Influence of intertree distance on foraging behaviour of Rhagoletis pomonella in the field

Abstract. 1. We tested a prediction from contemporary foraging theory that animals should decrease their allocation of energy to the searching of individual patches when interpatch travel costs decrease.
2. We used individual Rhagoletis pomonella Walsh (Diptera: Tephritidae) females foraging for oviposition sites (= Crataegus fruit) in a host tree which was surrounded by four other trees at varying distances.
3. We found that flies generally invested less search, measured as time spent searching a tree or number of leaves visited on a tree, when neighbouring trees were nearby than when farther away.
4. Under our test conditions, flies appeared to have difficulty locating neighbouring trees at a distance of more than 1.6 m.
5. Our study calls into question the interpretation of search effort by insects within resource patches in the absence of information on interpatch distances.     

Maggot therapy: a review of the therapeutic applications of fly larvae in human medicine, especially for treating osteomyelitis

In traditional medical practice, the larvae of some Diptera: Calliphoridae, notably Lucilia illustris (Meigen), L.sericata (Meigen) and Phormia regina (Meigen), have been employed for maggot therapy, i.e. to help clean lesions antiseptically, especially for treatment of chronic osteomyelitis. This mode of treatment remains appropriate for cases where antibiotics are ineffective and surgery impracticable.     

Further Studies on in vitro Development of Eimeria bovis and Attempts to Obtain Second-Generation Schizonts*

SYNOPSIS. Eimeria bovis merozoites occurred in tissue culture medium removed from Leighton tube cultures of embryonic bovine tracheal cells beginning 12-14 days after inoculation with 270,000-369,000 sporozoites per tube. The number of merozoites produced in these cultures increased daily until a peak was reached 18-21 days after inoculation. In 3 experiments an average of 2.0–15.6 million merozoites per tube was produced during the 20-day observation period. When such merozoites were frozen in liquid nitrogen and stored 26–42 days, some were motile upon thawing. These merozoites as well as others freshly obtained from cell cultures and from calves were inoculated into 11 different types of cultured mammalian cells including primary, cell line and established cell line cultures. Some merozoites were exposed to substances normally found in the lumen of the gut, before or at the time of inoculation. Altho small numbers of intracellular merozoites were found, no further development was observed. Gametocytes were observed in the cecum of a calf 4 days after merozoites from cell cultures were introduced into a ligated cecum of the calf.     

RFamide Peptides in the Leech, Hirudo medicinalis

RFamide peptides have been localized to a number of neuronsof the CNS of the leech, Hirudo medicinalis, using immunocytochemicaltechniques. The majority of this immunoreactivity appears tobe due to the peptide FMRFamide. Most of the identified RFamideimmunoreactive cells are cholinergic motor neurons, though someare interneurons. Superfused FMRFamide is active on the targetsof these identified neurons; in a few well studied cases, ithas been possible to show that FMRFamide mimics a specific physiologicalaction of an identified neuron on its target. In the leech as in other phyla where they occur, RFamide peptidesare widely distributed in neurons, and are neuromodulators withdiverse physiological effects.     

Potential for host range expansion in Ceratitis capitata flies: impact of proximity of adult food to egg-laying sites

Abstract.

• 1 In field cage and field tests, female Mediterranean fruit flies, Ceratitis capitata (Wiedemann), in trees alighted in significantly greater numbers upon sticky-coated (non-odour-emitting) kumquats, Fortunella japonica, that were in the vicinity of odorous natural proteinaceous food (bird faeces) or synthetic food odour than on similar kumquats distant from bird faeces or synthetic food odour.
• 2 In field cage tests, oviposition in non-sticky kumquats nearby bird faeces was significantly greater than in non-sticky kumquats distant from bird faeces.
• 3 In field tests, medflies laid significantly more eggs in host kumquat and non-host hawthorn, Crataegus mollis, fruit adjacent to bird faeces and synthetic food odour than in fruit of these types distant from food-type stimuli.
• 4 These findings suggest that odour of natural food of medflies could lure flies to plants whose fruit emit little or no attractive odour and are not permanent hosts but which are nonetheless susceptible to egg-laying and larval development, resulting in temporary expansion of host range.

     

Levels of genetic variability in sculpins (Gottidae: Teleostei) of the North American Pacific coast and an assessment of potential correlates

We examined levels of allozymic variation in intertidal sculpins of the genera Oligocottus, Clinocottus and Artedius. Variability in these species, as assessed by the proportion of loci polymorphic and average heterozygosity per locus, was generally low but within the range of values observed for other fish groups. In reviewing the ecological and life-history attributes of these sculpins, we found only one outstanding correlate of allozyme variability–larger-bodied species tended to have lower levels of variation. Also, the level of heterozygosity was not related in any obvious way to historical/ evolutionary aspects such as position in phylogenetic trees or the inferred relative ages of species. Our study of a relatively well-defined lineage of fishes that co-occur in the same geographical region and in the same, or broadly similar, habitats, underscores the difficulty of detecting correlations between genetic variability and seemingly relevant ecological features of species.     

Sexual Discrimination Using Visual Cues in the Checkered White Butterfly (Pieris protodice)

The cues used by ♂♂ and ♀♀ of the checkered white butterfly, Pieris protodice, were explored using an assay that involved timing the responses of free-flying butterflies to tethered animals (“angling”). The models included ones that were made from the wings of ♂♂ and ♀♀ that had been extracted in a dilute ammonia solution. This procedure removes an ultraviolet-absorbing pigment from the wings and renders them more ultraviolet reflectant than normal without altering any other aspect of their coloration. The results show that both sexes make sexual discriminations using the sexual dimorphism in ultraviolet reflectance found in this species rather than using differences in the melanic markings on the wings, movement patterns, or chemical signals.     

Cellular Aspects of Hormonally Controlled Pigment Translocations Within Chromatophores of Poikilothermic Vertebrates

Pigment movements triggered by the vertebrate melanocyte-stimulatinghormone (MSH) are known to be mediated at the cellular levelby cyclic adenosine monophosphate (cAMP). A similar role forcAMP is indicated in the melanosome-dispersing action of catecholaminesacting via rß3-adrenergic receptors. Thus, MSH andrß3-adrenergic agonists cause an elevation of cAMPwithin chromatophores. On the other hand, a lowering of cAMPlevel seems to be associated with the paling action of melatoninand -adrenergic agonists. Depending upon the cell type and speciestested, cyclic guanosme monophosphate (cGMP) may have no effector cause either darkening or paling. Although cGMP induces palingin frog skin, the lack of evidence for a physiological palingagent makes it difficult to assign a role for cGMP The mechanismof action of cyclic nucleotides and the details of the pigment-translocatingmechanism are far from clear, but recent studies indicate thatchanges in free calcium ion levels play a critical role. Thisarticle will primarily review three areas' the paling actionof cGMP, the darkening action of ionophore A23187 [GenBank] , and the actionsof enkephalms and endorphins on chromatophores. In addition,new data are presented to support the concept that the A23187 [GenBank] -induceddarkening of frog skin does not involve either prostaglandinbiosynthesis or adenylate cyclase stimulation.