Interactions among Carbon Dioxide, Heat, and Chemical Lures in Attracting the Bed Bug, Cimex lectularius L. (Hemiptera: Cimicidae)

Commercial bed bug (Cimex lectularius L.) monitors incorporating carbon dioxide (CO2), heat, and chemical lures are being used for detecting bed bugs; however, there are few reported studies on the effectiveness of chemical lures in bed bug monitors and the interactions among chemical lure, CO2, and heat. We screened 12 chemicals for their attraction to bed bugs and evaluated interactions among chemical lures, CO2, and heat. The chemical lure mixture consisting of nonanal, 1-octen-3-ol, spearmint oil, and coriander Egyptian oil was found to be most attractive to bed bugs and significantly increased the trap catches in laboratory bioassays. Adding this chemical lure mixture when CO2 was present increased the trap catches compared with traps baited with CO2 alone, whereas adding heat did not significantly increase trap catches when CO2 was present. Results suggest a combination of chemical lure and CO2 is essential for designing effective bed bug monitors

Fumigation of bed bugs (Hemiptera: Cimicidae): effective application rates for sulfuryl fluoride

Citation: Phillips, Thomas W., Michael J. Aikins, Ellen Thoms, Joe Demark, and Changlu Wang. 2014. “Fumigation of Bed Bugs (Hemiptera: Cimicidae): Effective Application Rates for Sulfuryl Fluoride.” Journal of Economic Entomology 107 (4): 1582–89. https://doi.org/10.1603/EC13471.The bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), has resurged recently as a domestic pest in North America with very limited options for decisive control. We report efficacy studies with sulfuryl fluoride (SF) toward use as a structural fumigant to control bed bugs. Laboratory studies were conducted in which eggs, adults, and nymphs from a pesticide susceptible laboratory population were fumigated for 24 h using SF at 99.8% purity in airtight, 3.8-liter glass containers under two temperatures, 25°C and 15°C. Bed bugs were placed in separate ventilated glass vials and wrapped in mattress padding before fumigation. The gas concentration within each jar was determined using quantitative gas chromatography‐mass spectrometry. Dose‐response trials using eggs of known age (48‐96 h) were conducted at five or six target concentrations measured as concentration × time accumulated dosages (g-h/m³) and one untreated control at each temperature. Each target dose was replicated in four different fumigation containers (replicates), with at least 32 eggs per replicate. The number of hatched and unhatched eggs postfumigation, and number of live and dead nymphs that resulted from hatched eggs, were evaluated daily for at least 1 wk after egg hatch. The lethal accumulated dosage (LAD99) for bed bug eggs was 69.1 (95% fiducial limits [FLs] of 62.9‐79.5) g-h/m³ at 25°C and 149.3 (95% FLs of 134.4‐177.9) g-h/m³ at 15°C. Confirmatory trials with dosages of 1.5× the LAD99 were conducted at 25°C and 1.5× the threshold mortality dose at 15°C with at least 15 adults, 13 late-instar nymphs and 79 eggs of known age per replicate. At 25°C, a target dosage of 103.7 g-h/m³ resulted in 100% mortality of adults and late-instar nymphs. Nymphs emerged and survived from two of 439 eggs treated with SF dosages that were 6‐7 g-h/m³ less than the target dosage. No nymphs emerged from eggs fumigated with dosages >97.9 g-h/m³ in the validation study. Therefore, the threshold dosage for complete egg mortality (97.9 g-h/m³) was used, rather than the LAD99, to calculate the monitored field dosage rate of 148.2 g-h/m³ (= 1.5 × 97.9 g-h/m³) for control of all life stages of bed bugs at 25°C. Based on these results, at 15°C, 1.5× the threshold dosage for complete egg control (189.7 g-h/m³) was used to calculate a target dosage of 285 g-h/m³ for the confirmatory trial, which resulted in 100% mortality of adults, late-instar nymphs, and eggs

Relationship between habitat and ant communities in oak-dominated Appalachian forests treated with microbial pesticides.

Ants in the George Washington (Augusta Co. VA, USA) and Monongahela National Forests (Pocahontas Co. WV, USA) were studied using pitfall traps and bait traps to assess the effect of Bacillus thuringiensis var kurstaki (Foray 48F) and gypsy moth nuclear polyhedrosis virus (Gypchek) application on ant communities and the association of habitat characteristics with ants. Ant samples were also compared by forest, sampling year and season, sampling method, and sampling micro-habitat. Pitfall traps were operated for 45 weeks during summers of 1995 to 1997. Bait traps were set up and collected 42 times during the same period. A total of 31,732 ants were collected from pitfall traps and 54,694 ants were collected from bait traps. They belonged to 4 subfamilies, 17 genera, and 33 species. The ant species richness, diversity, abundance, and species composition did not change as a result of the treatments. Both ant abundance and species richness were correlated with soil moisture, elevation, and vegetation structure of the plots. The correlation was stronger for species richness than for abundance. More mesic and higher elevation plots had fewer ants and lower species richness. Ants from the two sampling methods showed different relative abundance and species richness. Pitfall traps caught more species than bait traps. There was no clear seasonal trend in overall ant activities during the sampling season. Comparisons between sampling years showed a very similar species composition and species evenness. There was a significant decrease in ant abundance in 1997, which may have been caused by over-trapping. Some rare species did not appear in the second and third year of sampling. Ant communities on ridges had one more species than those in valleys in the George Washington National Forest. The difference in ant species richness between ridges and valleys was more distinct in the Monongahela National Forest, which had 5 more species on ridges than in valleys. The ants in valleys were also distributed less evenly. The abundance of ants between ridges and valleys was similar

Performance Evaluation and Control Strategy Comparison of Supercapacitors for a Hybrid Electric Vehicle

Electrification of powertrain system is a great technical progress of traditional vehicle, leading to a significant reduction of fuel consumption and emission pollution. Energy storage system (ESS) normally consisting of batteries is a key component of an electric vehicle or hybrid electric vehicle. An ESS can recover braking energy during the regenerative braking process. Currently, lithium-ion batteries are the main energy storage device due to their high energy density. However, sometimes, a sudden large increase of operation current is required during acceleration or regenerative braking processes, which will jeopardize the operation life of batteries. A supercapacitor takes advantage of high power density and can tolerate large current in a short time. Application of supercapacitor in an ESS can reduce the peak current of batteries effectively, and the life time of batteries can be extended. Meanwhile, the braking energy can also be recovered sufficiently. Supercapacitors can be used solely in some hybrid electric vehicles. In this chapter, the application of supercapacitors in electric vehicles or hybrid electric vehicles is reviewed briefly. Then, the performance of a series hybrid transit bus, which uses a compressed natural gas engine and supercapacitors as power sources, is analyzed

Polysaccharides: Structure and Solubility

Understanding the solubility of polysaccharides is extremely important for their food applications as most functions of polysaccharides including stability, emulsifying property, drug delivery, membrane forming properties, etc., are all achieved in aqueous solution. This chapter aims specifically at the mechanism of solubility of polysaccharides from the molecular level. General understandings of the solubility including definition, testing methods, and the solution behaviors were provided; the relationships between polysaccharide solubility and the structural features in terms of molecular weight, degree of branching, charging properties, chain flexibility, and the special groups were all discussed. With all the information provided, the molecular modification and further applications of polysaccharides in both food and nonfood areas could be promoted

2-[(3S)-5-Oxooxolan-3-yl]isoindoline-1,3-dione

The oxolan-2-one ring in the title compound, C12H9NO4, has an envelope conformation with the atom linking the two five-membered rings being the flap atom

Utjecaj temperature uzgoja na ekspresiju gena za biosintezu pigmenta monakolina K u plijesni Monascus sp.

In this study, the effects of temperature-shift (from 30 to 25 °C) and temperature-constant (at 30 °C) cultivation on the mass of Monascus fuliginosus CG-6 mycelia and concentration of the produced monacolin K (MK) were monitored. The expression levels of the MK biosynthetic genes of M. fuliginosus CG-6 at constant and variable culture temperatures were analysed by real-time quantitative polymerase chain reaction (RT-qPCR). The total protein was collected and determined by liquid chromatography-electrospray ionisation with tandem mass spectrometry (LC-ESI-MS/MS). Results showed that the maximum mycelial mass in temperature-shift cultivation was only 0.477 g of dry cell mass per dish, which was lower than that in temperature-constant cultivation (0.581 g of dry cell mass per dish); however, the maximum concentration of MK in temperature-shift cultivation (34.5 μg/mL) was 16 times higher than that in temperature-constant cultivation at 30 °C (2.11 μg/mL). Gene expression analysis showed that the expression of the MK biosynthetic gene cluster at culture temperature of 25 °C was higher than that at 30 °C, which was similar to the trend of the MK concentration, except for individual MK B and MK C genes. Analysis of differential protein expression revealed that 2016 proteins were detected by LC-ESI-MS/MS. The expression level of efflux pump protein coded by the MK I gene exhibited the same upregulated trend as the expression of MK I in temperature-shift cultivation. Temperature-shift cultivation enhanced the expression of proteins in the secondary metabolite production pathway, but suppressed the expression of proteins involved in the mycelial growth.U radu je istražen utjecaj promjene temperature (s 30 na 25 °C) i konstantne temperature uzgoja (30 °C) na masu micelija plijesni Monascus fuliginosus CG-6 i koncentraciju proizvedenog monakolina K, pri čemu je razina ekspresije gena za biosintezu monakolina praćena metodom RT-qPCR. Ukupni su proteini određeni metodom LC -ESI-MS/MS. Rezultati pokazuju da je maksimalna masa micelija dobivenog pri promjeni temperature uzgoja bila samo 0,477 g suhe tvari po Petrijevoj zdjelici, što je znatno manje od one dobivene uzgojem pri konstantnoj temperaturi (0,581 g suhe tvari po Petrijevoj zdjelici). Međutim, maksimalna koncentracija monakolina K pri promjeni temperature uzgoja bila je 34,5 μg/mL, tj. 16 puta veća od one dobivene uzgojem pri konstantnoj temperaturi (2,11 μg/mL). U skladu s tim, utvrđeno je da je razina ekspresije klastera gena za biosintezu monakolina K veća pri 25 nego pri 30 °C, osim za gene MK B i MK C. Analizom diferencijalne ekspresije proteina otkriveno je 2016 različitih proteina, identificiranih metodom LC-ESI-MS/MS. Ekspresija proteinske pumpe koju kodira MK I gen pokazala je isti trend kao i ekspresija samog gena pri promjeni temperature uzgoja s 30 na 25 °C. Promjena temperature uzgoja povećala je ekspresiju proteina uključenih u sintezu sekundarnih metabolita, no smanjila ekspresiju proteina odgovornih za rast micelija