscopists [or microscopically minded artists, however you wish to phrase it] have been known to create kaleidoscopic patterns through the careful arrangement of diatoms on a slide) and have commonly been divided between two major groups on the basis of the main symmetry of the valves. Centric diatoms have valves that are radial in appearance when viewed from above whereas pennate diatoms have elongated, more bilateral valves.

Melosira is a widespread genus of centric diatoms found in both fresh and salt water. It might be considered the classic centric: the test is circular in dorsal view and rectangular in side view so the overall shape is that of a hat box. Individual cells remain united by pads of mucilage following division, resulting in the formation of long chains. Species of the genus differ in their preferred habitats. One freshwater species, Melosira varians, is commonly found in polluted or poor quality waters. Conversely, a marine species M. arctica is the most abundant algal species known from the Arctic Ocean, responsible for nearly half the Arctic's primary production. Diatoms lack flagella for most of their life cycle (only their gametes are ever flagellate) so they are not active swimmers. In life, they are either found attached to a substrate or, if floating as planktonic, suspended in the water column by turbulence. One species, M. italica, is known to survive in sediment during quiescent periods of the year and resume growth when winter turbulence returns it to the light (Round & Crawford 1990).

Auxospores of Melosira varians, copyright Kristian Peters.


When diatom cells divide, each daughter cell receives one of the parent's original test valves and secretes a new valve to match it. As noted above, the marginal girdles of the valves overlap, and the new valve is always secreted as the inner partner of this overlap. As a result, and because the glass valves cannot change in size once secreted, successive generations of diatom cells become inexorably smaller over time. Obviously, this process cannot continue indefinitely least the cells dwindle to extinction, so sexual reproduction plays a vital role in resetting the process of diatom development. Centric diatoms like Melosira produce distinct gamete types, motile spermatozoids and immobile eggs (in contrast, many pennate diatoms produce only a single gamete type with no such distinction). Zygotes produced from the fusion of these gametes grow into a cell called an auxospore that differs from normal diatom cells in possessing a organic cell covering instead of solid glass valves. This organic covering may be reinforced with individual siliceous scales, but some Melosira auxospores remain contained and protected within the valves of their parent and lack scales of their own (Medlin & Kaczmarska 2004). The auxospore will not produce a uniform glass test until it has reached full mature size; in Melosira this initial test differs from the standard in being globular rather than pillbox-shaped. The auxospore will then begin dividing into daughter cells in the usual well which will themselves produce test valves of the standard shape. But each of the auxospore's daughters, of course, will receive one of it's initial valves, so as the Melosira chain develops it will remain hemispherical at each end.

REFERENCES

Medlin, L. K., & I. Kaczmarska. 2004. Evolution of the diatoms: V. Morphological and cytological support for the major clades and a taxonomic revision. Phycologia 43 (3): 245-270.

Round, F. E., & R. M. Crawford. 1990. Phylum Bacillariophyta. In: Margulis, L., J. O. Corliss, M. Melkonian & D. J. Chapman (eds) Handbook of Protoctista. The structure, cultivation, habitats and life histories of the eukaryotic microorganisms and their descendants exclusive of animals, plants and fungi. A guide to the algae, ciliates, foraminifera, sporozoa, water molds, slime molds and the other protoctists pp. 574–596. Jones & Bartlett Publishers: Boston.

How the Worm Turns (Into a Worm)

Those of you who have suffered through some of my posts on turrids may recall me discussing the subject of how differences in the mode of development of marine organisms relate to their classification. Features that were once considered of high significance are affected by whether the animal develops as a free-swimming larva or is nourished by a yolk supply provided in the egg, and may change more readily than previously thought. And indeed, it turns out that there are some cases where both developmental modes can be found in a single species.

Boccardia polybranchia, from here.


Boccardia is a genus of twenty-odd species of marine worm belonging to the family Spionidae. These are sedentary worms, living in tubes that they construct for themselves out of sediment bound together by mucus, or that they bore into substrates such as mollusc shells or coral. Boccardia and other spionids have a pair of long palps extending from the head that they use for feeding, sweeping them around to gather up detritus and such. Boccardia differs from other genera in the Spionidae in having branchiae (vascularised appendages that function as gills) starting on the second segment of the body, and two differentiated spine rows on the fifth segment with falcate spines in the upper row and bristle-tipped spines in the lower row (Williams 2001).

One of the best-studied Boccardia species is B. proboscidea, a species about one or two centimetres in length found around various parts of the Pacific, including along the western coast of North America. Boccardia proboscidea is very catholic in its habitat preferences: it can be found in the intertidal or shallow subtidal zones, and anywhere from mudflats to rubble to reefs to burrowed into the shells used by hermit crabs (Gibson et al. 1999). It also shows the aforementioned variation in larval development: some individuals hatch as small larvae and live and feed as plankton, others feed on the yolks from nurse eggs and don't hatch until they reach a more advanced stage of development. Whichever way the individual develops, the resulting adult seems to be more or less the same.

Nevertheless, it would be fair to wonder if this variation is as it appears. Combine the variation in development with the variation in habits, and you might wonder whether two or more morphologically similar species are being confused. However, not only are the adults of each larval type completely interfertile, but differently developing individuals may even come from a single egg case. Gibson et al. (1999) compared individuals of this species from two widely separated populations both morphologically and genetically, and found that while there were some differences between the populations, there was little or no difference between developmentally distinct individuals within each population. How and why this developmental variation is maintained seems to be an open question but there is some evidence that other spionids may show the same plasticity. After all, it doesn't matter how you get there, so long as you get there.

REFERENCES

Gibson, G., I. G. Paterson, H. Taylor & B. Woolridge. 1999. Molecular and morphological evidence of a single species, Boccardia proboscidea (Polychaeta: Spionidae), with multiple development modes. Marine Biology 134: 743–751.

Williams, J. D. 2001. Polydora and related genera associated with hermit crabs from the Indo-West Pacific (Polychaeta: Spionidae), with descriptions of two new species and a second polydorid egg predator of hermit crabs. Pacific Science 55 (4): 429-465.

Sweat Bees

For many people, the common domestic honey bee may be the only bee species that they are aware of. In fact, bees are incredibly diverse, with well over 17,000 species known worldwide (and counting). Not all bees live in social hives like honey bees: the majority are solitary, with individual females each constructing their own nest and stocking it with food stores for their young. One particularly diverse group of bees is the Halictinae.

Foraging Lasioglossum, copyright Beatriz Moisset.


Halictines are mostly small bees, sometimes referred to as 'sweat bees' owing to the predilection of many species for lapping up sweat from the skin of hot humans and other animals (a habit that, while generally harmless, can be rather annoying). They can be distinguished from other bees by a distinctive curve at the base of the basal vein in the forewing. Michener (2007) recognised two tribes within the Halictinae, the cosmopolitan Halictini and the strictly Western Hemisphere Augochlorini. Augochlorins are often bright metallic in coloration; Halictini are less commonly so. Even among bee specialists, halictines can be notorious for the difficulties involved in trying to make sense of them. For instance, the cosmopolitan genus Lasioglossum alone comprises over 1300 known species, and having spent my own time attempting to identify bee specimens back in Australia I can confirm that there are times when it feels like all Lasioglossum, all the time. The majority of halictines construct their nests in burrows in soil; some species build in rotting wood.

Female Augochlora pura mosieri, copyright Bob Peterson.


The Halictinae are a particularly interesting group for studies of bee evolution because they include both solitary and social species. Indeed, some species may be either depending on circumstances. The most common nest type in Halictinae involves a long central tunnel with radiating side branches leading to globular brood cells. In most Augochlorini and species of the genus Halictus, however, the cells are arranged in a single cluster that is suspended within an underground cavity, held in place by earthen struts or by the rootlets of plants. The cells are lined with a protective waxy membrane rich in lactones, secreted by the builder from a gland near the base of the sting. Some species may be communal, with more than one female sharing a single burrow but each building and laying in its own cells (such communality is not necessarily a step on the road towards true sociality but may be a response to a shortage of good nesting opportunities). In social species, the queen is commonly not that different in appearance from associated workers, and if the queen dies the workers may begin producing eggs of their own (if, indeed, they were not already doing so while the queen was alive). Some species, though, may exhibit development of a distinct soldier or major class among the workers with massively enlarged heads and mandibles. In the Australian species Lasioglossum hemichalceum, there may be similarly large-headed males. These big-headed males also have reduced wings, rendering them flightless and bound to the nest. No more than one major male may be present in a colony; if another such male is present, the two will fight to the death. Unlike honey bees, halictine colonies do not often live for more than one season; instead, males and reproductive females usually mate near the end of the growing season, followed by the death of the males. The females hibernate over winter before beginning construction of their own nests the following spring.

Sphecodes albilabris, copyright Fritz Geller-Grimm.


In contrast, a number of halictine species, such as members of the genus Sphecodes, do not construct their own nests but instead lay their eggs in the nests of other bees. This behaviour, known as kleptoparasitism, has arisen in many bee lineages and is usually associated with a recurring set of evolutionary trends. Many kleptoparasites are closely related to their hosts: most kleptoparasitic halictines attack the nests of other halictines though some Sphecodes species mooch off bees in more distant subfamilies and families. Kleptoparasitic bees are commonly less hairy than their self-sufficient relatives, as they have little or no need of the pollen-carrying hairs used by other bees. Many kleptoparasites are more heavily armoured than other bees, to protect them against host resistance. Female Sphecodes have blunt spines on the outside of the hind tibia that may help them push into a host nest. Females of most kleptoparasitic halictines destroy the host egg in a nest cell before laying their own egg; in contrast, bees of other kleptoparasitic lineages usually leave the host egg undisturbed and it is the parasitic larva that executes the host. In most cases, the kleptoparasitic female abandons the nest once she has laid there, but in some species parasitising social hosts, the kleptoparasite may remain in the nest and inveigle herself into society there, continuing to enjoy the fruit's of her hosts' labours.

REFERENCE

Michener, C. D. 2007. The Bees of the World 2nd ed. John Hopkins University Press: Baltimore.