The influence of color stimuli on visually controlled behavior inAglais urticae L. andPararge aegeria L. (Lepidoptera)

Summary In spontaneous-choice experiments on the butterfliesAglais urticae L. (Nymphalidae) andPararge aegeria L. (Satyridae) the spectral effectiveness and spectral sensitivity of various behaviors were investigated and compared.Pilot experiments with colored PVC films showed indications of an intensity dependence of the feeding reaction inP. aegeria. Moreover, they revealed a color discrimination independent of this intensity discrimination:P. aegeria distinguishes red from grey shades as well as from black and white (Fig. 3).According to subsequent spontaneous-choice experiments using monochromatic light stimuli, the various visually controlled functional categories of behavior can be assigned to the following spectral regions: 1. The open-space reaction corresponds to the UV and violet region, ca. 320–420 nm, inP. aegeria (Figs. 4, 7). 2. The feeding reaction corresponds to the blue region, ca. 420–500 nm, inA. urticae (Fig. 1) andP. aegeria (Fig. 4), and the yellow region, ca. 550–590 nm, inA. urticae (Fig. 1) and the orange-red region, ca. 570–670 nm, inP. aegeria (Fig. 4).In these experiments with monochromatic light stimuli the intensity dependence of the reactions is also obvious (Figs. 2, 5, 6).The open-space reaction is elicited inP. aegeria by white light dependent on its UV content (Fig. 8). This is also valid for the feeding reaction inP. aegeria (Fig. 5b). To elicit this reaction it was necessary to offer light stimuli simultaneously with the odour stimulus of honey water. As the latter was of the same quality in combination with all light stimuli the results can be attributed definitely to the different effectiveness of the various light stimuli.Pure wavelength-specific behavior can be ruled out inA. urticae andP. aegeria. Wavelength-specific behavior and color vision are probably present simultaneously.Abbreviation RNQ relative number of quanta Supported by the Deutsche Forschungsgemeinschaft Ko 445/5-3     

Retinal ultrastructure in the dorsal rim and large dorsal area of the eye of Aglais urticae (Lepidoptera)

Summary The ommatidia in the two dorsal rows at the rim of the eye of Aglais urticae differ from all the other ommatidia of the large dorsal area, in rhabdom structure, length, and configuration of the ninth retinula cell. The type of rhabdom in this dorsal rim zone provides the structural prerequisites for the reception of polarized light; functional subdivision of the retina into two parts is indicated.     

Voltage- and calcium-activated currents in cultured olfactory receptor neurons of male Mamestra brassicae (Lepidoptera)

Insect olfactory receptor neurons (ORNs) grown in primary cultures were studied using the patch-clamp technique in both conventional and amphotericin B perforated whole-cell configurations under voltage-clamp conditions. After 10-24 days in vitro, ORNs had a mean resting potential of -62 mV and an average input resistance of 3.2 GOmega. Five different voltage-dependent ionic currents were isolated: one Na(+), one Ca(2+) and three K(+) currents. The Na(+) current (35-300 pA) activated between -50 and -30 mV and was sensitive to 1 microM tetrodotoxin (TTX). The sustained Ca(2+) current activated between -30 and -20 mV, reached a maximum amplitude at 0 mV (-4.5 +/- 6.0 pA) that increased when Ba(2+) was added to the bath and was blocked by 1 mM Co(2+). Total outward currents were composed of three K(+) currents: a Ca(2+)-activated K(+) current activated between -40 and -30 mV and reached a maximum amplitude at +40 mV (605 +/- 351 pA); a delayed-rectifier K(+) current activated between -30 and -10 mV, had a mean amplitude of 111 +/- 67 pA at +60 mV and was inhibited by 20 mM tetraethylammonium (TEA); and, finally, more than half of ORNs exhibited an A-like current strongly dependent on the holding potential and inhibited by 5 mM 4-aminopyridine (4-AP). Pheromone stimulation evoked inward current as measured by single channel recordings.     

Ultrastructure and adaptation in the retina of Aglais urticae (Lepidoptera)

Summary The apposition eye of Aglais urticae is composed of eucone ommatidia. Serial sectioning of blocks from the laterofrontal and lateroventral eye regions and mapping at different levels revealed that there is no torsion of whole ommatidia along their long axes.The sensory part of the ommatidium comprises nine retinula cells. The most significant features of the complicated rhabdom structure (diagrammed in Fig. 3) are as follows. The vertically aligned receptor cells V₁ and V₅, which become axonal at the level at which the ninth cell begins, have microvilli arranged in bundles. The microvilli bundles of these cells generally make an angle between 30 and 55° on one or the other side of the dorsoventral axis in the ommatidium cross section. The two orientations alternate regularly along the length of the rhabdom. The repeated sweeps of these bundles in regular intervals in combination with the curvature of the V-cell microvilli is considered to be a substitute for rhabdomere twisting. The four diagonally aligned receptor cells D_2,4,6,8 have rhabdomers that are continuous, though of variable size. These rhabdomeres, like those of the horizontally aligned cells (H₃ and H₇), extend along the entire rhabdom, though there is a small (1–2 m) interruption in the H-cell rhabdomeres; the latter have the most constant orientation. Pigment granules are most abundant in the D cells, followed by the H cells and finally the V cells. RC₉ lacks pigments.Light- and dark-adaptation experiments reveal marked horizontal migration of the retinula-cell pigment (pupil reaction) and slight vertical migration. Monochromatic adaptation experiments at wavelengths =342, 436, 522, 578, and 626 nm indicate special sensitivity of the D-cells around -520 nm. There are indications for sensitivity of V cells in the UV, and possibly of H cells in the blue. The H cells are regarded as suited for the detection of polarized light. The functional significance of these findings is discussed and compared with what is known of other butterfly eyes.This work was supported by grants from the Deutsche Forschungsgemeinschaft and the Stiftung Volkswagenwerk     

The structure of the eye ofPieris brassicae L. (Lepidoptera)

Summary The apposition eye of the large Cabbage Butterfly,Pieris brassicae L., was investigated electronmicroscopically (TEM). Diagrams based on micrographs show details of the structure of an ommatidium.The dioptric apparatus is made up of cornea, corneal process, and crystalline cone. The sensory part consists of nine visual cells. The retina is tiered. Four distal visual cells (type I) participate in forming the distal rhabdome, the proximal part being formed by four proximal visual cells (type II) with proximal main sections. There are ultrastructural differences between these two types of receptors. The basal ninth visual cell forms, if any, only stubby microvilli that have no part in the formation of the banded rhabdome. There is no gap between the distal and proximal parts of the rhabdome, but the two parts differ morphologically. In the distal part the rhabdomeres do not interlock at right angles and are, for the most part, not exactly perpendicular to the optical axis of the ommatidium; their microvilli may be bent and sometimes extend more than halfway across the rhabdome. In the proximal rhabdome the microvilli are straight and parallel, though they too vary in extent across the rhabdome. The microvilli plates of neighbouring rhabdomeres interlock here at right angles. Basally the rhabdome ends at a large tracheal fork that acts as a tapetum.There are five different types of pigment granules in the ommatidium each belonging to a particular cell type. Distal and proximal visual cells each have one type of pigment; the other three types of pigment granules belong to two principal, six secondary, and six basal pigment cells, respectively. Each distal process of the secondary pigment cells contains microtubule bundles and is joined horizontally to the processes of neighbouring secondary pigment cells. Bundles of microtubules running parallel to the optical axis are found in the primary pigment cells, too. The ultrastructure is described, and its relevance for the eyes function, especially in the ultraviolet wavelength-range, is discussed.

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Zusammenfassung Das Appositionsauge des gro\en Kohlwei\lings,Pieris brassicae L. wurde elektronenmikroskopisch (TEM) untersucht. Der Bau eines Ommatidiums wird im Schema und Details anhand von Aufnahmen wiedergegeben.Der dioptrische Apparat besteht aus Cornea, Corneafortsatz und Kristallkegel.Der sensorische Teil ist aus neun Sehzellen zusammengesetzt. Die Retina ist mehrreihig. Vier distale einfache Sehzellen vom Typ I haben Anteil am distalen, vier proximale Sehzellen (Typ II) mit ihrem proximalen Hauptabschnitt am proximalen Rhabdomaufbau. Diese Rezeptortypen unterscheiden sich feinstrukturell. Die basale neunte Sehzelle besitzt keine oder stummeiförmige Microvilli, die keinen Anteil am gebÄnderten Rhabdom haben. Distales und proximales Rhabdom gehen ineinander über, unterscheiden sich aber morphologisch. Im distalen Rhabdom verlaufen die Rhabdomere in einer horizontalen Ebene nicht senkrecht zueinander und auch vielfach nicht exakt senkrecht zur optischen Achse des Ommatidiums; ihre Microvilli können gebogen sein und sich stellenweise über mehr als die HÄlfte des Rhabdoms erstrecken. Im proximalen Rhabdom sind die Microvilli gerade orientiert, überqueren aber auch verschieden weit das Rhabdom. Die Microvilliplatten benachbarter Rhabdomere sind proximal senkrecht zueinander orientiert. Das Rhabdom endigt basal an einer gro\en Tracheengabel, die als Tapetum wirkt. Fünf verschiedene Pigmentgranulatypen erscheinen in jedem Ommatidium.Jeder Pigmentgranulatyp ist einem bestimmten Zelltyp zugeordnet. Distale und proximale Sehzellen enthalten jeweils verschiedene Pigmente; die anderen drei Pigmenttypen sind auf zwei Haupt-, sechs Nebenpigmentzellen und sechs basale Pigmentzellen verteilt. Jeder distale Fortsatz der Nebenpigmentzellen enthÄlt Microtubulibündel und steht horizontal mit den FortsÄtzen benachbarter Nebenpigmentzellen in Verbindung. Au\erdem verlaufen auch in den Hauptpigmentzellen gebündelte Microtubuli parallel zur optischen Achse.Die Feinstrukturen werden beschrieben und ihre Bedeutung für die Funktion des Auges insbesondere im ultravioletten WellenlÄngenbereich wird diskutiert.

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This publication is dedicated to Professor Dr. Dr. h. c. H. Autrum on the occasion of his 70th birthday

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This work was supported by grants from the Deutsche Forschungsgemeinschaft and the Stiftung Volkswagenwerk. — The author thanks Dr. H. Kayser, Biology Department, Ulm University, for specimens ofPieris brassicae and for advice on rearing methods, as well as Dr. Noli (Leitz) for the SEM micrographs, Figure 3 a and b, taken with a Leitz AMR 1000. A Leitz Metallbeschichtungskammer with gold cathode in argon was used for gold vapour coating. — For Figure 3c I sincerely thank Mrs. Dr. Pietsch-Rohrschneider (REM Cambridge MK II)     

Candidate insecticides for the control of larvae of Mamestra brassicae (Lepidoptera) (Noctuidae)

Fifteen insecticides were tested in the laboratory against larvae of Mamestra brassicae, a chrysanthemum pest. Seven of these, methomyl, chlorpyrifos, leptophos, iodofenphos, methamidophos, mephosfolan and fenitrothion were significantly more potent than carbaryl, the standard adopted. The performance of the insecticides is discussed in relation to selective action against insects and to mammalian toxicity, to identify those which might be suitable for integrated control or chemical control of noctuid larvae under glass. A technique for monitoring the amount of pesticide deposited on to a target by a Potter Tower sprayer is described.     

Plant volatiles activating specific olfactory receptor neurons of the cabbage moth Mamestra brassicae L. (Lepidoptera, Noctuidae)

Herbivore insects are suitable model organisms for studying how plant odor information is encoded in olfactory receptor neurons (RNs). By the use of gas chromatography linked to electrophysiological recordings from single RNs, screening for sensitivity to naturally produced plant odorants is possible in order to determine the molecular receptive ranges of the neurons. Using this method, we have in this study of the cabbage moth, Mamestra brassicae, classified 21 types of olfactory RNs according to their responses to odorants present in the host plants of Brassicae, in the related species of Arabidopsis, as well as in essential oils of nonhost plants like ylang-ylang. Most of the RNs were tuned to one or a few structurally similar compounds, showing minimal overlap of their molecular receptive ranges. Whereas some RNs displayed a novel tuning, others were tuned to the same compounds as neurons in other insect species. We also found colocation in the same sensillum of 3 RN types with the same response characteristics and tuning as 3 colocated types described in heliothine moths living on different host plants. The presence of similar RN types across different insect species implies conservation or reappearance of the RN types, independent of the evolution of host plant ranges.     

A new mimetic species of Heliconius (Lepidoptera: Nymphalidae), from southeastern Colombia, revealed by cladistic analysis of mitochondrial DNA sequences

A new species of Heliconius and a new geographical race of Heliconius melpomene are described from the vicinity of Mocoa, Dpto. Putumayo, Colombia, based on molecular and morphological characters. The new species, H. tristero , is a close relative of H. cydno , a geographically differentiated species which lacks red coloration and engages in Müllerian mimicry with other blue and yellow Heliconius species in Central and northwestern South America. H. tristero has switched mimetic associations, instead mimicking the local, sympatric forms of two widespread mimetic species, H. erato and H. melpomene. This discovery provides evidence that the splinter species H. heurippa, H. tristero and H. timareta represent phenotypically divergent members of the H. cydno group that are endemic to successive river valleys on the eastern slope of the northern Andean Cordillera. The nominal taxon Heliconius amaryllis bellula Stichel, currently misapplied to both H. tristero and H. melpomene populations from the Mocoa region of Colombia, is considered here to represent a hybrid between H. heurippa and H. tristero. The Mocoa melpomene race is formally named Heliconius melpomene mocoa , new subspecies.     

Identification of a new hobo element in the cabbage moth, Mamestra brassicae (Lepidoptera)

A complete hobo-like element, called Mbhobo, was identified in the cabbage moth, Mamestra brassicae. This element has a high sequence similarity to the HFL1 hobo element of Drosophila melanogaster. Amplification of Mbhobo termini indicated that transposition occurred into a 5'-GTGGGTAC-3' target sequence that was duplicated upon insertion. This target site conforms to the consensus sequence established for the insertion sites of insect hAT elements. Mbhobo has a single 1935 bp long ORF with significant homology to the D. melanogaster HFL1 hobo transposase. FISH experiments evidenced Mbhobo clusters located in heterochromatic regions of Z and W sex chromosomes and in heterochromatic areas of chromosome pair 10.     

The courtship behavior of the cabbage moth,Mamestra brassicae (Lepidoptera: Noctuidae), and the role of male hair-pencils

The courtship behavior of the cabbage moth, Mamestra brassicae(L.), was studied in moving air conditions in a wind tunnel, using video techniques. Quantitative analyses were undertaken to determine the behavioral sequence occurring in the courtship. Comparison of successful and unsuccessful courtship suggested that courtship success was more dependent on the behavior of the female than that of the male. In an attempt to elucidate the function of the male hair-pencils (HPs), courtships involving males without HPs were also studied. HP removal did not affect the overall courtship success rate of males, but detailed analysis showed significant changes infernale behavior during such courtships. HP removal also affected female behavior following pair formation, with females struggling more when paired with males without HPs. Consequently, it is proposed that the HP volatiles act as an arrestant for the female, both during courtship and after pair formation, to increase female acceptance and to prevent premature termination of copulation. Experiments were also conducted to test previous hypotheses for HP function. However, no evidence was found to suggest that the HP volatiles in M. brassicaeact to attract females, affect female calling behavior, or affect the behavior of other males. A further possible function of HPs in defense is discussed.     

Genetic variation among Mediterranean populations of Sesamia nonagrioides (Lepidoptera: Noctuidae) as revealed by RFLP mtDNA analysis

Restriction fragment length polymorphism analysis of two segments of mitochondrial DNA (COI and 16S rRNA) was used to examine genetic variation in Sesamia nonagrioides (Lefèbvre) populations from the Mediterranean basin. Four populations were collected from central and southern Greece, and five from northern latitudes: Greece, Italy, France and Spain. No variation was observed in COI, while 16S rRNA segment proved highly polymorphic and 28 different haplotypes were found. Lower intra-population polymorphism was found in the northern populations than in southern ones. Although no significant isolation by distance was found, the UPGMA tree based on Nei's raw number of nucleotide differences separated the populations into two major groups, i.e. one with the northern (40.6 degrees N-43.4 degrees N) and the other with the southern populations (37.3 degrees N-39.2 degrees N). Analysis of molecular variance revealed that most of the variation was between the two major groups (Phi(CT)=0.559), and all pairwise comparisons between the northern and southern populations resulted in high and significant F(ST) values (overall F(ST)=0.604). The high F(ST) values and the strong spatial genetic structure indicate that long-distance migration may be a rare event. The populations do not seem to have experienced a strong historical bottleneck. The occurrence of a few widespread haplotypes and the genetic similarity of the northern populations could be attributed to a historical expansion of certain haplotypes from the south towards to the northern borders of the species' distribution area.     

Behavioral experiments on the visual processing of color stimuli inPieris brassicae L. (Lepidoptera)

Summary In spontaneous-choice experiments on the butterflyPieris brassicae L. (Pieridae), spectral-effectiveness and spectral-sensitivity functions were obtained for various behaviors.Pilot experiments with colored PVC films, for which the relative number of reflected quanta with regard to the given illumination had been calculated, showed that the feeding response is distinctly intensity-dependent (Fig. 4). The animals are also capable of color discrimination independent of this intensity discrimination;P. brassicae prefers blue to other colors (e.g., orange, red and purple) with higher relative quantum numbers (Fig. 3) and distinguishes golden yellow and red from gray shades as well as from black and white (Fig. 5a, b).The results of subsequent spontaneous-choice experiments, using as stimuli monochromatic lights with known quantum flux, indicate that the various visually controlled functional categories of behavior can be assigned to the following spectral regions (Figs. 6, 8): 1. The open-space reaction corresponds to the UV and violet region, ca. 320–420 nm; 2. The feeding reaction corresponds to the blue region, ca. 420–500 nm, and the orange-red region, ca. 590–610 nm; 3. Egg-laying and drumming correspond to the green-yellow region, ca. 520–580 or 590 nm, respectively. The intensity dependence of the individual responses is again apparent in these experiments with monochromatic light stimuli (Figs. 7, 11, 12a).Even at very high intensities and when the content of the relevant wavelength is high, white light is practically ineffective for the feeding reaction (Fig. 9), drumming and egg-laying (cf. Results), regardless of its UV content. The open-space reaction, however, can be elicited by white light according to its UV content (Fig. 12 b).P. brassicae cannot be trained to give a feeding response to monochromatic light stimuli (Fig. 10).Experiments with mixtures of wavelengths have shown that the combination of the two maxima in the spectral sensitivity curve for the feeding reaction (=600 plus 447 nm) is just as effective as =447 nm alone (Fig. 13, left). Moreover, the mixture producing the hypothetical Pieris purple (=600 plus 370 nm) is no more or less effective in eliciting the feeding and open-space reactions than the more effective component for each of these reactions when presented alone (Fig. 13, right). With the mixture of =600 plus 558 nm, both the feeding reaction and drumming are distinctly reduced (Fig. 13, middle). This mixed color, unlike the other two mixtures tested, has a color quality different from that of the component colors.That the behavior ofP. brassicae is exclusively wavelength-specific can thus be ruled out. There are indications that wavelength-specific behavior and color vision are both present.Abbreviation RNQ relative number of quanta This publication is dedicated to Professor Dr. Dr.h.c. H. Autrum on the occasion of his 80th birthday     

Component analysis and growth process of nasopharyngeal calculus as revealed by Fourier transform infrared (FT-IR) spectroscopy.

A quite rare case of nasopharyngeal calculus in a woman in her twenties associated with the nasal discharge of pseudomonas infection was reported. As the substance was irregularly large in size, we extracted it partially by piecemeal resection using forceps and also by cracking technique using the holmium yttrium-aluminum-garnet (YAG) laser, under saline irrigation and stereotactic microscopic navigator (SMN) system under endoscopic observation. The substance was firmly fixed to the pharyngeal tonsil bed. The final extract was a small piece of singly folded bandage, which is probably the focal background for calculus formation. In a cross section of calculus specimen removed during surgery, Fourier transform infrared (FT-IR) analysis revealed that a) signal ratio of methylene group (organic substance) to amide I (protein) was 21.6% at the nasal cavity side, gradually decreased toward nasal mucous membrane showing approximate 50%, b) signal ratio of amide I to P04(3-) (inorganic substance) ranged between 17.7% and 26.7% at the different sites and inside the calculus, the protein content was approximate 1/5 of the inorganic substance, and c) signal ratio of the methylene group to amide I at the nasal cavity site showed that their contents were almost equal. The quantity of the organic substance was estimated at approximate 1/2 quantity of the protein at both the central part and the part contacted with the mucous membrane. From these results, it seems that throughout the course of calculus growth, both inorganic substance and protein remain almost constant inside the calculus, while organic substance is released from the internal part of the calculus being probably formed at an early stage.