Cantharidin analogues and their attractancy for ceretopogonid flies (Diptera: Ceratopogonidae)

Several ceratopogonid flies are attracted to cantharidin and ingest it from both cantharidin-baits and from meloid beetles, one of the few known natural sources for cantharidin. Because meloids are absent in northern Bavaria, and certain canthariphilous flies of the genusAtrichopogon are temporarily associated with certain plants (Apiaceae, Aristolochiaceae), it was suggested that canthariphilous ceratopogonids might be generally attracted by chemically similar plant-derived compounds. At first the seasonal fluctuating attractancy, sex ratio and behaviour ofA. oedemerarum Storå was studied at cantharidin baits. Synthetic cantharidin analogues exhibited an attractancy forA. oedemerarum if the exo,exo-7-oxabicyclo[2.2.1]heptane skeleton of cantharidin was associated with a 2,3-dicarboxylic anhydride or a 2,3--lactone. According to structure-activity studies, the analogues seem to fit best into the active site of the receptor if the carbonyl function of the -lacton is in the exo- and 2-position. This is the first report indicating that molecules other than cantharidin are attractive for canthariphilous insects.     

A simple method for in vivo testing of glandular enzymatic activity on potential precursors of larval defensive compounds inPhratora species (Coleoptera: Chrysomelinae)

The presence of glandular -glucosidase and oxidase-specific activities, and the possible role of phenolglucosides and related compounds as precursors for larval defensive compounds, were directly demonstrated by introducing salicin, saligenin and helicin into the defensive glands ofPhratora species.Ph. tibialis andPh. laticollis that normally secrete endogenously-produced iridoid monoterpenes and do not use phenolglucosides from their food sources as precursors, were able to produce salicyladehyde from helicin when the latter was introduced into the defensive glands.     

The sensitive period for yellow phenocopy induction inDrosophila melanogaster

Summary Yellow phenocopies ofDrosophila melanogaster were produced by raising larvae on -DMT contaminated media. Using a survivorship test, the sensitive period for phenocopy induction was found to occur during the third larval instar of development, with increased survivorship at 1% -DMT compared with lower concentrations. It was also found that treatment with -DMT significantly slowed development. These findings are related to the relevant morphological and behavioral developmental pathways and to phenocopy induction.Publication No. 35 from the Evolutionary Genetics Laboratory, University of Auckland.Acknowledgments. We thank the New Zealand Entomology Society for a grant from their Anniversary Fund to R. D. Newcomb and the University Grants Committee, Research Grant No. 394.597 to D.M. Lambert.     

Gustatory sensitivity of an anuran to cantharidin

Summary Glossopharyngeal nerve stimulation of the bullfrog,Rana catesbiana revealed responsiveness to low levels of cantharidin (1.3×10^–6M), providing a first demonstration of neural gustatory sensitivity of an animal to this defensive chemical from blister beetles, (Meloidae).Acknowledgments. Study supported in part by grant AI 02908 from NIH.     

Transfer of cantharidin (1) during copulation from the adult male to the femaleLytta vesicatoria (‘Spanish flies’)

Summary Adult males of the spanish flyLytta vesicatoria (Meloidae, Coleoptera) are able to biosynthesize cantharidin (1) in copula after injection of E, E-11-(³H,¹⁴C)-farnesol and 2-¹⁴C-methylfarnesoate. During mating, the cantharidin biosynthesized in the males is transferred to the females, who are unable to biosynthesize cantharidin from any terpenoid precursors. After injection of (³H,¹⁴C)-cantharidin into males during copulation, more than 10% is transferred into the female sex organs. Males injected with 2-(³H,¹⁴C)-mevalonate 24–30 h prior to copulation transferred 93–98% of the biosynthesized cantharidin to the females during mating. After mating, the males continue to produce cantharidin. It seems that in the male the biosynthesis of cantharidin is stimulated during copulation.III. Communication on the Biosynthesis of Cantharidin; II. Communication¹⁶.Dedicated to ProfessorKurt Mothes' (Halle/Saale, DDR) 75th birthday, 4.11.1975. J. R. Sierra, Thesis in preparation University Zürich. J. R. S. thanks the Eidgenössischen Stipendienkommission für ausländische Studierende for a fellowship.Research supported by the Schweizerische Nationalfonds.     

Die Zucht vonLytta vesicatoria im Laboratorium und Nachweis der Cantharidinsynthese in Larven

Summary Adult males ofLytta vesicatoria (Coleopt., Meloidae) synthesize cantharidin, but females do not, although the substance is present in the females too. We developed a method for rearing larvae of this parasitic beetle in the laboratory. It is shown that there exist 7 larval stages and 4 hypermetamorphic forms (triungulinus, second larva,pseudochrysalis and fourth larva). Larvae from the second to the fifth stage (second larva) synthesize cantharidin. Therefore, we conclude that the substance present in the adult female is at least in part synthesized in the larval period. Nothing is known about the biological significance of this biochemical sexual dimorphism.

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Coleoptera, Meloidae.     

A cyanoglucoside stored by aSedum-feeding Apollo butterfly,Parnassius phoebus

A bitter tasting cyanoglucoside, sarmentosin, was isolated from an aposematic Apollo butterfly,Parnassius phoebus, and from its plant-host,Sedum stenopetalum. The content of sarmentosin in the body tissues was as high as 500 g/insect, suggesting a defensive role for this substance; a high concentration was detected in the wings. Sarmentosin was also present in the eggs.     

Evolutionary and ecological implications of cardenolide sequestration in the monarch butterfly

Summary Monarch butterflies sequester cardenolides from their larval host plants in the milkweed genusAsclepias for use in defense against predation. Of 108Asclepias species in North America, monarchs are known to feed as larvae on 27. Research on 11 of these has shown that monarchs sequester cardenolides most effectively, to an asymptote of approximately 350 g/0.1 g dry butterfly, from plants with intermediate cardenolide contents rather than from those with very high or very low cardenolide contents. SinceAsclepias host plant species are distributed widely in space and time across the continent, monarchs exploit them by migration between breeding and overwintering areas. After overwintering in central Mexico, spring migrants east of the Rocky Mountains exploit three predominantAsclepias species in the southern USA that have moderately high cardenolide contents. Monarchs sequester cardenolides very effectively from these species. First generation butterflies are thus well protected against predators and continue the migration north. Across the northern USA and southern Canada most summer breeding occurs on a fourthAsclepias species and in autumn most of these monarchs migrate back to Mexican overwintering sites. The ecological implications of this cycle of cardenolide sequestration for the evolution of monarch migration are discussed.     

Gustatory sensitivity of an anuran to cantharidin

Glossopharyngeal nerve stimulation of the bullfrog, Rana catesbeiana, revealed responsiveness to low levels of cantharidin (1.3 x 10(-6) M), providing a first demonstration of neural gustatory sensitivity of an animal to this defensive chemical from blister beetles (Meloidae).     

Individual recognition and incest avoidance in eusocial common mole-rats rather than reproductive suppression by parents

Non-reproductive females in families of eusocial common mole-rats (Cryptomys sp., Rodentia) are not suppressed by their mother, (either behaviourally or pheromonally) as is generally assumed. They do not mate with their father and brothers simply because they are not sexually attractive for them (and vice versa). The incest avoidance is based on the capability to recognize (and keep in memory for up to three weeks) each family member individually. A sterile daughter may conceive and deliver young in her parental family if given the opportunity to mate with an unfamiliar mate in a separate cage. In this way, two females may breed side by side in one family.     

Sexual dimorphism in the lipid fraction of the defensive secretion ofGastrophysa viridula (Coleoptera: Chrysomelidae)

The lipid fraction of the defensive secretion of adultGastrophysa viridula was analyzed by gas-liquid chromatography and gas chromatography-mass spectrometry. Three long chain acetates and two methyl-branched hydrocarbons were identified and their amounts in the secretion of single field-collected and laboratory-reared beetles determined. The composition of the secretion was affected by the sex, reproductive status, and age of the beetle. The ratio of (Z)-11-eicosenyl acetate to (Z)-13-docosenyl acetate ranged from 0.30 to 0.78 in male beetles and from 1.05 to 2.06 in female beetles. The biological significance of this sexual dimorphism is discussed.     

Pregnanes from defensive glands of a belostomatid bug

The aquatic bugAbedus herberti (Hemiptera: Belostomatidae) secretes a mixture containing four pregnanes (desoxycorticosterone (I), pregnenolone (II), progesterone (III), and 3-hydroxy-pregn-5-en-20-one (IV)) from its cephalic glands. Pregnanes had previously been characterized from the defensive glands of aquatic beetles (Dytiscidae) and shown to be deterrent to fish. It may be specifically under predation pressure from fish thatA. herberti and Dytiscidae evolved their comparable defenses.     

Effect of urochordamines on larval metamorphosis of ascidians

Two pteridine-containing bromophysostigmine alkaloids, urochordamine A and B, which were isolated from ascidians as larval metamorphosis promoters, were converted to more polar compounds, urochordamine A and B, respectively, when left standing in protic solvents. These four compounds promoted larval metamorphosis of the ascidianHalocynthia roretzi in the order A>A>B>B, and induced metamorphosis of the pediveliger larvae of the musselMytilus edulis galloprovincialis.     

Artificial triploid hybrids by interspecific mating ofOdontophrynus (Amphibia,anura)

Résumé Des hybrides triploïdes ont été obtenus par croisement deOdontophrynus cultripes, amphibien diploïde, avecO. americanus, tétraploide. Les hybrides interspécifiques présentent normalement 33 chromosomes dans les cellules somatiques. Les hybridesO. cultripes ×O. americanus sont plus viables que lesO. americanus ×O. cultripes .

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This work was supported by Public Health Service Research Grant No. GM-14577-02 from the National Institute of General Medical Sciences and by Fundo de Pesquisas do Instituto Butantan.     

Sclerotization of mosquito cuticle

Summary The mode of sclerotization ofAedes aegypti pupal and adult cuticle was examined by employing biochemical and radioactive techniques. During larval-pupal metamorphosis, tyrosine is converted to tanning precursors and is incorporated into aryl-amino adducts and -crosslinks. The major hydrolysis product of -crosslinks in pupal cases is identified to be arterenone. Examination of tanning modes in five different mosquito species shows that the ratio of quinone to -sclerotization not only differs within the life stages of the insects, but also differs between species.Study supported by N.I.H. Grant ROI-AI-14753.     

The toxicity of twoBacillus thuringiensis δ-endotoxins to gypsy moth larvae is inversely related to the affinity of binding sites on midgut brush border membranes for the toxins

Summary The-endotoxin fromBacillus thuringiensis subspecieskurstaki strain HD1-9 is almost 400 times more potent than the-endotoxin from strain HD-73 as a gypsy moth larvicide. The two-endotoxins compete for a high-affinity binding site on the brush border membrane of larval gypsy moth midguts. The affinity for the-endotoxin from strain HD-73 is much greater than the affinity for the-endotoxin from strain HD1-9.     

Identification of mucondialdehyde as a novel stress metabolite

In a survey of antifungal stress compounds induced by cupric chloride we found that leaves ofChenopodium album exuded a highly fungitoxic metabolite mucondialdehyde (trans-2,trans-4-hexadienedial), which was associated with 13-oxo-9,11-tridecadienoic acids (cis-9,trans-11 andtrans-9,trans-11 isomers) presumably resulting from -scission of 13-hydroperoxy-octadecadi(tri)enoic acid. The biogenesis and role as a general defensive agent in plants are briefly discussed.     

Involvement of circadian system in photoperiodic control of pubertal development in female deer mice,Peromyscus maniculatus

Summary Pubertal development in female deer mice,Peromyscus maniculatus, was stimulated by exposure to light cycles of LD 168, LD 630 or LD 654, but not by exposure to cycles of LD 618 or LD 642. These results support the hypothesis that female deer mice use a circadian rhythm of responsiveness to light to measure photoperiodic time.This investigation was supported in part by National Science Foundation Grant PCM 8116880 and U.S. Environmental Protection Agency Grant CR809428010. H.U. is the recipient of Research Ca-reer Development Award 5 KO4 HD00276-02 from the National Institute of Child Health and Human Development.     

Identification and seasonal quantification of defensive secretion components ofOreina gloriosa (Coleoptera: Chrysomelidae)

Tyrosine betaine, four new cardenolides (4, 5, 6, and7) and three known cardenolides (2, 3, and8) were isolated from the defensive secretion, of the leaf beetleOreina gloriosa and their chemical structure determined. 16 secretion components of individual beetles were quantified. Secretion composition of field-collected beetles was affected by season, sex and body weight.     

Structure revision and cytotoxicity of the germacranolide,stizolicin, fromStizolophus balsamitus (Asteraceae)

Summary The structure of the cytotoxic sesquiterpene lactone, stizolicin, reisolated fromStizolophus balsamitus (Centaurea b.) was revised to atrans, trans germacranolide (1) on the basis of simultaneous application of lanthanide shift reagent and NOE in the NMR.The authors acknowledge the use of the Purdue University Biomedical Magnetic Resonance Laboratory (NIH grant No. RR01077). Support of contract No. N01-CM-97296 and Grant No. CA-33326 from the National Cancer Institute, HHS is gratefully acknowledged. This is paper 18 in the series Potential Antitumor Agents.