EJE, vol. 91 (1994), issue 2

Measuring variation in abundance, the problem with zeros


Eur. J. Entomol. 91 (2): 145-161, 1994

Using time series of estimates of population abundances of moths from a light-trap in Brno, Czech Republic, the usefulness of a number of variability measures was examined. There are two problems that may occur. One is that time series data of population counts usually do not constitute a series of independent data, another is the occurrence of zeros when logarithms need to be taken. It is assumed here that the observed zeros no not represent extinction. All but one of the measures used suffered from the problem with interdependent abundances, making these measures difficult to use in statistical testing. The exception, ln{var(ln[Ri])},...

Gene regulation by steroid hormones: Vertebrates and insects


Eur. J. Entomol. 91 (2): 163-187, 1994

In both vertebrates and insects, steroid hormones are known to control diverse physiological events from reproduction to growth and development, primarily by affecting the expression of specific genes. Despite the vast evolutionary distance between arthropods and vertebrates, the molecular mechanisms by which steroids act to regulate genes appear to be conserved. Our understanding of these principles has been advanced significantly during the past few years, owing to the molecular characterisation of genes which encode steroid hormone receptors. This article provides a general survey of the superfamily of nuclear hormone receptors and their mode of...

Eclosion hormone-like immunoreactivity in the nervous system of Bombyx mori (Lepidoptera: Bombycidae) and Antheraea yamamai (Lepidoptera: Saturniidae) before and after hatching


Eur. J. Entomol. 91 (2): 189-196, 1994

A monoclonal antibody to Bombyx mori eclosion hormone (EH) reacted in whole mounts of the nervous system from pharate and freshly hatched larvae of this species with 4 ventromedial brain neurons and a pair of nerve fibers runing down the ventral nerve cord. Weak immunoreactivity was occasionally detected in similar whole preparations of the nervous system from Antheraea yamamai. In paraffin sections of the nervous system of A. yamamai, an EH-like antigen was found in 4 ventromedial brain neurons, in 2 or 3 pairs of neurons in each of the ventral ganglia, and in a pair of nerve fibers extending through the nerve cord. The intensity...

Sex pheromone characterisation and field trapping of the European corn borer, Ostrinia nubilalis (Lepidoptera: Pyralidae), in South Moravia and Slovakia


Eur. J. Entomol. 91 (2): 197-203, 1994

The analysis of pheromone glands from individual females of the European corn borer, Ostrinia nubilalis (Hübner), originating in South Moravia and Slovakia showed that this population utilizes the ''Z'' pheromone system. The ratio of (Z)- and (E)-11-tetradecenyl acetates was found in the range of 98.5:1.5-99.5:0.5. Field experiments confirmed the identity of the local population as being predominantly of the Z strain. Individuals responding to E and hybrid blends were detected.

Queen substitutes for small pollination colonies of the honey bee, Apis mellifera (Hymenoptera: Apidae)


Eur. J. Entomol. 91 (2): 205-212, 1994

Ethanol extracts of egg-laying queens, extracts of unmated queens, and a mixture of four synthetic components of the queen mandibular pheromone were tested as queen substitutes. Worker bees were attracted to the extracts of fertile queens and to the synthetic mixture, but complete inhibition of queen rearing occurred with the extracts. However, the extracts of reproducing queens and the synthetic mixture and, with slightly lower efficiency, also the extract of virgin queens proved to be suitable queen substitutes in trials with queenless bee colonies, used for pollination in greenhouses.

Diversity and variability of Lepidoptera populations in urban Brno, Czech Republic


Eur. J. Entomol. 91 (2): 213-226, 1994

Lepidoptera populations were monitored during 29 years by a light-trap in urban Brno. Compared with other sites in the Czech Republic (Prague-Ruzynì, Èeské Budĕjovice, Černiš) urban Brno was extraordinarily rich in species, richer than the other Czech sites studied and richer than many British sites in an urban to natural gradient. Variability of the more common species at Brno was as high as that at the ruderal/deteriorated agricultural setting at Ceske Budejovice, and generally higher than that in the wet forest environment at Cernis and much higher than in the park-like/suburban/agricultural setting of Prague. Voltinism had no...

The effect of plant quality on the abundance of Metopolophium dirhodum (Homoptera: Aphididae) on maize


Eur. J. Entomol. 91 (2): 227-236, 1994

In 1989-1991, populations of Metopolophium dirhodum (Walker) on maize in western Czechoslovakia were investigated. Aphid abundance was followed on plants subject to water stress and weed competition and of different ages, sown between late March-late June. Shoot size, growth rate and leaf nitrogen content of the plants affected the performance of aphid populations. Aphids colonized maize stands in early June, after 400 to 500 day degrees (dd), above a 5°C threshold, had accumulated since January 1. Initial abundance varied annually and with host plant size, between 0.1 and 9.9 aphids per plant. Population peak was attained in late June-early...

Revision of the subgenus Dryopomera s. str. (Coleoptera: Oedemeridae)


Eur. J. Entomol. 91 (2): 237-254, 1994

Species of the nominotypical subgenus Dryopomera Fairmaire are revised, illustrated and keyed and species-groups are proposed. The following new species are described: Dryopomera (Dryopomera) ceylonica sp. n. (Sri Lanka), D. (D.) sundaica sp. n. (Indonesia), D. (D.) tonkinensis sp. n. (Vietnam), D. (D.) longissima sp. n. (Nepal), D. (D.) nepalensis sp. n. (Nepal), D. (D.) malaccana sp. n. (Malaya), D. (D.) burmanica sp. n. (Burma), D. (D.) rugicollis sp. n. (Malaya) and D....

Obituary: The nestor of insect physiologists, Sir Vincent Wigglesworth


Eur. J. Entomol. 91 (2): 255-256, 1994