Control of Ichneumonoptera chrysophanes (Meyrick) (Lepidoptera: Sesiidae) by mating disruption in persimmons

Abstract A ca 0.62 ha block of 480 persimmon trees at Woombye, Queensland, was treated with the pheromone of Ichneumonoptera chrysophanes emitted from polyethylene dispensers placed at a rate equivalent to 1480/ha early in September 2000. A second block of 219 trees was left untreated and served as the control. The technique was assessed using traps to measure the ability of I. chrysophanes males to locate synthetic pheromone baits, and by the incidence of fresh damage detected during December and June surveys of a minimum of 67 trees in each block. Pheromone release rates were determined approximately weekly by measuring the amount of pheromone remaining in a sample of 10 dispensers suspended within the treated block. A second orchard at Amamoor, Queensland, was partly treated with pheromone applied at a similar rate, but was monitored only in terms of trap catch. No assessments were made of damage levels. Mean pheromone-release rates ranged from 15.8 to 1.6 mg/ha/h. Over the entire period of the trial, from 8 September 2000 to 27 June 2001, no males were caught in any of the 12 traps in the pheromone-treated block of the Woombye orchard, while 944 were caught in the five traps in the untreated block. The proportion of trees with fresh damage was significantly higher in the untreated block (0.188 and 0.567; December and June surveys, respectively) than in the treated block (0.027 and 0.205), although there was no significant difference between treatments in the mean number of strikes/infested tree in either survey. In the Amamoor orchard no moths were caught in any of the 32 traps in the treated blocks, compared with a total of 303 in the 13 traps in the untreated block.     

Location,morphology and histology of sex pheromone glands of the female gypsy moth, Lymantria dispar (L.)

Scanning electron microscopy, histology and a male wing fanning bioassay were used in this study to locate the sex pheromone-producing glands of the female gypsy moth, Lymantria dispar. When exposed to female sex pheromone, adult males exhibit a strong wing fanning behaviour prior to take off. We found that adult males showed positive response to calling females and to tissue extract from both dorsal and ventral portions of the intersegmental membrane between 8th and 9th-abdominal segments. A typical male response usually starts with elevation of antennae, movement of head in different directions, walking, wing fanning and onset of search flight. Histological and scanning electron microscopic studies suggested that the sex pheromone glands are located on the dorsal and ventral aspects of the intersegmental membrane. The glands appear as two highly convoluted integumentary areas with hypertrophied glandular epidermal cells.     

Spatial and temporal distribution of pheromone biosynthesis-activating neuropeptide in Helicoverpa (Heliothis) armigera using RIA and in vitro bioassay.

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 radio-immunoassay 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 immunoactivity 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.     

Correlation between glycerolipids and pheromone aldehydes in the sex pheromone gland of female tobacco hornworm moths,Manduca sexta (L.)

Analysis by TLC and HPLC revealed that the triacylglycerols comprise the most abundant lipid class in the sex pheromone glands of Manduca sexta females. Also, conjugated olefinic acyl analogs of the major pheromone aldehydes occur principally in the triacylglycerols. The amount of triacylglycerols with conjugated diene acyl moieties significantly decreased when the period of pheromone production was extended by 7 h beyond the normal period of pheromone production by 3 injections of pheromone biosynthesis activating neuropeptide (PBAN) at 3 h intervals. This decrease indicates that the triacylglycerols stored in the gland may serve as major sources of pheromone precursors in the biosynthesis of the sex pheromone aldehydes. Furthermore, analysis of pheromone aldehydes and triacylglycerols in the gland from moths treated with PBAN showed that the proportions of the triacylglycerols with conjugated diene moieties were closely correlated with the proportions of aldehydes found in the same gland. This correlation suggests that the proportions of fatty acids bound to certain triacylglycerols regulates the proportions of aldehydes in biosynthesis of the pheromone blend in M. sexta. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

The Releaser Effects of the Tergal Gland Secretion of Queen Honeybees (Apis mellifera)

Queen honeybees are attractive to their workers, due partially to the pheromonal bouquet they secrete. Queen mandibular gland pheromone is a powerful attractant to worker honeybees but it is not solely responsible for eliciting retinue behavior. The attractiveness of virgin queen tergal gland secretions and queen mandibular pheromone to worker honeybees was tested using a retinue bioassay. The number of workers attending the treated pseudoqueen lures was videorecorded in order to allow for the quantification of attractiveness. Queen mandibular gland secretions were more attractive than tergal gland secretions (P 0.008), and both queen tergal gland secretions (P 0.0002) and mandibular gland secretions (P 0.0001) were significantly more attractive than the control treatment. This laboratory bioassay indicates that queen tergal gland secretions have a releaser effect that evokes retinue behavior from worker honeybees.     

Sexual dimorphism of arrestment and gregariousness in the bed bug (Cimex lectularius) in response to cuticular extracts from nymphal exuviae

Releaser pheromones have direct behavioural effects to arrest, attract or disperse insects, whereas interactions within groups of social insects are often influenced by primer pheromones. The behaviour of insects displaying intermediate levels of sociality is largely unexplored in this context. In the present study, both the gregariousness and arrestment (settling near the odour source) of bed bugs Cimex lectularius L. (Hemiptera: Cimicidae) in response to conspecific exuvial extracts are described. Adult males are arrested on filter papers with extracts derived from exuviae of fifth‐instar nymphs. Adult females and nymphs display no significant evidence for such behaviour. Adults of both sexes show no preference for extracts of male versus female fifth‐instar exuviae. Arrestment of adult males does not occur on papers treated with fourth‐instar exuvial extracts. Because the insects are assayed behaviourally in groups, an index is calculated describing how far bugs are away from being located independently of one another, as a measure of gregariousness. Adult males have lower values for this index (i.e. locations are closer to independence). Adult females, nymph cohorts and mixed age groups all have higher values for this index, which tend to increase over time. Females exhibit a clear increasing dose‐dependent relationship for this index. It is concluded that the extracts of fifth‐instar nymphal exuvia arrest males on refuges that possess the odour source. However, gregariousness is induced in females, without evidence of a tendency to assemble near the odour source.     

Evidence for an oviposition-deterring pheromone in Tephritis bardanae (Schrank) (Diptera: Tephritidae)

Summary Female Tephritis bardanae (Schrank) exhibit a characteristic ovipositor-dragging behaviour immediately after laying eggs into a flowerbud of Arctium minus (Hill) Bernh. To establish whether this behaviour is associated with an oviposition-deterring pheromone (ODP), female T. bardanae were presented with clean, unattacked flowerbuds and fly activity was monitored using video recording equipment. The distribution of oviposition and fly behaviour were analysed. Avoidance of attacked buds was revealed by the oviposition pattern becoming overdispersed. Spacing out of eggs continued until, on average, each bud contained one egg-batch, after which the distribution became more random or clumped. Analysis of fly behaviour showed that attacked and unattacked buds received similar numbers of visits, but fewer oviposition attempts were made on attacked buds. This behaviour was consistent with use of a contact pheromone deterring repeated oviposition and applied to the bud surface during ovipositor-dragging. Avoidance of attacked buds should increase the efficiency of resource use by T. bardanae populations in the field; however, distributions of egg-batches in flowerhead samples collected from Monks Wood NNR, Cambridgeshire, during 1983–1985, were highly clumped and did not provide supportive evidence. This suggests that the effectiveness of oviposition deterrence in the field is reduced, because the active life of ODP under natural conditions is short, and/or because wild females frequently experience high oviposition drive due to scarcity of suitable flowerbuds.     

A reinvestigation of the role of (E)-2-hexenal in female calling behaviour of the polyphemus moth (Antheraea polyphemus)

Calling periodicities in the saturniid moth Antheraea polyphemus were similar in virgin females that were intact, intact and exposed to (E)-2-hexenal and antennectomised. Virgin females and antennectomised virgin females were of comparable attractiveness to males in the field.     

Aggregation Pheromone Activity of the Female Sex Pheromone, β-Acaridial,in Caloglyphus polyphyllae (Acari: Acaridae)

Caloglyphus (=Sancasania) polyphyllae discharges from a pair of opisthonotal glands a characteristic set of volatiles, i.e. three monoterpenes and seven hydrocarbons. Among them, β-acaridial, which is known as the female sex pheromone of the species and has antifungal activity, was newly identified as the aggregation pheromone for unfeeding and unmating mites. Feeding mites, however, exhibited sexually aroused behavior instead of the tendency to cluster when exposed to β-acaridial. This is the first example of the compound demonstrating two pheromone functions depending upon the circumstances faced by the mites.     

实夜蛾属和铃夜蛾属昆虫性信息素通讯系统的研究进展

实夜蛾属Heliothis和铃夜蛾属Helicoverpa昆虫的性信息素通讯系统主要包括雌蛾的性信息素合成和雄蛾对性信息素接收两个方面,每方面都有分子、细胞、系统水平上进行协同作用的生物过程。性信息素生物合成激活肽（PBAN）与其受体作用,启动信号转导系统,从而激活合成性信息素的酶系统来合成性信息素,利用化学和生物测定的方法鉴定出具有诱蛾活性的性信息素腺体组分及行为功能;性信息素分子与性信息素结合蛋白（PBP）的复合体同受体相互作用,启动信号转导系统,诱导产生神经信号,从而引起一系列性行为反应。这些生物过程受到各种内部和外部因素的影响。     

Possible antagonism of (Z)‐2‐hexenyl (E)‐3‐hexenoate against the attractiveness of (E)‐2‐hexenyl (Z)‐3‐hexenoate to Ooencyrtus nezarae (Hymenoptera: Encyrtidae)

Ooencyrtus nezarae (Hymenoptera: Encyrtidae) is an egg parasitoid of bean bug Riptortus pedestris (Hemiptera: Alydidae) which is a major pest of beans. Females of O. nezarae are attracted to (E)‐2‐hexenyl (Z)‐3‐hexenoate (EZ), one of the components of aggregation pheromone of R. pedestris. Effects of three isomers (ZE, EE and ZZ) of EZ on the attractiveness of O. nezarae were tested using electroantennography (EAG) and field bioassays. EAG analyses revealed that the response of O. nezarae to ZE was significantly higher than those to air, hexane and two other isomers, even though the response was lower than that to EZ. ZE affected the attractiveness of EZ dose‐dependently in the field. Addition of ZE (100 mg) to EZ (10 mg) caused a significant reduction in the catches of O. nezarae females. Single or binary addition of two other isomers (EE and ZZ) to EZ could not decrease or increase significantly the number of O. nezarae catches of EZ. Even though addition of ZZ (10, 50 or 100 mg) to EZ (10 mg) caused dose‐dependent reduction in the number of O. nezarae female catches, the reductions were not significantly different from that of EZ. EZ and its three isomers were not attractive to O. nezarae males at all.     

Site of production of an oviposition-deterring pheromone component in Rhagoletis pomonella flies

Using behavioural and electrophysiological assay techniques, we identified the posterior half of the midgut as being a principal site of production of a major component of the oviposition-deterring, fruit-marking pheromone of female Rhagoletis pomonella flies. Following secretion into, and accumulation in, the gut lumen, this component is released, together with other gut contents, in the marking trail deposited during dragging of the ovipositor on the fruit surface after egg-laying, as well as in the faeces. Other components of the pheromone may be produced elsewhere.     

Chemical Communication in the Gregarious Psocid Cerastipsocus sivorii (Psocoptera: Psocidae)

The objectives of this study were: (1) to test the existence of an aggregation pheromone in the gregarious psocid Cerastipsocus sivorii; (2) to compare the attractiveness of odors from different aggregations; (3) to test whether nymphs are able to chemically recognize damage-released alarm signals. In a choice experiment conducted in the laboratory, we showed that psocids are able to detect chemical cues from groups of conspecifics. Laboratory experiments also showed that nymphs are capable of chemically recognizing the aggregations where they came from. Finally, in a field experiment, most aggregations dispersed when exposed to the body fluids of a crushed conspecific, but no aggregations dispersed upon exposure to a crushed termite. The implications of these results for the evolution of sociality in psocopterans are discussed.     

Attraction range of a sex pheromone trap for the damson‐hop aphid Phorodon humuli (Hemiptera: Aphididae)

The attraction range of olfactory response by winged female gynoparae (autumn migrants that give birth to oviparae, the sexual females) and male damson–hop aphids Phorodon humuli (Schrank) is investigated in field experiments over 2 years by analyzing the spatial patterns of catches in concentric circles of yellow‐painted traps (60 in total) around a central trap releasing the species' sex pheromone, (1RS,7S,7aS)‐nepetalactol. Males are more likely than females to be found in the central trap, with 65.6% of the 1824 males caught there compared with 11.2% of 1346 females. Both morphs are more numerous in traps axial with the mean wind direction and centred on the pheromone‐release trap than at other angles. Males are approximately five‐fold more numerous in traps downwind than at similar distances upwind of the pheromone, showing that its presence stimulates landing. For males, the estimated active space of the lure extends 6 m downwind. Catches of females are equally numerous up and downwind of the pheromone lure because females orienting on the axis of the pheromone source continue to respond to visual cues in their flight path if they overshoot the olfactory one. For females, the active space of a pheromone lure is less than 2 m downwind. It is unimportant for either morph whether the pheromone‐release trap is yellow or transparent. In these experiments, both morphs orient with, track and probably arrive in the pheromone source trap from at least 26 m, the distance to the nearest aphid‐infested hops.     

蛾类性信息素研究进展

蛾类是昆虫性信息素中研究较多的类群,已有565种的性信息素成份被鉴定,其相关研究在害虫监测和防治上得到实际应用的同时,已涉及到生态、生化、遗传等诸多方面,特别是在物种多样性的化学表达及物种的生殖隔离现象的分子水平的表达上,提供了研究的典范。本文将介绍蛾类性信息素的多样性、性信息素化学结构鉴定、微量成分的作用、合成性信息素的利用、性信息素生物合成酶、性信息素生产的调节机制及性信息素的感受机制等方面的研究现状和存在的问题。     

Control of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in greenhouse tomato crops using the mating disruption technique

The effectiveness of mating disruption to control the tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), in greenhouse tomato crops was evaluated in four trials carried out in winter–spring and summer–winter growing seasons in Southwestern Sardinia (Italy). Pheromone dispensers loaded with 60 mg of the natural blend of the major and minor sex pheromone component (rate 90 : 10) were applied in disrupted greenhouses at a rate of 1000/ha (60 g of active ingredient/ha). Male captures in monitoring pheromone traps, percentage of tomato plants infested by T. absoluta and damage on leaves and fruits were monitored weekly and compared in disrupted and untreated (control) greenhouses. In greenhouses disrupted with 1000 dispensers/ha, a reduction of 93–97% in male trap captures was observed, compared with control. Leaf damage was significantly lower in greenhouses disrupted with 1000 dispensers/ha than in control ones, with a reduction of infestation throughout the growing season ranging from 57% to 85%. Pheromone dispensers applied at the density of 1000/ha significantly reduced the percentage of damaged fruits by 62–89%. In control greenhouses, the highest damage on leaves and fruits was generally observed in edge plants, while leaf and fruit infestation was uniformly distributed in pheromone‐treated greenhouses, indicating an even distribution of the pheromone cloud inside the greenhouse. Mating disruption showed to be an efficient strategy to control in greenhouse the tomato leafminer and can be included in the overall tomato integrated pest management programs.     

The role of queen mandibular pheromone and colony congestion in honey bee (Apis mellifera L.) reproductive swarming (Hymenoptera: Apidae)

The roles of honey bee queen mandibular pheromone and colony congestion in the inhibition of swarming were investigated. Two colony siz.es were used: small, congested colonies and large, uncongested colonies. Both groups of colonies were treated with various dosages of the five-component, synthetic queen mandibular pheromone in the spring, and the extent and timing of swarming were followed. Most treatment groups received pheromone or a solvent blank (control) on a stationary slide; one group of the congested colonies received a pheromone treatment via an aerosol spray. The pheromone was not effective at delaying swarming in the congested colonies at any dosage applied on slides, but the aerosol spray-treated colonies swarmed significantly later in the season than the control colonies. The uncongested, pheromone-treated colonies exhibited a dose-dependent delay in swarming, with the highest dosage colonies swarming almost four weeks later than the control colonies. These results indicate an interaction between congestion and pheromone in the control of honey bee reproduction. While congestion may in itself be a factor stimulating swarming, these results are consistent with the interpretation that colony congestion reduces the transmission of queen pheromone within the nest, thereby removing the queen 's pheromone-based inhibition of queen rearing and subsequent swarming by workers.     

Determination of the site of pheromone emission in the virgin females Culicoides nubeculosus Meigen (Diptera: Ceratopogonidae)

The zone of emission of the sex pheromone from the body of Culicoides nubeculosus was investigated. The amount of pheromone emitted was evaluated by counting the number of matings between males and females exposed to a flow of air coming from a chamber containing virgin females. The number of matings is higher than that recorded when the air flow comes from an empty chamber (control). Three parts of the body were examined: head, thorax and abdomen. Each part was studied by neutralizing the effect of the others. The head was neutralized by decapitation and the females continued to emit pheromone. The head is, therefore, not indispensible for pheromone emission. The roles of the thorax and abdomen were studied by coating these with paraffin wax. When the thorax is coated, pheromone emission continues, but when the abdomen is coated, it stops. It appears that the abdomen alone is responsible for emission of the sex pheromone.