scholarly journals Optimality in a partitioned task performed by social insects

2008 ◽  
Vol 4 (6) ◽  
pp. 627-629 ◽  
Author(s):  
Martin Burd ◽  
Jerome J Howard
Keyword(s):  
Social Insects ◽  
Social Insect ◽  
Leaf Tissue ◽  
Leaf Fragment ◽  
Ant Colonies ◽  
Tissue Processing ◽  
Leaf Cutting ◽  
Laboratory Colonies ◽  
Atta Colombica ◽  
Behavioural Adaptations

Biologists have long been aware that adaptations should not be analysed in isolation from the function of the whole organism. Here, we address the equivalent issue at the scale of a social insect colony: the optimality of component behaviours in a partitioned sequence of tasks. In colonies of Atta colombica , a leaf-cutting ant, harvested leaf tissue is passed from foragers to nest workers that distribute, clean, shred and implant the tissue in fungal gardens. In four laboratory colonies of A. colombica , we found that the highest colony-wide rate of leaf tissue processing in the nest was achieved when leaf fragment sizes were suboptimal for individual delivery rate by foragers. Leaf-cutting ant colonies appear to compromise the efficiency of collecting leaf tissue in order to increase their ability to handle the material when it arrives in the nest. Such compromise reinforces the idea that behavioural adaptations, like adaptations in general, must be considered within the context of the larger entity of which they are a part.

scholarly journals Endophytic fungi reduce leaf-cutting ant damage to seedlings

2010 ◽  
Vol 7 (1) ◽  
pp. 30-32 ◽  
Author(s):  
L. S. Bittleston ◽  
F. Brockmann ◽  
W. Wcislo ◽  
S. A. Van Bael
Keyword(s):  
Leaf Area ◽  
Plant Communities ◽  
Endophytic Fungi ◽  
Cordia Alliodora ◽  
Neotropical Forests ◽  
Ant Colonies ◽  
Leaf Toughness ◽  
Leaf Tissues ◽  
Leaf Cutting ◽  
Atta Colombica

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high ( E high ) or low ( E low ) densities of endophytes. The E high seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the E low treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from E low relative to E high seedlings and had a tendency to recruit more ants to E low plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities.

scholarly journals Queen loss increases worker survival in leaf-cutting ants under paraquat-induced oxidative stress

2021 ◽  
Vol 376 (1823) ◽  
pp. 20190735 ◽  
Author(s):  
Megha Majoe ◽  
Romain Libbrecht ◽  
Susanne Foitzik ◽  
Volker Nehring
Keyword(s):  
Oxidative Stress ◽  
Social Insects ◽  
Worker Reproduction ◽  
Theme Issue ◽  
Leaf Cutting ◽  
Stress Oxidative ◽  
Myrmicine Ants ◽  
Atta Colombica ◽  
Acromyrmex Echinatior ◽  
Solitary Species

Longevity is traded off with fecundity in most solitary species, but the two traits are positively linked in social insects. In ants, the most fecund individuals (queens and kings) live longer than the non-reproductive individuals, the workers. In many species, workers may become fertile following queen loss, and recent evidence suggests that worker fecundity extends worker lifespan. We postulated that this effect is in part owing to improved resilience to oxidative stress, and tested this hypothesis in three Myrmicine ants: Temnothorax rugatulus, and the leaf-cutting ants Atta colombica and Acromyrmex echinatior . We removed the queen from colonies to induce worker reproduction and subjected workers to oxidative stress. Oxidative stress drastically reduced survival, but this effect was less pronounced in leaf-cutting ant workers from queenless nests. We also found that, irrespective of oxidative stress, outside workers died earlier than inside workers did, likely because they were older. Since At. colombica workers cannot produce fertile offspring, our results indicate that direct reproduction is not necessary to extend the lives of queenless workers. Our findings suggest that workers are less resilient to oxidative stress in the presence of the queen, and raise questions on the proximate and ultimate mechanisms underlying socially mediated variation in worker lifespan. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?’

scholarly journals Transcriptomic analyses of the termite, Cryptotermes secundus, reveal a gene network underlying a long lifespan and high fecundity

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Silu Lin ◽  
Jana Werle ◽  
Judith Korb
Keyword(s):  
Life History ◽  
Social Insects ◽  
Social Communication ◽  
Gene Network ◽  
Social Insect ◽  
Nutrient Sensing ◽  
Model Organisms ◽  
Termite Species ◽  
High Fecundity ◽  
Trade Off

AbstractOrganisms are typically characterized by a trade-off between fecundity and longevity. Notable exceptions are social insects. In insect colonies, the reproducing caste (queens) outlive their non-reproducing nestmate workers by orders of magnitude and realize fecundities and lifespans unparalleled among insects. How this is achieved is not understood. Here, we identified a single module of co-expressed genes that characterized queens in the termite species Cryptotermes secundus. It encompassed genes from all essential pathways known to be involved in life-history regulation in solitary model organisms. By manipulating its endocrine component, we tested the recent hypothesis that re-wiring along the nutrient-sensing/endocrine/fecundity axis can account for the reversal of the fecundity/longevity trade-off in social insect queens. Our data from termites do not support this hypothesis. However, they revealed striking links to social communication that offer new avenues to understand the re-modelling of the fecundity/longevity trade-off in social insects.

scholarly journals Ammonia Production by Streptomyces Symbionts of Acromyrmex Leaf-Cutting Ants Strongly Inhibits the Fungal Pathogen Escovopsis

2021 ◽  
Vol 9 (8) ◽  
pp. 1622
Author(s):  
Basanta Dhodary ◽  
Dieter Spiteller
Keyword(s):  
Fungal Pathogen ◽  
Closed Loop ◽  
Pathogenic Fungus ◽  
Ant Colonies ◽  
Strong Activity ◽  
Streptomyces Sp ◽  
Mutualistic Symbiosis ◽  
Leaf Cutting ◽  
Leucoagaricus Gongylophorus ◽  
Production Of Ammonia

Leaf-cutting ants live in mutualistic symbiosis with their garden fungus Leucoagaricus gongylophorus that can be attacked by the specialized pathogenic fungus Escovopsis. Actinomyces symbionts from Acromyrmex leaf-cutting ants contribute to protect L. gongylophorus against pathogens. The symbiont Streptomyces sp. Av25_4 exhibited strong activity against Escovopsis weberi in co-cultivation assays. Experiments physically separating E. weberi and Streptomyces sp. Av25_4 allowing only exchange of volatiles revealed that Streptomyces sp. Av25_4 produces a volatile antifungal. Volatile compounds from Streptomyces sp. Av25_4 were collected by closed loop stripping. Analysis by NMR revealed that Streptomyces sp. Av25_4 overproduces ammonia (up to 8 mM) which completely inhibited the growth of E. weberi due to its strong basic pH. Additionally, other symbionts from different Acromyrmex ants inhibited E. weberi by production of ammonia. The waste of ca. one third of Acomyrmex and Atta leaf-cutting ant colonies was strongly basic due to ammonia (up to ca. 8 mM) suggesting its role in nest hygiene. Not only complex and metabolically costly secondary metabolites, such as polyketides, but simple ammonia released by symbionts of leaf-cutting ants can contribute to control the growth of Escovopsis that is sensitive to ammonia in contrast to the garden fungus L. gongylophorus.

scholarly journals Mathematical Modelling on Avoidance-to- Acceptance Transition in Leaf Cutting Ant Colonies

2016 ◽  
Vol 9 (11) ◽  
Author(s):  
J. Amudhavel ◽  
C. Kodeeswari ◽  
S. Jarina ◽  
S. Jaiganesh ◽  
B. Bhuvaneswari
Keyword(s):  
Mathematical Modelling ◽  
Ant Colonies ◽  
Leaf Cutting

scholarly journals Oral transfer of chemical cues, growth proteins and hormones in social insects

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Adria C LeBoeuf ◽  
Patrice Waridel ◽  
Colin S Brent ◽  
Andre N Gonçalves ◽  
Laure Menin ◽  
...  
Keyword(s):  
Social Insects ◽  
Social Insect ◽  
Oral Fluid ◽  
Chemical Cues ◽  
Fluid Exchange ◽  
Camponotus Floridanus ◽  
Growth Development ◽  
Behavioral Maturation ◽  
Related Proteins ◽  
Complete Metamorphosis

Social insects frequently engage in oral fluid exchange – trophallaxis – between adults, and between adults and larvae. Although trophallaxis is widely considered a food-sharing mechanism, we hypothesized that endogenous components of this fluid might underlie a novel means of chemical communication between colony members. Through protein and small-molecule mass spectrometry and RNA sequencing, we found that trophallactic fluid in the ant Camponotus floridanus contains a set of specific digestion- and non-digestion related proteins, as well as hydrocarbons, microRNAs, and a key developmental regulator, juvenile hormone. When C. floridanus workers’ food was supplemented with this hormone, the larvae they reared via trophallaxis were twice as likely to complete metamorphosis and became larger workers. Comparison of trophallactic fluid proteins across social insect species revealed that many are regulators of growth, development and behavioral maturation. These results suggest that trophallaxis plays previously unsuspected roles in communication and enables communal control of colony phenotypes.

Dispersal of Miconia argentea seeds by the leaf-cutting ant Atta colombica

1998 ◽  
Vol 14 (5) ◽  
pp. 705-710 ◽  
Author(s):  
J. W. Dalling ◽  
Rainer Wirth
Keyword(s):  
Seedling Recruitment ◽  
Atta Cephalotes ◽  
Brazilian Cerrado ◽  
Atta Laevigata ◽  
Cerrado Vegetation ◽  
Brosimum Alicastrum ◽  
Leaf Cutting ◽  
Single Night ◽  
Local Recruitment ◽  
Atta Colombica

While leaf-cutter ants are thought to collect mainly vegetative plant material, they have also been observed collecting seeds or fruit parts on the forest floor (Alvarez-Buylla & Martínez-Ramos 1990, Kaspari 1996). For example, leaf-cutter ants have been observed carrying considerable numbers of Brosimum alicastrum Sw. and Cecropia spp. seeds into their nests (Wirth 1996) and Leal & Oliveira (1998; pers. comm.) found them foraging on the fruits and seeds of 19 different species of Brazilian cerrado vegetation, including six Miconia species. Under some circumstances, seed removal and relocation by leaf cutter ants might even be sufficient to affect local recruitment patterns of trees. For example, in Costa Rica, Atta cephalotes can remove all fallen fig fruit from beneath a Ficus hondurensis crown in a single night (Roberts & Heithaus 1986), while in Venezuela, seedling recruitment of the savanna tree Tapirira velutinifolia was positively associated with the seed harvesting and seed cleaning activities of the ant Atta laevigata (Farji Brenner & Silva 1996).

Size-related foraging behaviour of the leaf-cutting ant Atta colombica

1991 ◽  
Vol 69 (6) ◽  
pp. 1530-1533 ◽  
Author(s):  
Dave Shutler ◽  
Adele Mullie
Keyword(s):  
Body Size ◽  
Leaf Litter ◽  
Tree Species ◽  
Foraging Behaviour ◽  
Foraging Theory ◽  
Costa Rican ◽  
Leaf Cutting ◽  
Foraging Trail ◽  
Atta Colombica ◽  
Load Mass

In a Costa Rican forest adjacent to cattle pasture, larger individuals of the leaf-cutting ant Atta colombica carried heavier loads and foraged farther from the colony, as predicted by foraging theory. Counter to foraging theory, individual ants did not increase their load mass if they foraged farther from the colony. However, the colony avoided this apparent inefficiency by sending larger ants to more distant trees. The colony harvested simultaneously from several individuals of the same tree species, even though distant trees were twice as far from the colony as nearby trees. The reasons for this behaviour require further investigation. In a wide foraging trail, larger ants travelled faster than their smaller counterparts. In addition, ant velocity was reduced when loads were experimentally supplemented, and increased when loads were experimentally reduced. Ants using narrow trails in the leaf litter may all be constrained to travel at the same speed, irrespective of load or body size, simply because they get in each other's way.

Potential for Use of Erythritol as a Socially Transferrable Ingested Insecticide for Ants (Hymenoptera: Formicidae)

2020 ◽  
Vol 113 (3) ◽  
pp. 1382-1388 ◽  
Author(s):  
Meghan Barrett ◽  
Virginia Caponera ◽  
Cheyenne McNair ◽  
Sean O’Donnell ◽  
Daniel R Marenda
Keyword(s):  
Social Insect ◽  
Fire Ants ◽  
Dependent Manner ◽  
Agricultural Pests ◽  
Concentration Dependent Manner ◽  
Ant Colonies ◽  
Ad Libitum ◽  
Ant Control ◽  
Imported Fire Ants ◽  
Red Imported Fire Ants

Abstract Ants are significant structural and agricultural pests, generating a need for human-safe and effective insecticides for ant control. Erythritol, a sugar alcohol used in many commercial food products, reduces survival in diverse insect taxa including fruit flies, termites, and mosquitos. Erythritol also decreases longevity in red imported fire ants; however, its effects on other ant species and its ability to be transferred to naïve colony members at toxic doses have not been explored. Here, we show that erythritol decreases survival in Tetramorium immigrans Santschi (Hymenoptera: Formicidae) in a concentration-dependent manner. Access to ad-libitum water reduced the toxic effects of erythritol, but worker mortality was still increased over controls with ad-lib water. Foraging T. immigrans workers transferred erythritol at lethal levels to nest mates that had not directly ingested erythritol. Similar patterns of mortality following erythritol ingestion were observed in Formica glacialis Wheeler (Hymenoptera: Formicidae), Camponotus subarbatus Emery (Hymenoptera: Formicidae), and Camponotus chromaiodes Bolton (Hymenoptera: Formicidae). These findings suggest that erythritol may be a highly effective insecticide for several genera of ants. Erythritol’s potential effectiveness in social insect control is augmented by its spread at lethal levels through ant colonies via social transfer (trophallaxis) between workers.

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