Explore the vast range of titles available.

The dispersal flight activity (“swarming”) of two invasive subterranean termite species, Coptotermes gestroi (Wasmann) and Coptotermes formosanus Shiraki, was monitored in metropolitan southeastern Florida, where both species are now sympatric and major structural pests. Historical records of alates collected in the area showed that the two species have distinct peaks of flight activity, from mid-February to late April for C. gestroi, and from early April to late June for C. formosanus. However, an overlap of the two dispersal flight seasons has been observed since at least 2005. The daily monitoring of dispersal flight events in southeastern Florida in 2014, 2015, and 2016 confirmed that simultaneous flights occurred several times each year. In addition, environmental conditions for favorable flights were identified, and it was established that low temperature was the primary factor inhibiting both species from dispersal flights, while all other factors had little impact on the occurrence of major dispersal flight events. However, both species shared similar temperature requirements for favorable dispersal flight conditions despite distinct peaks of activity over time. The analysis of sex ratios and average weights of the alates suggests that intrinsic colony factors are important for the timing of the maturation of alates, and that once a cohort of individuals is ready to disperse, a flight may occur as soon as the environmental conditions are favorable.

Airflow is a crucial variable for insect orientation and navigation, particularly in flying insects whose antennae have several setae with flexible sockets. Termites occasionally dispatch their soldier caste to the frontline of the nest or shelter tube opening as the colony is alerted by the disturbances or preparing the alates’ nuptial flight. Hence, soldier termites’ contact with airflow outside the nest is inevitable. We analyzed subterranean termite (Coptotermes formosanus) soldiers’ sensitivity and orientation toward sustained airflow by manipulating the organs that bear setae with flexible sockets (e.g., antennal trimming, thorax pronotum covering). Four functional groups of soldier termites were tested against 10 min sustained airflow in three test chamber types. Soldier termites showed highly variable sensitivity and orientation toward airflow. The soldiers with antennae tended to orient and spend more time in the “region of interest” near the chamber opening. Adding airflow into the chamber increased movement. Significantly lower sensitivity toward the airflow source occurred when the antennae were trimmed and the pronotum was covered. When the antennae were trimmed, setae on the pronotum and other body parts might enhance the sensitivity to airflow, but their spatial ability was reduced as the soldiers demonstrated an alerting behavior by frequently bumping into the wall and opening their mandibles. The alerting behavior was significantly lower when air flowed into the chamber. These results demonstrated that setae with flexible sockets on the antennae and pronotum assisted soldier termites’ orientation to the airflow and enhanced their spatial ability.

Species identification in the genus Reticulitermes is often difficult because of ambiguous morphological characters. Challenges in Reticulitermes spp. recognition have also been encountered in East Asia, includingTaiwan. Because of unknown Reticulitermes taxa in Taiwan and the possible origin of alien Reticulitermes kanmonensisTakematsu in Japan and Korea, reexamining Reticulitermes fauna in Taiwan is imperative. To clarify the Reticulitermes fauna in Taiwan, this study applied two mitochondrial genes (cytochrome oxidase subunit II [COII] and 16S rDNA) and morphological characters for species delimitation. Reticulitermes specimens collected from 63 localities across the main and adjacent islands ofTaiwan were analyzed. Phylogenetic analyses, morphological comparisons, and ecological traits suggested the existence of three species inTaiwan: Reticulitermes flaviceps (Oshima), R. kanmonensis, and Reticulitermes leptomandibularis Hsia and Fan. Altitudinal distributions among the three Reticulitermes termites tended to differ: R. flaviceps adapted to low hills, but R. kanmonensis and R. leptomandibularis occurred in medium mountainous areas. The combined data, including haplotype diversities and distribution range, suggest that 1) R. flaviceps is an endemic species and only found in Taiwan; 2) R. kanmonensis and R. leptomandibularis are both native species in Taiwan and China; 3) Japanese R. kanmonensis populations originated from southern China and/or Taiwan and that Korean populations were possibly introduced from Japan.

The discoloration and resistance to subterranean termite attack of four furfurylated fast-growing tropical wood species were evaluated after outdoor exposure for 1 year in Bogor, Indonesia. For comparison purposes, imidacloprid-preserved and untreated wood samples were also prepared. Discoloration of all treated samples was measured before and after the furfurylation process. The wood specimens were then placed vertically to three-fourths of their length in the ground for 1 year, at which point they were evaluated for resistance to subterranean termite attack. After furfurylation, wood samples were darker in color than untreated wood, while imidacloprid-preserved wood was lighter. After 1-year exposure, furfurylated wood samples appeared to have the highest resistance to subterranean termite attack. These samples had minimal weight loss, indicating a substantial protection level. Imidacloprid-preserved wood had less resistance to termite attack, but was more resistant than untreated wood.

Durable baits, Recruit HD, were installed in 45 Sentricon stations between September 2010 and July 2014 in the 32-acre Armstrong Park, New Orleans. After eliminating all detectable termite colonies in the Park, 6–12 mo elapsed before new activity was detected. Newly invading termite colonies were usually found near the Park border or were smaller colonies that originated from recently paired alates. After colony elimination, Recruit HD baits were left in the stations to intercept newly invading colonies of subterranean termites, leading to their elimination, and multiple cycles of such interception and elimination events were recorded. Because the presence of Recruit HD baits continues to eliminate incoming colonies with little effort in maintaining and resupplying baits in the target areas, the bait system offers an economically sustainable option for managing subterranean termite populations in a large area. The 32-acre Armstrong Park is a manageable size to carry out an area-wide (AW) project. If the number of such AW projects is gradually increased over time in selected metro areas of New Orleans, we predict that we may be able to turn the tide against the ever-increasing populations of C. formosanus in the entire city.

Following the elimination of all detectable termite colonies in the 32-acre Louis Armstrong Park in New Orleans, LA, in 2002–2003, termite activity was monitored by using 808 Sentricon stations. Between January 2004 and July 2005, termites were found in 8–11 stations. In August 2005, the Park was flooded by Hurricane Katrina, but termites remained active. Post-Katrina termite activity levels of 16–21 stations were recorded throughout 2006, and in October 2007, the activity drastically increased to 43 stations. This rapid increase of termite activity continued into 2008, and a total of 94 stations harbored termite activities by July 2008. Termite activity peaked at 109 stations in September 2008 and then leveled down to 64 stations in March 2009. Termite activity in the Park between 2004 and 2009 was described by a Sigmoid model with a carrying capacity of 76 stations, and a Sigmoid mid-point of 1,202 d. In April 2009, a total of 14 colonies of Coptotermes formosanus Shiraki and one colony of Reticulitermes flavipes (Kollar) were delineated by using microsatellite genotyping and mark–recapture protocol. Of the 15 colonies, eight near the Park border probably originated from existing colonies from outside, and seven C. formosanus colonies found inside the Park were probably initiated by alate pairs. Our results showed that, if surrounded by high population pressure of termites and no control measures are applied, an area cleared of termite populations by baits can be completely re-populated by termites from outside in 53 mo.

In addition to being a structural pest, the Asian subterranean termite, Coptotermes gestroi (Wasmann) (Blattodea [Isoptera]: Rhinotermitidae), appears to be a serious pest of the native urban tree canopy of southeastern Florida. Asian subterranean termite colonies have the ability to cause feeding damage to a wide range of trees comprising the urban canopy, some potentially to a lethal level. Slash pine, Pinus elliottii Engelm. (Pinaceae), appears to be particularly susceptible to C. gestroi feeding damage, as the termites feed primarily on the outer layers of the wood, immediately beneath the bark, wounding live tissues and ultimately girdling the tree. In comparison, hardwood trees such as live oak, Quercus virginiana Mill. (Fagaceae), sustain damage to the heartwood at the center of the tree, resulting in a central cavity, but leaving the live tissue intact. Our results suggest that C. gestroi has the potential to kill pine trees within the local urban canopy, which may irreversibly alter the urban forest composition. In addition, many large trees in our survey have been consumed partially by mature C. gestroi colonies, potentially compromising their structural integrity. Some large oak trees that were extensively hollowed out by C. gestroi collapsed in 2017 during hurricane Irma. We discuss different potential approaches for protecting susceptible trees, as a comprehensive IPM strategy is needed for this invasive termite pest species, especially in the complex and extensive urban forest of southeastern Florida.

A field study was initiated in 2009 with 0.5% novaluron the BASF Advance Termite Bait System, which was 100% effective in controlling Reticulitermes sp. Holmgren and Coptotermes formosanus Shiraki infestations on 11 structures in the Texas City, TX area. Stations with inspection cartridges (cellulose tablets) and monitoring bases (southern yellow pine) and independent monitoring devices were installed in an alternating pattern around each structure and were inspected every 30 d postinstallation. When subterranean termite activity was confirmed on the inspection cartridge or the monitoring base, the inspection cartridge was removed and replaced with a bait cartridge containing 0.5% novaluron insecticide on a proprietary matrix (124 g/cartridge) in a station. Once the novaluron-treated bait was inserted, inspections of that station were made on a 4-mo cycle until no termite activity was observed. The mean time to achieve control of the subterranean termites on the structures was 10.5 mo post initial installation of bait. Mean time to achieve control of the termites on the structures after the baits were installed was 5.4 mo. Control of the termites on the structures required consumption of a mean of 1.3 bait cartridges (166.2 g) of 0.5% novaluron bait matrix per structure. These results indicate that the baits with 0.5% novaluron were effective in controlling termites on the structures used in this study.

Termite infestations in urban areas are a serious problem because they cause negative economic effects, reduce the esthetic value of buildings, damage crops, and require household repairs. Chemical controls are the most common method used against subterranean termites, and baiting has emerged as one of the prominent control methods. The goal of this research was to determine the efficacy of termite baiting by treating one of six active termite stations (selective baiting) with chlorfluazuron baits to eradicate six populations of subterranean termites. This work shows that the placement of chlorfluazuron baits in one of the active stations was sufficient to destroy a colony that was interconnected with multiple chlorfluazuron-free stations. In general, it requires an average of 4–8 weeks for a quantity of less than 300 g of chlorfluazuron bait to remove a termite infestation at the study site.

This study compared percentage of total body water (%TBW), water loss rate under desiccative conditions, and cuticular permeability (CP) of four termite species (Order: Blattodea, Infraorder: Isoptera) from different habitats, including one subterranean termite, Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae), one dampwood termite, Neotermes jouteli (Banks) (Blattodea: Kalotermitidae), one ‘wetwood’ termite, Cryptotermes cavifrons Banks (Blattodea: Kalotermitidae), and one drywood termite, Cryptotermes brevis Walker (Blattodea: Kalotermitidae). There was no consistent pattern associated with the habitat relative humidity (RH) levels and the %TBW among the four termite species tested. Because C. formosanus forage for food, its lowest %TBW may be due to its ability to access water sources, and its need to be more mobile than kalotermitids that remain in wood. Body water loss rate and CP were lower for xeric species such as Cr. brevis than hydric species such as N. jouteli. An RH equilibrium represents the capacity of termite water retention mechanisms that may include the physical structure of cuticular layers, behavioral manipulation of natural openings, and physiological means. As with water loss rate and CP data, RH equilibria were lower for xeric species such as Cr. brevis than hydric species such as N. jouteli. Moreover, RH equilibria for dead individuals of the four termite species were significantly higher than those of live individuals, indicating dead termites lost more water after losing their physiological and behavioral means of retaining water. RH equilibria represent termites’ capability in water retention, and there is a strong linear relationship between RH equilibria and CP values. Hence, RH equilibria may offer simpler alternatives to CP estimates.