Effect of temperature on the neurosecretory activity inNezara viridula Linn. (Heteroptera; pentatomidae)

Zusammenfassung Die neurosekretorischen Zellen und die davon ausgehenden Nerven vonNezara viridula Linn enthalten bei Zucht in niedriger Temperatur bedeutend weniger Neurosekret als in Normaltemperatur.     

Photoperiodic summation is temperature-dependent inPyrrhocoris apterus (L.) (Heteroptera)

Summary InPyrrhocoris apterus, a low temperature, 15°C, prevented the termination of diapause by long days and, unexpectedly, also the induction of diapause by short days. Both responses were enabled at a higher temperature, 26°C. In contrast to current concepts, it was proved that the summation of photoperiodic signals was temperature-dependent, since the morphogenetic development was prevented by starvation.     

Instar-specific defensive secretions of stink bugs (Heteroptera: Pentatomidae)

Defensive secretions (allomones) from first-instar nymphs of stink bugs in the subfamily Pentatominae contain (E)-4-oxo-2-decenal as a major constituent, whereas this compound is absent from later instars. In contrast, first instars ofEdessa meditabunda (Edessinae) produce allomones like those of later instars. The C₆ and C₈ (E)-4-oxo-2-alkenals are common, characteristic exocrine compounds of nymphal and adult Heteroptera, but (E)-4-oxo-2-decenal is previously unknown as a major natural product for which a biological role has yet to be established.     

Observations on the neurosecretory axons in the aortal wall ofHalys dentatus F. (Heteroptera: Pentatomidae)

Zusammenfassung Neurosekretorisches Material kann in der Wand der Aorta eines Insekts nachgewiesen werden. Das Material befindet sich dort ausschliesslich in den sich verzweigenden Axonen der NS-Zellen.     

Dilation of nervi corporis allati 2 (NCA 2) — a neurohaemal structure inChrysocoris stolli wolf. (Heteroptera: Pentatomidae)

Summary The NCA 2 is dilated in about the middle of its length. Neurosecretory material is stored in this dilation. It serves as a secondary neurohaemal organ for lateral neurosecretion.     

The male pheromone of the old house borerHylotrupes bajulus (L.) (Coleoptera: Cerambycidae): Identification and female response

We report here the identification of the long-range, male-produced sex pheromone of the Old house borerHylotrupes bajulus. Chemical analysis of hexane extracts obtained by surface extraction from dissected prothoracic glands and from headspace samples of the two sexes, revealed male-specific compounds: (3R)-3-hydroxy-2-hexanone, 2-hydroxy-3-hexanone, the diastereomeric diols (2R, 3R)-2,3-hexanediol and (2S, 3R)-2,3-hexanediol, 2,3-hexanedione, as well as 1-butanol.In wind tunnel bioassays we tested the influence of these male-specific compounds from the prothoracal glands on the behaviour of unmated and mated females. Specific behavioural sequences of the tested females (activity, running behaviour, searching, cleaning, flying, extension of ovipositor) were recorded. Unmated females were attracted by male beetles, headspace extracts of males, synthetic blends of the major pheromone compounds as well as by the components (3R)-3-hydroxy-2-hexanone, and the diastereomeric diols. Hexane, female beetles and 2,3-hexanedione did not attract unmated females. The reactions of mated females to male beetles and headspace samples did not differ significantly from those of the controls.The results of the bioassays show that the two-stage premating behaviour is initiated by emission of a long-range sex pheromone from the male prothoracal glands, which functions as an activator, attractant, and possibly aphrodisiac for unmated females.     

Identification and biological significance of 4-methyl-3Z,5-hexadienoic acid produced by males of the gall-forming tephritidsUrophora cardui (L.) andUrophora stylata (Fab.) (Diptera: Tephritidae)

Summary A new natural substance has been identified in the rectal ampullae of gall-forming fruit flies. The substance was found to be the only volatile compound in the rectal ampulla of maleUrophora cardui andUrophora stylata. GC-MS methods were used to characterize its structure as 4-methyl-3Z,5-hexadienoic acid. Physiological parameters such as the amount of the acid at different ages and under different conditions were investigated. The biological significance of the new volatile as an arresting pheromone was tested in several bioassays. The arrestant function could not be established, but the results gave hints of a territorial function between conspecific males. The results are discussed with respect to gland morphology and predictions of communication models among fruit flies.     

Abnormalities in the development and reproduction of Blattella germanica (L.) (Dictyoptera: Blattellidae) treated with insect growth regulators with juvenile hormone activity

Summary Laboratory populations of German cockroach reared on food treated with R-20458 (75 ppm) or Ro 20-3600 (3000 ppm) became completely sterile and eventually extinct. The hypertrophied oocytes had excessively laid chorion, and the hypertrophied accessory sex glands contained excessive amounts of protein.     

Further evidence of a positive correlation between exposure to nitrate fertilizers (NaNO3 and KNO3) and gastric cancer death rates: nitrites and nitrosamines.

Mean age-adjusted death rates for gastric cancer in Chile for 1960, 1962 and 1964 were associated with exposure to sodium nitrate and nitrates (NaNO3 and KNO3) used as fertilizers, by province. The general population exposure to NaNO3 and nitrates exhibited correlation coefficients of 0.745 and 0.718 with the death rates, respectively.     

Effects of exogenous juvenile hormone I on the numbers and distribution of antennal and maxillary and labial palp sensilla of maleBlattella germanica (L.) (Dictyoptera: Blattellidae)

Summary Unlike in the female, application of exogenous juvenile hormone I to 6th-instar male nymphs does not result in the retention of nymphal characteristics on the antennae and maxillary and labial palps. JH-treatment differentially affects the numbers of sensilla on the 3 appendages of adult maleB. germanica.