bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of 28‐ and 27‐Carbon ecdysteroids and sterols in developing worker pupae of the leaf‐cutting ant acromyrmex octospinosus (reich) (hymenoptera, formicidae: Attini)
Authors: Maurer Patricia , Royer Corinne , Mauchamp Bernard , Porcheron Patrick , Debieu Danièle , Riba Guy
Published: February 2005

The major ecdysteroids in large worker pupae of the leaf‐cutting ant Acromyrmex octospinosus were characterized at the peak ecdysteroid concentration by using high‐performance liquid chromatography, enzyme immunoassay, and mass spectrometry. In decreasing amounts, they were determined to be makisterone A, an unidentified C28 ecdysteroid bearing a molecular weight of 494, 20‐hydroxyecdysone (ratio of 1 to 6 as compared to makisterone A), and putative but negligible ecdysone. The presence of both C28 and C27 ecdysteroids is discussed in relation to the content of 4‐desmethylsterols determined by gas chromatography and mass spectrometry to be ergosta‐5,7,24 (28)‐trien‐3β‐ol, ergosterol, ergosta‐5,7‐dien‐3β‐ol and ergosta‐7,24(28)‐dien‐3β‐ol for the main sterols, and with a small amount of cholesterol.
Action of Taurine, 3‐aminopropanesulfonic acid, and GABA on the hindgut and heart of the cockroach, Leucophaea maderae
Authors: Wagner Renée M. , Cook Benjamin J. , Cooper June F.
Published: February 2005

Taurine, glycine, glutamate, and γ‐aminobutyric acid (GABA) were all present in concentrations of greater than 1% of the total free amino acid content in the brain, thoracic, and abdominal ganglia of Leucophaea maderae. Hemolymph, subesophageal ganglia, and hindgut had substantial amounts of glutamate and glycine, but less than 0.3% taurine or GABA. Taurine, 3‐aminopropanesulfonic acid (3‐APS), cysteine‐sulfinic acid (CSA), and GABA each had myotropic activity on the isolated cockroach hindgut, with 3‐APS having the most consistent effect (ED50 = 0.63 mM), while taurine and CSA activities were similar to that of GABA on the hindgut. Both taurine and 3‐APS had anti‐arrhythmic effects on semi‐isolated heart preparations of L. maderae, while GABA was inhibitory and induced arrhythmia. Bicuculline was antagonistic to the effects of GABA, taurine, and 3‐APS on the hindgut, and induced arrhythmia in heart preparations; this arrhythmia was reversible by taurine, but not by GABA or 3‐APS.
Two‐step regulation of sex‐pheromone decline in mated gypsy moth females
Authors: Giebultowicz Jadwiga M. , Raina Ashok K. , Uebel Edward C. , Ridgway Richard L.
Published: February 2005

The regulation of post‐mating decline of sex‐pheromone in the gypsy moth, Lymantria dispar, was studied. An initial, transient suppression of pheromone production was found to be caused by the introduction of male genitalia into the bursa copulatrix, which results in mechanical pressure being transmitted via innervation of the bursa. However, if sperm was not transferred during mating, pheromone production resumed and females returned to calling behavior. Permanent suppression of pheromone production resulted from an adequate supply of sperm in the spermatheca and could be prevented in females from which spermatheca was removed. During the initial period of suppression of pheromone production females were sexually receptive and could remate. They became nonreceptive only when pheromone production was terminated and oviposition begun.
Musca domestica larval lipoprotein
Authors: de Bianchi Antonio G. , de L. Capurro Margareth
Published: February 2005

A larval specific high‐density lipoprotein (HDL) has been isolated from Musca domestica hemolymph by a combination of density gradient and glycerol gradient ultracentrifugations. The larval lipoprotein has a density of 1.134 g/ml and is formed by at least four apoproteins with molecular weights equal to 26,000, 23,000, 21,000, and 20,000. This lipoprotein contains large amounts of hydrocarbons and phospholipids and minor amounts of diacylglycerols and cholesterol. The larval lipoprotein is completely distinct from lipophorin in regard to apoprotein composition, lipid moiety, physiological pattern, and immunological reactions. Larval lipoprotein is accumulated until the end of the feeding period. During the pupal molt this protein is utilized and is no longer detected after 2 days of pupal stadium. The results obtained imply a possible role of this protein in the puparia and/or pupal cuticle formation. Judging from the properties shown, the Musca domestica larval lipoprotein is a completely new type of insect lipoprotein.
Identification of vitellogenin in the ant, camponotus festinatus: Changes in hemolymph proteins and fat body development in workers
Authors: Martinez Teresa , Wheeler Diana
Published: February 2005

Vitellogenin has been identified in the ant Camponotus festinatus, both in queens and workers. In the workers, it is already present before adult eclosion in low concentrations (<1 μg/μl hemolymph). Vitellogenin and vitellin are immunologically identical and are composed of a single type of apoprotein with an apparent Mr = 185,000. The molecular weight of the native molecules was estimated as ∼460,000 by pore limiting gradient electrophoresis. Vitellogenin was detected as a major protein in the hemolymph of young workers, both under queenright and queenless conditions. Thus, in spite of their sterility in the presence of the queen, C. festinatus workers are able to synthetize vitellogenin which is identical both in size and immunologically to the queen vitellogenin. About 6–7 weeks after adult eclosion, however, vitellogenin was usually undetectable in the hemolymph of queenright workers, particularly the minor workers, while it constituted about 30% of total protein in queenless workers. Protein concentration in the hemolymph of queenless insects increased up to 20‐fold as compared to 1‐day‐old insects. Queenless workers also developed large amounts of perivisceral fat body, while queenright workers, particularly the minor workers, showed a dramatic fat body regression about 6 weeks after emergence.
Binding of vitellogenin to membranes isolated from mosquito ovaries
Authors: Dhadialla Tarlochan S. , Raikhel Alexander S.
Published: February 2005

The presence of specific receptors for vitellogenin (Vg) in ovary membranes of the mosquito, Aedes aegypti, was demonstrated by an in vitro binding assay. The binding reaction, which is dependent on pH and Ca2+, uses 4 μg membrane protein, 35S‐Vg labeled metabolically by fat body culture in vitro, and unlabeled vitellin (Vn) for competition. At pH 7.0 and in the presence of 5 mM Ca2+, the binding of Vg to its receptor reaches equilibrium within 60–90 min at both 4 and 25°C. The binding is specific to membranes prepared only from ovaries. While mosquito Vg and Vn bind with equal affinity to Vg receptors on ovary membranes, neither locust Vg nor mouse IgG has any measurable affinity towards these sites. Nonlinear least square analysis of the saturation isotherms is consistent with the presence of a single class of Vg receptors on ovary membranes with a dissociation constant (Kd) of 0.18 μM.
Makisterone C: A 29‐carbon ecdysteroid from developing embryos of the cotton stainer bug, Dysdercus fasciatus
Authors: Feldlaufer Mark F. , Weirich Gunter F. , Lusby William R. , Svoboda James A.
Published: February 2005

An ecdysteroid RIA was used to determine the ecdysteroid titer in developing embryos of Dysdercus fasciatus and revealed that peak titer occurred approximately 120 h post‐oviposition. Analysis of neutral sterols at this time indicated sitosterol to be the predominant neutral sterol with lesser amounts of campesterol. Embryonic sterols were highly reflective of the sterols found in the cotton seed diet upon which previous generations of the bugs had fed. Analysis of the embryonic extract for ecdysteroids indicated the presence of both makisterone A and the 29‐carbon ecdysteroid makisterone C. Isolation of these compounds was accomplished by reversed‐phase and silica HPLC in conjunction with RIA, and the identification of both compounds was confirmed by mass spectrometry. No ecdysone or 20‐hydroxyecdysone was detected in the embryonic sample.
Biosynthesis of a volatile, methly‐branched hydrocarbon sex pheromone from leucine by arctiid moths (Holomelina spp.)
Authors: Charlton Ralph E. , Roelofs Wendell L.
Published: February 2005

The biosythesis of 2‐methylheptadecane was investigated in three moth species, Holomelina lamae, H. immaculata, and H. aurantiaca, all of which use this hydrocarbon as the principal component of their volatile sex pheromone. Following injection into adult females, deuterium‐labeled leucine and isovaleric acid were readily incorporated into pheromone but valine and isobutyric acids were not. Radiolabeled acetate and malonic acid also gave good incorporation into pheromone as did 13‐methyltetradecanoic acid and 15‐methlhexadecanoic acid. These findings support a biosynthesis pathway whereby leucine is converted to isovaleric acid, which serves as the methly branch donor and chain initiator; malonic acid donates seven additional 2 carbon units to from 17‐methloctadecanoic acid, which is then deccarboxylated to produce the odd‐carbon chain hydrocarbon pheromone. Methyl‐branched fatty acids were detected in only small amounts or were absent in pheromone gland extracts, and among the different glandular lipid classes, labeled leucine and acetate were only incorporated into hydrocarbons. These findings suggest that onceinitiated, biosynthesis of the pheromone proceeds rapidly with little or no accu mulation of intermediates and/or that the pheromone or some long‐chain intermediate is biosynthesized elsewhere in the insect and transported to the gland.
Gut chitin synthase and sterols from larvae of Diaprepes abbreviatus (Coleoptera: Curculionidae)
Authors: Ward Gordon B. , Mayer Richard T. , Feldlaufer Mark F. , Svoboda James A.
Published: February 2005

Gut chitin synthase was characterized and the sterols and ecdysteroids in the sugarcane rootstalk borer weevil, Diaprepes abbreviatus, were identified. An in vitro cell‐free chitin synthase assay was developed using larval gut tissues from D. abbreviatus. Subcellular fractionation experiments showed that the majority of chitin synthase activity was located in 10,000g pellets. The gut chitin synthase requires Mg2+ to be fully active: 7–8‐fold increases in activity were obtained with 10 mM Mg2+ present in reaction mixture. Calcium also stimulated activity (4–5‐fold with 10 mM Ca2+), while Cu+2 completely inhibited at 1 mM. Other monovalent and divalent cations had little or no effect on activity. The pH and temperature optima were 7 and 25°C, respectively. Gut chitin synthesis was activated ca. 50% by trypsin treatments. GlcNAc stimulated chitin synthase activity, but Glc, GlcN and glycerin did not. Polyoxin D, UDP, and ADP inhibited the chitin synthase reaction with I50's of 75 μM, 2.3 mM, and 3.6 mM, respectively. Nikkomycin Z was a potent inhibitor of chitin synthase (91% inhibition at 10 μM). Tunicamycin and diflubenzuron had no effect on the enzyme. The apparent Km and Vmax for the gut chitin synthase were, respectively, 122.5 ± 7.4 μM and 426 ± 19.7 pmol/h/mg protein utilizing UDP‐GlcNAc as the substrate. Sterol analyses indicated that cholesterol was the major dietary and larval sterol. HPLC/RIA data indicated that 20‐hydroxyecdysone was the major molting hormone.
Spatial and temporal distribution of pheromone biosynthesis‐activating neuropeptide in Helicoverpa (Heliothis) armigera using RIA and in vitro bioassay
Authors: Rafaeli Ada , Hirsch Jaquelyn , Soroker Victoria , Kamensky Batya , Raina Ashok K.
Published: February 2005

A [3H]‐PBAN (pheromone biosynthesis‐activating neuropeptide) analog was synthesized, and binding of the radioligand to a specific PBAN‐antiserum was achieved. The inhibition of binding of the radioligand by unlabeled PBAN, several PBAN analogs, and other competitors was studied and a specific radioimmunoassay was developed. Using this radioimmunoassay we found PBAN‐like immunoreactivity in methanol extracts of hemolymph and neural tissues from females. Higher levels of PBAN‐like immunoreactivity in extracts of brain‐suboesophageal ganglion complexes, corpora cardiaca, thoracic ganglia, and abdominal ganglia were observed during the 4‐5th h scotophase when compared to the PBAN‐like immunoreactivity levels during the 6–11th h photophase. On the other hand, the concentrations of PBAN‐like immunoreactivity in the terminal abdominal ganglion were higher during the photophase relative to minimal levels observed during the scotophase, indicating an accumulation before the onset of pheromone production. These differences in concentrations of PBAN were also reflected in the stimulation of in vitro pheromone glands, whereby significant stimulations were obtained by scotophase and photophase brain extracts, scotophase thoracic ganglia extracts, and photophase terminal abdominal ganglia extracts. No detectable levels of PBAN were found in hemolymph extracts during the sampling periods.
Functional assay for GABA receptor subtypes of a cockroach giant interneuron
Authors: Hue Bernard
Published: February 2005

γ ‐ Aminobutyric acid (GABA) receptors were examined in the cockroach central nervous system (CNS) using the single fiber‐oil gap method applied to an identified giant interneuron. Short‐lasting pressure application of 10 mM GABA developed a multiphasic response composed of a fast hyperpolarization followed by a transient depolarizing component and a stable hyperpolarization. This triphasic characteristic shape of the response was modified according to the dose of GABA injected or bath‐applied and to the precise localization of the injection within the dendritic area. The transient depolarizing phase showed a negative reversal potential of −70 mV. Both hyperpolarizing phases reversed at a more negative level ranging to −80 mV. A positive shift of these values was caused by a decrease in external chloride concentration. Bath‐application of 0.1 mM picrotoxin (Ptx) decreased the depolarizing phase which was progressively replaced by a stable hyperpolarization. The transient depolarizing component desensitized quickly and was the most sensitive phase to Ptx action. The Ptx‐resistant response reversed at a mean value of −100 mV close to the equilibrium potential for potassium ions (EK+), suggesting that it was generated by a K+‐channel coupled receptor. Although baclofen was unable to mimic the Ptx‐resistant GABA response, the compound CGA 147823, known to bind with a high specificity to vertebrate GABAB receptors, has been successfully used to reproduce the Ptx‐resistant GABA response. It is suggested that, in addition to GABA receptors linked to chloride channels, the insect CNS possesses GABA receptors sharing ionic characteristics of GABAB receptors especially those located in the vertebrate CNS, although they are insensitive to baclofen.
Parasite‐induced enhancement of hemolymph tyrosinase activity in a selected immune reactive strain of Drosophila melanogaster
Authors: Nappi Anthony J. , Carton Yves , Frey Francoise
Published: February 2005

Larval hemolymph tyrosinase activity in Drosophila melanogaster was detected with high performance liquid chromatography with electrochemical detection. The enzyme hydroxylated L‐tyrosine, and oxidized the diphenol substrates L‐dopa and dopamine. In larvae of a selected immune‐reactive strain the rates of tyrosine hydroxylation, dopa oxidation, and dopamine oxidation were markedly increased during the early stages of melanotic encapsulation of the eggs of the parasitic wasp Leptopilina boulardi. Tyrosinase activity was not modified in parasitized larvae of a selected susceptible strain of D. melanogaster, in which hosts the parasitoids developed unmolested. During the same period of parasitization, the amount of free tyrosine in immune reactive larvae was approximately three times higher than in susceptible hosts. These data indicate that the tyrosinase system of the immune reactive strain is activated during parasitization, and this results in the synthesis of some precursors which ultimately produce a melanotic and sclerotic capsule around the eggs of the parasite. Based on known genetic information of the enzyme system in Drosophila, it appears that at least two genes may be involved in the activation process, one associated with the proenzyme for monophenol oxidase activity, and the second with the proenzyme for diphenol oxidase activity.
Stimulation of embryonic development in microplitis croceipes (Braconidae) in cell culture media preconditioned with a fat body cell line derived from a nonpermissive host, gypsy moth, Lymantria dispar
Authors: Ferkovich Stephen M. , Dillard Charles , Oberlander Herbert
Published: February 2005

A cell culture medium, IPL‐52B, was preconditioned with host fat body and two insect cell lines to determine if they would support embryonic development of Microplitis croceipes in vitro. The medium was preconditioned with the cell line IPL‐LdFB, derived from fat body of the gypsy moth, Lymantria dispar, cell line IAL‐TND1, derived from imaginal discs of the cabbage looper, Trichoplusia ni, and whole fat body tissue from host Helicoverpa zea. A second cell culture medium, Excell 400, was preconditioned with only the cell line, IPL‐LdFB. Pregerm band eggs were dissected from third instar host larvae and incubated in the conditioned medium for 20 h. Newly laid parasitoid eggs did not develop in unconditioned IPL‐52B, but did develop to germ band stage in unconditioned Excell 400. The IPL‐52B medium conditioned with both cell lines induced germ band formation, but only the L. dispar cell line (IPL‐LdFB) promoted significant development to eclosion comparable to host fat body tissue. Excell 400 medium preconditioned with the cell line, IPL‐LdFB also supported development to eclosion.
Temporal molt inhibition by anti‐ecdysone serum injected into lepidopteran larvae
Authors: Birkenbeil Heiner , Eckert Manfred
Published: February 2005

Injections of an anti‐ecdysone serum into Galleria mellonella L. after the beginning of the wandering stage of the last instar resulted in delayed pupation. Injections before this time did not produce this effect and simultaneous injection of antiserum together with 20‐hydroxyecdysone leads to immediate initiation of molt. Immunocytochemical studies demonstrated the anti‐ecdysone serum specifically bound to the prothoracic glands labeling the peripheral extracellular lacunar system and sites of ecdysteroid release.
Neuromodulator octopamine attenuates extrajunctional glutamate sensitivity in insect muscle
Authors: Yamamoto Daisuke , Ishikawa Sachiyo
Published: February 2005

Octopamine was found to decrease extrajunctional, but not junctional glutamate responses, in mealworm neuromuscular preparations. This action of octopamine was mimicked by forskolin, 8‐(4‐chlorophenylthio)‐adenosine 3′:5′‐cyclic monophosphate (CPT‐cyclic AMP), and 8‐bromoguanosine 3′:5′‐cyclic monophosphate (8‐bromo‐cyclic GMP), but not by 1,2‐oleoylacetylglycerol (OAG), a protein kinase C activator. We suggest that the octopamine‐induced reduction in the glutamate sensitivity of extrajunctional membranes may enable the muscle to more closely follow its neuronal input by preventing a depolarization (and hence a conductance increase) due to the discharge of unsequestered transmitter molecules at nonsynaptic sites.
Bacteria‐induced protein P4 (hemolin) from Manduca sexta: A member of the immunoglobulin superfamily which can inhibit hemocyte aggregation
Authors: Ladendorff Noma E. , Kanost Michael R.
Published: February 2005

The synthesis of a number of hemolymph proteins is induced in insects in response to bacterial infections. The major induced hemolymph protein in larvae of Manduca sexta is a glycoprotien of Mr = 48,000 known as P4. We have isolated a clone for P4 from a fat body cDNA library constructed from RNA isolated from larvae injected with bacteria. The cDNA has an open reading frame encoding a 411 residue polypeptide with a hydrophobic NH2‐terminal sequence, which appears to be a signal peptide. Analysis of the deduced amino acid sequence shows that P4 is a member of the immunoglobulin (Ig) gene superfamily, and is composed largely of four C2 type Ig domains. The M. sexta P4 amino acid sequence is 60% identical with hemolin (P4) from Hyalophora cecropia. The name “hemolin” has also been adopted for the M. sexta P4 protein. Hemolin mRNA levels in fat body begin to increase within 1 h after injection of bacteria into fifth instar larvae and within 4 h after injection of adults. Hemolin associates with the surface of hemocytes and inhibits hemocyte aggregation responses, suggesting a role for the protein in modulating hemocyte adhesion during recognition and response to bacterial infections in insects.
Comparative metabolism of isoleucine by corpora allata of nonlepidopteran insects versus lepidopteran insects, in relation to juvenile hormone biosynthesis
Authors: Brindle Philip A. , Baker Fred C. , Tsai Leslie W. , Schooley David A.
Published: February 2005

We studied the metabolism of [U‐14C]isoleucine by intact and homogenized corpora allata (CA) from various insect species to determine how this substrate is converted to precursors of juvenile hormone (JH). CA homogenates of the lepidopterans Manduca sexta, Hyalophora cecropia, and Samia cynthia metabolize [U‐14C]isoleucine to several products including 2‐keto‐3‐methyl‐valerate, 2‐methylbutyrate, CO2, propionate, and acetate. Intact CA of male H. cecropia produce particularly high levels of 2‐keto‐3‐methylvalerate, indicating a highly active branched‐chain‐amino acid transaminase. In contrast, CA homogenates from the nonlepidopterans Periplaneta americana, Schistocerca nitens, Tenebrio molitor, and Diploptera punctata barely metabolize [U‐14C]isoleucine. However, P. americana CA homogenate metabolizes [U‐14C]2‐keto‐3‐methylvalerate, the transamination product of [U‐14C]isoleucine, more rapidly than does a homogenate of M. sexta CA. Furthermore, intact CA from P. americana incubated with [U‐14C]2‐keto‐3‐methylvalerate incorporate low levels of 14C into JH III, but do not metabolize this substrate to JH II or JH I. Intact CA from female Diploptera punctata produce very high levels of JH III, but are also unable to incorporate radiolabel from [U‐14C]isoleucine into JH III, which substantiates our findings with other nonlepidopteran CA. The results suggest that CA of nonlepidopteran insects lack an active branched‐chain amino acid transaminase and, consequently, are unable to utilize these substrates for JH biosynthesis.
Reduced neuronal sensitivity to dieldrin and picrotoxinin in a cyclodiene‐resistant strain of Drosophila melanogaster (Meigen)
Authors: Bloomquist Jeffrey R. , Roush Richard T. , Ffrench‐Constant Richard H.
Published: February 2005

Toxicological and neurophysiological studies were performed to characterize the resistance mechanism in a cyclodiene‐resistant strain of Drosophila melanogaster (Maryland strain). Dieldrin had an LC50 of 0.058 ppm against the larvae of susceptible D. melanogaster (Oregon‐R wild type) when formulated in the rearing media. The LC50 of the resistant Maryland strain was 10.8 ppm, giving a resistance ratio (LC50‐Maryland/LC50‐susceptible) of 186‐fold. Suction electrode recordings were made from peripheral nerves of the larval central nervous system of test whether reduced nerve sensitivity played any role in the observed resistance. In susceptible preparations (n = 5), inhibition of nerve firing by 1 mM γ‐aminobutyric acid (GABA) was effectively antagonized within 3–10 min by 10 μM dieldrin. In contrast, 30 min incubations with 10 μM dieldrin had no effect on preparations from cyclodiene‐resistant individuals (n = 5). Similarly, 10 μM picrotoxinin blocked GABA‐dependent inhibition in susceptible nerve preparations (n = 3). In recordings from resistant insects (n = 4), picrotoxinin displayed either weak antagonism of GABA or hyperexcitation indistinguishable from susceptible preparations. These results demonstrate that cyclodiene resistance in the Maryland strain of D. melanogaster (1) is expressed in immature stages, (2) is present at the level of the nerve, and (3) extends to picrotoxinin, albeit at a reduced level compared with dieldrin. The possible role of an altered GABA receptor in this resistance is discussed.
Ascorbate oxidation reduction in Helicoverpa zea as a scavenging system against dietary oxidants
Authors: Felton Gary W. , Duffey Sean S.
Published: February 2005

We provide evidence of an important role for ascorbate free radical (AFR) reductase, dehydroascorbate (DHA) reductase, glutathione, and glutathione reductase as components of an oxidant‐scavenging system in the midgut of larval Helicoverpa zea. Also, midgut ortho‐quinone reductase is a potentially important constituent of the protective system against quinones. The midgut activities of AFR reductase, DHA reductase, glutathione reductase, and ortho‐quinone reductase were, respectively, 168, 22.1, 6, and 39.5 nmol/min/mg protein. The relatively high activity of these enzymes in the midgut provides circumstantial evidence for a protective mechanism utilizing ascorbate as an antioxidant and glutathione and/or NADPH as reductants. To our knowledge, the enzymes AFR reductase and DHA reductase have not been reported in insects. The particular relevance of this system to antioxidant protection, and in particular to the detoxication of quinones formed in damaged leaf tissues, is discussed.
Sublethal effects of chlordimeform on chemical communication and other reproductive behaviors in the female cabbage looper moth (Lepidoptera: Noctuidae)
Authors: Clark Deborah Campero , Haynes Kenneth F.
Published: February 2005

Insecticides can affect the complex coordination of activities associated with reproduction through their sublethal impact on the nervous system. Our objective was to document the effects of a sublethal dose (1% mortality) of chlordimeform on reproductive events in the female cabbage looper moth, Trichoplusia ni. A significantly higher percentage of females treated with chlordimeform initiated calling at some time during the scotophase. Chlordimeform stimulated pheromone emission early in the scotophase. However, late in the scotophase pheromone emission was significantly lower in chlordimeform‐treated females when compared with control females. Overall, a lower amount of pheromone was detected in glands of chlordimeform‐treated females. This effect was significant only during the second half of the scotophase. We suggest that chlordimeform stimulates pheromone transport to the gland surface and calling behavior resulting in depletion of pheromone reserves over the course of the scotophase. Chlordimeform also decreased the mating success of males. Oviposition and egg hatch were also affected by chlordimeform. Mated females treated with chlordimeform laid significantly fewer eggs than acetone‐treated females. In addition, hatchability of eggs laid by mated female T. ni treated with chlordimeform was significantly lower than for eggs laid by control females.
Further characterization of nuclear DNA RFLP markers that distinguish African and European honeybees
Authors: Hall H. Glenn
Published: February 2005

Two nuclear honeybee DNA probes, 12R1C1 and 2A2, were reported previously to detect restriction fragment patterns specific to African and neotropical African honeybee populations. Individual drones and workers from several additional Old and New World populations, African and European, were tested further with these probes. With probe 12R1C1, only two of several Hhal fragment patterns were seen among haploid drone progeny of each queen bee, indicating that the patterns represented alleles at a single locus. Four alleles detected by probe 12R1C1 were described previously, three of which had been found only in populations of African descent. In this study, one of the three was found at a low frequency among samples from western Europe, northern Mexico, and the United States. However, ten additional alleles were discovered in South African drones, six of which were seen also in neotropical African colonies. With probe 2A2, only one or the other of two Alul restriction fragments was detected in drones indicating that the fragments represented alles at a single locus. One of the two alleles, seen previously only in populations of African descent, was found at a very low frequency in bees from western Europe and northern Mexico.
Degradation of the neuropeptide proctolin by membrane bound proteases of the hindgut and ovary of Locusta migratoria and the effects of different inhibitors
Authors: Puiroux Jacques , Loughton Barry G.
Published: February 2005

Proctolin was incubated in vitro with crude membrane preparations derived from hind gut and ovary of Locusta migratoria. The metabolites of proctolin were separated and identified by reversed phase‐high performance liquid chromatography which allowed the determination of the time course of degradation. At pHs 9.2 and 7.4, aminopeptidase activity predominated but some evidence of a carboxypeptidase could be inferred. At pH 6, aminopeptidase activity was slightly reduced compared to the level of aminopeptidase activity at the two former pHs; by contrast the carboxypeptidase was more important. At this pH, the presence of a membrane bound endopeptidase was detected.

Phenanthroline, actinonin, amastatine, bestatin, and (2S,3R)‐3‐amino‐2‐hydroxy‐4‐(4‐nitrophenyl)‐butanoyl‐L‐leucine (HNBL) were tested at the concentration of 0.1 mM at pHs 8.2 and 6 and their ability to prevent the degradation of proctolin was estimated. A both pHs, HNBL and amastatin were revealed to be the most efficient inhibitors (50 to 75% inhibition) and o‐phenanthroline appeared particularly efficacious at pH 6 (70% inhibition), whereas it was relatively poor inhibitor at pH 8.2. Furthermore, the use of these inhibitors confirmed the importance of carboxypeptidase activity at pH 6.

These data are the first to describe proctolin degradation in ovary and hindgut muscle, important targets of proctolin action.
Selectivity in storage hexamerin clearing demonstrated with hemolymph transfusions between Hyalophora cecropia and Actias iuna
Authors: Pan Muh‐Liang , Telfer William H.
Published: February 2005

When Hyalophora cecropia hemolymph was injected into wandering Actias Iuna Iarvae, a methionine‐rich hexamerin was selectively transferred to the host's fat body, and completely cleared from the hemolymph by the time of pupal eclosion. Donor arylphorin was 30–40% removed from the hemolymph, and riboflavin‐binding hexamerin was even less completely cleared. During the pupal‐adult molt, these rates were reversed: methionine‐rich hexamerin disappeared no faster than bovine serum albumin, while riboflavin‐binding hexamerin was rapidly and completely cleared from the hemolymph, even though A. Iuna hemolymph lacks a homologue of this protein; arylphorin, again, was cleared at an intermediate rate. Selective clearing of the three hexamerins occurred at similar stages in H. cecropia, their species of origin.

Developmentally programmed clearing, with selectivity at least partially conserved between genera, was also demonstrated with transfused vitellogenin: in A. Iuna females that were forming yolk, H. cecropia vitellogenin was cleared more rapidly than bovine serum albumin; but in younger females, and in males at all stages of metamorphosis, this Mr 510,000 molecule was instead an indicator of nonselective, large protein clearing.

Nonselective clearing was more complete during adult development than during pupation. It also showed signs of being more effective for small than for large proteins, insensitive to carbohydrate conjugates, and unsaturated at the protein levels used.
Cyanoprotein: Developmental stage, sex and diapause‐dependent expression, and synthesis regulation by juvenile hormone in the bean bug, Riptortus clavatus
Authors: Chinzei Yasuo , Miura Ken , Kobayashi Lumi , Shinoda Tetsuro , Numata Hideharu
Published: February 2005

Cyanoprotein (CP) synthesis was studied in nymphal and nondiapause adult, diapause adult, and juvenile hormone (JH) treated adult bean bugs, Riptortus clavatus. Hemolymph collected from bugs injected with [35S]‐methionine was analyzed by native polyacrylamide gel electrophoresis (PAGE) and fluorography, and CP synthesis was also determined quantitatively by rocket immunoelectrophoresis of hemolymph and counting. In the nymphal stages synthesis of CP‐1, 2, 3, and 4 (with CP‐4 synthesis predominant) reached a maximum at mid‐instar and was not detected at each ecdysis, so that the synthetic activity of CPs changed cyclically in each instar. During the nymphal stages CP synthesis showed the same pattern and level in both females and males, and both diapause and nondiapause oriented bugs. In the adult stage, however, CP synthesis differed in the two sexes and nondiapause or diapause conditions. In nondiapause males CP synthesis was not detected in the adult, but in nondiapause females CP (only CP‐1) was synthesized through the reproductive stages. CP‐1 accumulated in the egg yolk together with vitellogenin. In diapause adults (both females and males) CP‐1 to 4 were synthesized at a very low rate for over 2 months and accumulated in the hemolymph. JH or JH analog (JHA) methoprene and also long day condition, which terminate diapause, switched the main CP synthesis CP‐4 to CP‐1 in females. CP synthesis in diapause males stopped after JH(A) treatment. The activities of CP synthesis, thus, changed in developmental stages, sexes, and diapause. This is an excellent system for study of specific gene expression and switching controlled by insect hormones and sex. © 1992 Wiley‐Liss, Inc.
Juvenile hormone metabolism in the plasma, integument, midgut, fat body, and brain during the last instar of the tobacco hornworm, Manduca sexta (L.)
Authors: Jesudason Princy , Anspaugh Douglas D. , Roe R. Michael
Published: February 2005

Juvenile hormone (JH) III esterase and JH III epoxide hydrolase activity was found in the integument, midgut, fat body, and brain during last instar development of the tobacco hornworm, Manduca sexta. JH esterase activity was primarily located in the cytosol in these tissues while the majority of the JH epoxide hydrolase activity was found in the microsomes. A prewandering (on day 3) and postwandering (on day 8) peak in plasma JH III esterase activity occurs in the last instar of gate I M. sexta. The JH esterase activity profile in integument, midgut, fat body, and brain followed a similar pattern to that of the plasma. The only exception to this was the absence of the postwandering, prepupal (on day 8) JH esterase peak in the fat body. The topical application of the juvenoid, (RS)‐methoprene, failed to induce fat body JH esterase activity but increased activity in the plasma, integument, midgut, and brain in M. sexta prepupae. These results indicate that the source of plasma JH esterase activity is not always the fat body as previously hypothesized. The developmental profile of tissue JH epoxide hydrolase activity was also similar to that of JH esterase suggesting that both enzymes may be regulated partly by the same factors and that JH epoxide hydrolase may also have an important, previously unrecognized functional role in JH regulation and insect metamorphosis. Multiple isoelectric forms of tissue‐specific JH esterases and JH epoxide hydrolases were found in integument, midgut, fat body, and brain. The JH esterases in these tissues had isoelectric points more acidic than that for plasma. Tissue α‐naphthyl acetate esterase, developmental profiles, and inhibitor sensitivity to 3‐(octylthio)‐1,1,1‐trifluoropropan‐2‐one differed significantly from that for JH esterase, suggesting that they represent different enzymes. ©1992 Wiley‐Liss, Inc.
Genetic control of voltinism characteristics in European corn borer races assessed with a marker gene
Authors: Glover Thomas J. , Robbins Paul S. , Eckenrode Charles J. , Roelofs Wendell L.
Published: February 2005

The post‐diapause development (PDD) time for univoltine European corn borers (ECB) under diapause breaking conditions averages approximately 44 days, whereas the PDD time for bivoltine ECB under the same conditions is approximately 15 days. This difference is the principal component of the life cycle that determines the number of generations possible in a summer. Previous workers have demonstrated some genetic control of differences in voltinism among populations, including apparent control by sex‐linked (Z‐linked) genes.

In the present study allozymes of the enzyme, triose phosphate isomerase (TPI), were used as markers of the Z chromosomes in crosses of a bivoltine colony (Tpi‐1) and a univoltine colony (Tpi‐2). The F1 resulting from a cross of univoltine females (Z2W) and bivoltine males (Z1Z1) consisted of hemizygous Tpi‐1 females (Z1W) with a mean PDD time of 19 days and heterozygous Tpi‐1/Tpi‐2 males (Z1Z2) with a mean PDD time of 34 days. The F2 progeny consisted of Tpi‐1 females (Z1W) (mean PDD time = 15 days), Tpi‐2 females (Z2W) (mean PDD time = 40 days), homozygous Tpi‐1 males (Z1Z1) (mean PDD time = 16 days), and heterozygous Tpi‐1/Tpi‐2 males (Z1Z2) (mean PDD time = 25 days). The close correlation of TPI phenotypes and PDD times in these crosses, along with similar results for the maternal and paternal backcrosses of the F1 individuals, indicates that the PDD time is principally controlled by genes on the Z chromosome and that heterozygous males exhibit incomplete or partial dominance of these genes. © 1992 Wiley‐Liss, Inc.
Identification of 3,4‐dihydroxyphenylalanine, 5,6‐dihydroxyindole, and n‐acetylarterenone during eumelanin formation in immune reactive larvae of Drosophila melanogaster
Authors: Nappi Anthony J. , Vass Emily , Carton Yves , Frey Francoise
Published: February 2005

3,4‐Dihydroxyphenylalanine, 5‐6‐dihydroxyindole, and N‐acetylarterenone were detected by electrochemical methods in the hemolymph of immune reactive larvae of Drosophila melanogaster following parasitization by the wasp Leptopilina boulardi. Determinations of the catechols were made after separation by reverse phase, ion‐pairing high pressure liquid chromatography with electrochemical detection. The presence of 5,6‐dihydroxyindole unequivocally establishes the eumelanin pathway in the defense reponse of Drosophila, and confirms previous investigations which have implicated certain catecholamine metabolizing enzymes in insect immunity. The occurrence of N‐acetylarterenone, a derivative of the principal sclerotizing agent N‐acetyldopamine, verifies the existence and proposed involvement of quinone methide isomerase in the regulation of catecholamine metabolism, and suggests that the cellular capsule formed by Drosphila in immune reactions against parasites is most likely a composite of both eumelanin and sclerotin. The absence of 3,4‐dihydroxyphenylacetic acid in hemolymph samples from immune reactive hosts suggests that during parasitization certain catecholamines and metabolic precursors may be re‐employed in alternate pathways, some of which may be used in defense reactions. © 1992 Wiley‐Liss, Inc.
Allatostatins in the nerves of the antennal pulsatile organ muscle of the cockroach Diploptera punctata
Authors: Woodhead Andrea P. , Stoltzman Carrie A. , Stay Barbara
Published: February 2005

The presence of allatostatins in the nerves of the antennal pulsatile organ muscle of the cockroach Diploptera punctata was confirmed by immunocytochemistry, bioassay, and HPLC. Immunocytochemical reactivity with monoclonal antibody against allatostatin I showed strong allatostatin immunoreactivity in the antennal heart nerve which innervates this muscle with varicostities along the muscle fibers and in the insertion of the muscle on the pulsatile ampullae. Bioassay of Sep‐Pak purified muscle extract demonstrated inhibition of juvenile hormone synthesis by corpora allata in vitro. A dose‐response curve showed maximum inhibition of juvenile hormone synthesis was achieved with 10–20 pulsatile organ muscle eq/corpora allata, and 50% inhibition achieved with an estimated 2.6 pulsatile organ muscle eq. Two successive HPLC separations of the Sep‐Pak purified extract yielded bioactive fractions corresponding to the elution times of the five known allatostatins. © 1992 Wiley‐Liss, Inc.
Evidence for the induction of cuticle proteins by 20‐hydroxyecdysone in two established insect cell lines
Authors: Stiles Brad , Newman Samuel M.
Published: February 2005

We have studied two different established insect cell lines capable of synthesizing chitin, UM‐BGE‐4 from the cockroach and BRL‐AG‐2 from the boll weevil, for their ability to produce putative cuticle proteins. Mouse polyclonal antibodies were raised against the abdominal cuticle proteins extracted from the cuticle of nymphal and adult stage cockroaches, and larval, pupal, and adult stage cotton boll weevils. On Western blots, these antibodies detected several cross‐reacting proteins in untreated control cells and a variety of induced proteins in cells first exposed to a double pulse of the molting hormone, 20‐hydroxyecdysone (a low concentration followed by a higher concentration of hormone). The majority of these hormone induced proteins recognized by the anti‐cuticle protein antibodies were found to correspond in size to specific proteins observed in abdominal cuticle extracts. Electron microscopy utilizing colloidal gold to identify antibody binding sites indicated the antigenic proteins were present in the extracellular material found on the surface of the cultured cockroach and boll weevil cells. The evidence presented suggests that these cell lines can produce cuticle proteins. © 1992 Wiley‐Liss, Inc.
Soluble cuticular phenoloxidase in the gypsy moth Lymantria dispar
Authors: Thangaraj Thirumalaisamy , Aruchami Marappa
Published: February 2005

The soluble enzyme phenoloxidase (tyrosinase) from the larval cuticle of Lymantria dispar has been partially purified using Ultrogel ACA 34, and the activity has been determined using phenolic substrates. The enzyme exhibited more activity toward O‐diphenolic substrates and monophenolic substrates. The enzyme is inhibited by diethyl dithiocarbamate, phenylthiourea, and thiourea. The enzyme has been localized in the 7% slab and disc PAGE as an intense band. The enzyme is suggested to be involved in wound healing. © 1992 Wiley‐Liss, Inc.
An indirect mechanism by which a protein from the male gonad hastens salivary gland degeneration in the female Ixodid tick, Amblyomma hebraeum
Authors: Lomas Lee O. , Kaufman W. Reuben
Published: February 2005

In the adult female tick, Amblyomma hebraeum Koch (Acari: Ixodidae), salivary gland degeneration is triggered by an ecdysteroid, provided the female is above a critical weight (approximately 300–400 mg). In mated females, salivary gland degeneration is virtually complete within 4 days of detachment from the host. In virgin females, salivary gland degeneration is delayed by 4 days. This delay can be reversed by the injection of a male reproductive tract homogenate directly into the hemocoel. In this study, we consider a possible mechanism of action for this “male factor.” Once mated, male factor likely gains access to its target tissue(s) as a humoral factor. Male factor, however, appears not to act by sensitizing the salivary glands to the action of ecdysteroids. Instead, it appears to act by accelerating the appearance of ecdysteroids in the hemolymph. © 1992 Wiley‐Liss, Inc.
Enzymatic characterization of subcellular samples from gypsy moth larval midgut following differential centrifugation and fractionation on Percoll‐sucrose gradient
Authors: Sheppard Carol Anelli , Loeb Marcia J.
Published: February 2005

A method is described for isolation of an enriched fraction of plasma membranes from gypsy moth (Lymantria dispar) larval midgut tissue. Following differential centrifugation of tissue homogenate, a microsomal sample is obtained and fractionated on a Percoll®‐sucrose gradient that yields 2 distinct regions of high protein concentration: one enriched in plasma membranes, the other in mitochondrial membranes. The procedure is relatively rapid, being completed within approximately 5 h. Protein yields and accompanying specific activities are reported for marker enzymes used to indicate the presence of plasma membranes (leucine aminopeptidase and alkaline phosphatase), endoplasmic reticulum (NADPH‐cytochrome c reductase), and mitochondria (succinate dehydrogenase). The apparent differences between the plasma membrane enriched fraction vs. brush border membrane vesicles prepared from insect midguts are discussed, as is the suitability of the plasma membrane enriched fraction for ATP‐dependent calcium ion transport studies. © 1992 Wiley‐Liss, Inc.
5‐Hydroxytryptamine‐sensitive adenylate cyclase affects phagocytosis in cockroach hemocytes
Authors: Baines Danica , Downer Roger G. H.
Published: February 2005

The effects of 5‐hydroxytryptamine (5‐HT), octopamine, and dopamine on adenylate cyclase activity were studied using fragmented hemocyte membranes of the American cockroach, Periplaneta americana. 5‐HT and octopamine increased cAMP production with maximal effects at 10 nM and 10 μM respectively. Dopamine did not affect adenylate cyclase activity. The effects of octopamine and 5‐HT are not additive, indicating that both are working through the same receptor. A pharmacological profile suggests that the receptor present on the cockroach hemocytes is more similar to a 5‐HT receptor than an octopamine receptor. Mammalian antagonists of 5‐HT‐receptors blocked the 5‐HT‐induced increase in cAMP production with the following order of potency: mianserin > ketanserin > spiperone > ICS 205,930. In phagocytosis assays using whole hemocytes, 5‐HT increases cAMP production above control levels at 0.25, 0.75, 15, and 65 min. Addition of Bt2cAMP at 0.1 mM inhibits phagocytosis whereas, at 10 nM, Bt2cAMP enhances phagocytosis. Imidazole at 0.1 mM also enhanced phagocytosis. A 5‐HT‐mediated elevation in cAMP production may result in either an activation or inhibition of phagocytic activities. © 1992 Wiley‐Liss, Inc.
Insecticide action at the GABA‐gated chloride channel: Recognition, progress, and prospects
Authors: Casida John E.
Published: February 2005

Three billion (3 × 109) pounds of hexachlorocyclohexanes, polychlorobornanes, and chlorinated cyclodienes (such as lindane, toxaphene, and endosulfan, respectively) were used to control pest insects before their mode of action was established as blocking the GABA‐gated chloride channel. With the restricted use or demise of these polychlorocycloalkanes (each ∼ 50 to ∼ 75% by weight of chlorine), the GABAergic system is for now an underutilized target of insecticide action. Newer compounds with outstanding potency at this receptor and as toxicants to houseflies are suitably‐substituted 2,6,7‐trioxabicyclo[2.2.2]‐octanes, particularly the bicycloorthobenzoates, and 1,3‐dithianes, including those with no halogenated substitutents. Picrotoxinin analogs and alkynylphenylsilatranes also act at this target but are of lower insecticidal activity. [3H]n‐Propyl‐ethynylbicycloorthobenzoate ([3H]EBOB) is for now the best radioligand for this insecticidally‐relevant binding site in insects. Macrocyclic lactones such as the avermectins and moxidectin act at a different binding site to disrupt chloride flux and they have a different spectrum of insecticidal activity and no cross resistance with cyclodienes in houseflies. The search for new insecticides has provided the incentive and probes for a better understanding of the insect GABAergic system. © 1993 Wiley‐Liss, Inc.