No abstract

From an acarid mite, Lardoglyphus konoi (Sasa et Asanuma) (Acarina: Acaridae), with its culture medium,an aggregation pheromonewas isolated. The structure of the pheromonewas determined as 1,3,5,7-tetramethyldecyl formate and identified by 1 1 steps of organic synthesis. The absolute configuration of Q was assigned as R. The compound has been assigned the trivial name lardolure. The synthesized diastereomeric mixture of racemates showed one-tenth of the activity of the natural pheromone against the test mite, Carpoglyphus lactis.

No abstract

Wehave tested various chemicals for their modifying effects on the behavior of the pine woodnematode. Several compounds containing the oleyl group, i.e., ethylene glycol monooleate, 1-monoolein, oleic acid and oleyl alcohol were attractive.X) Allyl isothiocyanate, naringenin, 1-tyrosine, 1-tryptophan and calcium chloride were also attractive, while capsaicin and magnesium chloride exhibited repellency.2)As a continuation of these works, we tested behavioral responses of the nematode to terpenes. The results are presented in this paper. MATERIALS AND METHODSTest chemicals. Commercially available terpenes (analytical grade) were used without further purification.Bioassay. The procedure for behavioral tests was de-scribed in detail in the preceding paper.2) Agar plates in petri dishes were perforated to makea pair of holes, and filled with agar containing the test chemical and untreated agar respectively. A pad of absorbent cotton impregnated with a suspension of the nematodes reared on colonies of Botrytis cinerea was placed in the center of the agar plates.After incubating in darkness at 25°C for 3 days, the number of nematodes in the treated and untreated agar discs were counted and analysed statistically. All the test compounds had been previously dissolved in ethanol and water was added to provide ethanol concentration below 6%. A preliminary check showed that the effect of ethanol was negligible below 10%. The test was not performed for concentrations higher than 10~3m, since the chemicals could not be maintained in suspension. RESULTSAll the chemicals were first tested at 10~3m. If a significant activity was noted, the concentration waslowered successively by an order of magnitude. The results obtained with 26 terpenes are presented in Table I. Abietic acid and phytol were attractive at the order of 10~5 m, followed by /?-myrcene and geraniol, which were active at 10~4m. carene and camphene,were weakly attractive.3) Our results coincided with his concerning the high attractancy of /?-myrcene, but jS-pinene was repellent in our test system. Behavioral effects of monoterpenes on insects have been frequently reported. In particular, ipsenol, a monoterpene structurally related to /?-myrcene, was found to be an aggregation pheromoneof Ipsproconfusus, one of the bark beetles which infest pine.4) Reports on the behavioral activity of diterpenes have not often appeared, but the present work disclosed the remarkable attractiveness of phytol and abietic acid to the nematode. Recently, the latter compoundwas found to be a feeding stimulant to the larch saw fly.5) Abietic acid is contained in the pine resin, and this might be connected with infestation of the pine by the nematode.

No abstract

No abstract

No abstract

In random screening of nematicidal compounds against the pine wood nematode Bursaphelenchus lignicolus using the so-called immersion test, a series of mono-and di-functional alkanes, aromatics and other miscellaneous compounds (total 105) were tested. Among these, thenalkylamines were identified as the most potentially-active nematicidal compound. Relationship between nematicidal activity and the carbon-chain length of amines, mono-basic acids and alcohols was observed. Among those tested, n-octadecylamine showed the highest activity (LC50; 8.61 x 10-6 M, 2.08 ppm) on a molar basis.