Patterns of pupal mortality in field populations of Hydropsyche and Cheumatopsyche (Trichoptera: Hydropsychidae)

SUMMARY. 1. Up to 40% of hydropsychid pupal cases (from three stations on the Credit and Humber Rivers, Ontario, Canada) contained insects already dead when collected; chironomid infestation accounted for up to 82% of total mortality within a taxon from any one station. The remaining mortality appeared to be due to siltation.
2. For all taxa ( Cheumatopsyche Wallengren and four species of Hydropsyche Pictet), and at all stations, prepupae suffered significantly more chironomid-related mortality than did fully-developed pupae.
3. Chironomid infestation generally affected all species of Hydropsyche equally; at some stations, Cheumatopsyche pupae appeared to suffer less chironomid-related mortality than did co-existing Hydropsyche species.
4. Chironomid infestation affected a greater proportion of pupae at the station where the density of pupal cases (per sampling quadrat) was greatest.
5. Vertical distribution of the pupation site had no apparent influence on mortality attributed to either siltation or chironomid infestation.
6. Chironomid infestation varied seasonally; it was greatest in May and July-August at an upstream station, and peaked in June at the downstream stations.
7. Mortality attributed to siltation was relatively constant for all stages and taxa, at all stations, throughout the sampling programme.     

Foraging movements of the Shy Albatross Diomedea cauta breeding in Australia; implications for interactions with longline fisheries

Satellite telemetry was used to identify the foraging zones of Shy Albatrosses Diomedea cauta breeding at two sites off Tasmania, Australia (Albatross Island in western Bass Strait and Pedra Branca to the south) to assess their level of interaction with longline fisheries. Adult birds from both colonies fed locally both in and outside the breeding season. Breeding birds from Albatross Island foraged over the Australian continental shelf or slope waters off northwest Tasmania, while those from Pedra Branca foraged between the colony and the southeastern edge of the continental shelf. The distances travelled by the birds and the duration of their foraging trips varied during the breeding cycle and tended to decrease as eggs approached hatching. Adults which were tracked near the end of the breeding season (March-April, n = 7 birds) deserted their chicks prematurely, and while dispersing further than incubating or brooding birds, they remained over the continental shelf and slope waters off southeast Australia. Home range analyses indicated 41% overlap between foraging zones of birds during successive breeding stages. Dispersal during the postbreeding period extended the foraging zones with less overlap between individuals (10% for Albatross Island and 19% for Pedra Branca). The recent contraction of the Japanese Southern Bluefin Tuna longline fishery to the south and east coasts of Tasmania has resulted in extensive overlap with adult Shy Albatrosses from Pedra Branca, but appears to pose a minimal threat to adult birds from Albatross Island. Coupled with the concomitant increase in the Australian domestic tuna longlining industry, adult Shy Albatrosses from southern Tasmania (Pedra Branca and the Mewstone) are vulnerable to incidental capture through out their annual cycle.     

Changes in Carotenoid Composition of Certain Roses with Age

The carotenoid composition of the anthers and styles and thefruits of four roses of different ages have been investigated.ß-carotene and its epoxides were present at all stagesstudied, as were the ß-carotene derived xanthophyllauroxanthin and the -carotene derived flavoxanthin and chrysanthemaxanthin.As the various parts aged, the control of carotenoid synthesiswas removed, oxidative processes took place with the resultthat very few members of the -carotene series were found, andepoxy-carotenoids and their derivatives were the main carotenoidspresent. Rubixanthin, 3-hydroxy--carotene characteristic ofrose hips was found in fairly large amounts in anthers and stylesand -carotene was probably the precursor of this pigment. Rosehips were also investigated for their vitamin-A contents whichwere not as high as those of All Gold flowers.     

Monitoring populations of the carrot fly, Psila rosae, with sticky and water traps

The relative, effectiveness of Rebell®, small cylinder, large cylinder, windmill and water traps, the five types of trap used currently for monitoring populations of the carrot fly, Psila rosae, was assessed in nine field experiments, three in south west Lancashire, four in the Fens (Suffolk, Norfolk, Cambridgeshire), one in East Suffolk and one at Wellesbourne, Warwickshire. Regression analysis of the numbers of flies caught on each type of trap against the numbers caught on the Rebell® trap indicated that each trap samples a constant proportion of the fly population relative to the other traps. Therefore, provided the fly population was sufficiently large for insects to be caught on the least effective traps, any of the five traps would monitor adequately fluctuations in carrot fly populations. However, the Rebell® trap caught 4–17 times as many flies/trap and 5–7 times as many flieshnit area of trap as any of the other traps tested.
Operators considered the Rebell® trap to be the easiest to use. However, it was more expensive than any of the other traps tested.     

A LOCAL-LESION TECHNIQUE FOR MEASURING THE INFECTIVITY OF CONIDIA OF BOTRYTIS FABAE SARDIÑA

Discrete lesions developed when conidial suspensions of Botrytis fabae Sardiña were rubbed with the forefinger on leaves of broad bean plants ( Vicia faba L.) subsequently kept in a water-saturated atmosphere. The numbers of lesions which developed were directly proportional to the concentration of inoculum. At equal concentrations, conidia from young cultures produced more lesions than conidia from old cultures.
Variation in lesion numbers between plants within a pot always considerably exceeded the variation between opposite half-leaflets of a leaf, as did variation between pots and between leaves of old, but not of young plants.
As the standard error of the number of lesions developing per half-leaflet ( x ) increases as the mean increases, the values of x need to be transformed before being statistically analysed. A suitable transformation is
z = log₁₀ 1/2{x + c +√(x²+ 2cx)}, where c = 20.     

The Biology of the Prothoracicotropic Hormone Peptidergic Neurons in an Insect

SYNOPSIS. The prothoracicotropic hormone and the cerebral peptidergicneurons that produce it have traditionally been thought to havethe singular function of acting as a primary effector of insectpostembryonic development. Recent investigations of this neuroendocrineaxis in the tobacco hornworm, Manduca sexta, are leading toa new view that these peptidergic neurons and their peptidephenotypes may be multifunctional. They may act in differentways depending upon the animal's developmental stage and siteof phenotype release. The possibility for this functional diversityof the prothoracicotropic hormone is possibly even greater dueto multiple neuronal sites of peptide expression within thecentral nervous system. Similarly, the L-NSC III may have morefunctions due to the expression of multiple peptide phenotypes.The data, thus far, have not enabled us to identify additionalphysiological roles for the peptide, but they have providedinsight into the experimental approaches that might be effectivein resolving these functions.     

Phylogenetic relationships and neotenic evolution of Metzgeriopsis (Lejeuneaceae) based on chloroplast DNA sequences and morphology

The systematic position of the enigmatic Asiatic liverwort Metzgeriopsis pusilla (Marchantiophyta), the single thalloid member of the largest family of leafy liverworts, Lejeuneaceae, was investigated based on sequences of the rbc L gene and the trn L-F region of chloroplast DNA, and morphology. Metzgeriopsis is not phylogenetically isolated from other taxa of Lejeuneaceae, as previously suggested, but is nested within Cololejeunea . The two genera share many morphological features, especially in the sporophyte generation, which is newly described. Metzgeriopsis and Cololejeunea are members of the Tuyamaella – Cololejeunea clade, characterized by neotenic features that probably evolved as adaptations to ephemeral habitats in tropical rain forests. Three different types of neoteny occur in this clade, which apparently originated by multiple heterochronic events. Within Lejeuneaceae, protonemal neoteny is unique to Metzgeriopsis and apparently resulted by evolution from a primary neotenic ancestor. The occurrence of protonemal neoteny in bryophytes is briefly reviewed and two types are recognized: species having a persistent thalloid protonema and species having a persistent filamentous protonema. The thalloid type is very rare and exclusive to epiphyllous liverworts, whereas the filamentous type is much more common and is characteristic of many terrestrial bryophytes, including the rare genus Protocephalozia . The new combination Cololejeunea metzgeriopsis (K.I.Goebel) comb. nov. is proposed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 293–308.     

Measurement of fluorescence intensity in microscope preparations using a photodiode detector

The development of a photodiode detector to measure fluorescence intensity in biological samples is described and the circuit is given for the amplication of the signal.