Sociobiology: Volume 45, Number 3, 2005

Feature Articles:


Termite Nest Structure and Impact on the Soil at the Radar Site, Embakasi, Kenya (Isoptera: Termitidae)

By J.P.E.C. Darlington

ABSTRACT


This project extends what was previously known about the Embakasi moundfield, which is on a shallow clay soil. Because of heavy grazing it was possible to see surface features of the soil that are interpreted as gilgai. Four large lenticular mounds that spanned the size range occurring at this site were trenched across the middle. Each contained a large nest of the fungus-growing termite, Odontotermes montanus. One young nest of the same species was completely excavated. The soil profiles, and especially the surface of the bedrock beneath the mounds, indicate that live termite nests have a great impact on soil structure and dynamics, and also on weathering processes at the surface of the rock beneath mounds.

KEY WORDS: Termitidae, Macrotermitinae, Odontotermes montanus clay, gilgai, weathering, fungus combs and chambers.

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Consequences of Harvester Ant Incursion into Urbanized Areas: A Case History of Sting Anaphylaxis (Hymenoptera: Formicidae)

By John H. Klotz, Justin O. Schmidt, Jacob L. Pinnas, & Stephen A. Klotz

ABSTRACT


Over a two-year period in Arizona, there were 237 reported cases of people stung by ants. Most of these cases were caused by harvester ants and native fire ants, which pose a significant health risk to a small percentage of the population who are allergic to their sting. We report a case of anaphylaxis in Tucson caused by a sting of Pogonomyrmex rugosus. In addition, due to the severity of their sting, harvester ants can also become a nuisance pest when they infest urban environments. A field survey and a phone survey of pest control companies in Tucson demonstrated the prevalence of harvester ants in residential areas. Increasing urbanization in the habitat of Pogonomyrmex species will lead to increasing numbers of serious reactions to their stings.

KEY WORDS: Pogonomyrmex, harvester ants, stings, allergic reaction, anaphylaxis.

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Effects of Resource Availability on Search Tunnel Construction by the Eastern Subterranean Termite, Reticulitermes flavipes (Isoptera: Rhinotermitidae)

By Nicola T. Gallagher & Susan C. Jones

ABSTRACT


The effect of food availability on tunnel construction was assessed in the laboratory during a 15-day period for three colonies of Reticulitermes flavipes. Termites were introduced into arenas with food continually present, food continually absent, or food removed at day 8. Number and length of primary, secondary and tertiary tunnels were measured daily. Significant variability was observed among the three colonies in terms of the number of tunnels constructed. Although nonsignificant, secondary tunnels were the most numerous, followed by primary and tertiary tunnels. Treatments had no measurable effect on the numbers of tunnels and on primary tunnel length. However, termites without food tended to build longer secondary tunnels than termites with food (P ≤0.05). The most consistent response was that termites lengthened tertiary tunnels after food removal (P ≤0.05). Tertiary tunnels may have been the optimal foraging route due to the limited size of the foraging arena.

KEY WORDS: Reticulitermes flavipes, tunnel construction, food availability, search behavior.

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The Effects of Social Interaction of Reticulitermes speratus (Isoptera: Rhinotermitidae) on the Conidia-Mass Elongation of the Termite Exoparasitic Fungi Termitaria sp. (Deuteromycetes: Termitariales)

By Kiyoto Maekawa, Satoru Saito, & Masaru Hojo

ABSTRACT


The termite exoparasitic fungus Termitaria sp. sometimes has a protuberant mass on the surface of the sporodochium when found in isolated conditions. To investigate how termites eliminate the fungi from their body surfaces, we focused on this protuberant mass of Termitaria sp. on the Japanese subterranean termite Reticulitermes speratus. Based on morphological observations performed with the SEM and optical microscope, this mass was shown to be composed of conidia, which were connected to each other and intricately intertwined but easily divided into individual conidium. The growth of the conidia-mass after 48 hours of infected individuals isolated from or kept with nestmates was significantly different (P<0.01; Mann-Whitney U test). These results, together with the preliminary observations of the conidia in the foregut contents of non-infected workers kept with infected individuals, suggest that social interactions, such as grooming, play an important role in the elimination of the exoparasitic fungi from termite bodies. We also suggest that measurement of conidia-mass elongation is a useful index for estimation of social interactional effects on the exoparasitic fungi.

KEY WORDS: fungus, parasite, conidium, grooming.

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Morphological Embryonic Development of the Eastern Subterranean Termite, Reticulitermes flavipes (Isoptera: Rhinotermitidae)

By Xing Ping Hu & Yongyu Xu

ABSTRACT


This paper describes the morphological dynamics of the embryonic developmental process of Reticulitermes flavipes (Kollar). The embryo developed from an extremely short germ-type. Six distinctive successive stages were defined based on external characteristics of the developmental process: cleavage and blastoderm formation, formation of embryonic disc and band, elongation and segmentation, caudal flexure formation, revolution, and eclosion. The first visual embryonic rudiment was a germ-disc positioned at the posterior-convex region of the egg. The germ-disk elongation was accompanied by successive segment formation in an anterior-posterior sequence. The tail end of the embryonic band proceeded along the periphery around the posterior pole toward the anterior pole of the egg. Continuing elongation resulted in a characteristic double caudal flexure at the anterior pole of the egg. Revolvement (blastokinesis) occurred after the completion of segmentation. Two consecutive rotations were observed during the revolvement. The first rotation was an revolving movement of the embryo around the short axis, followed by the second rotation around the longitudinal axis of the egg. The dorsal surface of embryo closed upon the completion of the revolvement. During the entire embryonic developmental period, the embryo maintained a superficial position and never sank into the yolk mass. The rate of egg growth during early the development process, namely from egg deposition to larval eclosion, was measured. The phylogenetic relationship, according to embryonic development patterns, between Isoptera, Blattaria, and Orthoptera was discussed.

KEY WORDS: early developmental process, external morphology, R. flavipes, Isoptera.

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Esterase Activity in Apis mellifera After Exposure to Organophosphate Insecticides (Hymenoptera: Apidae)

By Valeria Maria Attencia, Maria Claudia Colla Ruvolo-Takasusuki, & Vagner de Alencar Arnaut de Toledo

ABSTRACT


Changes in the relative activity of A. mellifera esterases after application of different sublethal concentrations of the insecticides (methyl-parathion and malathion) in hives have been evaluated. Homogenates of adult workers were collected in experimental colonies 1, 7, 14 and 21 days after insecticide application. Horizontal electrophoresis was carried out on 14% corn starch gel using tris-HCl buffer (0.1M Tris) pH 7.5. The esters substrates 4-methylumbelliferyl and α-naphthyl were used. Sublethal exposition to the insecticides provides information on the ecological impact of these pesticides on the pollinators. Esterases 3 and 4 of A. mellifera from 1 to 14 days after insecticide application may be used as methyl-parathion and malathion bioindicators, since they reveal outstanding activity alterations when compared to the control.

KEY WORDS: Apis mellifera, esterases, methyl-parathion, malathion, electrophoresis.

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Continuous Monitoring of the Black Carpenter Ant, Camponotus pennsylvanicus (Hymenoptera: Formicidae), Trail Behavior

By Andrew B. Nuss, Daniel R. Suiter, & Gary W. Bennett

ABSTRACT


Capacitive proximity sensors were used to monitor Camponotus pennsylvanicus (DeGeer) foraging patterns. Datalogging computers recorded five min totals of the number of ants traveling past a point on a foraging trail at three field colonies from mid-June through October 1999. Air temperature, light intensity, humidity, precipitation, atmospheric pressure, and wind speed data were recorded and were regressed with nightly activity of each C. pennsylvanicus colony. Temperature was highly correlated with ant activity (r2 = 0.66 – 0.72). Night length (r2 = 0.06 – 0.13) and wind speed (r2 = 0.01 – 0.04) were also significantly correlated with ant activity. A distinct nightly pattern of activity of C. pennsylvanicus was detailed, and included peaks of activity at both dusk and dawn. The initiation of nocturnal foraging appeared to be closely related to light intensity. Daylight foraging activity was documented, though at much lower and unpredictable levels than night foraging.

KEY WORDS: ant, foraging, sensors, datalogger, electronic monitoring.

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Estimation of Wood Volume Losses by Heartwood Termites (Insecta: Isoptera) in Eucalyptus Plantations in the Brazilian Savannah

By Ronald Zanetti, Nélio Ricardo Amaral-Castro, Jair Campos Moraes, José Cola Zanuncio, Antônio Claret Oliveira, & Nívia Dias

ABSTRACT


Volume losses of heartwood by termites were estimated at 0.65 m3.ha-1 (1.60%) for Eucalyptus urophylla and 0.32 m3.ha-1 for Eucalyptus camaldulensis (1.17%). The equation with the best fit to estimate wood volume (Vc) of E. camaldulensis consumed by heartwood termites was based on tree diameter (DBH) (Vc= e(-8.2334 + 0.1131*DBH)) while the equation based on plant height (H) (Vc= e(-12.1271 + 0.3087*H)) was better for E. urophylla. Models with data based on diameter classes had better fits than those based on individual trees. Equations based on diameter at breast height (DBH) were similar for both eucalyptus species. The model used to estimate wood volume consumed (Vc= e(-8.4912 + 0.1485*DBH)) was adequate to express damage by heartwood termites as a function of tree diameter for both eucalyptus species.

KEY WORDS: Termitidae, Isoptera, eucalyptus, wood production, damage, heartwood termites.

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Response of Ant Communities to Sand Dune Vegetation Burning in Brazil (Hymenoptera: Formicidae)

By Marcos C. Teixeira, José H. Schoereder, Jaciara T. Nascimento, & Júlio N.C. Louzada

ABSTRACT


This study tests the hypothesis that ant species richness and composition change after burning sand dune vegetation in Brazil. We compared a periodically burnt plot with an unburned control plot, by sampling ants with baited traps and by hand collection. The control site presented higher species richness (31 species) than the burnt site (17 species). Species composition also changed: 27 species were exclusive to the control area, 13 species occurred only in the burnt area, while only four species were sampled in both areas. Species reduction in the burnt area may be considered a symptom of the environmental change caused by the destruction of vegetation and litter by fire. Some ant species, such as Pachycondyla stigma, Ectatomma muticum, Ectatomma permagnum and Atta robusta were severely affected by the fire, disappearing in the burnt area. On the other hand, Linepithema humile, which is described as an invader in several other ecosystems, appeared only in the burnt area. From the species affected by burning, we suggest the use of A. robusta as a bioindicator, as it builds conspicuous nests, is easily identified by the layman, and exhibits a clear response to fire.

KEY WORDS: bioindicators, disturbance, fire, Formicidae, restinga.

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Numerical Dominance of the Argentine Ant vs Native Ants and Consequences on Soil Resource Searching in Mediterranean Cork-Oak Forests (Hymenoptera: Formicidae)

By Jordi Oliveras, Josep M. Bas, David Casellas, & Crisanto Gómez

ABSTRACT


This study is focused on the dominance exerted by the invasive Argentine ant over native ants in a coastal Mediterranean area. The impact of this invasive ant on native ant assemblages and its consequences on total ant biomass and on the intensity of habitat exploration were evaluated. Foraging ants were observed and their trajectories recorded during 5-minute periods in two study zones, one invaded and the other non-invaded. Ant species detected, ant worker abundance, ant biomass and the intensity of soil surface searching done by ants were compared between the two zones. The Argentine ant invasion provoked a drastic reduction of the ant species richness. Apparently only one native ant species is able to coexist with the Argentine ant, the cryptic Plagiolepis pygmaea. Ant worker abundance was also modified after the invasion: the number of Argentine ant workers detected, which represented 92% of the invaded zone, was two times higher than the number of native ant workers detected in the non-invaded zone. The total ant biomass was inversely affected, becoming four times lower in the invaded zone highly dominated by Linepithema humile. The higher number of Argentine ant workers and their fast tempo of activity implied an alteration of the intensity of soil surface searching: scanning by the Argentine ants in the invaded zone was higher than that done by the native ants in the non-invaded zone, and the estimated time for a complete soil surface scan was 64 minutes in the invaded zone and 108 minutes in the non-invaded zone. Consequently, resources will be discovered faster by ants in the invaded zone than in the non-invaded zone. The increase of the mean temperature and the decrease of the relative humidity from May to August reduced the ant activity in the two study zones but this reduction was greater in the invaded zone.

KEY WORDS: Ant biomass, biological invasion, habitat exploration, Linepithema humile, Mediterranean region, numerical dominance.

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Structure of the Spermatheca in Five Families of Isoptera

By Ana Maria Costa-Leonardo & Gleiciani Bürger Patricio

ABSTRACT


The structure of the spermatheca was investigated in specimens of five termite families with the aid of light microscopy. In longitudinal section, the spermatheca of Zootermopsis nevadensis (Termopsidae) showed the shape of an umbrella with a secretory portion and duct. The other termite species, which belong to the families Kalotermitidae, Serritermitidae, Rhinotermitidae and Termitidae showed a spermatheca constituted only by the secretory portion. This structure was an elongate, fingerlike tube with a recurved and blind extremity. The spermatheca wall was composed of a single epithelium formed by class 3 secretory cells with a lumen lined by cuticle. The cuticle was thin and smooth or thick with digitiform projections in the species examined. All the termite females showed bundles of musculature outside of the spermatheca.

KEY WORDS: spermatheca, sperm storage, termite, reproductive system, histology.

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Plasticity and Specificity of Termite Nest Structure (Isoptera)

By Tetsushi Inoue, Yuichi Hongoh, Chirasak Klangkaew, Yoko Takematsu, Charunee Vongkaluang, Napavarn Noparatnaraporn, Moriya Ohkuma, & Toshiaki Kudo

ABSTRACT


Morphology, nest structure and phylogenetic relationships of the Microcerotermes termites in Thailand were examined. Termites were divided into four groups using the morphological measurements (head and mandible size) of the soldier caste. Of these, three were morphologically distinct and identified as M. annandalei, M. minutus and M. paracelebensis. The remaining morphospecies was morphologically similar to M. crassus but built three different types of nests, namely epigeal conical, epigeal domed and arboreal rounded nests. Phylogenetic analyses of 46 colonies of Microcerotermes using the mitochondrial cytochrome oxidase II (COII) gene suggested that the morphospecies was split into three distinct lineages. One of these, the lineage classified as M. crassus built both epigeal domed and arboreal nests, indicating plasticity of nesting behavior. The remaining two distinct lineages, both of which constructed epigeal conical nests, were considered to be two distinct species.

KEY WORDS: Isoptera, Thailand, Microcerotermes, morphology, termite nest structure, phylogenetic relationships.

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Comparison of Tunnel Geometry of Subterranean Termites (Isoptera: Rhinotermitidae) in “Two-dimensional” and “Three-dimensional” Arenas

By Paul Bardunias & Nan-Yao Su

ABSTRACT


Discovering the rules by which termites tunnel through soil and locate resources may allow for more efficacious treatment schemes to be devised. Many studies have made use of “two- dimensional” arenas, a thin later of soil sandwiched between transparent plates, in laboratory settings that might induce behavior that diverges from what occurs under natural conditions. In this study we made use of a novel “three-dimensional” arena to compare tunnels excavated in planar arenas with those not bound to a single plane. Our findings show no significant difference in tunneling values such as tunnel number, linear length, turn angles, and branching angles between these two arena types.

KEY WORDS: Isoptera, tunnel geometry, three-dimensional arena.

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Endosymbiont Biosynthesis of Norharmane in Reticulitermes Termites (Isoptera: Rhinotermitidae)

By Matthew S. Siderhurst, David M. James, Tamla D. Blunt, & Louis B. Bjostad

ABSTRACT


Although termites are known to contain the fluorescent alkaloid norharmane, the physiological distribution and biosynthetic origin of this compound has not previously been reported. Histological observations under UV light showed that norharmane is contained in the termite internal fluids. This is in contrast to the physiological distribution of norharmane in scorpions, in which the alkaloid is contained in the epicuticle. GC/MS analyses showed that norharmane is mainly located in the hemolymph with hemolymph removal causing the loss of all observable fluorescence in termite carcasses. GC/MS analyses further showed that norharmane was biosynthesized as a metabolite from endosymbionts cultured in isolation from Reticulitermes tibialis and R. flavipes termites. Actinomycetes bacteria are likely candidates as the endosymbionts that biosynthesize norharmane, because they are components of the termite gut and are the only microbes known to produce norharmane.

KEY WORDS: Isoptera, Reticulitermes, norharmane, endosymbiont.

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Wood Consumption Rates of Coptotermes formosanus (Isoptera: Rhinotermitidae): A Three-Year Study Using Groups of Workers and Soldiers

By Juan A. Morales-Ramos & M. Guadalupe Rojas

ABSTRACT


Wood consumption of Coptotermes formosanus Shiraki groups consisting of 200 workers and 50 soldiers was measured over time intervals of 2 mo at 27°C, 95% RH, at constant darkness for a period of 32 months. Consumption of wood was compared between termite groups feeding on yellow birch, Betula alleghaniensis Britton, and loblolly pine, Pinus taeda L. Wood consumption was significantly higher in the loblolly pine treatment, but the rate of decline of group wood consumption rates over time was not significantly different between treatments. Differences in consumption rate may have been due to differences in wood hardness rather than feeding preferences. Mean life span of termite groups was 518.3 ± 46.5 and 584.3 ± 51.1 days for the yellow birch and loblolly pine treatments, respectively. Approximately 30% of the termite groups exceeded a life span of 2 years; however, no termites differentiated into neotenic reproductives in any of the groups. Decline in wood consumption rates with group age fitted a negative linear model, which was used to estimate per capita wood consumption rates. Per capita wood consumption rates were estimated to be 86.9 ± 2.2 and 101.3 ± 1.2 μg/day for birch and loblolly pine food treatments, respectively.

KEY WORDS: Coptotermes formosanus, feeding, survival, neotenic reproductives, caste differentiation.

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A New South Vietnamese Species of the Genus Pheidole with a Truncated Head in the Major and Queen (Insecta, Hymenoptera, Formicidae)

By Katsuyuki Eguchi & Tuan Viet Bui

ABSTRACT


A new species of Pheidole Westwood, Pheidole aspidata sp. nov., is described from S. Vietnam. In contrast with the “normal-bodied” minor, the major and queen of this species are quite remarkable among Oriental species of the genus in having the truncated front of the head which recalls that of Pheidole colobopsis Mann from the Neotropics.

KEY WORDS: Ant, Pheidole aspidata, new species, Indo-china, truncated head.

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Tunnel Formation by Different Numbers of Eastern Subterranean Termites (Isoptera: Rhinotermitidae) in Laboratory Arenas

By Cynthia L. Tucker, Philip G. Koehler, & Faith M. Oi

ABSTRACT


Eastern subterranean termite, Reticulitermes flavipes (Kollar), workers in six groups of 30 to 1000 were introduced into arenas containing moist builder’s sand. In arenas containing low (30 to 125) termite numbers, 30 to 50% of the tunnel distance was constructed in 1 d, significantly less than the 72 to 83% of the tunnel completion in arenas with higher (250 to 1000) termite numbers. At test completion (14 d), the tunnel distance of 84.73 ± 7.86 to 140.02 ± 8.43 cm in arenas with low (30 to 125) termite numbers was significantly less than the tunnel distance of 198.00 ± 6.86 to 199.83 ± 11.87 cm in arenas with high (500 and 1,000) termite numbers. Doubling termite numbers did not result in a doubling of termite tunnel distance.

Regression analysis performed on tunnel distance recorded on days 1, 3, 7, and 14 for each termite number resulted in slopes that were significantly >0 except for arenas with 250 termites. Results indicated that the lower termite numbers (30 to 250) continued to tunnel at a greater rate and longer time.

The number of both primary and secondary tunnels at 14 d in arenas with 1000 termites (3.58 ± 0.24 and 3.19 ± 0.34, respectively) was significantly greater than in arenas with 30 termites (1.10 ± 0.70 and 1.00 ± 0.00, respectively). Overall, higher termite numbers within an arena increased in both number and diameter of primary and secondary tunnels. The tunnel network was constructed faster with high termite numbers (1000) and resulted in a 93% reduction in tunneling per termite compared with tunnel network construction at lower termite numbers (30). Higher termite numbers had higher survivorship but did not significantly affect the angle between the primary and secondary tunnel. Also, regardless of termite numbers fixed secondary tunnel angle efficiently divided the arena.

KEY WORDS: Reticulitermes flavipes, termite population, tunnel construction, secondary tunnel angle, tunnel diameter.

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Micromorphology of Modern Epigean Termite Nests and Possible Termite Ichnofossils: A Comparative Analysis (Isoptera)

By Marcela I. Cosarinsky, Eduardo S. Bellosi, & Jorge F. Genise

ABSTRACT


Fossil termite nests are an important line of evidence in understanding the origin and evolution of termite societies. However the reliability of attributions of trace fossils to termites has been uneven until now. Micromorphological features may be a powerful tool for comparisons between modern and fossil termite nests, particularly for the correct identification of the latter. However, micromorphological studies on modern species are scarce in the literature, and comparative analyses between modern and fossil material were lacking until now. Recent studies on micromorphological features in epigean nests of Neotropical species of termites, in addition to the previous information, enabled the possibility of listing and analyzing nine characters, which provide a first database for comparisons. Analyzed characters include: pellets, microstructure, size and sorting of coarse material, fine materials including types of birefringence fabrics and coatings and sinuous bands of fecal origin, clay microaggregates, relative distributions of fine and coarse components, plant remains, and fragments of termite cuticle. The usefulness of these micromorphological characters were tested in ichnofossils tentatively attributed to termites from the Eocene-Miocene Sarmiento Formation and from the Miocene Pinturas Formation in Patagonia, Argentina, and from the Paleogene Asencio Formation in Uruguay. The lack of some termitic characters in the ichnofossils, such as pellets, alteration of soil microstructure and in the frequency, granulometry and sorting of coarse components, plant remains, and fragments of termite cuticle, is interpreted as negative evidence. The presence in the ichnofossils of clay coatings and a circular striated birefringence fabric, the latter in all cases, is interpreted as evidence of soil diagenetic processes, instead of termitic evidence. Clay microaggregates, porphyric distribution of fine/coarse components, hypocoatings and sinuous bands of organic pigment are characters present in both modern termite nests and some or all of the ichnofossils analyzed. However, further analysis is necessary before these characters can be used as a definitive positive evidence of termitic activity/structures. The presence of sinuous bands of organic pigment in ichnofossils of the Sarmiento Formation, which are recorded from modern termite nests and are lacking in the bearing paleosol, can probably be related to the original presence of hypocoatings, which are also associated with fossil bee cells and coleopteran pupation chambers, and roots in modern soils. Clay microaggregates and porphyric distribution are also present in the surrounding paleosols, suggesting that the acquisition of them could have a non-termitic origin or on the contrary, as shown in modern tropical soils, the incorporation of abandoned termite nests to soils would have played an important role in the formation of these paleosols. In addition, such characters were also found in paleosols with no other termitic evidence, arguing against their termitic origin.

KEY WORDS: Micromorphology, termite nests, ichnofossils.

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Comparative Laboratory Efficacy of Noviflumuron and Diflubenzuron on Reticulitermes flavipes (Isoptera: Rhinotermitidae)

By J. Edward King, Joseph J. DeMark, & Amy J. Griffin

ABSTRACT


Noviflumuron and diflubenzuron are benzoylphenylurea chitin synthesis inhibitors used in termite bait systems for control of subterranean termites. In this paper we report comparative laboratory efficacy data between noviflumuron and diflubenzuron on the eastern subterranean termite, Reticulitermes flavipes (Kollar). Noviflumuron (0.5% bait concentration) and diflubenzuron (0.25%-0.5%) showed equivalent levels of feeding acceptance on cellulose bait; however, noviflumuron caused significantly faster and higher levels of mortality than diflubenzuron after 2-wk bait exposure in no-choice and choice feeding tests held under moderate temperature conditions (~21ºC). The commercial implications of this laboratory study suggest that against R. flavipes, noviflumuron would be faster acting and more robust than diflubenzuron under field baiting conditions.

KEY WORDS: Eastern subterranean termite, Reticulitermes flavipes (Kollar), Isoptera, Rhinotermitidae, benzoylphenylureas, chitin synthesis inhibitors, noviflumuron, diflubenzuron, termite baits.

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Survival and Growth of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae) on Various Types of Wood Used in Construction

By Ashok Raina & Christopher Florane

ABSTRACT


The Formosan subterranean termite, Coptotermes formosanus, is a serious pest of wooden structures and live trees in several southern states and Hawaii. We tested five types of wood and wood composites; spruce (Picea sp.), southern pine (Pinus sp.), redwood (Sequoia sempervirens), plywood and Oriented Strand Board (OSB) for survival and incipient colony formation by primary reproductives and, mortality and feeding by workers of C. formosanus. None of the primary reproductives survived on redwood and OSB. On the remaining three wood types, mortality ranged from 31.1% for pine to 48.9% for plywood. Mean number of progeny did not differ significantly between these three woods. Workers, on the other hand, survived on all the test woods, but mortality was highest (62.9%) for OSB and lowest for spruce (19.2%). Wood type and colony both had significant effect on consumption with the highest mean consumption recorded for spruce. The results indicate that redwood and OSB can not support the development of incipient colonies and also adversely affect worker survival thereby provide some degree of protection against subterranean termite damage.

KEY WORDS: Coptotermes formosanus, colony formation, survival, wood.

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Enzymatic Variability Among Venoms from Different Subspecies of Apis mellifera (Hymenoptera: Apidae)

By Márcia Regina Brochetto-Braga, Paulo Renato Marques De Lima, José Chaud-Netto, Alberto Arab, Giselly Pereira Da Silva, & Jeny Rachid Cursino-Santos

ABSTRACT


The enzymatic variability was analyzed in venom extracts from bees reared in different colonies of the Africanized, A. m. ligustica and A. m. carnica subspecies. The implications of this variation focused on the biochemistry differentiation and immunogenicity of these venoms. The results showed the existence of a huge variability among the subspecies as well as among the colonies for three out of the six tested components - hyaluronidase, acid phosphatase and proteases - suggesting the utilization of these features as possible biochemical markers. Furthermore, although not statistically significant, it was found that the Africanized bee venom presented slightly higher levels of protein content and esterase activity, when compared to the other subspecies. If the esterase plays a role in the pain intensity caused by the sting, as suggested elsewhere, this might suggest a reason for a bigger algogenicity of this venom in relation to that of European bees. On the other hand, A. m. ligustica bees presented the highest levels of proteolytic and acid phosphatase activities, whose functions are not enlightened in Hymenoptera venoms. The A. m. carnica workers presented the highest hyaluronidase and the lowest acid phosphatase activity levels. The extremely variable results among colonies of the same subspecies and among subspecies, for the tested venom components, justify the absence of correlation between allergic reactions and tests with pooled venom.

KEY WORDS: Apis mellifera, subspecies, honeybees, venom, enzymatic variability.

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Laboratory Evaluation of Subterranean Termite (Isoptera: Rhinotermitidae) Response to “Thermal Shadows” in an Environment of Homogenous Temperature

By L.E. Swoboda & D.M. Miller

ABSTRACT


Subterranean termites, Reticulitermes spp., from the state of Virginia were bioassayed in the laboratory to determine their preferred temperature range within a sand substrate. The mean preferred temperature for termite workers was 22.5ºC, with a range of 18-27ºC. Termites were also assayed to determine their behavioral response to spot locations of different temperature within an arena of homogeneous (ambient) temperature. These spot locations, or thermal shadows, were artificially created by placing a small heated or cooled reservoir on top of a bioassay arena in a specific location. This way the heating or cooling effects created a spot of different temperature within the arena which was held at ambient temperature. The ambient temperatures selected for testing were 20ºC and 25ºC. Both of these temperatures fell within the termites preferred temperature range. Both warm and cool thermal shadows were tested and shadow temperatures were selected from within and outside the termites preferred temperature range. Significantly more subterranean termites aggregated in the cool thermal shadows than in the ambient portions of the arena. When the ambient temperature of the arena was held at 25ºC significantly more termites aggregated in the cool thermal shadow (20ºC) than in the other portions of the arena (25ºC). When the ambient temperature was held at 20ºC significantly more termites aggregated within a cool thermal shadow at 15oC even though this temperature was outside the preferred temperature range. Subterranean termites did not respond to warm thermal shadows therefore the number of termites aggregating within the warm thermal shadow was not significantly different from those in the ambient portions of the arena.

KEY WORDS: Aggregation, Isoptera, Reticulitermes, Rhinotermitidae, temperature, termites, thermal shadows.

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Reduction of the Ant Mandible Gap Range After Biotic Homogenization Caused by an Ant Invasion (Hymenoptera: Formicidae)

By Jordi Oliveras, Josep M. Bas, & Crisanto Gómez

ABSTRACT


After most of the native ant species are displaced by the Argentine ant invasion, it is probable that some ecological processes carried out by natives are not replaced. In some cases this could be due to a morphological difference between the Argentine ant and the displaced native ants. The significant decrease in ant richness after the invasion (only two species detected in the invaded zones vs. 25 species in surrounding non-invaded zones) implies a drastic reduction in the ant mandible gap range (the mandible gap spectra of all the ant species in a community) in the invaded zones. This reduction could explain why some roles that were previously carried out by the displaced native species are not performed by the invasive species. This could be due to a functional inability to carry out these activities. The mandible gap was positively correlated with the ant body mass in the 26 ant species considered. The functional inability hypothesis could be applied to other invasive ants as well as to the Argentine ant.

KEY WORDS: Argentine ant, biotic invasion, functional inability, mandible gap, resource searching.

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Comparative Micromorphology of Arboreal and Terrestrial Carton Nests of the Neotropical Termite Nasutitermes aquilinus (Isoptera: Termitidae)

By Marcela I. Cosarinsky

ABSTRACT


Carton nests of Nasutitermes aquilinus show different micromorphologies in the walls of arboreal and terrestrial constructions. In arboreal nests, the walls are composed of thin, superposed laminae of fine organic matter, of fecal origin. In terrestrial nests and covered galleries adhered to the basal tree trunk, walls are composed of soil pellets molded in the buccal cavity surrounded by organic laminae, similar to those observed in arboreal nests. The fecal origin of these laminae was demonstrated by comparing their components with those of the worker’s hindgut content. The same materials are found in the coating of underground galleries.

KEY WORDS: termite nests, micromorphology, Nasutitermes aquilinus.

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Update on Taxonomy and Distribution of Isoptera from Argentina

By Gladys J. Torales, E.R. Laffont, M.C. Godoy, J.M. Coronel, & M.O. Arbino

ABSTRACT


The updated list of Isoptera from Argentina includes 31 genera and 81 species, belonging to Kalotermitidae, Rhinotermitidae, Termitidae and Termopsidae. The geographical distributions of the termite species, in 214 localities of 21 provinces, partially taken from literature, are indicated on maps. The collection sites and diet of the different species are also detailed.

KEY WORDS: distribution, Isoptera, Argentina, taxonomy.

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New Species and New Records of Scuttle Flies (Diptera: Phoridae) Associated with Army Ants (Hymenoptera: Formicidae) in Trinidad and Venezuela

By R. Henry L. Disney & Stefanie M. Berghoff

ABSTRACT


Host records for ten species of Phoridae recorded with Ecitoninae are presented, six being newly recorded hosts. Ecituncula berghoffae Disney n. sp. is described from Trinidad, E. glandularis Borgmeier is synonymized with E. inquirenda (Silvestri), and a revised key to the females of the subgenus Ecituncula is given. Lepidophoromyia labida Disney is transferred to the genus Thalloptera.

KEY WORDS: new species, new record, Phoridae.

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Fungal Communities of the Foraging Soil Sheeting Built by Several Fungus-Growing Termite Species (Isoptera, Termitidae: Macrotermitinae) in a Dry Savanna (Thičs, Senegal)

By M. Diouf, A. Brauman, E. Miambi, & C. Rouland-Lefèvre

ABSTRACT


Three different techniques were used to study the fungal population present in the foraging soil sheeting of three species of fungus-growing termites (Ancistrotermes guineensis, Macrotermes subhyalinus and Odontotermes nilensis) and in the neighboring soil in a dry savanna (Thičs, Senegal). The termite soil sheeting showed a significant increase in fungal density compared with the control soil. The structure of the fungal community of each sample obtained using plate count methods as well as Denaturing Gradient Gel Electrophoresis on rDNA 18S and rDNA 28S fragments was compared and is discussed. Although the structure and diversity of the fungal communities differ significantly depending on the technique used, the similarity dendograms obtained from the results using each of the three techniques showed the same sample groupings in all cases. The fungal communities of the biogenic structures were always closer to each other than they are to the control soil while the biogenic structures built by O. nilensis and M. subhyalinus were always closer to each other than to those built by A. guineensis.

KEY WORDS: Macrotermitinae, termite sheeting, fungal communities, culturable fungi, DGGE.

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Effects of Land Use on Ant Species Composition and Diaspore Removal in Exotic Grasslands in the Brazilian Pantanal (Hymenoptera: Formicidae)

By Marcio Uehara-Prado

ABSTRACT


The influence of pasture use intensity on ant-diaspore interactions was investigated in the Brazilian Pantanal. Ants were sampled using models of myrmecochorous diaspores placed in pastures with intensive and extensive use. The two types of pasture showed low ant species richness and high species similarity, suggesting that only a few species are able to persist in this simplified environment. Diaspore removal was higher in intensive use pastures, indicating a disturbance-related change in the interaction among ants and diaspores. The factors that may account for the observed pattern are discussed.

KEY WORDS: biological indicators, Brachyaria humidicola, pasture, seed dispersal.

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Diversity Patterns in Termite Communities: Species-Area Relationship, Alpha and Beta Diversity (Isoptera: Termitidae)

By Carla Galbiati, Og DeSouza, & José H. Schoereder

ABSTRACT


Several processes may generate the relationship between species richness and area. The relationship between alpha and beta diversity with area may indicate which biological process was involved in a given species-area relationship. In this paper we aimed to test the response of termite species richness to remnant area, testing how alpha and beta diversity vary with remnant area, and which processes may be involved in such relationships. We sampled termites in 12 remnants with areas ranging from 3.21 to 60.63 hectares in Viçosa, Minas Gerais, Brazil. The species area relationship was not confirmed for termites in these remnants, and alpha and beta diversity did not increase with remnant area. The SARs found in termite communities by other authors was attributed to sampling effects. There was no significant relationship between local and regional species richness. Therefore, termite communities were considered saturated. Habitat specialists seem to be an explanation for the absence of a relationship between alpha and beta diversity with remnant area.

KEY WORDS: Isoptera, local diversity, regional diversity, remnant area, termite species richness.

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Interference of Epicuticular Wax from Leaves of Grasses in Selection and Preparation of Substrate for Cultivation of Symbiont Fungus by Atta capiguara (Hym. Formicidae)

By Marise G. Garcia, Luiz C. Forti, Sandra S. Verza, Newton C. Noronha Jr., & Nilson S. Nagamoto

ABSTRACT


The selection of plants is one of the stages of foraging behavior, executed by leaf-cutting ants for the cultivation of symbiont fungus. Anatomical, biochemical and physiological characteristics of vegetal species are some of the factors that influence selection of substrate; however, most studies described in the literature refer to leaf-cutting ants. Due to the scarcity of studies on the role of epicuticular waxes of grasses in relation to foraging behavior of monocotyledonous leaf-cutters, we completed three experiments with the ant species Atta capiguara in which we analyzed: the attractiveness or selectivity of leaves of Saccharum officinarum (sugarcane) and/or Hypharrenia rufa (capim jaraguá), with and without epicuticular wax in relation to the worker of this ant species, their processing and elimination in the form of pellets of epicuticular wax from the referred fragments removed by the workers for cultivation of symbiont fungus. We observed that vegetal fragments without wax were those most transported by workers to the inside of the nests; that they processed the fragments equally with as much as without wax, and eliminated, in the form of pellets, wax removed from the same into garbage chambers of the colonies, leading us to conclude that for monocotyledonous leaf-cutters, epicuticular wax from vegetal leaves has great importance in vegetal integrity by being used as substrate, representing a physical barrier to the growth of symbiont fungus.

KEY WORDS: Atta capiguara, leaf-cutting ant, selection of substrate, preparation of substrate, foraging, epicuticular wax.

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Study of the Venom Glands in Ectatomma quadridens (Hymenoptera: Formicidae) . Evolutionary Hypothesis in Subfamily Ponerinae

By Pablo Henrique Nunes & Maria Izabel Camargo-Mathias

ABSTRACT


The venom glands of worker ants of the species Ectatomma quadridens morphologically resemble an elongated sac or reservoir ending in a narrower portion that has the function of releasing the secretion to the exterior. Two external secretory filaments are individually inserted into the proximal portion of the gland and end inside the convoluted gland. The venom gland of workers of E. quadridens is, therefore, morphologically subdivided into four distinct portions: a) sac-shaped reservoir measuring approximately 1mm in length; b) excretory duct, proximal portion of the reservoir that joins the gland to the sting apparatus; c) convoluted gland, final portion of the external secretory filaments located inside the reservoir; and d) two secretory filaments measuring about 2 mm in length; their free extremities end blindly and are individually inserted into the reservoir wall at the proximal region of the venom gland. The histological data showed that the filaments and the convoluted gland are composed of cubic cells of secretory function. The reservoir consists of a simple cubical epithelium externally surrounded by muscle fibers. A thick cuticle internally coats the epithelium of the reservoir. The application of histochemical tests allowed us to establish that the final secretion of the venom gland of Ectatomma quadridens is of glycoproteic nature. This secretion undergoes several modifications at the secretory filaments, at the convoluted gland, and in the reservoir before reaching the excretory duct, the point at which the secretion is released in its final composition, namely the venom. Based on the differences among various Ponerinae species we propose a hypothesis suggesting a probable evolutionary process that the venom glands of members of this subfamily might have undergone.

KEY WORDS: venom gland, Ponerinae, ants, morphology, convoluted gland, histology, phylogenetic relationship.

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