Garden substrate preparation behaviours in fungus-growing ants

2007 ◽  
Vol 139 (6) ◽  
pp. 841-849 ◽  
Author(s):  
D.M. Mangone ◽  
C.R. Currie
Keyword(s):  
Fungal Pathogens ◽  
Food Source ◽  
The Other ◽  
Filamentous Bacteria ◽  
Fungus Garden ◽  
Substrate Preparation ◽  
Attine Ants ◽  
Leaf Cutting ◽  
Main Food Source ◽  
Fungus Growing Ants

AbstractFungus-growing ants (Hymenoptera: Formicidae: tribe Attini) engage in mutually beneficial symbioses with fungi (Basidiomycota) that serve as their main food source. The leaf-cutters (genera Acromyrmex Mayr and Atta Fabricius), the most derived attine ants, employ elaborate nest-hygiene behaviours, including substrate preparation. By preparing substrate prior to its incorporation into the fungus garden, workers facilitate the physical breakdown of leaf material while reducing the abundance of potentially harmful microbes that contact their fungal mutualist. Despite its importance in ant fungiculture, substrate preparation has not been investigated in other genera of fungus-growing ants. We examined substrate-preparation procedures used by five genera of fungus-growing ants (Apterostigma Mayr, Cyphomyrmex Mayr, Trachymyrmex Forel, Acromyrmex, and Atta) representing most of the phylogenetic range of the Attini. Behavioural observations revealed that all five genera engage in substrate-preparation behaviours. Furthermore, these behaviours vary by genus, with Trachymyrmex, Acromyrmex, and Atta engaging in more elaborate preparation behaviours than the other genera. Additionally, we found that during substrate preparation, leaf-cutting ants inoculate leaf fragments with actinomycetous bacteria. These filamentous bacteria are known to produce antibiotics that suppress fungal pathogens, which suggests that inoculation with the bacterial mutualist during substrate preparation helps protect the fungus gardens of leaf-cutter ants from these parasites. Our finding that substrate-preparation behaviours occur across the phylogenetic range of attine ants suggests that these behaviours are a critical component of successful fungiculture by ants.

scholarly journals BIOLOGICAL CONTROL IN LEAF-CUTTING ANTS, Atta sexdens (HYMENOPTERA: FORMICIDAE), USING PATHOGENIC FUNGI

2021 ◽  
Vol 45 ◽  
Author(s):  
Tarcísio Marcos Macedo Mota Filho ◽  
Luis Eduardo Pontes Stefanelli ◽  
Roberto da Silva Camargo ◽  
Carlos Alberto Oliveira de Matos ◽  
Luiz Carlos Forti
Keyword(s):  
Biological Control ◽  
Chemical Control ◽  
Pathogenic Fungi ◽  
Behavioral Changes ◽  
The Other ◽  
Fungus Garden ◽  
Atta Sexdens ◽  
Main Method ◽  
New Methods ◽  
Leaf Cutting

ABSTRACT Chemical control using toxic baits containing the active ingredient sulfluramid at 0.3% (w/w) is the main method for controlling leaf-cutting ants of the genera Atta and Acromyrmex. However, since 2009, when sulfluramid was included in Annex B of the Stockholm Convention on Persistent Organic Pollutants, there has been an intense search for new methods that are efficient in controlling these insects. Among said new methods, biological control using pathogenic fungi has shown promising results in laboratory conditions. The objective of this study, given the context presented, was to assess the potential of the fungi Beauveria bassiana and Trichoderma harzianum in controlling Atta sexdens. Colonies of A. sexdens were exposed to the fungi by means of formulated baits provided in a foraging chamber, or of suspensions sprayed on the fungus garden, and had their behavioral changes recorded for 21 days. For both formulations, concentrations of 10 and 20% (w/w) of the fungi being studied were used. The results allowed concluding that baits containing 10 and 20% (w/w) of the fungi B. bassiana and T. harzianum were not efficient in controlling colonies of A sexdens. On the other hand, spraying suspensions of 20% (w/w) of B. bassiana and 10% and 20% (w/w) of T. harzianum was efficient and resulted in 100% mortality of the colonies 11, 9 and 7 days after application, respectively. These findings indicate that the fungi B. bassiana and T. harzianum are promising as agents for the control of A. sexdens colonies, when sprayed on the fungus garden, although there are still some challenges as to their use related to the development of technologies for the application of the pathogen.

Dispersal of Schinus fasciculatus seeds by the leaf-cutting ant Acromyrmex striatus in a shrubland of the dry Chaco, Argentina

2003 ◽  
Vol 19 (1) ◽  
pp. 91-94 ◽  
Author(s):  
R. Omar Varela ◽  
Teresa C. Perera
Keyword(s):  
Seed Dispersal ◽  
Plant Material ◽  
Food Source ◽  
Different Types ◽  
Leaf Cutting ◽  
Fungus Growing Ants

Ants are important agents of seed dispersal and they can play a fundamental role in the establishment and survival of plants (Beattie 1985). Leaf-cutting or fungus-growing ants (Myrmicinae: Attini) are dominant elements of the ant fauna throughout the neotropics. They collect different types of vegetative and reproductive plant material that serve as substrate for underground fungus gardens,which are the only food source for their larvae (Stradling 1991).

Phylogenetic analysis of mutualistic filamentous bacteria associated with fungus-growing ants

2005 ◽  
Vol 51 (6) ◽  
pp. 441-446 ◽  
Author(s):  
Matías J Cafaro ◽  
Cameron R Currie
Keyword(s):  
Phylogenetic Analysis ◽  
Morphological Type ◽  
Phylogenetic Position ◽  
Bacterial Cells ◽  
Filamentous Bacteria ◽  
Attine Ants ◽  
Dense Membrane ◽  
Transmission Electron ◽  
The Family ◽  
Fungus Growing Ants

The attine ant–microbe system is a quadripartite symbiosis, involving a complex set of mutualistic and parasitic associations. The symbiosis includes the fungus-growing ants (tribe Attini), the basidiomycetous fungi the ants cultivate for food, specialized microfungal parasites (in the genus Escovopsis) of the cultivar, and ant-associated mu tualistic filamentous bacteria that secrete antibiotics specifically targeted to suppress the growth of Escovopsis. In this study, we conduct the first phylogenetic analysis of the filamentous mutualistic bacteria (actinomycetes) associated with fungus-growing ants. The filamentous bacteria present on 3 genera of fungus-growing ants (Acromyrmex, Trachy myrmex, and Apterostigma) were isolated from 126 colonies. The isolated actinomycetes were grouped into 3 distinct morphological types. Each morphological type was specific to the ant genus from which it was isolated, suggesting some degree of host specificity. The phylogenetic position of the 3 morphotypes was estimated using 16S rDNA for representative strains. The 8 isolates of actinomycetes sequenced are in the family Pseudonocardiaceae (Actino mycetales) and belong to the genus Pseudonocardia. Transmission electron microscopy examination of the actino mycete associated with the cuticle of Acromyrmex sp. revealed bacterial cells with an outer electron-dense membrane, consistent with actinomycetes in the genus Pseudonocardia. Ant-associated Pseudonocardia isolates did not form a monophyletic group, suggesting multiple acquisitions of actinomycetes by fungus-growing ants over their evolutionary history.Key words: actinomycetes, Pseudonocardia, phylogeny, mutualism, attine ants.

Direct ingestion of plant sap from cut leaves by the leaf-cutting ants Atta cephalotes (L.) and acromyrmex octospinosus (reich) (Formicidae, Attini)

1976 ◽  
Vol 66 (2) ◽  
pp. 205-217 ◽  
Author(s):  
M. Littledyke ◽  
J. M. Cherrett
Keyword(s):  
Plant Material ◽  
Atta Cephalotes ◽  
Fungus Garden ◽  
Acromyrmex Octospinosus ◽  
Substrate Preparation ◽  
Fungus Culture ◽  
Large Numbers ◽  
Leaf Cutting ◽  
Laboratory Colonies ◽  
Reduced Drinking

AbstractIngestion of radiolabelled plant juices from cut surfaces of leaves during foraging and during substrate preparation for the fungus garden was demonstrated for laboratory colonies of the leaf-cutting ants Atta cephalotes (L.) and Acromyrmex octospinosus (Reich). Using P32 isotope, up to one-third of the radioactivity in the leaves was taken in directly by the colony as a whole, but this was much less when C14 was used. Additional plant material was taken in by the ants via the fungus garden. Large numbers of ants spend time in investigating cut surfaces of leaves and also in cutting and crimping leaves. Ingestion of plant material during these processes could play an important nutritional role in the colony and this may explain why many ants return from foraging apparently unladen. Large ants obtained most of their plant juice intake during foraging and the medium and small ants took much of theirs during substrate preparation. Inhibitory chemicals did not affect cutting but they reduced drinking and also reduced the intake of P32 from leaves during substrate preparation. The ants also ingested different amounts of P32 from leaves of different acceptability. It is suggested that leaf-cutting ants use fungus culture as a means of ‘sidestepping’ plant inhibitors. Nutrients are ingested directly from leaves when these are palatable, and the less palatable components are made available to the ants via the fungus.

scholarly journals Community structure of fungal pathogens causing spikelet rot disease of naked oat from different ecological regions of China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Longlong Liu ◽  
Mingchuan Ma ◽  
Zhang Liu ◽  
Lijun Zhang ◽  
Jianping Zhou
Keyword(s):  
Fungal Pathogens ◽  
The Other ◽  
Qinghai Province ◽  
Naked Oat ◽  
Ecological Regions ◽  
Yield And Quality ◽  
Spray Inoculation ◽  
Grain Yield And Quality ◽  
Rot Disease ◽  
Grain Surface

AbstractSpikelet rot disease (SRD) is an emerging disease of the grain surface of naked oat in China that affects both grain yield and quality. The typical symptom is discoloration from the black structures of the causal fungi. Here, we investigated the fungal communities on the grain surfaces of cultivar Bayou 13 grown in ten ecological oat-producing regions of China, to identify the main pathogens of naked oat SRD. Our results showed that the growth of Alternaria spp. and Davidiella spp. exhibited a competitive relationship and was mainly affected by the elevations of all 10 ecological regions. The dominant pathogens were Davidiella spp. in Shannan Prefecture in Tibet and Haidong Prefecture in Qinghai Province and Alternaria spp. in the other eight regions. The ratios of black pathogens of interest to all pathogens in Shannan Prefecture and Haidong Prefecture were significantly lower than those of the other eight regions, thus indicating that SRD mainly occurred in regions below 2000 m (elevation). We isolated black fungal pathogens from grain surfaces and deduced that they were Alternaria spp. by sequence comparison. The blackened appearance of the grain surfaces was more evident under spray inoculation with a spore suspension of Alternaria than under the control in greenhouse experiments. The recovered pathogen was the same as the pathogen used for inoculation. We thus concluded that Alternaria alone causes naked oat SRD and mainly infects naked oat in regions below 2000 m, which provides a basis for the recognition and management of SRD of naked oat.

Performance and microbial dynamics in the coarse pore filtration activated sludge process at different SRTs (solids retention times)

2003 ◽  
Vol 47 (12) ◽  
pp. 73-80 ◽  
Author(s):  
M.R. Alavi Moghaddam ◽  
Y. Guan ◽  
H. Satoh ◽  
T. Mino
Keyword(s):  
Microbial Population ◽  
The Other ◽  
Activated Sludge Process ◽  
Filamentous Bacteria ◽  
Microbial Dynamics ◽  
Effluent Quality ◽  
Solids Retention ◽  
Microbial Population Dynamics ◽  
Operation Pressure ◽  
Filter Clogging

In this research, three SRTs (about 10, 30 and 75 days (without wasting the sludge except for sampling)) were applied to three reactors equipped with non-woven and coarse pore filter modules. The flux was adjusted to about 1 m/d during operation. The main objective of the study was to compare the performance and microbial population dynamics under different SRTs in this process. The results of reactors with SRTs of about 10 and 30 days have shown very good effluent quality without any clogging problem for more than 4 months of operation. For the reactor with long SRT (75 days), the filter clogging was observed after about 80 days of operation and caused an increase in the operation pressure and deterioration in effluent quality on some days. Excessive abundance of filamentous bacteria was observed in the reactor with SRT of about 10 days, which had the best effluent quality. According to the FISH results, type 021N was predominant in the reactor with long SRT, which had the clogging problem. On the other hand, other reactors (with SRTs of about 10 and 30 days) did not contain much type 021N, but some other filamentous bacteria dominated. Maximum EPS concentration (as mg/L) was observed in the reactor with long SRT. Also the abundance of two types of metazoa (Pristina sp. and tardigrades) was observed in the reactor with long SRT, which had the clogging problem and poor effluent quality.

scholarly journals Conditions Favoring Proliferation of Glycogen Accumulating Organisms for Excess Biological Carbon Removal in Treating Nutrient Deficient Wastewater

2017 ◽  
Vol 61 (3) ◽  
pp. 149 ◽  
Author(s):  
Andrea Jobbágy ◽  
Bernadett Kiss ◽  
Vince Bakos
Keyword(s):  
Activated Sludge ◽  
Continuous Flow ◽  
The Other ◽  
N Availability ◽  
Filamentous Bacteria ◽  
Severe Deficiency ◽  
And Performance ◽  
Experimental Stage ◽  
Activated Sludge Systems ◽  
P Sources

Impact of marginal availability and severe deficiency of nitrogen on the growth of glycogen accumulating organisms (GAOs) and performance of anaerobic/aerobic activated sludge systems treating nutrient deficient wastewater was investigated at marginal availability and severe deficiency of phosphorus. Two continuous-flow lab-scale systems were operated simultaneously fed by model winery wastewater, one with marginal availability and the other one at severe deficiency of nitrogen. In the second experimental stage, marginal availability of P was converted into severe deficiency by interrupting external dosing.Common practice of dosing N- and P-sources to marginal availability caused enhanced proliferation of filamentous bacteria leading to poor biomass settling and instable operation. At marginal N-availability accumulation of GAOs started when conditions became deficient for phosphorus. In severe lack of nitrogen GAOs overgrew filaments, and outcompeted phosphorous accumulating organisms (PAOs) initially present in the seed. Stable and good performance could be maintained even after withdrawal of phosphorous dosing.

scholarly journals Variability in Postharvest Decay Among Apple Cultivars

Plant Disease ◽  
1999 ◽  
Vol 83 (11) ◽  
pp. 1051-1054 ◽  
Author(s):  
R. A. Spotts ◽  
L. A. Cervantes ◽  
E. A. Mielke
Keyword(s):  
Botrytis Cinerea ◽  
Fungal Pathogens ◽  
Decay Resistance ◽  
The Other ◽  
Penicillium Expansum ◽  
Epidermal Layer ◽  
Apple Industry ◽  
Mucor Piriformis ◽  
Apple Cultivars ◽  
Potential Decay

The level of resistance to decay caused by four fungal pathogens, the force required to break the epidermis, and the extent of open sinuses as measures of potential decay resistance were determined for the fruit of several apple cultivars. No single cultivar was the most resistant to each of the four pathogens in this study. In addition, each cultivar that was the most resistant to one pathogen also was the most susceptible to one of the other pathogens. However, Royal Gala was the most resistant to the wound pathogens Botrytis cinerea, Penicillium expansum, and Mucor piriformis. Fuji and Oregon Spur II were more resistant than other cultivars to Pezicula malicorticis. The epidermis (skin) of Fuji and Granny Smith were the most resistant to puncture, requiring an average of 81.5 and 87.0 Newtons, respectively, to break the epidermal layer. Fuji had the highest percentage of fruits with open sinuses, with a mean of 38%, whereas Braeburn had 0% of fruit with open sinuses. The cultivar information presented herein may be a valuable measure of decay resistance and may be of use to the apple industry.

scholarly journals Chlorine-Susceptible and Chlorine-Resistant Type 021N Bacteria Occurring in Bulking Activated Sludges

2001 ◽  
Vol 67 (11) ◽  
pp. 5303-5307 ◽  
Author(s):  
M. A. Séka ◽  
Y. Kalogo ◽  
F. Hammes ◽  
J. Kielemoes ◽  
W. Verstraete
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Morphological Features ◽  
The Other ◽  
Filamentous Bacteria ◽  
Staining Techniques ◽  
Effect Of Chlorine

ABSTRACT Two filamentous bacteria causing bulking in two activated sludges were examined. Investigations using morphological features, staining techniques, and fluorescent in situ hybridization identified both filaments as type 021N. However, an examination of the effect of chlorine on the sludges revealed a chlorine-susceptible type 021N in one sludge and a chlorine-resistant type 021N in the other.

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