Solvent Deactivation of Mimosa Webworm Larval Webbing (Lepidoptera: Plutellidae)

Untreated larval webbing of the mimosa webworm, Homadaula anisocentra stimulated oviposition. Six-week-old webbing was as active as two-day-old webbing. Stimulatory activity of webbing was lost after rinsing with highly polar solvents, but not after rinsing with nonpolar solvents. Addition of the polar solvent rinses did not induce activity in other substrates nor restore activity to rinsed webbing. No differences in structure were found in a scanning electron microscope examination of unrinsed webbing and webbing rinsed with solvents of varying polarity

Oviposition behavior of the mimosa webworm Homadaula anisocentra Meyrick (Lepidoptera: Plutellidae)

Oviposition preference studies evaluated the response of female mimosa webworms, Homadaula anisocentra Meyrick (Lepidoptera: Plutellidae) to chemical and tactile stimuli. Mimosa, Albizzia julibrissin Durazzini and honeylocust, Gleditsia triacanthos L. trees were utilized. A search for mimosa webworm eggs on honeylocust trees was conducted in four geographic areas. Females emerging from overwintering pupae in June showed an oviposition preference for mature foliage. The petiole and rachis were preferred over leaflets as oviposition sites. This was substantiated in laboratory studies, in which females laid more eggs on mature (over six weeks old) than on fresh (less than two weeks old) leaves from both hosts. From field observations and laboratory experiments, it was found that females preferentially oviposited on larval webbing when it was present. It was concluded that females were responding to a pheromone(s) associated with larval silk. Partial and complete ablation of the flagella demonstrated that the pheromone(s) was perceived by the antennae via contact chemoreception;Larval webbing rinsed with polar solvents eliminated or reduced oviposition on webbing. Rinsing webbing with a non-polar solvent had little effect on oviposition. Six-week-old webbing, rinsed or non-rinsed, was oviposited on as readily as was two-day-old webbing. The pheromone(s) most probably is a highly polar, non-volatile molecule. Extracts of larval mandibular and labial glands, webbing, silk, and macerated honeylocust leaves were pipetted onto various substrates. Oviposition was not elicited on any substrate or solvent combination. The pheromone probably is degraded or inactivated by polar solvents

Reactions of phosphorus (III) reagents with nitro compounds and nitroxyls

Reactions of triethyl or trimethyl phosphite with 2- aryl -1-phenyl-1-nitroethenes at elevated temperatures gave small yields only of non-phosphorus-containing heterocyclic compounds. Observation of the reactions by n. m. r. spectroscopy, however, showed that 3, 4-diaryl -4, 5-dihydro-1, 2, 5-oxazaphosph(v)ole-2-oxides were formed, and subsequently decomposed, under the reaction conditions. The use of t-butanol as solvent for the reaction enabled a range of novel 4, 5-dihydro-1, 2, 5-oxazaphosph(v)ole -2- oxides to be prepared and isolated at room temperature. The reaction was extended by the use of dimethyl phenylphosphonite and 2-phenyl-1, 3, 2-dioxaphospholan, instead of trialkyl phosphites.Further investigations, of the thermolysis of the 1, 2, 5-oxazaphosph(v)ole-2-oxides and their reactions with tervalent phosphorus reagents, suggested that the compounds were not intermediates in the formation of the non -phosphorus- containing heterocycles isolated previously. The results suggested that the reaction of a tervalent phosphorus reagent with a 2-aryl-1-phenyl-1-nitroethene involves two competing pathways:- Michael-type addition of the phosphorus reagent to the nitroethene, with the possibility of subsequent ring-closure to give a 4, 5-dihydro-1, 2, 5-oxazaphosph(v)ole-2-oxide, or deoxygenation of the nitro-group to give a vinyl nitrene, and hence nitrene-derived products.The thermolyses of two aryl 2-azidophenyl ethers in triethyl phosphate were found to give significantly different yields of products than the corresponding reactions in decalin. The possible formation of a zwitterionic nitrene-phosphate adduct as a reactive intermediate seems to be insufficient explanation of the observed results.Reaction of N-t-butylphenylnitroxyl and diphenylnitroxyl with triethyl phosphite, in ethanol or methanol saturated with lithium chloride, gave ring-chlorinated anilines. This was taken as evidence in support of a reaction mechanism in which pairs of aminyl radicals undergo an electron-transfer reaction to give an anilino-anion and a delocalised nitrenium ion, which readily undergoes nucleophilic aromatic substitution by the solvent or chloride ion.The decomposition of 1, 4-di-t-butyl-1, 4-bisphenyltetraz-2-ene in ethanol or methanol also gave ring- substituted N-t -but ylanilines

Oviposition Preference of the Mimosa Webworm, Homadaula anisocentra (Lepidoptera: Plutellidae)

In the field, the mimosa webworm, Homadaula anisocentra Meyrick (Lepidoptera: Plutellidae), oviposits preferentially on branches or on leaf rachises or petioles of uninfested ornamental honeylocust, Gleditsia triacanthos L. On infested trees, oviposition occurs almost entirely on larval webbing. In the laboratory, uninfested mature leaves of both honeylocust and mimosa, Albizzia julibrissin Durazzini, are preferred over uninfested young leaves as oviposition sites. The addition of larval webbing to leaves of any age or to nonhost substrate induces oviposition preferentially on the webbin

Dynamic size and speed cursor for large, high-resolution displays

As larger displays become more available their lack of adequate input techniques becomes apparent. In this paper we show the scalability of the dynamic size and speed cursor for large, high-resolution displays. We introduce the idea of a dynamic paradigm for input devices, explain three implementations of the dynamic size and speed (DSS) cursor and explain results of an experiment. In our experiment we compared the three different implementations of the dynamic size and speed cursor to cursor warping and standard cursor settings. In the experiment we found gender bias for two different tasks (clicking and simple drag and drop), found that one of the dynamic size and speed cursor implementations generally outperformed cursor warping and the standard cursor setting, and explain how distance to and size of targets effected results. We conclude by suggesting the use of a dynamic size and speed cursor with large, high-resolution displays

Swedish vocational teachers’ informal workplace learning during the initial phase of the COVID-19 crisis

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