MALE PEACH APHID ATTRACTION IN THE FIELD BY SEX PHEROMONES1)

Abstract Field trials by sex pheromone of aphid to trap peach aphids Myzus persicae have been carried out in 1995 and in 1996. Suitable time and the effect of ratio of two components nepetalactone and nepetalactol to apply the lure have been observed.     

Aim‐then‐shoot anemotaxis involved in the hopping approach of potato tuberworm moth Phthorimaea operculella toward a sex pheromone source

Male moths locate conspecific females by pheromone‐induced upwind flight maintained by detecting a visual flow, termed optomotor anemotaxis. Their behavioural pattern is characterized by an upwind surge in response to a pheromone stimulus and crosswind casting after odour loss, which is considered to be reset and restarted on receipt of another pheromone pulse. However, pheromone‐stimulated males of the potato tuberworm moth Phthorimaea operculella exhibit a series of short and straight intermittent flights, or hops, when moving upwind. It is unclear whether they navigate by employing the same behavioural pattern and wind detection mechanism as that used by flying moths. To analyze odour‐modulated anemotaxis in male potato tuberworm moths, a flat wind tunnel is constructed to give regular odour stimuli to an insect regardless of its location. Moths are subjected to pheromone pulses of different frequencies to test whether they show a behavioural pattern that is reset and restarted by a pheromone pulse. Moths on the ground are also subjected to crosswind shear to examine their detection of wind direction. Path analyses reveal that males surge upwind when they receive a pheromone pulse and exhibit casting by successive hops when they lose odour. This behavioural pattern appears to be similar to that of flying moths. When the direction of the airflow is switched orthogonally, males adjust their course angle accordingly when they are on the ground. It is suggested that, instead of optomotor anemotaxis, this ‘aim‐then‐shoot’ system aids the detection of wind direction, possibly by mechanosensory means.     

Ants adjust their pheromone deposition to a changing environment and their probability of making errors

Animals must contend with an ever-changing environment. Social animals, especially eusocial insects such as ants and bees, rely heavily on communication for their success. However, in a changing environment, communicated information can become rapidly outdated. This is a particular problem for pheromone trail using ants, as once deposited pheromones cannot be removed. Here, we study the response of ant foragers to an environmental change. Ants were trained to one feeder location, and the feeder was then moved to a different location. We found that ants responded to an environmental change by strongly upregulating pheromone deposition immediately after experiencing the change. This may help maintain the colony''s foraging flexibility, and allow multiple food locations to be exploited simultaneously. Our treatment also caused uncertainty in the foragers, by making their memories less reliable. Ants which had made an error but eventually found the food source upregulated pheromone deposition when returning to the nest. Intriguingly, ants on their way towards the food source downregulated pheromone deposition if they were going to make an error. This may suggest that individual ants can measure the reliability of their own memories and respond appropriately.     

10 000 years later: evolution of body shape in Haida Gwaii three-spined stickleback

The body shape of 1303 adult male three-spined stickleback Gasterosteus aculeatus from 118 populations on Haida Gwaii archipelago off the mid-coast of British Columbia was investigated using discriminant function analysis on partial warp scores generated from 12 homologous landmarks on a digital image of each fish. Results demonstrated geographical differences in adult body shape that could be predicted by both abiotic and biotic factors of the habitat. Populations with derived shape (CV1−), including thick peduncles, posterior and closely spaced dorsal spines, anterior pelvis, small dorsal and anal fins, were found in small, shallow, stained ponds, and populations with less derived shape (CV1+), with small narrow peduncles, anterior and widely spaced dorsal spines, posterior pelvis, large dorsal and anal fins were found in large, deep, clear lakes. This relationship was replicated between geographic regions; divergent mtDNA haplotypes in lowland populations; between predation regimes throughout the archipelago, and in each geographical region and between predation regimes in lowland populations monomorphic for the Euro and North American mtDNA haplotype. There were large-bodied populations with derived shape (CV2−), including small heads and shallow elongate bodies in open water habitats of low productivity, and populations with smaller size and less derived shape (CV2+), with large heads and deeper bodies in higher productivity, structurally complex habitats. This relationship was replicated between geographic regions, and partially between divergent mtDNA haplotypes in lowland populations. Field tests for phenotypic plasticity of body shape suggest that <10% of the total variation in body shape among populations throughout the archipelago can be attributed to plasticity.     

Hickory shuckworm Cydia caryana: electroantennogram and flight tunnel studies of potential sex pheromone components

Electroantennogram (EAG) measurement of male Cydia caryana moth antennal olfactory response to monounsaturated 12 and 14 carbon alcohols and acetates indicated that the (E)-8-, (E)-10- conjugated double bond system of a dodecadien-1-ol acetate is a critical chemical structural component of the C. caryana sex pheromone. Additionally, EAG measurements implicated (E)-8-dodecen-1-ol acetate, (Z)-8-dodecen-1-ol acetate, (Z)-9-dodecen-1-ol acetate and (Z)-12-tetradecen-1-ol as potential minor pheromonal components. An EAG dosage-response study suggested that there were at least two heterologous populations of pheromone acceptors. Behavioral analysis of male moth response in a flight tunnel to compounds which evoked the stronger EAG responses suggested that (E,E)-8,10-dodecadien-1-ol acetate and (Z)-9-dodecen-1-ol acetate resemble or are C. caryana sex pheromonal components, while (Z)-8-dodecen-1-ol acetate and (E)-10-dodecen-1-ol acetate are either parapheromones or are minor pheromone components. Behavioral significance of (Z)-12-tetradecen-1-ol was difficult to interpret in the flight tunnel.

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Résumé Les réponses olfactives antennaires de Cydia caryana, mesurées par électroantennogrammes (EAG), aux alcools et acétates à carbones monounsaturés en positions 12 et 14, ont montré que le système conjugué de double liaison, (E)-8-, (E)-10- du dodecadien-1-ol acétate constitue un composé chimique strutural critique de la phéromone sexuelle de C. caryana.De plus, les acétates: (E)-8-dodecen-1-ol,(Z)-8-dodecen-1-ol,(Z)-9-dodecen-1-ol, et le (Z)-12-tetradecen-1-ol, se sont révélés en AEG comme des composés secondaires de la phéromone. L'étude par AEG de la relation dose-réponse a conduit à l'hypothèse de deux catégories de populations de récepteurs de phéromones. L'analyse comportementale des résponses des papillons mâles dans le tunnel de vol aux composés qui ont provoqués les plus forts AEG, on fait estimer que les acétates (E,E)-8,10-dodécadien-1-ol et (Z)-9-dodecen-1-ol ressemblent (ou sont) les constituants de la phéromone sexuelle de C. caryana; tandis que les (Z)-8-dodecen-1-ol et (E)-10-dodecen-1-ol sont, soit des paraphéromones, soit des constituants mineurs de la phéromone.La signification biologique du (Z)-12-tétradécen-1-ol a été difficile à interprêter avec les expériences en tunnel de vol.

     

鼎突多刺蚁群体结构和生活史的研究

本文报告了鼎突多刺蚁(Polyrhachis vicina Roger)的群体结构和生活史。通过研究表明,鼎突多刺蚁一年发生一代,以蚁后、雄蚁、工蚁、幼虫和卵越冬。卵和幼虫在冬天发育停滞(或极慢)。到了春天,随着气温的上升,卵和幼虫又恢复正常发育。据室内人工饲养观察,卵的发育历期为23.8±2.5天(平均温度26℃)幼虫为20.4±4.4天(26℃),工蚁蛹为19.8±5.5天(27℃)。成长工蚁在5—11月出现;8—11月,雄蚁从蛹中羽化;10月,雌蚁从蛹中羽化。雌蚁分飞交尾后,进入邻近蚁巢或回到原巢,脱翅成为蚁后。蚁巢内存在着多后现象。     

Z-linked inheritance of male olfactory response to sex pheromone components in two species of tortricid moths, Ctenopseustis obliquana and Ctenopseustis sp.

The olfactory response from male pheromone sensitive sensilla was investigated in the endemic New Zealand brownheaded leafrollers Ctenopseustis obliquana (Walker) and C. sp. ropeana (Lepidoptera, Tortricidae). The responses from 281 sensilla from the parental strains and from both the reciprocal crosses, including F₁, F₂ and maternal and paternal backcrosses were recorded, and statistically analysed using a multivariate analysis.In males of both the parental strains, a large amplitude cell responded to the main pheromone component of the conspecific female, in C. obliquana (Z)-8-tetradecenyl acetate (Z8-14:OAc) and in C. sp ropeana (Z)-5-tetradecenyl acetate (Z5-14:OAc). Both male types also possessed a small amplitude cell, which in C. obliquana responded weakly to Z5-14:OAc and tetradecyl acetate (14:OAc), and in C. sp ropeana responded to Z8-14:OAc. The responses from the different types of hybrid males were more variable than the responses from parental males. A main pattern could, however be seen, corresponding with the expected pattern in a sex-linked inheritance on the Z-chromosome of a C. sp ropeana type dominant genetic factor. The more pronounced variation in the hybrids could not be explained by this model, and might be due to the involvement of additional genes.

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Résumé Les réactions olfactives des sensilles mâles sensibles aux phéromones ont été examinées par enregistrement de l'extrémité de la sensille chez les tordeuses C. obliquana Walker et C. sp. ropeana. Les enregistrements ont porté sur 281 sensilles des lignées parentales et des croisements réciproques de F₁, F₂ et de croisements en retour maternel et paternel. Les résultats des enregistrements d'une sensille ont été soumis à une analyse en composantes principales.Chez les mâles de chaque lignée parentale un seul type physiologique de sensille a été découvert; une cellule répond par un pic grand au principal constituant de la phéromone femelle conspécifique. (Z)-8-acétate tétradécényl (Z8-14:OAc) pour C. obliquana, et (Z)-5-acétate tétradécényl (Z5-14:OAc) pour C. sp. ropeana. Une seconde type de cellule dans les sensilles des deux espèces de mâles présente un pic petit pour Z5-14:OAc et pour l'acétate tétradécyl (14:OAc) chez C. obliquana, et pour C. sp. ropeana au Z8-14:OAc. Les réponses des sensilles des différents types de mâles hybrides sont plus hétérogènes que celles des sensilles de leurs pères. Un schéma général pourrait cependant être décelé, correspondant au schéma prévu avec une hérédité d'un facteur dominant liée au sexe sur le chromosome Z de C. sp. ropeana. La variation plus accentuée chez les hybrides ne peut être expliquée par ce modèle, et pourrait impliquer des gènes additionnels.

     

Use of pheromone chemistry to identify Grapholita lobarzewskii as an occasional pest of apple and plum

As shown by chemical analysis and field trapping, the sex pheromone of Grapholita lobarzewskii consists of a blend of (E)-8-dodecenyl acetate and (Z)-8-dodecenyl acetate. Maximum attractiveness was found at 80–95%. Dodecyl acetate and tetradecyl acetate, both present in the female gland, did not affect trap catch. G. lobarzewskii has recently gained importance as a pest of apple and plum, but has so far been referred to as Grapholita janthinana. The latter is attracted to the same two compounds, but in reversed portions (20% E).

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Zusammenfassung Chemische Analysen und Feldversuche zeigen, dass das Sexualpheromon des Kleinen Fruchtwicklers, G. lobarzewskii aus (E)-8-Dodecenylacetat (Z8-12:Ac) und (Z)-8-Dodecenylacetat (Z8-12:Ac) besteht. Die grösste Lockwirkung wurde mit einem Gemisch der beiden Substanzen bei einem E-Anteil von 80–95% erzielt. Dodecylacetat (12:Ac) und Tetradecylacetat (14:Ac) wurden ebenfalls in den weiblichen Pheromondrüsen nachgewiesen, hatten aber im Freiland keinen Einfluss auf die Lockwirkung. G. lobarzewskii tritt seit einiger Zeit in der Schweiz als Schädling von Apfel und Zwetschge auf und ist an ihrem charakteristischem Frassgang leicht erkennbar. Die Art wurde bisher irrtümlich als G. janthinana bezeichnet. G. janthinana lebt auf Rosaceen, und wird vom gleichen Substanzpaar angelockt, allerdings bei umgekehrtem Mischungsverhältnis (20% E).

     

Determination of the enantiomeric composition of (R*,S*)-1-ethylpropyl 2-methyl-3-hydroxypentanoate, the male-produced aggregation pheromone of Sitophilus granarius

The enantiomeric composition of sitophilate, the granary weevil [Sitophilus granarius (L.)] male-produced aggregation pheromone [(R^*,S^*)-1-ethylpropyl 2-methyl-3-hydroxypentanoate)], was determined by three methods: (1) bioassaying the synthetic (2S,3R) and (2R,3S) enantiomers of the active (R^*,S^*) diastereomer; (2) ¹H NMR spectroscopy of Mosher ester derivatives of the natural pheromone and synthetic (2S,3R)-and (2R,3S)-sitophilate; and (3) capillary GLC comparisons of the retention times of derivatized natural pheromone and the two synthetic enantiomers. The combined methods confirmed the (2S,3R) enantiomer as the active form of sitophilate. Male granary weevils were shown to produce >96% (2S,3R)-sitophilate. No significant attraction of S. granarius by the (2R,3S) enantiomer was observed. Rice and maize weevils [S. oryzae (L.) and S. zeamais Motschulsky] were not attracted by (2S,3R)-sitophilate. S. granarius L. est un déprédateur important des grains stockés. Le (R^*,S^*)-1-éthylpropyl 2-méthyl-3-hydroxypentanoate a été identifié en 1987 comme le principal composé du sitophilate, la phéromone mâle d'agrégation de S. granarius. La composition énantiométrique du sitophilate a été déterminée par 3 méthodes: