Female sex pheromone and male behavioral responses of the bombycid moth <Emphasis Type="Italic">Trilocha varians</Emphasis>: comparison with those of the domesticated silkmoth <Emphasis Type="Italic">Bombyx mori</Emphasis>

Analysis of female sex pheromone components and subsequent field trap experiments demonstrated that the bombycid moth Trilocha varians uses a mixture of (E,Z)-10,12-hexadecadienal (bombykal) and (E,Z)-10,12-hexadecadienyl acetate (bombykyl acetate) as a sex pheromone. Both of these components are derivatives of (E,Z)-10,12-hexadecadienol (bombykol), the sex pheromone of the domesticated silkmoth Bombyx mori. This finding prompted us to compare the antennal and behavioral responses of T. varians and B. mori to bombykol, bombykal, and bombykyl acetate in detail. The antennae of T. varians males responded to bombykal and bombykyl acetate but not to bombykol, and males were attracted only when lures contained both bombykal and bombykyl acetate. In contrast, the antennae of B. mori males responded to all the three components. Behavioral analysis showed that B. mori males responded to neither bombykal nor bombykyl acetate. Meanwhile, the wing fluttering response of B. mori males to bombykol was strongly inhibited by bombykal and bombykyl acetate, thereby indicating that bombykal and bombykyl acetate act as behavioral antagonists for B. mori males. T. varians would serve as a reference species for B. mori in future investigations into the molecular mechanisms underlying the evolution of sex pheromone communication systems in bombycid moths.     

Future year ozone source attribution modeling studies for the eastern and western United States

Three modeling approaches, the U.S. Environmental Protection Agency’s (EPA) Community Multiscale Air Quality (CMAQ) zero-out, the Comprehensive Air quality Model with extensions (CAMx) zero-out, and the CAMx probing tools ozone source apportionment tool (OSAT), were used to project the contributions of various source categories to future year design values for summer 8-hr average ozone concentrations at selected U.S. monitors. The CMAQ and CAMx zero-out or brute-force approaches predicted generally similar contributions for most of the source categories, with some small differences. One of the important findings from this study was that both the CMAQ and CAMx zero-out approaches tended to apportion a larger contribution to the “other” category than the OSAT approach. For the OSAT approach, this category is the difference between the total emissions and the sum of the tracked emissions and consists of non-U.S. emissions. For the zero-out approach, it also includes the effects of nonlinearities in the system because the sum of the sensitivities of all sources is not necessarily equal to the sum of their contributions in a nonperturbed environment. The study illustrates the strengths and weaknesses of source apportionment approaches, such as OSAT, and source sensitivity approaches, such as zero-out. The OSAT approach is suitable for studying source contributions, whereas the zero-out approach is suitable for studying response to emission changes. Future year design values of summer 8-hr average ozone concentrations were projected to decrease at all the selected monitors for all the simulations in each city, except at the downtown Los Angeles monitor. Both the CMAQ and CAMx results showed all modeled locations project attainment in 2018 and 2030 to the current National Ambient Air Quality Standards (NAAQS) level of 75 ppb, except the selected Los Angeles monitor in 2018 and the selected San Bernardino monitor in 2018 and 2030.

Implications:This study illustrates the strengths and weaknesses of three modeling approaches, CMAQ zero-out, CAMx zero-out, and OSAT to project contributions of various source categories to future year design values for summer 8-hr average ozone concentrations at selected U.S. monitors. The OSAT approach is suitable for studying source contributions, whereas the zero-out approach is suitable for studying response to emission changes. Future year design values of summer 8-hr average ozone concentrations were projected to decrease, except at the downtown Los Angeles monitor. Comparing projections with the current NAAQS (75 ppb) show attainment everywhere, except two locations in 2018 and one location in 2030.     

The Validation of a Passive Sampler for Indoor and Outdoor Concentrations of Volatile Organic Compounds

Abstract

Volatile organlcs compounds (VOCs) are ubiquitous in the air we breathe. The use of passive samplers to measure these concentrations can be an effective technique. When exposed for long durations, a passive sampler may be a good tool for investigating chronic exposures to chemicals in the environment. A passive sampler that was designed for occupational exposures can be used as such a tool. Laboratory validation under as many conditions as possible needs to be accomplished so as to characterize the sampler with known parameters. This paper describes the methods and results of an investigation into the validity of using a passive monitor to sample VOCs for a three-week period. Two concentration levels, two relative humidities, and five VOCs were studied. Results indicate that the samplers work best under conditions of high concentration with low relative humidity and low concentration with high relative humidity. For the passive sampler, excluding chloroform, percent deviations from the predicted values varied between ?41 and +22 percent; while the values between the passive and the active samplers varied between ?27 and +24 percent. Benzene, heptane, and perchloroethylene were sampled with equal precision and accuracy.     

Feasibility investigation on a dual waste-plastics recycling system concept

Fiber-reinforced plastics (FRP) were first used as a material for boats and bath tubs about 40 years ago. Because of their great durability, wastes including FRP products are increasing. In addition, since the FRP resin is synthesized from expensive reactants, material recycling is highly desirable. Recycling using supercritical water is one solution; however, the cost of producing the high pressure and temperature needed to produce supercritical water prevents the concept from being realized. Therefore, we proposed a system concept based on dual waste-plastics recycling. A numerical survey of the results confirmed that our concept was feasible and would contribute to resource recycling as we expected. Received: January 6, 1998 / Accepted: July 23, 1999     

An Analytical Method to Determine Henry’s Law Constant For Selected Volatile Organic Compounds At Concentrations And Temperatures Corresponding To Tap Water Use

Henry’s law constants (H) are needed to model human exposure to Volatile Organic Compounds (VOCs) in Indoor air resulting from the use of tap water. This paper presents an experimental method to determine Hs for several common tap water pollutants at concentrations and temperatures used in household water. For 5 VOCs Henry’s law constants were obtained simultaneously over the 25° C to 45° C temperature range, providing data on H beyond the currently available data (up to 35° C). Henry’s law constants were obtained as the ratio of equilibrium concentrations of VOCs in air and water, using simultaneous sampling from sealed bottles kept at constant temperatures. Air and water samples were concentrated by a purge-and-trap method, thermally desorbed from a Tenax trap, and analyzed with a gas chromatograph with an electron capture detector (GC-ECD). Experimental results agreed well with available literature data.     

The photolysis of organic substances under atmospheric conditions with a cylindrical photoreactor using ethyl nitrite and nitrogen dioxide

The first-order rate constants of 8 organic substances were measured using the ethyl nitrite and nitrogen dioxide photolyses and their relative rates with respect to n-hexane rate constant were calculated. These were compared with literature data. Relatively small photolysis rates of alkane and aromatics were shown for our photosystems and the alkenes were rapidly photolyzed. For mixed photooxidation reactions of various organics, it would be reasonable for organics of the group classified by their molecular structures to be discussed on their reactivities with OH radicals.     

Chemically mediated group formation in soil-dwelling larvae and pupae of the beetle Trypoxylus dichotomus

Many insects form groups through interactions among individuals, and these are often mediated by chemical, acoustic, or visual cues and signals. In spite of the diversity of soil-dwelling insects, their aggregation behaviour has not been examined as extensively as that of aboveground species. We investigated the aggregation mechanisms of larvae of the Japanese rhinoceros beetle Trypoxylus dichotomus, which live in groups in humus soil. In two-choice laboratory tests, 2nd- and 3rd-instar larvae gathered at conspecific larvae irrespective of the kinship. The ablation of maxillae, which bear chemosensilla, abolished aggregation behaviour. Intact larvae also exhibited aggregation behaviour towards a larval homogenate. These results suggest that larval aggregation is mediated by chemical cues. We also demonstrated that the mature larvae of T. dichotomus built their pupal cells close to a mesh bag containing a conspecific pupal cell, which indicated that larvae utilize chemical cues emanating from these cells to select the pupation site. Thus, the larvae of T. dichotomus may use chemical cues from the conspecifics in two different contexts, i.e. larval aggregation and pupation site selection. Using conspecific cues, larvae may be able to choose suitable locations for foraging or building pupal cells. The results of the present study highlight the importance of chemical information in belowground ecology.     

Comparative studies on the sex pheromones of Ostrinia spp. in Japan: the burdock borer, Ostrinia zealis

Summary. To gain insight into the evolution of the sex pheromone communication system in Ostrinia (Lepidoptera Pyralidae), the sex pheromone of the burdock borer, O. zealis was analyzed by means of gas chromatography-electroantennographic detection (GC-EAD), GC-mass spectrometry and a series of bioassays. Four EAD-active compounds were detected in the female sex pheromone gland extract, and these were identified as tetradecyl acetate (14:OAc), (Z)-9-tetradecenyl acetate (Z9–14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc) and (Z)-11-tetradecenyl acetate (Z11-14:OAc). The average amounts (ratio) of the four compounds in single sex pheromone glands were 2.5 ng (13%), 11.6 ng (61%), 4.1 ng (21%) and 0.9 ng (5%), respectively. In a wind-tunnel bioassay, the ternary blend of Z9-, E11- and Z11-14:OAc at a ratio found in the sex pheromone gland elicited the same behavioral responses from the males as did virgin females. 14:OAc did not show any enhancement or inhibition of the males’ behavioral responses when added to the ternary blend. The attractiveness of the 3-component lure to O. zealis males was also confirmed by field trapping experiments. Based on these results, we concluded that the sex pheromone of O. zealis is composed of Z9-14:OAc, E11-14:OAc and Z11-14:OAc at a ratio of 70:24:6. The evolutionary changes of the sex pheromones in Ostrinia are also discussed based on the presently available information on the sex pheromones and phylogenetic relationships of Ostrinia spp. Received 25 September 1998; accepted 2 December 1998.