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Semiochemicals, 5-methyl-nonacosane, Alkanes, Chromatography.Ants are eusocial organisms with great relative abundance and species richness. Studies on these organisms are scarce, especially in the high altitude humid forest environments of the state of Ceará. In view of this condition, an evaluation of the chemical composition of cuticular hydrocarbons (CHCs) of the species Odontomachus bauri found and recorded for the first time in this study in the tropical forest of Maranguape was carried out, based on the hypothesis that different nests have different compositions of CHCs. For this purpose, collection incursions were carried out in the region to obtain individuals from three different nests. In the laboratory, the extraction of CHCs was performed by immersing the ants in hexane for 30 minutes. After removing the ants, the extracts were subjected to drying to assess the yield of the samples. Then, the extracts were subjected to a silica gel column, before performing an analysis by gas chromatography coupled with mass spectrometry. The chromatograms obtained were analyzed and demonstrated a great similarity, showing long-chain saturated hydrocarbons, mainly represented by alkanes and methyl-alkanes. 5-Methyl-nonacosane was the component with the highest relative abundance. Statistical analysis of similarity and correlation between samples was performed using non-parametric tests. These analyzes provided sufficient statistical evidence to confirm the existence of a strong positive correlation between the samples and also a significant difference in the composition of HCCs in two of the three paired analyzes performed, thus confirming the study hypothesis. Las hormigas son organismos eusociales con gran abundancia relativa y riqueza de especies. Los estudios sobre estos organismos son escasos, especialmente en los ambientes de bosque húmedo de altura del estado de Ceará. Ante esta condición, se realizó una evaluación de la composición química de los hidrocarburos cuticulares (CHCs) de la especie Odontomachus bauri encontrada y registrada por primera vez en este estudio en el bosque tropical de Maranguape, con base en la hipótesis de que diferentes nidos tienen diferentes composiciones de CHC. Para ello, se realizaron incursiones de recolección en la región para obtener individuos de tres nidos diferentes. En el laboratorio, la extracción de CHC se realizó sumergiendo las hormigas en hexano durante 30 minutos. Después de retirar las hormigas, los extractos se sometieron a secado para evaluar el rendimiento de las muestras. Luego, los extractos se sometieron a una columna de gel de sílice, antes de realizar un análisis por cromatografía de gases acoplada a espectrometría de masas. Los cromatogramas obtenidos fueron analizados y demostraron una gran similitud, mostrando hidrocarburos saturados de cadena larga, principalmente representados por alcanos y metil-alcanos. El 5-metil-nonacosano fue el componente con mayor abundancia relativa. El análisis estadístico de similitud y correlación entre muestras se realizó mediante pruebas no paramétricas. Estos análisis proporcionaron evidencia estadística suficiente para confirmar la existencia de una fuerte correlación positiva entre las muestras y también una diferencia significativa en la composición de los CHC en dos de los tres análisis pareados realizados, confirmando así la hipótesis del estudio. As formigas são organismos eussociais com grande abundância relativa e riqueza de espécies. Estudos sobre esses organismos são escassos, em especial nos ambientes de florestas úmidas de altitude do estado do Ceará. Tendo em vista essa condição, foi realizada uma avaliação da composição química dos hidrocarbonetos cuticulares (CHCs) da espécie Odontomachus bauri encontradas e, registradas pela primeira vez neste estudo, na floresta tropical de Maranguape, partindo da hipótese de que ninhos diferentes possuem diferentes composições de CHCs. Para tal, foram realizadas incursões de coleta na região para obter indivíduos de três diferentes ninhos. Em laboratório, foi realizada a extração dos CHCs por imersão das formigas em hexano durante 30 minutos. Após a remoção das formigas, os extratos foram submetidos à secagem para se avaliar o rendimento das amostras. Em seguida, os extratos foram submetidas à coluna de sílica gel, antes da realização de uma análise por cromatografia gasosa acoplada à espectrometria de massas. Os cromatogramas obtidos foram analisados e demonstraram uma grande similaridade, apresentando hidrocarbonetos saturados de cadeia longa, representados principalmente alcanos e metil-alcanos. O 5-metil-nonacosano foi o componente com maior abundância relativa. A análise estatística de similaridade e de correlação entre as amostras foi realizada por meio de testes não paramétricos. Essas análises forneceram evidência estatística suficiente para confirmar a existência de uma forte correlação positiva entre as amostras e, também, de uma diferença significativa na composição de CHCs em duas das três análises pareadas realizadas, confirmando assim, a hipótese do estudo.

Resumo. O estudo da atividade de forrageio diurno de Odontomachus bauri Emery (Hymenoptera: Formicidae) em um plantio de Eucalyptus sp. foi realizado na Fazenda Volta Redonda localizada no municipio de Volta Redonda, Rio de Janeiro. Para as observacoes foram demarcados tres ninhos distantes no minimo 50 m entre si. Estes foram monitorados alternadamente a cada 20 min., ao longo do dia no periodo de 6:00 h as 18:00 h totalizando 108 horas em nove dias no periodo de abril a agosto de 2015. As saidas dos ninhos foram mais frequentes no periodo da tarde (35%), e a chegada com recurso alimentar acontecia ao longo do dia com maior frequencia no periodo da manha. Dentre a diversidade dos itens coletadosestao insetos de varias ordens, sementes, folhas, flores e aranhas, demonstrando um ecletismo alimentar peculiar do genero. Os itens mais coletados foram pupas de insetos e sementes. A especie O. bauri apresentou um padrao de atividade similar ao ja descrito na literatura, entretanto, demonstrou maior atividade ao final da manha, acompanhando o aumento de temperatura. Daytime foraging of Odontomachus bauri Emery in eucalyptus plantation in the municipality of Volta Redonda, Rio de Janeiro State, Brasil Abstract. The study of Odontomachus bauri Emery (Hymenoptera: Formicidae) daytime foraging activity in a plantation of Eucalyptus sp. was conducted in the Farm Volta Redonda, located in the city of Volta Redonda, Rio de Janeiro State, Brazil. Three nests were marked for observations. The nests were distant more than 50 m apart. These were monitored alternately every 20 min. throughout the day in the period of 6:00 h to 18:00 h. In total, the nests were monitored by 108 hours. The outputs of the ants of the nests were higher in the afternoon (35%), but the arrival with some kind of food resources was happening throughout the day more often in the morning. Amongst the diversity of items collected by O. bauri are insects of various orders, seeds, leaves, flowers and spiders. The most collected items were pupae of insects and seeds. The activity of this species was positively affected by air temperature. Thus, O. bauri shown a generalist species with foraging activity at the end of the morning, accompanying the increase in temperature.

Climatic factors, such as temperature variation, interfere with the survival of insects. To respond to these variations, insects have some specific characteristics. These include water content of the body, thickness of the lipid layer, as well as the qualitative and quantitative characteristics of cuticular chemical components. This study hypothesizes that different ant species respond to temperature changes in different ways and that such differences may be associated with cuticle hydrocarbons (CHCs) and fatty acids. As model ant species, Atta sexdens, Odontomachus bauri and Ectatomma brunneum were used for experimental analyses. Ants were submitted to a water bath for 5 h at different temperatures, and their CHCs and fatty acids were identified and quantified, followed by correlating these chemical compounds with temperature variations and the survival. Temperatures below 30 °C did not affect the survival of the three species. E. brunneum had a higher percentage of survival at temperatures above 30 °C. O. bauri was the most sensitive species with 100% mortality at 40 °C. Survival was found to be unrelated to any of the identified fatty acids. However, CHCs underwent significant quantitative and qualitative variation, as shown by an increased percentage of CHCs with longer chain length of linear alkanes at temperatures above 30 °C. These increase enables these ants to maintain the integrity of their cuticle and survive at temperatures above 30 °C. It can be concluded that the forager ants studied respond differently to temperature variation and that changes in the conformation of CHCs are in line with the ecological characteristics of the different studied species because, they vary in terms of diurnal/nocturnal foraging and types of environments foraged. Among the three species, E. brunneum foragers were found to be more active under adverse conditions and more tolerant to temperature variation with the correspondingly appropriate changes in CHCs composition.

Ponerine ants are known to contain mixtures of pyrazines in their mandibular glands. We analyzed the mandibular gland contents of four ponerine species (Odontomachus chelifer, O. erythrocephalus, O. ruginodis, and O. bauri) by gas chromatography coupled with mass spectrometry, and found that each species contains specific mixtures of trisubstituted alkylpyrazines among other volatiles. Attempts to identify alkylpyrazines solely by mass spectral interpretation is unrealistic because spectra of positional isomers are indistinguishable. To avoid misidentifications, we synthesized a large number of reference compounds and compared their mass spectral and gas chromatographic properties with those present in the Odontomachus species under investigation. Most of the compounds identified were 2-alkyl-3,5-dimethylpyrazines. Interestingly, when the third substituent was an isopentyl group, the two methyl groups were found to be located at the 2 and 5 ring positions. Using our data, we recognized several misidentifications in previous publications.

Hymenoptera venoms constitute an interesting source of natural toxins that may lead to the development of novel therapeutic agents. The present study investigated the enzymatic and biological characteristics of the crude venom of the ant Odontomachus bauri. Its crude venom presents several protein bands, with higher staining for six proteins with gelatinolytic activity (17, 20, 26, 29, 43 and 48 kDa). The crude venom showed high proteolytic activity on azocasein at optimal pH 8.0 and 37 °C. In the presence of protease inhibitors as aprotinin, leupeptin and EDTA, the azocaseinolytic activity was reduced by 45%, 29% and 9%, respectively, suggesting that the enzymes present in the crude venom belong to the three classes of proteases, with the serine proteases in greater intensity. The crude venom degraded the fibrinogen α-chain faster than the β-chain, while the fibrinogen γ-chain remained unchanged. In biological assays, O. bauri venom showed hemolytic and coagulant activity in vitro, and defibrinating activity in vivo. In addition, the venom showed antimicrobial activity against Staphylococcus aureus and Escherichia coli as well as antiparasitic activity on Toxoplasma gondii infection in vitro. In that sense, this study sheds perspectives for pharmacological applications of O. bauri venom enzymes.

Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s−1, with some swimming at absolute speeds >10 cm s−1. Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants.

Made available in DSpace on 2018-12-11T16:42:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-03-01 Symbiotic microorganisms are directly related to the ecological success of host insects, influencing many aspects of their biology. The present study is the first to investigate the microbiota associated with ants of the subfamily Ponerinae and aims to identify the bacterial midgut communities of Dinoponera lucida, Neoponera curvinodis, Pachycondyla striata, Odontomachus brunneus and Odontomachus bauri relied on culture-dependent technique, particularly 16S rRNA sequencing. The greatest species richness was observed in O. bauri, with 15 OTUs, followed by D. lucida with five OTUs, O. brunneus, with four OTUs, and N. curvinodis and P. striata, both with three OTUs. There were representatives of the phyla Actinobacteria, Proteobacteria, Tenericutes and Firmicutes, including the genera Bartonella, Mesoplasma, Mesorhizobium, Spiroplasma, Wolbachia and Serratia in the guts of the studied Ponerine ants. Spiroplasma and Mesoplasma were found to be prevalent in the studied ants and they were the only genera of bacteria found in more than one of the analyzed ant species suggesting they might be beneficial symbionts. The low microbial diversity observed given the predatory trophic habits of the species studied suggests that there is selection for these microorganisms, predominantly preserving symbionts with functional roles that are able to colonize this environment. It is also valid to infer that the identified bacteria are predominant in the gut and exhibit mutualistic functions that are important mainly for immunity, but also to reproduction and nutrition; moreover, a subset may be parasites that could have considerable impacts on the studied ants. Universidade Estadual de Santa Cruz Departamento de Ciências Biológicas Laboratório de Microbiologia, Rodovia Jorge Amado, Km 16, Salobrinho Universidade Estadual Paulista (UNESP) Universidade Federal do Tocantins (UFT) UESC Laboratório de Mirmecologia CEPLAC Universidade Estadual Paulista (UNESP)

The interactions of the antOdontomachus bauriwith nymphs of the sap-sucking bugXedreota tuberculata(Cicadellidae: Ledrinae) were studied onSipaneaaff. (Rubiaceae) along a trail in an upland forest in the Ecological Reserve of Anavilhanas, AM, Brazil. Five complete interactions at day and at night (about 60 minutes) were analyzed. The care of cicadelid nymphs ranged between 12 and 961 seconds.

We conducted ultrastructural studies to examine the presence of microorganisms in the midgut of the ant Odontomachus bauri (Ponerinae), as a contribution towards understanding the relationships between microorganisms and their hosts. The presence of microorganisms in this region, including inside the cells, suggests their participation in food digestion as symbiontic organisms and represent a new possibility to exploit food sources in the environment.

Extreme animal movements are usually associated with a single, high-performance behavior. However, the remarkably rapid mandible strikes of the trap-jaw ant, Odontomachus bauri , can yield multiple functional outcomes. Here we investigate the biomechanics of mandible strikes in O. bauri and find that the extreme mandible movements serve two distinct functions: predation and propulsion. During predatory strikes, O. bauri mandibles close at speeds ranging from 35 to 64 m·s −1 within an average duration of 0.13 ms, far surpassing the speeds of other documented ballistic predatory appendages in the animal kingdom. The high speeds of the mandibles assist in capturing prey, while the extreme accelerations result in instantaneous mandible strike forces that can exceed 300 times the ant’s body weight. Consequently, an O. bauri mandible strike directed against the substrate produces sufficient propulsive power to launch the ant into the air. Changing head orientation and strike surfaces allow O. bauri to use the trap-jaw mechanism to capture prey, eject intruders, or jump to safety. This use of a single, simple mechanical system to generate a suite of profoundly different behavioral functions offers insights into the morphological origins of novelties in feeding and locomotion.

The chemical contents of the mandibular glands of workers of eight species of ponerine ants have been analyzed and quantified. In three species (Ectatomma sp. from Brazil, Odontomachus bauri, and Pachycondyla striata) the contents were essentially a mixture of alkylpyrazines only. Three species (Odontoponera transversa, Pachycondyla indica, and Pachycondyla obscuricornis) contained a mixture of alkylpyrazines and oxygenated compounds and some simple terpenes; and the remaining two (Diacamma vagans and a Diacamma sp. from India) had only oxygenated compounds present. The two Diacamma species were notable in containing a dioxaspiroundecane (a spiroketal), not hitherto found in ants. All the 33 known mandibular gland analyses of workers of ponerine ant species have been brought together in order to seek some pattern in the type of glandular contents. Although the majority (24 species) produce alkylpyrazines, there is no observable pattern on a tribe or genus level.

About 85 different ant species were found nesting on coconut palms in Malaysia, the Philippines, Sri Lanka, Tanzania and Trinidad. Three occurred in all countries. With the exception of the leaf-nesting Oecophylla spp, all nested in leaf axils and spadices mostly between the two sheaths (spathes) and peduncle of the spadix. Up to eight species were found nesting in the same palm and five in the same spadix. In the latter circumstances the nest distribution of different non-dominant species is initially associated with the ‘height’ of available spaces, the smaller species nesting in the narrower, more distal end and the larger in the proximal end of the spadix. However, the small dominants, Pheidole spp and Wasmannia auropunctata, initially choose the large spaces in ageing spadices and leaf axils. In the spatially simple leaf axil the most striking association was between the small dominant Wasmannia auropunctata and the large ponerine Odontomachus bauri with W. auropunctata nesting below and between gall...

Measurements of oxygen consumption from ant colonies of various sizes of Odontomachus bauri, Camponotus rufipes and Zacryptocerus depressus showed a complex and nonlinear relationship between colony size and energy consumption per unit mass. Results show that at certain critical colony sizes, the colonies energy consumption is larger than the sum of the average energy requirement of the individually workers, and near maximal colony sizes, the energy consumption of the colony per unit mass tends exponentially to that of the average individual worker. We propose that social complexity is related to energy consumption in a discontinuous manner and is bound by both, negentropy content of a society and social optimization mechanisms.

Background Ant sting reactions are becoming an increasing problem in tropical countries. It is important for physicians to be aware of their possible cutaneous and systemic manifestations. Methods A child with a severe allergic reaction to an ant sting was examined and is discussed. This is the first case described in the literature caused by the ant Odontomachus bauri , and the biology of the ant and the clinical signs in the patient are described. Results A child developed a strong allergic reaction to an ant sting. The case was not associated with a previous ant sting. Treatment with the systemic antihistamine loratadine (Clarityn®) was favorable in this patient. Conclusions In tropical areas, ant stings are usually benign, self-limited pathologic processes. In some cases, however, severe allergic reactions can develop, including urticaria and anaphylactic shock. Physicians should be aware of the possible complications of ant stings.

Cryptococcus neoformans is the most common causative agent of cryptococcosis worldwide. Although this fungus has been isolated from a variety of organic substrates, several studies suggest that hollow trees constitute an important natural niche for C. neoformans. A previously surveyed hollow of a living pink shower tree (Cassia grandis) positive for C. neoformans in the city of Rio de Janeiro, Brazil, was chosen for further investigation. Odontomachus bauri ants (trap-jaw ants) found inside the hollow were collected for evaluation as possible carriers of Cryptococcus spp. Two out of 10 ants were found to carry phenoloxidase-positive colonies identified as C. neoformans molecular types VNI and VNII. The ants may have acted as a mechanical vector of C. neoformans and possibly contributed to the dispersal of the fungi from one substrate to another. To the best of our knowledge, this is the first report on the association of C. neoformans with ants of the genus Odontomachus.

The location and ultrastructure of bacteria associated with microvilli in the midgut of Odontomachus bauri were examined by transmission electron microscopy. These filamentous type bacteria are the second morphotype described in the midgut of this ant. They colonizes only the ectoperitrophic space, more specifically attaching along microvilli. A thick capsule attaches bacteria to microvilli and protect them from acidic pH and digestive enzymes. Details of the location and association with microvilli are discussed.

SUMMARYTrap-jaw ants of the genus Odontomachus produce remarkably fast predatory strikes. The closing mandibles of Odontomachus bauri, for example, can reach speeds of over 60 m s–1. They use these jaw strikes for both prey capture and locomotion – by striking hard surfaces, they can launch themselves into the air. We tested the hypothesis that morphological variation across the genus is correlated with differences in jaw speeds and accelerations. We video-recorded jaw-strikes at 70 000–100 000 frames s–1 to measure these parameters and to model force production. Differences in mean speeds ranged from 35.9±7.7 m s–1 for O. chelifer, to 48.8±8.9 m s–1 for O. clarus desertorum. Differences in species' accelerations and jaw sizes resulted in maximum strike forces in the largest ants (O. chelifer) that were four times those generated by the smallest ants (O. ruginodis). To evaluate phylogenetic effects and make statistically valid comparisons, we developed a phylogeny of all sampled Odontomachus species and seven outgroup species (19 species total) using four genetic loci. Jaw acceleration and jaw-scaling factors showed significant phylogenetic non-independence, whereas jaw speed and force did not. Independent contrast (IC) values were used to calculate scaling relationships for jaw length, jaw mass and body mass, which did not deviate significantly from isometry. IC regression of angular acceleration and body size show an inverse relationship, but combined with the isometric increase in jaw length and mass results in greater maximum strike forces for the largest Odontomachus species. Relatively small differences (3%) between IC and species-mean based models suggest that any deviation from isometry in species' force production may be the result of recent selective evolution, rather than deep phylogenetic signal.

Gorgona is one of the two insular areas of the Colombian tropical rain forest at the Pacific and is amongst the most diverse biogeographic regions of the world, the Choco. This study compiles information on ant species from published (1991) and unpublished (2006) studies and provides new records for ant species collected in 2010. Ants were sampled and information was obtained from 15 sites in Gorgona island (13.82km2), including the Gorgonilla atoll (0.49km2). Collecting methods included pitfall traps, tuna baits, mini-Winkler extraction of leaf litter, Malaise traps, entomological net and direct search. The soil and understory ant inventory resulted in 107 ant species and morphospecies, 46 genera in 12 subfamilies. Myrmicinae held the highest species richness (37 species), followed by Ponerinae (27) and Formicinae (12). The richest genera were Pachycondyla (15 species), Camponotus (nine) and Pheidole (eight), while 30 genera were represented by a single species. Twelve species were very common (both in distribution and time): Azteca sp., Atta cephalotes, Camponotus sericeiventris, Eciton vagans, Ectatomma goninion, Gnamptogenys annulata, Odontomachus bauri, Pachycondyla bugabensis, P. harpax, P. verenae, Paraponera clavata and Wasmannia auropunctata. Direct search was the most efficient method to collect diferent species and was responsible for 52% of the total species found. Compared to other Neotropical islands, Gorgona holds a suprisingly high number of ant species, none of them invasive. The invasive Monomorium floricola, which was collected 20 years ago, was not found in 2010. These evidences suggest that ecological mechanisms and natural recovery processes in the ecosystem have generated microhabitats allowing their coexistence. Rev. Biol. Trop. 62 (Suppl. 1): 265-276. Epub 2014 February 01.

Foraging behavior and partitioning of foraging areas ofOdonomachus bauriwere investigated on Barro Colorado Island in Panama. The activity of the ants did not show any daily pattern; foragers were active day and night. The type of prey captured byO. baurisupports the idea that in higherOdontomachusand Anochetus species, the high speed of mandible closure serves more for generating power than capturing elusive prey. Polydomous nests may enableO. bauricolonies to enlarge their foraging areas.

Ants of the ponerine genus Odontomachus have evolved a mechanism that allows them to instantaneously close their long mandibles to catch prey or defend themselves. This trap-jaw action is triggered by contact of trigger hairs with a potential prey item. Two of these long mechanosensory hair sensilla reside proximally on each mandible and are supplied by giant sensory cells.

The abilities of animals in movement and coor dination frequently surpass our own abilities and fascinate us. New record speeds found among ani mals, when recorded by the scientific literature, tend to be widely publicized. Such is the case of the trap-jaw ant, Odontomachus bauri Emery, whose mandibles close in 0.13 s at a rate of 35.5 meters per second (ms'1) during a predatory strike, the fastest movement recorded among all animals (Patek et al. 2006). The fastest tactile reflex time belongs to the star-nosed mole, Condylura cristata L., which uses 22 nasal appendages to navigate through soil and can react in just 120 ms, when one of these appendages comes in contact with food (Catania & Remple 2004). Here, I would like to report the startle reflex time in skipper butter flies, which is among the fastest recorded for the animal kingdom and which is at least twice as fast as startle eye-blink reflex of humans. Startle reflexes have evolved as fast defensive (usually escape) responses in animals, engaging subcortical reflex mechanism that bypasses cere bral processing and voluntary movement. Be cause circuits involved are shorter, the latencies of the startle reactions are much shorter than those of voluntary reactions. In terms of elec tromyographic responses recorded in vitro, acous tic startle reflexes tend to be very short. In rats, for example, electromyographic responses can be as fast as 5-10 ms, and in humans as fast as 14 ms (Yeomans & Frankland 1995). The actual behavioral responses recorded in vivo tend to be longer. For example, in the African butterfly fish, Pantodon buchholzi Peters, the fastest response time to an acoustic startle stim ulus recorded on an electromyogram is 5 ms. The fish's fins initiate a motion 10 ms later, hence with the possible reflex time (ballistic jump) ca. 15 ms (Starosciak 2008). The eye-blink reflex of humans elicited by an air puff is 30-50 ms (e.g., Halmagyi & Gresty 1983). Compared to that, voluntary reaction time to a visual 'go' signal in humans is around 150 ms (Brown et al. 1991), and it takes an average of 700 ms for a human driver to move the foot from the accelerator to the brake peddle after seeing a red light (Green 2000). Just like butterfly fish, skipper butterflies rely on jumping ballistic movements to evade preda tors, but they propel themselves through the air, not the water. They are, in fact, named for their quick, darting flight habits. They differ in several morphological characters from other butterflies (e.g., Ackery et al. 1999), most notably in having stockier bodies with stronger wing muscles. While photographing butterflies with a digital camera for several years, I have become convinced that skippers possess an extraordinary reflex time when startled by a photographic flash. Their star tle reflex is faster than I have observed in any other butterfly. Even though other butterflies and other insects are frequently startled by a photographic flash and flee after their picture is taken, their motor re sponse is normally slower than the shutter speed of the camera. Thus, even if they are startled by the flash, they appear still in photographs. Skippers, however, react so quickly to the flash, that their re action is frequently captured by the camera. In the specific camera settings I used in the photographs in Fig. 1, the shutter was open for 1/ 60 sec =17 ms. The flash, synchronized with the shutter, occurred during this time. During this ex posure time, skippers startled by the flash fre quently "jumped" into the air, and their image was captured in flight near the substrate. They tended to return to their original position imme diately, so that they appeared still to the human eye, and their jumping movement was captured only by the camera. In pairs of photographs (Fig. 1: A1-A2, B1-B2, and C1-C2), one individual was recorded in the act of "jumping" above the same plant when star tled repeatedly. These shots were captured by fir ing the camera with intervals of ca. 20 s. It was noted by previous studies that habituation (de cline and disappearance of response during repet itive stimuli) occur with other types of startle re flexes (Yeomans & Frankland 1995). I observed the same with the "jumping" skippers: if they did not escape after the first shot, their "jumping" re sponse ceased after 2-3 repeated firings of the flash (Fig. 1: C3, D2). These photographs illustrate the unique quickness of skipper reflexes among all the other insects that I have photographed. They document what might be one of the fastest reflex times (

Odontomachus bauri workers recognize conspecifics from other colonies and ants from different species as aliens. Colony specific recognition is based on endogenous odours, present in the different body parts. The chemicals responsible for these odours are volatiles, insoluble in water and soluble in CH2Cl2. No influence of the environment on the recognition signals could be detected. Evidence of intercolony differences in the relative proportions of the different volatile substances of cephalic and abdominal pheromones are presented. Thus, it is postulated that nestmate recognition is based on relative proportions of volatiles produced by the ant in different parts of the body. On the other hand, evidence of territorial defence is presented. Territorial pheromones, in case they exist in this species, are not necessary for recognition of territories, as is the case in other ant species. The possible relationship between nestmate recognition systems and territorial behaviour is discussed and an evolutionary hypothesis of their development is presented.