A mild winter delays supercooling point elevation in freeze tolerantChymomyza amoena larvae (Diptera: Drosophilidae)

Summary Supercooling point elevation to –3.2±1.3°C among 17 freeze tolerantChymomyza amoena larvae was delayed until January, 1983 in the mild winter of 1982–83 and occurred despite particulate matter in the gut. The larval population in mid-Michigan is polymorphic for both freeze tolerant and freeze sensitive larvae. One substrate,Malus coronaria fruits, appears to be a neutral niche supporting both phenotypes in the population.Discussions with K. E. Zachariassen and J. Duman before beginning the work onC. amoena cold-hardiness were invaluable. Visits of both at Michigan State University were jointly sponsored by the Depts. of Zoology and Entomology. H. Carson suggested thatC. ameona might be breeding in endemic crabapples. G. Parmalee at MSU showed one of us (HTB) a long established thicket ofMalus coronaria. The MSU Climatology Center supplied all Lansing area weather data.     

Overwintering ofChymomyza amoena larvae in apples in Michigan and preliminary studies on the mechanism of cold hardiness

Summary Chymomyza amoena, a member of the family Drosophilidae, is now breeding in fallen apples in the state of Michigan.C. amoena larvae can overwinter in fallen apples, completing development and emerging as adults in the summer. Cold resistance during the overwintering phase may not depend upon the accumulation of glycerol or other sugar alcohols.     

Aggregated oviposition byChymomyza amoena (Diptera: Drosophilidae)

Summary Aggregated oviposition byChymomyza amoena in Virginia and Michigan has been shown to be due to egg clustering, females attracted to fruits on whichC. amoena females have already oviposited, and to variation in fruit attractiveness. Negative binomialk values support behavioral similarities among females of this rarely seen species in both states. Discovery ofC. amoena in Europe may indicate that this larval overwintering drosophilid has a Holarctic distribution.The research in Virginia during summer 1986, conducted at Mt. Lake Biological Station, was supported by a fellowship from the University of Virginia. Thanks are gratefully extended to all property owners in Virginia and Michigan for allowing me to collect fruits and to Blaine Cole, Director and J.J. Murray, Chairman of the Biology Dept., University of Virginia for research space in 1986 and 1987. R. N. Band constructed the figures. Comments from reviewers have been helpful.     

Amino acid and allozyme frequency changes in overwinteringChymomyza amoena (Diptera: Drosophilidae) larvae

Summary Proline is accumulated by overwinteringC. amonea larvae. Mortality averages over 50% by spring. PGM^F in the population shifts from 70% in summer to less than 50% during winter, increasing again in summer. Product synthesis from stored glycogen may be mandated in dipteran larvae also using larval proteins for cold hardiness when completion of development is delayed until spring.Thanks are gratefully extended to Derek Lamport and Patrick Muldoon of the MSU/DOE Plant Biology Laboratory for the amino acid analyses. Thanks are also extended to Jerry Wolfe, Director of Mt. Lake Biological Station in summer, 1985 and Blaine Cole, Director beginning summer, 1986 for research space, to the University of Virginia, Charlottesville for a fellowship for the work at MLBS in summer, 1986 and to all the property owners in Michigan and Virginia who allowed collection at their orchards, farms, gardens or residences. Apples in January and March, 1986 were from a university research orchard. — This paper is dedicated to Hampton L. Carson on his retirement.     

The postpharyngeal glands and the cuticle of Formicidae contain the same characteristic hydrocarbons

Summary Comparison of the contents of the postpharyngeal gland and cuticular hydrocarbons of five species of ant have shown them to contain the same compounds and to be characteristic of the species. For four species (Formica selysi, Camponotus lateralis, Camponotus vagus andManica rubida), quantitative similarity was very close, but more divergent in the fifth (Myrmica rubra). Glands and cuticle ofM. rubra queens were shown to be closely similar to those of workers, except the glands of queens are larger, but the cuticle of larvae was different from that of adult cuticle and postpharyngeal glands.     

Conversion of clionasterol into both fucosterol and isofucosterol by the insectTenebrio molitor

Summary [7,7-³H₂]Clionasterol was synthesized and fed, together with [4-¹⁴C]sitosterol, toTenebrio molitor larvae; fucosterol and isofucosterol, recovered from the sterol fraction were found to be doubly labeled, indicating that clionasterol is converted into both the ethylidenic compounds.     

Desiccation in the black dragon,Hagenius brevistylus Selys

Summary Hagenius brevistylus lost mass by evaporation in a moderately desiccating environment at the rate of 20.4 mg h^–1, and died of desiccation in less than 1 day at a body mass of 79.8% of their normally hydrated mass. It was estimated thatHagenius minimally would have to consume the equivalent of 60% of its body mass each day to meet its daily water requirements. This amount of food is equivalent to that necessary to power flight of a dragonfly for 4.6h.This research was financed in part by a grant from the American Philosophical Society to C.R.T., and was conducted at the University of Michigan Biological Station, Douglas Lake (USA).     

Nachweis vonn-Butylamin in Äpfeln

Summary n-Butylamine, a new biogenic amine could be identified in apples by means of paper chromatography and micro-cristallography.     

Cryopreservation of parasites

Summary In this review, advances in cryopreservation of helminth parasites are reported. Our own studies demonstrate that metacestodes ofEchinococcus multilocularis can be maintained in a viable state for at least 1–2 years by appropriate deep-freezing and storage in liquid nitrogen. Infective larvae of the nematodeToxocara canis cryopreserved for 1 week in liquid nitrogen were maintained after thawing in vitro in a chemically defined medium for 35 weeks. Although motility of previously deep-frozen larvae was reduced they produced secretory/excretory antigens of similar immunodiagnostic quality as those from unfrozen larvae. Whereas infective larvae of several species of trichostrongylids can be easily cryopreserved, the infective larvae of the cattle lungworm,Dictyocaulus viviparus, and muscle larvae ofTrichinella spiralis are more sensitive to damage by subzero temperatures. Therefore, survival rates after cryopreservation are low, but improvement of the cooling schedules appears to be feasible. It is concluded that cryopreservation of certain stages of helminth and protozoan parasites is a useful technique for long-term storage of defined isolates, which can contribute considerably to reducing the number of experimental animals usually required for serial passages.     

Die Überwinterung des Erregers der Bitterfäule

Summary The cycle assuring infection of the fungusGlosporium fructigenum Berk. causing bitter-rot of cherries, rarely of apples and plums in Switzerland, is herewith discussed. The buds' raments on cherry-trees are discovered as new part of the cycle; the fungus can pass the winter in them as a parasit, just as it does in twigs. Probably the fungus begins to spread from the buds' raments in the following year.     

Influence of posttreatment temperature on the toxicity of pyrethroid insecticides to susceptible and resistant larvae of the Egyptian cotton leafworm,Spodoptera littoralis (Boisd.)

Summary The organophosphorus insecticides chlorpyrifos, leptophos, and phosfolan and the carbamate methomyl was found to be more toxic to larvae of a susceptible strain ofSpodoptera littoralis (Boisd.) when the posttreatment temperature was increased from 20 to 35°C. In contrast, the pyrethroids permethrin, fenvalerate, deltamethrin, cypermethrin, and flucythrinate were more toxic at 20°C than at 35°C. This effect was more pronounced in the pyrethroid-resistant strains. Evidently, resistance levels were reduced at low temperature. However, the application of piperonyl butoxide or DEF in combinations with the tested pyrethroids on R-strains resulted in reducing the effect of temperature.     

Exogenous melatonin and melanophore development inXenopus

Summary Xenopus larvae raised from stage 21 in melatonin solution and upon a dark background had fewer head melanophores at stage 48 than control animals not exposed to melatonin. Rearing larvae in melatonin solution seems to mimic rearing larvae on a light background.     

Der Vitaminbedarf des amerikanischen ReismehlkäfersTribolium confusum Duval

Summary As previously reported the larvae ofTribolium confusum require two unknown factors obtainable from yeast apart from various vitamines of the B-group for normal growth. One of these possesses acidic properties. This factor could be fully replaced by a folic acid preparation of potency 4000 kindly placed at our disposal by Prof.R. J. Williams. This may be regarded as a possibility but not as a proof that folic acid is the reported factor.

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C. A. Grob dankt der Haco-Gesellschaft AG., Gümligen, für die Unterstützung dieser Arbeit.     

Zuchtmethode und semisynthetische Nährmedien für Apfelwickler

Summary A method for the individual rearing of the codling mothLaspeyresia pomonella is described. The method allows the collection of exactly dated eggs and the rearing of a large number of larvae in a small space. By using the second medium described, it is possible to watch all developmental stages at any time without disturbing them. The average larval survival rate is 70–80%.     

Effect of hyperthermia upon gamma-ray induced crossing-over in an excision repair deficient maleDrosophila melanogaster

Summary Hyperthermia of 1 h at 38°C did increase gamma-ray induced crossing-over in meiotic cells of male larvae and adults. However, there was considerably less effect of the heat treatment upon radiation induced crossing-over (a chromosome breakage event) in an excision repair mutanty mei-9 ^a.5 January 1987     

Abbauprodukte von Simazin in Gramineen

Summary Coix lacryma-jobi L., about 20 days old and grown on watercultures, were fed with¹⁴C-ring-labelled simazine. After freeze drying, the plant tissue was extracted with chloroform and 80% ethanol. The ethanol extractable activities were fractionated on a cation exchange column. The radioactive metabolites seem to be identical with 2-hydroxy-4, 6-diethylamino-s-triazine (hydroxysimazine), 2-hydroxy-4, 6-diamino-s-triazine (ammelin) and 2-hydroxy-4-ethylamino-6-amino-s-triazine.     

Effects of the adenylate cyclase activator forskolin and its inactive derivative 1,9-dideoxyforskolin on insect cytochrome P-450 dependent steroid hydroxylase activity

The adenylate cyclase activator forskolin and its pharmacologically inactive derivative 1,9-dideoxyforskolin were found to inhibit in a dose-dependent fashion the ecdysone 20-monooxygenase activity associated with wandering stage larvae ofDrosophila melanogaster and fat body and midgut from last instar larvae of the tobacco hornworm,Manduca sexta. The concentrations of these labdane diterpenes required to elicit a 50% inhibition of the cytochrome P-450 dependent steroid hydroxylase activity in the insect tissues ranged from approximately 5×10^–6 to 5×10^–4 M.     

Beeinflussung der Borstendifferenzierung und Musterbildung durch Mitomycin beiDrosophila melanogaster

Summary Injection of mitomycin C into late third instar larvae ofDrosophila leads during metamorphosis to the differentiation of bristles without sockets and bracts, and to altered bristle patterns in structures of the integument.     

Analysis of the relationship between age of larvae at mutagen treatment and frequency and size of spots in the wing somatic mutation and recombination test inDrosophila melanogaster

The relationship between the induction of mutant clones and the time of mutagen treatment was studied in the somatic mutation and recombination test (SMART) in wing cells ofDrosophila melanogaster. Larvae trans-heterozygous for the recessive marker mutations multiple wing hairs (mwh) and flare (flr) were produced. Batches of these larvae were then treated with mutagen at different ages spanning all three larval instars. Methyl methanesulfonate was fed acutely for 2 h by immersing the larvae in a solution of the mutagen mixed with powdered cellulose. Wings of the surviving adult flies were mounted and scored for the presence of spots. The frequency and size of single and twin spots were recorded separately. Twin spots are produced exclusively by mitotic recombination, whereas single spots can results from various types of mutational and exchange events. There exists a clear correlation between time of induction and frequency as well as size of the single spots. In young larvae only few but very large spots are induced, whereas in older larvae the frequencies are considerably increased but the sizes are smaller. The twin spots show a different relationship. Practically no twin spots are found in very young and in very old larvae. The results demonstrate that in the wing spot test the optimal age of the larvae for mutagen treatment is 72 h.     

Chronic mercury vapor poisoning of aphids

Summary Exposure of green peach aphids,Myzus persicae (Sulz.), to an atmosphere containing mercury vapor resulted in a curtailment ofembryogenesis and larviposition by adults, and in the development by larvae and adults of a cuticular darkening of their legs, head capsule, antennae, cornicles and cauda. Mortality of affected larvae resulted from molting difficulties, particularly by last-instar alatiform female and male larvae. Greenbugs,Schizaphis graminum (Rond.), and pea aphids,Acyrthosiphon pisum (Harr.), responded to mercury vapor exposure in similar ways.