Monomorium Minimum Research Articles

Ants associated to prickly pear cactus crop in Texcoco, State of Mexico

In Mexico, center of domestication of prickly pear cactus species (also called “nopales”) few studies exist on insects associated with this crop. The studies are scantier on ants, since the majority are not considered to be pest. For this motive, the population dynamics of the ants was studied in experimental prickly pear crop in the installation of Colegio de Postgraduados, Mexico. The sample was fortnightly performed from February 2013 to March 2014. Ants were gathered with pitfall traps and arboreal traps, all of them with three baits and others without bait. Also recorded raiding, the nests in crop and inside to the cladodes. We collected a total of 10,953 individuals (74 % on ground and 26% on prickly pear cladodes), and seven species were determined: Hypoponera opacior (Forel), Neivamyrmex nigrescens (Cresson), Pogonomyrmex barbatus (Smith), Linepithema humile (Mayr), Camponotus atriceps (Smith), Pheidole obtusospinosa Forel and Monomorium minimum (Buckley). The last four were more abundant and frequent. We discuss the presence and nesting of ants in crop and their association with other insects of prickly pear crop.

Effect of agricultural land-use change on ant dominance hierarchy and food preferences in a temperate oak forest.

BackgroundThe discovery-dominance trade-off is the inverse relationship between the ability of a species to discover resources and the species’ dominance of those resources; a paradigm used to explain species coexistence in ant communities dependent on similar resources. However, factors such as stress (e.g., temperature) or disturbance (e.g., removal of biomass) associated with the change in land use, can modify this trade-off. Here, we aimed to determine the potential effects of land use change on dominance hierarchy, food preferences and on the discovery-dominance trade-off.MethodsAn experiment with baits was used to investigate the dominance hierarchies of ant communities in a temperate mountain habitat in central Mexico. We evaluated the dominance index (DI), food preferences and discovery-dominance trade-offs of ants inhabiting two types of vegetation: a native oak forest and agricultural land resulting from agricultural land use and grazing.ResultsThe ant communities in both environments were comprised of three species of ants (Monomorium minimum, Myrmica mexicana, and Camponotus picipes pilosulus), four morphospecies (Pheidole sp.1 and Pheidole sp.2, Temnothorax sp. and Lasius sp.) and one genus (Formica spp.). All Formicidae showed values of intermediate to low DI, and this factor did not seem to be influenced by the change in land use. Ants in the modified vegetation (i.e., agricultural land) were found to be numerically greater. Overall, a higher number of visits were registered to the tuna bait, although the duration of foraging events to the honey baits was longer. However, foraging times were dependent on the species considered: the generalized Myrmicinae, M. minimum, the ant species with highest DI, foraged for longer periods of time in the agricultural land and on the tuna bait. Meanwhile, the cold-climate specialist Formica spp., with a lower DI, foraged for longer periods of time in the oak (although not significant) and on the honey bait. We found little evidence of the discovery-dominance trade-off; instead, we found considerable diversity in the strategies used by the different species to access resources. This range of strategies is well represented by the generalized Myrmicinae M. minimum, the cold-climate specialists Formica spp. and Temnothorax sp., and the rare species, as the cold climate specialist Lasius sp. (insinuators).ConclusionsOur evaluation shows that transformation of the original habitat does not appear to affect the hierarchical dominance of the ant communities, but it does affect their food preferences. Species with higher DI values such as the generalized Myrmicinae are more skilled at resource acquisition in modified habitats. Our results suggest that change in land use promotes an increase in the diversity of foraging strategies used by different ant species. This diversity may contribute to resource partitioning which favors coexistence.

Freeze-Thaw Sample Preparation Method Improves Detection of Volatile Compounds in Insects Using Headspace Solid-Phase Microextraction.

Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) is commonly used in analyzing insect volatiles. To improve the detection of volatiles in insects, a freeze-thaw method was applied to insect samples before the HS-SPME-GC-MS analysis. Insect samples were first frozen at -80 °C for 10 min and then thawed at 25 °C for 5 min before SPME extraction was performed. The freeze-thaw method clearly improved the detection of volatile compounds for all six tested insect species, including red imported fire ants, Solenopsis invicta Buren, black imported fire ants, Solenopsis richteri Forel, little black ants, Monomorium minimum (Buckley), pharaoh ants, Monomorium pharaonis (Linnaeus), eastern subterranean termites, Reticulitermes flavipes (Kollar), and spotted lady beetles, Coleomegilla maculate De Geer. This method helped identify various volatile compounds in the tested insects which have never been reported previously. This improved method may facilitate the identification of insect derived volatiles such as insect semiochemicals.

Update on the defensive chemicals of the little black ant, Monomorium minimum (Hymenoptera: Formicidae)

Alkaloids, including 2,5-dialkylpyrrolidines and 2,5-dialkylpyrrolines, have been reported to be components in the venom of little black ants, Monomorium minimum (Buckley). Two fatty amines were recently reported as minor compounds. By analyzing the discharge collected from the stinger apparatus (milking), this study revealed the presence of an additional seven compounds in the defensive secretion of this ant species. Compounds identified were 9-decenyl-1-amine, N-methylenedecan-1-amine, N-methylenedodecan-1-amine, 2-(1-non-8-enyl)-5-(1-hex-5-enyl)-1-pyrroline, N-methyl-2-(hex-5-enyl)-5-nonanyl-1-pyrrolidine, β-springene ((E,E)-7,11,15-trimethyl-3-methylene-1,6,10,14-hexadecatetraene) and neocembrene ((E,E,E)-1-isopropenyl-4,8,12-trimethylcyclotetradeca-3,7,11-triene). β-springene and neocembrene were found only in the defensive secretion of queens. Analyses of the contents of isolated poison and Dufour's glands of the queen indicated that all amines and alkaloids were from the poison gland and that β-springene and neocembrene were from the Dufour's gland. This demonstrated that the defensive secretion in M. minimum queens consists of components from both glands. This is also the first report on the natural occurrence of 9-decenyl-1-amine, N-methylenedecan-1-amine, and N-methyllenedodecan-1-amine.

Species distribution models for natural enemies of monarch butterfly (Danaus plexippus) larvae and pupae: distribution patterns and implications for conservation

Prey populations can be strongly influenced by predators and parasitoids, and migratory prey whose distributions vary geographically throughout their breeding seasons encounter different combinations of predators and parasitoids throughout their range. North American monarch butterflies (Danaus plexippus) are susceptible to a wide variety of natural enemies, but the distribution of these natural enemies has not been quantified. We developed ecological niche models using environmental data to identify areas with suitable abiotic conditions for eight known natural enemies of monarchs, including six predators: Arilus cristatus, Harmonia axyridis, Monomorium minimum, Podisus maculiventris, Polistes spp., and Solenopsis geminata; and two parasitoids: Lespesia archippivora and Pteromalus cassotis. We combined correlated suitable areas for individual predators and parasitoids to identify regions with the most predator and parasitoid species potential. The Gulf Coast, West Coast, Florida, and parts of the eastern United States are predicted to have the most natural enemy species. We suggest that future research should assess monarch mortality rates in these areas, and that monarch conservation strategies consider pressure from natural enemies.

Fatty Amines from Little Black Ants, Monomorium minimum, and Their Biological Activities Against Red Imported Fire Ants, Solenopsis invicta.

Red imported fire ants, Solenopsis invicta, are significant invasive pests. Certain native ant species can compete with S. invicta, such as the little black ant, Monomorium minimum. Defensive secretions may contribute to the competition capacity of native ants. The chemistry of ant defensive secretions in the genus Monomorium has been subjected to extensive research. The insecticidal alkaloids, 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines have been reported to dominate the venom of M. minimum. In this study, analysis of defensive secretions of workers and queens of M. minimum revealed two primary amines, decylamine and dodecylamine. Neither amine has been reported previously from natural sources. Toxicity and digging suppression by these two amines against S. invicta were examined. Decylamine had higher toxicity to S. invicta workers than dodecylamine, a quicker knockdown effect, and suppressed the digging behavior of S. invicta workers at lower concentration. However, the amount of fatty amines in an individual ant was not enough to knockdown a fire ant or suppress its digging behavior. These amines most likely work in concert with other components in the chemical defense of M. minimum.

Improved method for preparation of anhydrous silica by microwave irradiation with spectroscopic characterization and toxicity assay

Amorphous anhydrous silica SiO2 (mw) (99.99%) is successfully synthesized through microwave irradiation technique and time of reaction is reduced up to 1h. The dehydration phase study of Si–water, Si–OH, Si–O–Si networking, elemental analysis and surface morphology was carried out by FTIR, FTNIR, SEM and EDAX spectroscopic techniques. The broad absorption stretching and bending of Si–OH and H2O at 3695.38–2832.96cm−1, 1638cm−1 and 1191.20–1017.14cm−1 completely disappeared and appearance of new bands at 946.93 and 797.63cm−1 confirmed the amorphous anhydrous silica with Si–O–Si networking. The SEM images of SiO2 (mwc) described the smooth and fine particle texture and confirmed 99.99% Si–O–Si networking of anhydrous silica. The 99.99% purity was verified by EDAX spectra which exhibited sharp signals only for oxygen and silicon. Toxicity against Monomorium minimum and Tribolium castaneum with 100% mortality and LT50 91min and 7.5h respectively is being reported. It can be used for long storage of grains in the future.

Caste-specific tyramides from Myrmicine ants.

Analysis of the extracts of male ants of Monomorium minimum and Monomorium ebeninum by GC-MS and GC-FTIR revealed the presence of tyramides 2 and 4c, for which the structures were established by comparison with synthetic samples. These compounds and their analogues 1 and 3 were also found in males of other Monomorium species, males of Myrmicaria opaciventris, and males of several Solenopsis (Diplorhoptrum) species. Vapor-phase FTIR spectra revealed critically important structural clues to two of the tyramides, which had methyl branching in the tyramide acyl moiety. Tyramide 4c exhibited a strong intramolecular amide NH hydrogen bond where an alpha-keto group was deduced to be present in the acyl moiety and also showed the overlap of this ketone group frequency with that of the amide nu(C horizontal lineO). The biological function of these compounds is uncertain; however, their role in ant-mating behavior may be suggested by a large body of evidence.

Composition and functional groups of epiedaphic ants (Hymenoptera: Formicidae) in irrigated agroecosystem and in nonagricultural areas

The objective of this work was to evaluate the species composition and functional groups of ants in nonagricultural (NA) and in irrigated areas (S, seasonal irrigation; P, irrigation with well water; W, irrigation with wastewater) in an arid agricultural region in central Mexico, throughout 2005 and 2006. A total of 52,358 ants belonging to 6 subfamilies, 21 genera and 39 species was collected using pitfall traps. The species best represented in all plots were: Forelius pruinosus, Pheidole obtusospinosa, Monomorium minimum and Dorymyrmex spp. NA plots recorded the highest density of ants. The highest values for diversity (H') and equitativity (J') were recorded in NA and P plots, while the lowest were recorded in W plots. Cluster analysis showed two different groups regarding species composition: NA-S and W-P. Functional groups recorded were: dominant Dolichoderinae, three species; subordinate Camponotini, five species; hot climate specialists, three species; tropical climate specialists, seven species; cold climate specialists, five species; cryptic species, one species; opportunists, six species; generalized Myrmicinae, nine species. Agricultural activity affects the structure of the ant community with epiedaphic forage, and the constant use of irrigation wastewater in conjunction with intense agricultural practices has negative effect upon species richness of epiedaphic ants.

The Initial Behavioral Sequences and Strategies of Various Ant Species During Individual Interactions with Solenopsis invicta

Abstract The flexibility in behavior and strategies used by ants is both individual and collective. Here, we studied the behavior of individual ants during one-on-one interactions to gain insight into how resident ant species behave when they encounter incipient red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae) colonies. The one-on-one interactions revealed that the red imported fire ant and Pheidole dentata (Mayr) were more “aggressive” compared with Solenopsis molesta (Say), Forelius pruinosus (Roger), Tetramorium bicarinatum (Nylander), Monomorium minimum (Buckley), and Monomorium pharonis (L.), which were more “defensive.” All of the species displayed “disturbed” behaviors such as excessive grooming, paralysis, and restlessness after being in contact with red imported fire ant. The apparent disparity in one-on-one interactions between a particular species and red imported fire ant illustrates how variation in these behavioral strategies can influence their success in defending themselves against red imported fire ant. The ant species tested also displayed a sequential behavior during the interaction, in which, certain subsequent behaviors were dependent on the preceding behaviors.

Reproductive biology of two species of Canavalia DC. (Fabaceae)—A non-conventional wild legume

The reproductive biology of two important species of Canavalia, i.e. Canavalia gladiata and Canavalia virosa, was investigated in detail by studying floral phenology, floral biology including fruit and seed set, breeding system and pollinator's activity. Both the species flower and set their seed primarily from August to December. The study of pollen–-pistil interaction indicated the existence of morphological protandry in both species, and pollen germination occurred only after rupture of the stigmatic surface. This suggests that some form of self-incompatibility operates in these species. Ants were the common vectors tripping the stigma and transporting some foreign pollen. Campylomma verbasci (large black ants) were only seen on the flowers of C. virosa, while Monomorium minimum (small black ants) were restricted to the flowers of C. gladiata. Inadequacy of reliable pollinators and high rate of bud/flower drop may be the main factors for low fruit and seed set in both the species.

Effect of Ant Attendance by <I>Monomorium minimum</I> (Buckley) (Hymenoptera: Formicidae) on Predation and Parasitism of the Soybean Aphid <I>Aphis glycines</I> Matsumura (Hemiptera: Aphididae)

Ant attendance is known to affect the population dynamics of aphids and may increase or decrease aphid populations through stimulation, predation, or protection. In this study, we performed a series of laboratory experiments to examine the effects of ant attendance on populations of the soybean aphid Aphis glycines. Aphid colonies were exposed to the predators Harmonia axyridis (Coccinellidae) and Orius insidiosus (Anthocoridae) and a parasitoid Aphidius colemani (Aphidiidae) in the presence and absence of attending Monomorium minimum (Formicidae). We also tested for direct effects of ant attendance in the absence of natural enemies. Ants attending soybean aphid populations were observed harassing or killing O. insidiosus and H. axyridis. Attendance interfered with both predator species, resulting in reduced predation and an increase in aphid numbers up to 10-fold in the presence of ants. Ants were not observed directly interfering with the parasitoid A. colemani, but the number of parasitized aphids was higher in aphid colonies that were left unattended by ants.

Occurrence of antennal glands in ants

A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals are connected to spherical reservoirs in queens. T. bicarinatum was the only non-Solenopsis species examined, which showed evidence for antennal glands in the distal funiculus.

Distribution of Hybrid Imported Fire Ants (Hymenoptera: Formicidae) and Some Native Ant Species in Relation to Local Environmental Conditions and Interspecific Competition in Mississippi Forests

Studies of interactions between imported fire ants and other ant species (Hymenoptera: Formicidae) have generally addressed populations in open areas where imported fire ant densities are highest. Forest habitats harbor a different assemblage of ant species and interactions between ant species in forests are occurring under different environmental conditions. We have asked three questions about the distribution of hybrid imported fire ants and native ant species in a Mississippi forest: 1) Is their distribution influenced primarily by interspecific competition or by local conditions? 2) Are the communities at locations with and without hybrid imported fire ants different? and 3) Which native ant species are using the same resources as hybrid imported fire ants? To answer these questions, ant species were collected at baits, along with the metrics for a set of local conditions, over a representative sample of forest habitats. Data were analyzed using permutation tests comparing the observed characteristics of the ant community to those expected by random processes. The community of ant species collected at baits was not structured competitively and their distribution was strongly associated with the distribution of local conditions. The assemblage of ant species was different at locations with hybrid imported fire ants from the assemblage at locations without them, but the two groups of locations were equal in richness when samples were standardized by rarefaction. Of the 28 species collected, 14 occurred with hybrid imported fire ants. One species, Aphaenogaster carolinensis Wheeler, was negatively associated, and another, Monomorium minimum (Buckley), was positively associated with hybrid imported fire ant occurrence.

Effects of Interspecific Competition Between Two Urban Ant Species, Linepithema humile and Monomorium minimum, on Toxic Bait Performance

We evaluated the effects of interspecific competition on ant bait performance with two urban pest ants, the Argentine ant, Linepithema humile (Mayr), and the little black ant, Monomorium minimum (Buckley). In a laboratory study, the impact of a solid sulfluramid bait on M. minimum was diminished when L. humile were present, whereas the presence of M. minimum reduced the performance of a liquid fipronil bait against L. humile. Argentine ants were not adversely affected by sulfluramid bait at any time, whereas M. minimum was unaffected by fipronil bait until 14 d of exposure. In field studies measuring diel foraging activity, M. minimum seemed to delay L. humile foraging to food stations by approximately 30 min during summer 2001. However, L. humile subsequently recruited to food stations in very high numbers, thereby displacing M. minimum. L. humile visited food stations over an entire 24-h period, whereas M. minimum was only observed visiting food stations during daylight hours. Adjusting the timing of bait placement in the field may minimize any negative effects of interspecific competition between these two species on toxic bait performance.

Timing bait applications for control of imported fire ants (Hymenoptera: Formicidae) in Mississippi: Efficacy and effects on non-target ants*

An experiment was conducted to assess the efficacy of mid-day (11:00 – 13:00 h) and late evening (18:00 – 20:00 h) broadcast bait (Seige Pro®, 0.73% hydramethylnon) applications against black and hybrid imported fire ants (Solenopsis richteri Forel and S. richteri × invicta, respectively) and their impact on native ant species. It was hypothesized that evening bait applications would have less impact on native ant species that slow or cease foraging at night relative to mid-day applications. Bait was applied to a series of plots in northeastern Mississippi, USA, in summer of 2002 and 2003. Population densities and foraging activity of imported fire ants and native ants were compared between treated and control plots. Population density and foraging activity of imported fire ants were equally suppressed in plots receiving mid-day and evening broadcast bait applications. Population density of Monomorium minimum (Buckley), the little black ant, approached zero in treated plots during 2003 but remained relatively high in untreated control plots. Species richness declined in treated plots with no difference between mid-day and evening bait application. These data indicate that evening bait application offers no advantage over mid-day application in terms of preserving some native ant species.

Ability of Resident Ants to Destruct Small Colonies ofSolenopsis invicta(Hymenoptera: Formicidae)

The ant Solenopsis invicta Buren has spread across the United States and is reported to have significantly reduced the diversity of the native ants. Much of this spread is occurring on land that has been repeatedly disturbed by continually changing land use practices. S. invicta seems to outcompete and eliminate other resident ant species. However, this inference may not be true because several resident native ant species are known to persist in S. invicta-infested areas. Thus, in this study, we analyze the aggressive interaction between selected resident ants and S. invicta by evaluating whether some of these ants are capable of attacking small worker-defended S. invicta colonies or are instead attacked by the S. invicta colonies. Our results suggest that the native ant species Monomorium minimum (Buckley), Pheidole dentata Mayr, and Solenopsis molesta (Say) and exotic tramp ants Tetramorium bicarinatum (Nylander) and Monomorium pharonis (L.) do interact with the S. invicta and will attack and eliminate worker-defended S. invicta colonies of varying sizes ranging from 30 to 480 workers. M. minimum, P. dentata, S. molesta, T. bicarinatum, and M. pharonis also were observed to prey upon S. invicta brood once most of the defending workers were eliminated. The native species Forelius sp. was not observed to invade the S. invicta colonies; instead, it prevented S. invicta workers from leaving their nest to forage, which may have contributed to the decline of S. invicta colonies of up to 60 workers over time.

Circadian and Circannual Patterns of Activity and Territory Shifts: Comparing a Native Ant (<I>Solenopsis geminata</I>, Hymenoptera: Formicidae) with Its Exotic, Invasive Congener (<I>S. invicta</I>) and Its Parasitoids (<I>Pseudacteon</I> spp., Diptera: Phoridae) at a Central Texas Site

Abstract We studied the phenologies of phorid flies from the genus Pseudacteon; their host, the native tropical fire ant (TFA), Solenopsis geminata (F.); a second native ant, Monomorium minimum (Buckley); and the non-native red imported fire ant (RIFA), Solenopsis invicta Buren, at a site in Austin, TX. We took a census on an hourly basis from dawn until dusk once a month for a year (July 1998–June 1999). Previous studies have focused largely on the RIFA’s escape from natural enemies (e.g., phorid parasitoids) as an explanation for the ant’s competitive success. Here, we show that the RIFA has additional advantages over its native congener. We found the RIFA had a significantly greater association than the TFA with extremes in ambient temperature, relative humidity, and light levels. However, M. minimum was found at temperatures that were significantly higher than for the RIFA. Native TFA-specific phorids had activity patterns that were similar to their host’s. In addition, we documented the expansion of ...

Conservation of biodiversity in an area impacted by the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae)

A conservation study was conducted at Camp Swift, Bastrop County, Texasto determine if the red imported fire ant, Solenopsisinvicta, could be selectively managed to protect endemic antdiversity. The study site was deemed to be an area where S.invicta had recently invaded, and was still in the process ofexpanding its population. The study was conducted between 1998 and 2001, andresulted in significantly higher ant diversity in the area where S.invicta was managed by prescription bait treatments. The controlsite, which was not conserved, lost four endemic ant species during the test,while the treatment site had an increase in one species. This provides evidencethat S. invicta populations can be managed, but may notneed to be eliminated, to preserve ant diversity. New county records are givenfor Brachymyrmex depilis, Foreliusmccooki, F. pruinosus, Gnamptogenyshartmani, Monomorium minimum,Pogonomyrmex comanche, and Tetramoriumspinosum.

Abundance, Diversity, and Spatial Distribution of Ants (Hymenoptera: Formicidae) on Mixed-Grass Rangelands Treated with Diflubenzuron

Abundance of ants on mixed-grass rangelands was not significantly reduced by aerial applications of Dimilin 2 F, Dimilin 25 W, and Sevin 4-Oil. Ant diversity, measured by a probability of interspecific encounter index, temporarily declined in plots treated with Dimilin 25 W from 13 to 19 d after treatment. However, diversity immediately recovered the following week and no further declines were observed even at 349-356 d after treatment. Twenty species of ants were encountered at the experimental site. Lasius neoniger Emery; little black ant, Monomorium minimum (Buckley); thief ant, Solenopsis molesta (Say); odorous house ant, Tapinoma sessile (Say); and Formica neogagates Emery were the 5 most abundant species at 25.8, 20.1, 9.9, 7.6, and 7.5% of the total number of ants encountered, respectively. Spatial distribution of ant species on rangeland appeared to be soil related. Factor analysis of soil parameters (weighted for relative ant abundances) indicated associations between ant species and certain combinations of soil properties.