Occurrence and Distribution of Mosquitoes (Diptera: Culicidae) of Public Health Importance on the Island of Oahu

The Vector Control Branch of the Hawaii State Department of Health has accumulated a large volume of written inspection data on pests of public health for the island of Oahu. By far, the greatest amount of arthropod pest information available is on mosquitoes. The objectives of this study were to conduct a survey of the occurrence of mosquito complaints on Oahu over a 10-year period, determine the distribution of complaints over time, graphically compare mosquito occurrence within and between district/areas, and correlate mosquito occurrence and distribution with season. Mosquito data were drawn from inspection reports from 1990 to 1999, population information was obtained from Hawaii Census and State of Hawaii Data Books, 125 district/area geographic locations were defined, and mosquito occurrence and distribution were adjusted for population and mapped using ArcView GIS 3.2. Most of the mosquito activity was found within the central, south and east urban districts. Drier areas from Kalihi Kai to Portlock had the highest number of complaints, and the levels of mosquito activity were highest during the winter, spring and summer. The primary mosquito species recorded was Aedes albopictus (Skuse), the Asian tiger mosquito, and the main breeding sources were various containers, plus bromeliad plants. Aedes albopictus populations are being maintained in urban districts by human activities. As a result, dengue transmission is possible in the drier, urban areas of Oahu. These results indicate that educational programs should be carried out in late fall and early spring, and that residential mosquito surveys may be concentrated in a limited number of district/areas

Efficacy of localized chemical treatments for Cryptotermes brevis (Isoptera: Kalotermitidae) in naturally infested lumber.

Localized injection of insecticides into termite galleries in infested wood represents an alternative to whole-structure fumigation for drywood termite control. The efficacy of this method is limited, however, by the use of repellant insecticides and the difficulty of locating drywood termite colonies. The present study addressed both issues by the use of an experimental acoustic emissions (AE) detector to assist in location of termite infestations in naturally infested shipping pallets, and application of the non-repellant insecticide spinosad (Dow AgroSciences). Chlorpyrifos 0.5% aerosol, 15% aqueous disodium octaborate tetrahydrate (DOT), resmethrin 0.25% aerosol, distilled water (control) and two treatments of 0.5% spinosad suspension concentrate (one with the injection site based on visual evidence and the other on acoustic evidence) were injected into boards in hardwood shipping pallets naturally infested with the drywood termite Cryptotermes brevis Walker. Termite mortality was greatest with spinosad treatments, although variability was high due to the continued difficulty of identifying and treating all separate areas of infestation in the boards

Comparison of Coptotermes formosanus and Coptotermes gestroi (Blattodea: Rhinotermitidae) Field Sites and Seasonal Foraging Activity in Hawaii

Field surveys were carried out from January 2010 to June 2011 to record the environmental properties of Coptotermes formosanus Shiraki and C. gestroi (Wasmann) (Blattodea: Rhinotermitidae) field sites on the island of Oahu, Hawaii; and to document seasonal patterns in C. formosanus and C. gestroi foraging activity. The two field sites selected differed in elevation, soil characteristics, vegetation, and mean temperature and humidity patterns. The C. formosanus colony was located on the Manoa campus of the University of Hawaii, near Miller Hall; while the C. gestroi colony was located 40 km away at the Barber’s Point Horse Stables in Kalaeloa, Oahu (formerly Barber’s Point Naval Housing). Mean temperature and humidity were recorded monthly at each field site using a Hobo® data logger (1000-1100h), soil samples were taken from each site and analyzed for physical properties, and vegetation type/s were observed, photographed, and samples brought to laboratory for identification. During each site visit, the number of active termite collection traps (termites present) out of a total of 22 traps per site were counted. The C. gestroi field site was generally warmer than that of C. formosanus. Both termite species exhibited irregular activity throughout the year, although C. formosanus was more active in general during cooler months (winter) than C. gestroi; while C. gestroi was generally more active during late spring and summer months. These results, as well as introduction histories, may help to explain C. gestroi distribution patterns in Hawaii

Do Tunnel Patterns of Coptotermes formosanus and Coptotermes gestroi (Blattodea: Rhinotermitidae) Reflect Different Foraging Strategies?

Tunnel network construction and time to food (wood) discovery by Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae) (formerly known as Coptotermes vastator Light in the Pacific region) was examined when wood was present in a clumped distribution that mimics field conditions in the subtropical and temperate regions where C. formosanus naturally occurs. Previous research has noted that the tropical species C. gestroi constructs a highly branched tunnel network, while the subtropical C. formosanus constructs longer tunnels with few branches. Grace et al. (2004) hypothesized that this difference in tunneling behavior may relate to a more homogenous distribution of woody resources in the tropics vs. a disjunct and clumped distribution of fallen wood in the cooler subtropics. Thus, C. gestroi may exhibit a thorough search of the immediate area where wood is initially located, while it may be more energetically efficient for C. formosanus to tunnel greater distances in search of scattered resources. To test this hypothesis, we placed two wood resources at the opposite ends of laboratory foraging arenas, and released 1500 termites (1350 workers: 150 soldiers) into each arena. Arenas were observed every 24 hours for 14 days. We measured the total daily tunnel length, number of tunnels created in each quadrant of the arenas, and average time to discover food at both ends. Total daily tunnel length was relatively longer with C. formosanus and average time to discover food at either end was longer for C. gestroi. Although replication was limited in this study, these observations lend support to the hypothesis that C. formosanus is able to locate distant resources more efficiently than C. gestroi

SNP-Based Mapping of Crossover Recombination in \u3cem\u3eCaenorhabditis elegans\u3c/em\u3e

Caenorhabditis elegans is an important experimental organism for the study of recombination during meiosis. Here, we provide methods for the use of single-nucleotide polymorph isms (SNPs) for the study of crossing over in C. elegans

New Technology for Managing the Formosan Subterranean Termite

Methods for discouraging termites include the basaltic termite barrier and metal mesh barriers under foundations, baiting systems, removable baseboards, and resistant building materials

Laboratory Evaluation of the Formosan Subterranean Termite Resistance of Borate-treated Rubberwood Chipboard

Both no-choice and two-choice 4-week AWPA laboratory tests were performed to evaluate the resistance of borate-treated rubberwood (Hevea brasiliensis) chipboard prepared from a commercial mill run, against the Formosan subterranean termite Coptotermes formosanus. Boric acid (technical granular) was incorporated into the boards during manufacture to achieve loadings of 1.0% or 1.1% boric acid equivalents (BAE). In the no-choice test, both the untreated chipboard and solid rubberwood controls sustained heavy termite attack (respective mean visual ratings of 4.6 and 2.7 on a 10- point AWPA scale), while the two retentions of borate-treated chipboard showed only light grazing (mean rating 9.2). The two-choice test demonstrated a preference of termites for solid rubberwood (mean rating 2.4) instead of untreated chipboard (rating 8.4), and for untreated (mean rating 8.4 and 8.8) instead of borate-treated (mean ratings 9.8 & 9) chipboards. Complete termite mortality in the presence of borate-treated chipboard in both laboratory tests demonstrates the toxicity of borates to Formosan subterranean termites

Resistance of Borate-Treated Rubberwood Chipboard to the Formosan Subterranean Termite (lsoptera: Rhinotermitidae)

Both no-choice and two-choice 4-week AWPA laboratory tests were performed to evaluate the resistance of borate-treated rubberwood (Hevea brasiliensis) chipboard prepared from a commercial mill run, against the Formosan subterranean termite Coptotermes fonnosanus. Boric acid (technical granular) was incorporated into the boards during manufacture to achieve loadings of 1.0% or 1.1% boric acid equivalents (BAE). In the no-choice test, both the untreated chipboard and solid rubberwood controls sustained heavy termite attack (respective mean visual ratings of 4.6 and 2.7 on a 10-pointAWPA scale). while the two retentions of borate-treated chipboard showed only light grazing (mean rating 9.2). The two-choice test demonstrated a preference of termites for solid rubberwood (mean rating 2.4) instead of untreated chipboard (rating 8.4), and for untreated (mean rating 8.4 and 8.8) instead of borate-treated (mean ratings 9.8 & 9) chipboards. Complete termite mortality in the presence ofborate-treated chipboard in both laboratory tests demonstrates the toxicity of borates to Formosan subterranean termites

Termite resistance of selected lesser-known Malaysian hardwoods

A combination of field and laboratory termite tests were used to evaluate the subterranean termite resistance of lesser-known tropical hardwoods from Malaysia, which have potential future use where termites pose problems to timber structures. The 28-day lab test followed the procedure of AWPA E1-97 subjecting mainly the heartwood of selected woods to either Coptotermes formosanus (in Hawai’i) and/or C. Curvignathus (Malaysia). Up to 22 hardwoods were evaluated. Test block mass losses and termite ratings were compared to show a range of termite resistance between wood species and in cases, within a single tree species occurred due to different degrees of atacks between these termites especially with rubberwood and kempas. Overall the most termite-resistant woods are notably: Burmese teak, Casuarina, Kekatong, Perah and Rengas (including surprisingly its sapwood) while notable perishable woods are: Carribbean pine, Scots pine, Acacia mangium and Albizia sp. Malaysian teak sustained moderate resistance, as were the woods Tualang, Sentang, Hoop pine, Kedondong, Kelat, mempening, Pauh Kijang and Keledang. Such findings contribute to the selection of wood species for structural applications aboveground indoor (or outdoor) with options for wood protection among the lesser-resistant woods