Host-plant relations of the citrus butterfly Papilio demoleus L.: Orientational and ovipositional responses

The selection of a suitable plant for the establishment of Papilio demoleus is done by its females and involves their two main behavioural responses: (1) Orientation and (2) Oviposition, involving abdominal-curling followed by egg-delivery. The ovipositing females visit the host (Citrus) and non-host plants almost equally due to their almost equally high attraction to the green or yellowish-green colour of both the plants. On perceiving the specific attractant odour emitted by the ether-soluble constituents of the host plant (Citrus), the attraction of the butterflies to these plants becomes greater than that to the non-host plants and increases the chances of their visiting the host plants. Subsequently, the contact chemical stimuli provided by the ether as well as 80% ethanol-soluble constituent of the host plants, in combination with their odour and colour, elicit the ovipositional response of the butterflies. If the odour and contact stimuli are not appropriate, as in the case of non-host plants, the butterflies depart and visit other plants until they come to a host plant providing the above-mentioned combination of visual, olfactory and contact chemical stimuli to elicit increased attraction and ovipositional response.

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Résumé Ce travail étudie de rôle des réponses comportementales d'orientation et de ponte de Papilio demoleus, comme éléments déterminant sa sélection et son installation à l'égard d'une série de plantes: la plante-hôte principale Citrus limettioidés, l'hôte occasionnel Aegle marmelos et des plantes non-hôtes, Coriandrum sativum, Rosa indica, Gossypium hirsutum.Les réponses d'orientation (attraction) et de ponte du papillon à l'egard de la plante-hôte principale (Citrus) s'accroissent avec l'âge d'insecte, atteignant un maximum chez les femelles âgées de 3–4 jours, puis diminuent. Les papillons montrent une attraction presque aussi forte pour les plantes-hôtes et les plantes non-hôtes, mais les réponses consistant dans le recourbement de l'abdoment et le dépôt d'oeufs sont fortes pour Citrus, moindres par A. marmelos et nulles pour les plantes non-hôtes.Les stimuli visuels des plantes-hôtes et non-hôtes, en particulier la coloration vert ou jaune-vert, déclenchent une forte attraction mais non les réponses liées à la ponte. Ceci est confirmé par des tests avec des colorants de diverses couleurs. L'humidité ne provoque aucune réponse des papillons.Un extrait éthéré des feuilles de Citrus attire les papillons quand celui-ci est présenté sur un tissu de mousseline imprégné d'eau; il déclenche également les réflexes de ponte. Un extrait dans l'éthanol 80%, présenté sur un tissue humide ne provoque qu'une attraction faible et aucune réponse de ponte. Les stimuli de contact que l'on peut provoquer avec la fraction soluble dans l'éther et la fraction soluble dans l'éthanol 80% entrainent de fortes réactions de la courbure abdominale et de ponte. La combinaison d'une couleur vert jaunâtre, d'eau, d'odeur de l'extrait éthéré et de stimuli de contact avec des extraits dans l'éther et l'éthanol, déclenche les trois types de réponse des papillons.

     

Haemopoietic organs and effect of their ablation on total haemocyte count in lemon-butterfly,Papilio demoleus L

The haemopoietic organs in Vth instar larvae of P. demoleus are in the form of thin transparent cellular sheets, closely wrapped around the base of each wing-pad. Three cell types viz; prohaemocytes, plasmatocytes and oenocytoids appear to be derived from these organs and their ablation caused a reduction in cell number which, in turn, revealed that the haemocytes in general are derived both from the haemopoietic organs as well as from the circulating blood cells.     

美凤蝶觅食过程中的视觉和嗅觉利用

[目的]植物的花色和花香是访花蝴蝶识别花蜜的重要信息来源,本研究旨在利用花香挥发物、蜂蜜水加花色的诱集试验探讨美凤蝶Papilio memnon视觉、嗅觉在觅食行为中的作用.[方法]测试美凤蝶对不同颜色的假花和喷施蜂蜜的假花的行为反应,采用触角电位仪(EAG)测定美凤蝶对花香挥发物的触角电位反应,并通过行为学进行验证.[结果]在无气味的7种颜色的假花诱集时,美凤蝶对蓝色(440-475 nm)、紫色(380-420 nm)和红色(615-630 nm)显示出明显的颜色趋性;在假花上喷洒蜂蜜水后,雌雄蝶总体访花次数增加1.85倍;在单一蜂蜜水、苯甲醇和苯甲醛气味诱集时,美凤蝶访问次数较少,而在气味基础上加蓝色假花诱集时,蜂蜜水诱集时美凤蝶访问次数增加了27.40倍,苯甲醇和苯甲醛诱集时美凤蝶访问次数增加了52.59倍和75.80倍.而在颜色与颜色加气味比较时,蜂蜜水诱集时美凤蝶访问次数只增加了1.41倍,苯甲醇和苯甲醛诱集时美凤蝶访问次数增加了2.67倍和2.16倍.雌雄蝶对花颜色和挥发物的敏感性均有区别,美凤蝶雌蝶对颜色和挥发物(蜂蜜水、苯甲醇和苯甲醛)的敏感性高于雄蝶(P＜0.05).[结论]颜色是美凤蝶觅食的主要因子,单一气味对美凤蝶的引诱作用有限.美凤蝶在觅食过程中,以视觉为主嗅觉为辅,雌蝶对颜色和气味的识别能力和敏感性高于雄蝶,推断可能与雌蝶在繁殖中扮演的角色相关.     

Neuroendocrine organs of the lemon-butterfly, Papilio demoleus L. I. The corpora cardiaca-allata complex of the larva.

The histomorphology of the retrocerebral endocrine organs of the larva of the lemon-butterfly, P. demoleus has been described employing a conventional neurosecretory staining technique. The larval organs lie a little away from the brain and oesophagus and, therefore, are not sub-aortic in position unlike most other insects and the adult of this species itself. There are two long NCCs which innervate other target organs in addition to the CC. The recurrent nerve of the stomatogastric nervous system retains its normal connections with the CC even in absence of the hypocerebral ganglion. Histological evidence suggests that the NSM inside the CC remains intraaxonal without being possibly unloaded in the substance of these organs. Axonal transport of NSM to target organs is also in evidence and though NSM is seen in the NCA, it could not be detected inside the CA.     

Structure and metamorphic changes in the brain of the lemon butterfly Papilio demoleus L. (Lepidoptera: Papilionidae)

The morphology of the larval and adult brain of Papilio demoleus, and changes in the cell population and neuropile morphology during the pupal period have been described. The larval brain has more simple fibre areas than that of the adult. Dividing neuroblasts have been found which form the adult neurones. The larval brain contains the three neuromeres (proto-, deuto-, and tritocerebrum). The protocerebrum has well developed corpora pedunculata, a central body, a pons cerebralis and developing optic centres. The corpora ventralia are joined with each other by paired ventral commissures (single in adult). The deutocerebrum is simple and small, the antennal centres are small and simple (ef. adult). The glomerular tritocerebrum is posteroventral to the deutocerebrum, and fibres from the former travel to the crura cerebri. The cortex of the brain consists of four types of glial cells and of association cells, and large and medium sized motor neurones. The number of mitoses is greatest in the larval and prepupal stages; in the pupa it decreases gradually and in late stages it does not occur. Histolysis and pyknosis begin in the prepupa and decrease considerably in the late pupa. The entire neural lamella is broken down in the early pupa. Numerous haemocytes penetrate the laminae of the neural lambella and envelop the entire brain. In the adult, behind the well-developed central body is an ellipsoid body. The medulla interna is divided into two smaller lobes and the deutocerebral lobes are differentiated into cortical and medullary zones. Chiasmata between optic centres are also formed during the pupal period.     

Neuroendocrine organs of the lemon-butterfly, Papilio demoleus L. II. The corpora cardiaca-allata complex of the adult.

The retrocerebral endocrine organs of the adult lemon-butterfly; Papilio demoleus have been described. The organs are subaortic lying closely behind the brain. While the nervi corporis cardiaci I (NCCI) originate from the protocerebrum of the brain, the NCCII seem to take their origin in the tritocerebrum in common with another nerve named earlier as the tegumentary nerve. The corpora cardiaca (CC) and corpora allata (CA) are closely approximated to each other obliterating the nervi corporis allati (NCA) which are conspicuous in the larva of the same species. An intercardiacal bridge (ICB) connects the CC of the two sides and acts as a possible centre of distribution for the neurosecretory material (NSM) to the gut. Histological evidence suggests that the NSM inside the CC remains intraaxonal without being primarily unloaded in the organs for storage. The intrinsic secretory cell of the CC are intimately associated with the neurosecretory fibres from the brain and bear fairly thick axons. No NSM could be detected in the CA of this insect.     

Effects of repeated haemolymph withdrawals on haemocyte counts and moulting in lemon-butterfly, Papilio demoleus L

Total and differential haemocyte counts following repeated haemolymph withdrawals were made in V instar larvae of P. demoleus. While total count showed a steady reduction reaching its lowest in prepupal stage, much variation was observed in the relative percentage of various cell types. Further, the repeated removals of haemolymph from V instar larvae and pupae affected imaginal moulting and lengths of body and wings in adult butterflies.     

Establishment and characterization of a cell line developed from the neonate larvae of Papilio demoleus Linnaeus (Lepidoptera: Papilionidae)

A new cell line named RIRI-PaDe, developed from the neonate larvae of Papilio demoleus Linnaeus, was established in modified Grace’s medium supplemented with 20% fetal bovine serum. The cell line was incubated at 28°C and consisted of attached round and short spindle-like cells. The population doubling time was 55 h. The chromosome numbers varied widely from 24 to 136 with a mode of 59 at the 71st passage. Comparison of mitochondrial cytochrome c oxidase subunit I gene of the cell line and neonate larvae confirmed that the cell line was of P. demoleus origin. This cell line was susceptible to the Autographa californica multicapsid nucleopolyhedrovirus and Apocheima cinerarius nucleopolyhedrovirus.     

Behavioural responses of the pine weevilHylobius abietis L. (Col.: Curculionidae) to odours activating different groups of receptor cells

Summary A method for measuring the attractive effect of odorous compounds on a population of pine weevilsHylobius abietis L. is described. Three substances, which strongly activated different groups of sensory cells (Mustaparta, 1975) were examined. Trans-verbenol, which excited selectively certain trichodeal cells had the highest attraction and dominated the attractive effect of -pinene. The latter activated a special group of basiconic cells which indicated its importance as food attractant. The third compound, 5-hexen-2-one, activated a large number of olfactory receptor cells, but had almost no attractive effect on the weevils.This work was financed by the Norwegian Research Council for Sciences and Humanities NAVF, and also supported by Deutsche Akademische Austauschdienst DAAD.I would like to thank Dr. S. Gothilf, Israel Institute for Biological Research, Tel Aviv, Dr. J. Jansen, Institute of Physiology, University of Oslo, and Dr. S. Grillner, Institute of Physiology, University of Gothenborg, for discussions. For constantly providing insects I am thankful to Oberforstmeister H. Niemeyer, Niedersächsische Forstliche Versuchsanstalt, Göttingen.     

Electrophysiological and behavioural responses to lactic acid stimuli in larvae of Tenebrio molitor L. (Coleoptera: Tenebrionidae) and permeability of antennal sensilla

Abstract. Of the five types of antennal sensilla in larvae of Tenebrio molitor L., only the uniporous long pointed pegs and papillate plates are readily permeable to an aqueous solution of CoCl₂, which is generally indicative of a gustatory function. An electrophysiological investigation confirms the gustatory role of the papillate sensilla on the antenna, and it suggests that they are responsible for mediating the behaviour of larvae toward lactic acid stimuli. Larvae with ablated antennae do not aggregate as would normal animals in the presence of lactic acid stimuli. The uniporous long pointed pegs show no response to lactic acid or other aqueous stimuli.     

Asymmetrical generalisation between pheromonal and floral odours in appetitive olfactory conditioning of the honey bee (Apis mellifera L.)

The capacity to generalise between similar but not identical olfactory stimuli is crucial for honey bees, allowing them to find rewarding food sources with varying volatile emissions. We studied bees' generalisation behaviour with odours having different biological values: typical floral odours or alarm compounds. Bees' behavioural and peripheral electrophysiological responses were investigated using a combined proboscis extension response conditioning-electroantennogram assay. Bees were conditioned to pure linalool (floral) or to pure isoamyl acetate (alarm) and were tested with different concentrations of both compounds. Electrophysiological responses were not influenced by conditioning, suggesting that the learning of individual compounds does not rely on modulations of peripheral sensitivity. Behaviourally, generalisation responses of bees conditioned to the alarm compound were much higher than those of bees conditioned to the floral odour. We further demonstrated such asymmetrical generalisation between alarm and floral odours by using differential conditioning procedures. Conditioning to alarm compounds (isoamyl acetate or 2-heptanone) consistently induced more generalisation than conditioning to floral compounds (linalool or phenylacetaldehyde). Interestingly, generalisation between the two alarm compounds, which are otherwise chemically different, was extremely high. These results are discussed in relation to the neural representation of compounds with different biological significance for bees.     

Transplantation in relation to pigment formation of the integument in the larvae of the swallowtail, Papilio xuthus L

In the swallowtail, Papilio xuthus L., a switchover in the pigmentary system of epidermis occurs at the last larval molt: viz., from reddish brown xanthommatin to bluish green bile pigment. By transplantation of integument between the larvae of different developmental stages, a control by some humoral factor of the pigmentary system was revealed. But the transplantation of brain or of several combinations of known endocrine systems failed to affect the switchover of the pigmentary system at the last larval molt.     

Comparative study on the responses of maxillary sensilla styloconica of cotton bollwormHelicoverpa armigera and Oriental tobacco budwormH. assulta larvae to phytochemicals

Using the electro-physiological technique, the sensory mechanisms of maxillary sensilla styloconica to stimulants and deterrents were explored on two closely related species, the generalist Helicoverpa armigera and the specialist H. assulta. The results showed that: (i) in both species, cells sensitive to sucrose and azadirachtin were mainly in the lateral sensillum styloconicum, and those to inositol were in the medial sensillum styloconicum; (ii) sensitivity of medial sensillum styloconicum in H. assulta to inositol was higher than that in H. armigera; (iii) among 6 tested deterrents, only azadirachtin evoked high impulse discharge from the lateral sensillum styloconicum in both insects; (iv) the deterrents could disturb stimulants evoking impulse discharge from maxillary sensilla styloconica of both species in different degrees: To sucrose evoking impulses on lateral sensillum styloconicum, for H. armigera capsaicin had a strong inhibition and gossypol had a weak inhibition, while for H. assulta tann     

Responses to sex pheromone and plant odours by olfactory receptor neurons housed in sensilla auricillica of the codling moth, Cydia pomonella (Lepidoptera: Tortricidae)

Antennal olfactory receptor neurons located in a limited number of two types of sensilla auricillica, the rabbit-eared shoehorn and the regular shoehorn, located on the 5-30 flagellomere of the codling moth, Cydia pomonella, antenna were screened for selectivity to 11 plant compounds, the major sex pheromone component, three minor pheromone components and one behavioural antagonist. Both types of sensilla housed at least three neurons characterised by different action potential amplitudes. Neurons in both males and females responded to the plant compounds, ethyl (E,Z)-2,4-decadienoate, (+/-)-linalool, (E)-ss-farnesene, hexanol, (Z)-3-hexenyl acetate, 4,8-dimethyl-1,3,(E)7-nonatriene, nonanol, the major pheromone component codlemone [(E,E)-8,10-dodecadienol] and the minor pheromone component tetradecanol. Additionally, (E,E)-alpha-farnesene and (Z)-3-hexenol elicited responses specifically in female neurons, whereas (E,E)-farnesol elicited a specific response in a male neuron. Neurons responded to 1-3 odorants, with sometimes overlapping response spectra. A scanning electron microscopic study of the antennae of both sexes supported an earlier study, apart from that long s. trichodea were present in a wreath at the proximal margin of the flagellomere and in addition evenly distributed over the remaining surface, and a previously non-described sensillum type with external basiconic features was revealed, distributed on the proximal and medial region of the flagellomeres.     

Age-related responses from the maxillary sensilla styloconica of Choristoneura fumiferana larvae to foliage extracts from balsam fir hosts

An electrophysiological study of the sensilla styloconica of the galea in Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae) larvae showed a differential response between fourth- and sixth-instars to extracts of balsam fir foliage. Larvae raised on artificial diet were stimulated with the water soluble fraction of needle extracts obtained from terminal and lateral shoots of 30- and 70-yr-old balsam fir trees. An extract-sensitive neuron was found in the lateral styloconic sensillum of both instars. The lateral styloconica in the fourth-instar larvae were more sensitive to extracts from terminal than from lateral shoot foliage of both young and old trees. The lateral styloconica of sixth-instar larvae were more sensitive to lateral shoot foliage of old trees. Results are discussed with respect to their relationship to feeding preferences and feeding rates observed in a previous behavioural study.     

Characterization of olfactory sensilla of Stomoxys calcitrans and electrophysiological responses to odorant compounds associated with hosts and oviposition media

Stable flies, Stomoxys calcitrans L. (Diptera: Muscidae), are economically important biting flies that have caused billions of dollars in losses in the livestock industry. Field monitoring studies have indicated that olfaction plays an important role in host location. To further our understanding of stable fly olfaction, we examined the antennal morphology of adults using scanning electron microscopy techniques. Four major types of sensillum were found and classified as: (a) basiconic sensilla; (b) trichoid sensilla with three subtypes; (c) clavate sensilla, and (d) coeloconic sensilla. No significant differences between male and female flies in abundances (total numbers) of these sensillum types were observed, except for medium-sized trichoid sensilla. The distinctive pore structures found on the surface of basiconic and clavate sensilla suggest their olfactory functions. No wall pores were found in trichoid and coeloconic sensilla, which suggests that these two types of sensillum may function as mechano-receptors. Details of the distributions of different sensillum types located on the funicle of the fly antenna were also recorded. Electroantennogram results indicated significant antennal responses to host-associated compounds. The importance of stable fly olfaction relative to host and host environment seeking is discussed. This research provides valuable new information that will enhance future developments in integrated stable fly management.     

Female odours promote the activation of sheltered kissing bug Rhodnius prolixus males and modulate their orientation

The existence of a pheromone emitted during copulation has been reported for Rhodnius prolixus (Hemiptera: Reduviidae) Stål. Adults possess one pair of metasternal glands (MGs) from which female R. prolixus release volatiles mainly at night. We investigated whether these volatiles emitted by adult R. prolixus can modulate sexual‐related behaviours of opposite and/or same sex individuals. We first used a shelter bioassay to test if adult activity patterns can be affected by chemical signals emitted by opposite sex conspecifics. We observed that males left the shelter more frequently in the presence of females, showing higher activity and an increase of intrasexual copulation attempts. Females showed no shelter‐related activation in the presence of male odours. Second, we used a locomotion compensator device to investigate whether females or males show oriented responses to odours emitted by adults. We found that males oriented towards air currents carrying female odours but females did not orient towards odours emitted by adults. Finally, we observed that males oriented towards the female MG compounds. Thus, a volatile chemical signal emitted by females from their MGs promoted the activation of sheltered males and modulated orientation to air currents.     

Neurophysiological and behavioral responses to olfactory stimuli in the snail Helix pomatia L

Some aspects of olfactory sensitivity in the pulmonate Helix pomatia L. were studied by means of neurophysiological and behavioral methods. Single fiber recordings were carried out in the olfactory nerve of the posterior tentacles. Olfactory stimulations with different odors were performed by means of a continuous air stream. The order of neuronal sensitivity to different odors was as follows: ethanol > or = ethyl acetate > pentanol > hexanol > octanol > or = diethyl malonate > vanillin. Furthermore, the results revealed a relative specificity for some substances. A comparison between neurophysiological and behavioral data shows that those substances, which cause the highest increases in impulse frequency, also evoke a behavioral avoidance reaction.