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At least 19 recordsLinked to original sources

PubMed2005

Elimination and reinvasion studies with Coptotermes formosanus (Isoptera: Rhinotermitidae) in Louisiana.

Three Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), colonies located inside the 12.75-ha Louis Armstrong Park, New Orleans, were selected for elimination by using the chitin synthesis inhibitor hexaflumuron. Once eliminated, each vacated foraging territory was monitored for reinvasion by neighboring C. formosanus colonies, Reticulitermnes flavipes (Kollar) (Isoptera: Rhinotermitidae) colonies, or both. Each selected colony was eliminated in approximately 3 mo by using baits containing hexaflumuron. Overall activity of each untreated colony in the park remained unchanged during the same period. New C. formosanus and R. flavipes activity was detected in two of the three vacated territories, and in both areas, within days of selected colony elimination. The third vacated territory was completely reoccupied by a new C. formosanus colony approximately 7 mo later. Mark-recapture studies and DNA fingerprinting confirmed the distinctness of the reinvaders from eliminated and neighboring colonies.

Animals↗

PubMed2006

Anatomy of the frontal gland and ultramorphology of the frontal tube in the soldier caste of species of Nasutitermitinae (Isoptera, Termitidae).

All termite species (Isoptera) are eusocial. These insects live in societies where the division of labor is a predominant characteristic, conditioned by the presence of castes with different morphology, ontogeny, and development. The soldier caste is unique among social insects and it is responsible for colony defense. Soldiers belonging to the Nasutitermitinae subfamily are very peculiar, since they may be polymorphic and present a nasus in addition to either developed or vestigial mandibles. The defensive secretions of soldiers of the neotropical Nasutitermitinae have been the aim of several chemical studies, but few data exist concerning the anatomy and histology of the exocrine glands. This article presents a comparative study on the anatomy of the frontal gland of soldiers of several Nasutitermitinae species: Syntermes dirus (Burmeister), Syntermes nanus (Constantino), Constrictotermes cyphergaster (Silvestri), Nasutitermes corniger (Motschulsky) and Velocitermes heteropterus (Silvestri), with emphasis on the ultramorphology and ultrastructure of the frontal tube.

Animal Structures↗

PubMed2000

Phylogenetic analysis and trait evolution in Australian lineages of drywood termites (Isoptera, Kalotermitidae).

A phylogenetic analysis of Australian drywood termites (Isoptera, Kalotermitidae) based on partial sequence from the cytochrome oxidase II (COII) and cytochrome b genes is presented. In addition to providing new information on the evolutionary relationships among 25 species from seven genera, we evaluate the relative likelihoods of alternative topological hypotheses, including those derived from morphology-based classifications. We also test the applicability of a molecular clock for estimating the age of the Kalotermitidae and infer the evolution of species-specific variation for habitat type and soldier caste phragmosis by mapping this information onto the independently derived phylogeny. Maximum-likelihood analysis of both nucleotide and protein sequences from a multigene data set jointly support a single topology, which is shown to be the best estimate of the true phylogeny among the alternatives tested. Our results support the monophyly of all genera but question the discrimination between Procryptotermes and Cryptotermes. A basal dichotomy among generic groups suggests two principle lines of divergence within the family. Intergeneric relationships show mixed congruence to previous proposals, resulting in one morphology-based classification being rejected. A molecular clock hypothesis is not supported due to significant among-lineage rate heterogeneity in the COII gene. Patterns revealed through trait mapping suggest that the most recently diverged taxa tend to occupy the driest habitats and that these same taxa reflect a defensive transition away from large mandibulate soldiers toward small phragmotic soldiers. The association between habitat and defensibility supports the hypothesis that these two characters have been tightly linked throughout the social diversification of termites.

Animals↗

PubMedDate not supplied

Non-concerted evolution of the RET76 satellite DNA family in Reticulitermes taxa (Insecta, Isoptera).

The evolutionary dynamics of satellite DNA is most often studied in canonical mating systems, where bisexuality and panmixis are the rule. In eusocial termites, the limited number of reproducers starting a new colony and the maintenance of the colony through few neotenics act as bottle-necks both in space and time. No data on repetitive DNA are available for Isoptera and for their peculiar reproductive strategy. Here we present the first satellite DNA family isolated in European Reticulitermes. RET76 is a G+C rich satellite embodying two sub-families with a 76 bp monomer. RET76 sequences are highly variable (sequence homology is lower than 80% within sub-families and lower than 68% in the entire family) and this variability is equally distributed among the eight analysed taxa, thus depicting a pattern of non-concerted evolution. The absence of variant fixation--together with the strict monomer length conservation--may be explained at the molecular level as due to functional constraints acting on these sequences, and/or at the organismic level by considering the involvement of eusociality in preventing or greatly reducing variant fixation, somehow mimicking an unisexual strategy.

Animals↗

PubMed2004

Molecular phylogeny of Asian termites (Isoptera) of the families Termitidae and Rhinotermitidae based on mitochondrial COII sequences.

The families Termitidae and Rhinotermitidae are the most evolved and diverse groups of the social insects, termites (Order Isoptera), showing elaborated morphology and complex behavior. Molecular phylogeny of termites with the emphasis on these families was examined by Bayesian and maximum-likelihood analyses based on DNA sequence of mitochondrial cytochrome oxidase II (COII) gene of 31 genera sampled in Asia (mainly Thailand and Japan) along with those reported previously. Termitidae was monophyletic and originated from within polyphyletic Rhinotermitidae. Among the four subfamilies of Termitidae, Macrotermitinae was monophyletic suggesting a single common origin of fungus-growing habit characteristic for this subfamily, and was placed in the basal position in the family. A group consisting of other subfamilies Termitinae and Nasutitermitinae, though some important groups were still untouched, was the most apical but neither Termitinae nor Nasutitermitinae formed a monophyletic lineage. It was implied that, as defense systems of the soldier castes, the appearance of snapping mandibles has occurred at a single event, but the development of nasus for chemical secretion has probably not. Our tree provides some evidence concerning contradictions in the previously proposed phylogeny of termites.

Animals↗

PubMed2003

The life cycle of Reticulitermes spp (Isoptera: Rhinotermitidae): what do we know?

The subterranean termites in the genus Reticulitermes have a complex and plastic life cycle, which has been the subject of a number of publications over the past century. Given the inherent difficulties in studying such cryptic, eusocial organisms it is not perhaps surprising that the literature on their biology has failed to reach a consensus. An overview of the literature is given, which is followed by a discussion of the various theories on the life cycle of Reticulitermes spp. A substantial proportion of the review focuses on the French literature, which constitutes the majority of the primary sources and can be difficult to access. There are many discrepancies in the literature in terms of the number of instars, the definition of workers and the question of whether they should be termed pseudergates or, potentially, an additional terminology used to differentiate between pseudergates and the true workers seen in the higher termites (Isoptera: Termitidae). It remains very difficult to compare publications as there is little conformity; a problem that is aggravated by a general absence of drawings of the relevant instars. Further work on the biology of Reticulitermes is clearly required. There is also a need for researchers to agree on a standard terminology for this genus. A glossary is provided for the various synonyms and definitions.

Animals↗

PubMed2003

Targeted versus standard bait station placement affects subterranean termite (Isoptera: Rhinotermitidae) infestation rates.

A major challenge to termite baiting in soil habitats is the prolonged time that it may take for subterranean termites (Isoptera: Rhinotermitidae) to infest stations. The objective of this research study was to determine whether the location of food sources (Sentricon in-ground monitoring stations and wooden monitors) influences the likelihood of infestation by termites. In field trials conducted at 15 structures in central Ohio, standard placement of stations at 3-4.5 m intervals was compared with targeted placements based on evidence of termite activity indoors and outdoors as well as conducive moisture conditions. Termites infested significantly more targeted placements (70/374) than standard placements (35/372) around structures. At the targeted placement sites, termites infested more wooden monitors than Sentricon stations, but this was not statistically significant. This implies that placement, rather than cellulose composition, was the more important factor. Termites first infested stations/monitors an average of 38 d sooner at targeted sites than standard placement sites. This research indicates that evidence of termite activity indoors and outdoors should be a prime consideration when placing in-ground stations.

Animals↗

PubMed2000

The ootheca of Mastotermes darwiniensis Froggatt (Isoptera: Mastotermitidae): homology with cockroach oothecae.

The basal termite Mastotermes darwiniensis produces an egg mass, the nature of which is controversial. The debate centres on whether it is homologous with the oothecae of mantids and cockroaches and, if so, whether its simple structure is plesiomorphic or apomorphic within the Dictyoptera. To help resolve these issues we observed primary reproductives of M. darwiniensis during oviposition and examined the morphology of the reproductive product. Oviposition is cockroach-like in that the egg mass is assembled within the vestibulum and the eggs are issued externally in pairs. The reproductive product is an ootheca of the blattarian type. A distinct, tanned outer covering is stretched over the two parallel rows of eggs. No keel is present and no calcium oxalate crystals were apparent in the outer covering. We cannot rule out the possibility that the simple structure of the ootheca is plesiomorphic within Dictyoptera. However, based on (i) apomorphies shared by Mastotermes and Blattaria, and (ii) the life habits of Isoptera, a secondary reduction is the more plausible explanation.

Animals↗

PubMedDate not supplied

Cuticular hydrocarbons of Heterotermes tenuis (Isoptera: Rhinotermitidae): analyses and electrophysiological studies.

Termites have become an important pest of Eucalyptus and Pinus reforestations, sugarcane and other cultures. An alternative for the control of this pest would be the use of attractive traps that take in account the social behavior of these insects. Diverse factors are important for the insects in the localization of the habitat and the choice of the food and specific odors can facilitate this. Studies referring to Heterotermes tenuis (Isoptera: Rhinotermitidae) are scarce. The objective of this work was to analyze the tergal cuticular extract of H. tenuis and determine the selectivity and sensitivity of its antennae to the components of this extract by electroantennography (EAG). The composition of the cuticular extract was determined by GC-MS analysis. The hydrocarbons found were restricted to linear alkanes, being most abundant C24 to C27 that comprises ca. 65% of the total. Olefins were not detected. EAG and behavioral test responses to the cuticular hydrocarbons were greater and significantly different from the control and the high selectivity of the antennae to the extract indicates its potential as chemical messenger. Cuticular hydrocarbons mixture is species-specific and can be used to identify a given taxon without the diagnostic castes, soldiers or imagoes Difference in the composition appears to relate with the type of habitat of specie.

Alkanes↗

PubMed2003

Nutritional ecology of the Formosan subterranean termite (Isoptera: Rhinotermitidae): growth and survival of incipient colonies feeding on preferred wood species.

The wood of 11 plant species was evaluated as a food source significantly impacting the growth and survival of incipient colonies of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Colonies of C. formosanus feeding on pecan, Carya illinoensis (Wangenh.), and red gum, Liquidambar styraciflua L., produced significantly more progeny than colonies feeding on other wood species tested. Progeny of colonies feeding on pecan and American ash, Fraxinus americana L., had significantly greater survival than progeny of colonies feeding on other wood species. Colonies feeding on a nutritionally supplemented cellulose based matrix showed similar fitness characteristics as colonies feeding on the best wood treatments. These results indicate that differences observed in colony fitness can be partially explained by nutritional value of the food treatment, raising the possibility that wood from different tree species have different nutritional values to the Formosan subterranean termites. Colonies feeding on loblolly pine, Pinus taeda L., and ponderosa pine, Pinus ponderosa Laws., had significantly lower survival and produced significantly fewer workers and soldiers than colonies feeding on other wood species. Colony survival from 90 to 180 d of age and from 90 to 360 d of age was significantly correlated with the number of workers present at 90 d of colony age, indicating that colony survival depends on the presence of workers. Wood consumption in a multiple-choice study was significantly correlated with colony fitness value. This suggests that feeding preference of C. formosanus is at least partially influenced by the nutritional value of the food source.

Animal Nutritional Physiological Phenomena↗

PubMed2003

Catnip essential oil as a barrier to subterranean termites (Isoptera: Rhinotermitidae) in the laboratory.

The essential oil of catnip, Nepeta cataria (Lamiacae) was evaluated for behavioral effects on two populations of subterranean termite, Reticulitermes flavipes (Kollar) and R. virginicus (Banks) (Isoptera: Rhinotermitidae). The catnip essential oil contained approximately 36:64 E,Z-nepetalactone and Z,E-nepetalactone, respectively. The time to 50% dissipation (DT50) of the isomers in sand was dependent on dose, and ranged from 5.7 to 12.6 d for the E,Z-isomer and 7.7-18.6 d for the Z,E-isomer. For R. flavipes, the 24-h topical LD50 value was approximately 8200 microg/g termite. The 24-h fumigation LC50 value for R. flavipes was between 36 and 73 microg/ml air, and the 7-d fumigation LC50 value was between 14 and 36 microg/ml air. Exposure of R. virginicus to treated sand resulted in a 24-h LC50 value (95% F.L.) of 84 (67.6, 112) microg/cm2 and a 7-d LC50 value of 21.1 (16.4, 26.8) microg/cm2; for R. flavipes these values were 63.2 (53.7, 73.9) and 44.4 (34.6, 58.1) microg/cm2, respectively. Vertical tunneling through treated sand was eliminated at 500 ppm for R. virginicus and at 250 ppm for R. flavipes. Horizontal tunneling was stopped at 250 ppm for R. virginicus and reduced at doses above 250 ppm for R. flavipes. Although tunneling ceased in these tests, mortality was not high, indicating that the termites avoided the treated sand. Efficacy of catnip oil was equivalent to other monoterpenoids reported in the literature.

Animals↗

PubMed2006

Transferof chlorfenapyr among workers of Reticulitermnes flavipes (Isoptera: Rhinotermitidae) in the laboratory.

The potential for transfer of chlorfenapyr among subterranean termites was investigated using a donor-recipient (5:95 ratio) experiment. In one experiment, workers of Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) were exposed to treated sand at 0, 50, 100, 250, and 500 ppm chlorfenapyr (wt [AI]/wt sand). Exposed workers were allowed to interact with untreated nestmates for 14 d, after which mortality was assessed. The three colonies responded differently to the treatments in this experiment. For two colonies, donor exposure rates of 500 ppm (as well as 250 ppm for colony B) chlorfenapyr resulted in significantly greater recipient mortality than controls. For colony C, donor chlorfenapyr exposure did not significantly influence recipient mortality. In a second experiment examining donor mortality over time, donor termites exposed to all test concentrations of chlorfenapyr (except for 0 ppm) suffered 100% mortality within 5 d. Analysis of donor termite body washes using gas chromatography indicated a linear uptake of chlorfenapyr by termites over the concentration range studied. Thus, for this concentration range, no upper limit (saturation plateau) of termite uptake for chlorfenapyr was reached.

Animals↗

PubMed2006

Field and laboratory evaluation of persistence and bioavailability of soil termiticides to desert subterranean termite Heterotermes aureus (Isoptera: Rhinotermitidae).

Control information for the desert subterranean termite Heterotermes aureus (Snyder) (Isoptera: Rhinotermitidae) is limited, despite being one of three major termite pests in the United States. Annual control information comes from field evaluations by the USDA-Forest Service. This partial assessment of termiticide efficacy is likely deficient without concurrent residual analysis and laboratory bioassays of termiticides. In this study, six termiticides were evaluated using exposed and covered field plots in Tucson, AZ, over a 5-yr period for persistence and efficacy by using both residue analysis and laboratory bioassays. All the termiticides degraded significantly during the study. Termiticide degradation seemed to be consistently slower in covered plots than in exposed plots, although this trend was not statistically supported. A comparison of yearly degradation rates showed the three classes of termiticides degraded at different rates. Chlorpyrifos, the organophosphate, degraded quickest at a rate of 68.9% for each doubling of time, whereas chloronicotinyls and pyrethroids degraded at much slower rates (50.4 and 48.4% for each doubling of time, respectively). Bioassays showed termites tunneled 1.26 +/- 0.61 cm deeper in uncovered plots than in those that were covered. Mortality rates in bioassays from covered treatments were 16.13 +/- 9.87% higher than in uncovered treatments. Our study demonstrated that the termiticides evaluated could remain effective against H. aureus for at least 4 yr after application, particularly under covered conditions. Additionally, it is anticipated that retreatments may be necessary before the 5-yr warranty expires when using final grade applications to stem walls in warmer parts of Arizona.

Animals↗

PubMed2006

Comparison of localized injections of spinosad and selected insecticides for the control of Cryptotermes brevis (Isoptera: Kalotermitidae) in naturally infested structural mesocosms.

We investigated the efficacy of various chemical injections against Cryptotermes brevis (Walker) (Isoptera: Kalotermitidae) in hardwood shipping pallets. We had three principle interests: efficacy in whole structures, relative efficacy of the active ingredients, and whether acoustic evidence augmented treatment site selection. Infested pallets were delineated into boards with four monitoring sites each. Six chemical treatments were compared: chlorpyrifos aerosol, aqueous disodium octaborate tetrahydrate (DOT), resmethrin aerosol, distilled water (control), and two treatments of spinosad SC (one treatment applied based upon visual and the other treatment upon acoustic [AE] evidence). Individual boards were split apart; efficacy was determined by percentage mortality and pre- and posttreatment AE counts. Injections were constrained to a single point per board with the greatest level of termite activity. In whole pallets, mean percentage mortality ranged from 53.3 to 58.7% for the visual and AE spinosad treatments, respectively, whereas water averaged 6.8%. Remaining treatment mortalities were 33.2, 30.4, and 18.1% for chlorpyrifos, DOT, and resmethrin, respectively. Analysis of whole-pallet data indicated that none of the insecticides produced commercially acceptable mortality; localized injections of insecticides were not comparable with whole-structure treatments. We delineated independent groups of board sections (sectional aggregates; SA) that were connected by galleries. When treated SA were analyzed, spinosad and DOT treatments were significantly different from controls, whereas remaining treatments were not different from controls or spinosad and DOT. AE readings and visual termite evidence were compared with presence or absence of termites in SA, and it was determined that both AE and visual evidence were effective predictors of termite presence.

Animals↗

PubMed2006

Laboratory evaluation of bistrifluron, a benzoylphenylurea compound, as a bait toxicant against Coptotermes formosanus (Isoptera: Rhinotermitidae).

Bistrifluron, a benzoylphenylurea compound, was evaluated with regard to its efficacy against workers of Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) by using three laboratory tests. In the no-choice feeding test, the mortality of bistrifluron-treated worker termites was significantly higher than that of termites exposed to the same concentrations of hexaflumuron (e.g., 6 wk at 500 ppm, 4 wk at 5,000 ppm, and 2 wk at 50,000 ppm) and untreated controls. Bistrifluron showed higher dose dependence and a faster speed of action than hexaflumuron. Both bistrifluron and hexaflumuron had feeding-deterrent effects at 5,000 ppm in the two-choice feeding test, although the mortality of worker termites exposed to bistrifluron or hexaflumuron at 5,000 ppm was not significantly different from untreated controls. In the allogrooming inhibition test, to examine effects of bistrifluron on allogrooming behavior of termites, termite movement was affected at 1 wk before termites died when exposed to 5,000 ppm bistrifluron. These results indicate bistrifluron is effective as a bait toxicant at 5,000 ppm; however, bistrifluron may cause some feeding repellency at > or = 5,000 ppm.

Animals↗

PubMed2006

Borate protection of softwood from Coptotermes acinaciformis (Isoptera: Rhinotermitidae) damage: variation in protection thresholds explained.

Laboratory and field data reported in the literature are confusing with regard to "adequate" protection thresholds for borate timber preservatives. The confusion is compounded by differences in termite species, timber species and test methodology. Laboratory data indicate a borate retention of 0.5% mass/mass (m/m) boric acid equivalent (BAE) would cause > 90% termite mortality and restrict mass loss in test specimens to < or = 5%. Field data generally suggest that borate retentions appreciably > 0.5% m/m BAE are required. We report two field experiments with varying amounts of untreated feeder material in which Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae) responses to borate-treated radiata (Monterey) pine, Pinus radiata D. Don, were measured. The apparently conflicting results between laboratory and field data are explained by the presence or absence of untreated feeder material in the test environment. In the absence of untreated feeder material, wood containing 0.5% BAE provided adequate protection from Coptotermes sp., whereas in the presence of untreated feeder material, increased retentions were required. Furthermore, the retentions required increased with increased amounts of susceptible material present. Some termites, Nasutitermes sp. and Mastotermes darwiniensis Froggatt, for example, are borate-tolerant and borate timber preservatives are not a viable management option with these species. The lack of uniform standards for termite test methodology and assessment criteria for efficacy across the world is recognized as a difficulty with research into the performance of timber preservatives with termites. The many variables in laboratory and field assays make "prescriptive" standards difficult to recommend. The use of "performance" standards to define efficacy criteria ("adequate" protection) is discussed.

Animals↗

PubMed2002

Population structure and genetic diversity in insular populations of Nasutitermes takasagoensis (Isoptera: Termitidae) analyzed by AFLP markers.

Dispersal ability and degree of inbreeding in a population can indirectly be assessed using genetic markers. In general, it was suggested that winged termites are not able to fly distances greater than several hundred meters. Here, amplified fragment length polymorphism (AFLP) was used to analyze genetic diversity, population substructure, and gene flow among insular populations of the termite Nasutitermes takasagoensis (Isoptera: Termitidae) in the Yaeyama Islands, Okinawa, Japan. Samples were collected from 77 nests on seven islands of the Yaeyama Group. Using three primer combinations a total of 155 bands were generated with 78 (50%) polymorphic bands. Genetic distance and G(st) values among insular populations were calculated. Relatively high genetic diversity and low values of G (st), suggest there is moderate subpopulation structure. Based on these results, we discussed two possibilities; first, winged termites are able to fly over distances of several kilometers, and second, these results were obtained because insular populations share a recent common origin.

Animals↗

PubMed1998

Some aspects of intracellular symbiosis during embryo development of Mastotermes darwiniensis (Isoptera: Mastotermitidae).

All examined species of cockroaches have been shown to harbour intracellular bacteria in specialized cells (bacteriocytes) of the fat body. In termites, bacteria in specialized cells have been observed only in Mastotermes darwiniensis (Isoptera: Mastotermitidae). All of these bacteria have been assigned to the same eubacterial lineage, with the bacteria of M. darwiniensis as the sister group to the cockroach bacteria. While the main steps of the life cycle of cockroach bacteria have been described, little is known about the bacteria of M. darwiniensis. More specifically, no data are available on their behaviour during the development of this termite. Using both optical and electron microscopy methods, we examined embryos of M. darwiniensis at different developmental stages. Our results show that the integration of bacteria during the development of M. darwiniensis is implemented in the same way as in cockroaches. In particular, we observed the aggregation of a large amount of bacteria in a single mass in the yolk sac, with vitellophage-associated bacterial lysis. In cockroaches, a similar process has been described in detail for Periplaneta americana (Blattaria: Blattidae), where the bacterial mass is referred to as the transitory mycetome. The formation of a transitory mycetome could thus be regarded as an ancestral condition for cockroaches and termites.

Animals↗