Effects of insecticides on sex pheromone communication and mating behavior in <Emphasis Type="Italic">Trichogramma chilonis</Emphasis>

Trichogramma chilonis Ishii is an important natural enemy of several lepidopterous pests on crops. The effects of two common insecticides on sex pheromone communication and mating behavior in T. chilonis were evaluated in the laboratory. When only males were exposed to insecticide, beta-cypermethrin LC₂₀ exposure induced significant decrease in sex pheromone perception by males and significant increase in males’ courtship and copulation frequency; beta-cypermethrin LC₁ exposure caused significant decrease in males’ courtship and copulation frequency. Males exposed to spinosad LC₂₀ exhibited significantly slower initiated courtship and significantly shorter total copulation duration, and the males exposed to spinosad LC₁ exhibited significantly increased sex pheromone perception, compared with control. When both males and females were exposed to insecticide, significantly more courtship and copulation were conducted by treated pairs that survived insecticide (beta-cypermethrin or spinosad) LC₂₀ than control pairs. Our study suggests that even the LC₁ and LC₂₀ of tested insecticides could affect the sex pheromone communication and mating behavior in T. chilonis.     

First evidence of deuterotokous parthenogenesis in the tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), originates from South America and is now considered to be one of the most damaging invasive pests of tomatoes in the Mediterranean Basin countries of Europe and North Africa. The preventing pest mating control methods include: (1) the use of synthetic pheromones for male attraction and annihilation inside insecticide-containing traps; (2) mating disruption by saturating the atmosphere with sex pheromones which alter the ability of males to locate females; and (3) massive applications of sterile males to alter the overall reproductive success of the pest population. However, all these methods achieve only a poor success rate in controlling T. absoluta populations under greenhouse conditions. Sex pheromone management and sterile insect techniques are both based on an important biological trait: the insect must breed through sexual reproduction. Here, we report for the first time laboratory evidence of deuterotokous parthenogenesis, an asexual reproduction where both males and females are produced from unfertilized eggs. We discuss the consequences for T. absoluta control strategies.     

Sexual communication and related behaviours in Tephritidae: current knowledge and potential applications for Integrated Pest Management

Tephritidae are an enormous threat to fruit and vegetable production throughout the world, causing both quantitative and qualitative losses. Investigating mating sequences could help to unravel mate choice dynamics, adding useful information to improve behaviour-based control strategies. We review current knowledge about sexual communication and related behaviours in Tephritidae, with a focus on six key agricultural pests: Anastrepha ludens, Bactrocera cucurbitae, Bactrocera dorsalis, Bactrocera oleae, Ceratitis capitata and Rhagoletis pomonella. We examine features and the role of male–male combat in lekking sites, cues affecting mating dynamics, and some fitness-promoting female behaviours that occur at oviposition sites [the use of oviposition marking pheromones (OMPs) and female–female fights for single oviposition sites]. We outline future perspectives and potential contributions of knowledge about sexual communication to Integrated Pest Management programs for tephritid pests. Sexually selected traits are frequently good indicators of male fitness and knowledge of sexual selection processes may contribute to the improvement of the sterile insect technique (SIT), to select genotypes with high reproductive success and to promote sexually selected phenotypes through mass-rearing optimization. Furthermore, males’ exposure to parapheromones, such as phenyl propanoids (PPs), ginger root oil and trimedlure can enhance the mating success of sterile flies used in SIT programs. PPs are also a powerful tool to improve reduced-risk monitoring dispensers and the male annihilation technique, with low side effects on non-target insects. Lastly, we outline the possibility to sensitise or train mass-reared parasitoids on OMPs during the pre-release phase, in order to improve their post-release performance in the field.     

An observation study on biological characters and mating behavior of Dahurian casebearer (Coleophora dahurica Flkv.) adults

Through rearing tests and observations under laboratory conditions, biological characters and mating behavior of Dahurian casebearer (Coleophora dahurica Flkv.) adults were studied in this paper. Results discovered that the time of emergense of male adults was 24h to 36h earlier than that of female adults. The peak of sex pheromone secretion of the female adults appeared of 24h to 42h after the emergence. The reaction of male adults on the sex pheromone was most sensitive during 30h to 48h after emerged, so the earlier emergence of the male adults was favorable to mating. The phenomenon of repeated mating did not exist in female adults, but the male adults could mate for several times, with maximum of 4 times. There was a definite behavioral reaction during the mating period of male and female adults, and the certain period of feeding and mating times could affect the adults longervity to a certain degree.     

<Emphasis Type="Italic">Lobesia botrana</Emphasis> males mainly fly at dusk: video camera-assisted pheromone traps and implications for mating disruption

Pheromone-mediated mating disruption (MD) is currently considered an effective strategy to control the European grapevine moth (EGVM), Lobesia botrana, with a successful interference on natural female calling during the male searching flight. However, little is known on the impact of the hour of the day on EGVM male flight. While various models forecasting the day of maximum presence of males per flight have been developed, field research on the male flight activity over 24 hours is scarce. Hence, we used video camera-assisted pheromone traps to allow a continuous monitoring of EGVM flights over daylight and night hours, quantifying captures of males. Experiments were carried out in three vineyards located in northern Spain over two years (2016 and 2017). Results showed that EGVM flight mainly occurred between 21:00 and 23:00 h (GMT+1, daylight saving time). Furthermore, male catches significantly differed over the study year, annual flight period and vineyard. Most of the dispensers used worldwide for EGVM MD continuously release the main sex pheromone component [(7E,9Z)-7,9-dodecadien-1-yl acetate], except for some automatic devices releasing puffs of sex pheromones at selected time intervals. The findings presented here can be useful to optimize the MD technique, identifying selected time intervals when the release of EGVM synthetic pheromones can be concentrated, boosting MD efficacy against this important pest, minimizing the release of synthetic sex pheromone molecules in the environment and reducing application costs.     

Reflections on structure and function of pheromone glands in storage insect species

Several polyphagous coleopteran and lepidopterous species, presently known as storage insects, have presumably evolved from free-living ancestral species, being capable of growth and reproduction on stored, desiccated and often nutritionally deficient foodstuffs. These potentially harmful insect species have probably adapted themselves to the newly acquired storage biotope by means of a well-developed sensory equipment serving food acquisition, aggregation and mate finding.Information by molecules may be communicated among the individuals of an insect species by means of relatively volatile pheromones (Greek, pher=convey) being emitted by exocrine glands and mainly carried by moving air to the sensilla of responsive individuals, or among the internal organs of an insect by means of relativelynonvolatile hormones (Greek, horma=impel), secreted fromendocrine glands and transported by the haemolymph to the receptors of target organs. It was postulated that pheromones were among the first chemical messengers utilized during evolution of animal behaviour, and that the pheromones of primitive protozoans could have been precursors of the hormones of metazoans. Hormones of the neurosecretory cells and corpora allata were found to induce sex pheromone biosynthesis in femaleTenebrio molitor, while dietary intake of a juvenile hormone analogue was shown to significantly enhance the production of aggregation pheromones in the males of certain silvanid and cucujid species.Aggregation pheromones are usually produced by the longlived and feeding males of several coleopteran species (Table 2) which deposit those chemical messengers to the substrate, where they induce the formation of bisexual assemblies supporting feeding, mating and reproduction. Sex pheromones are mostly produced by the short-lived and non-feeding females of several coleopteran and lepidopterous species (Table 2); females of those species usually release their sex pheromones to the air space during calling, and thus attract conspecific males for mating (Fig. 5 a–c).In some dermestid species, pheromone emission differs from the above scheme. Females of the short-lived and non-feedingTrogoderma granarium andT. inclusum release a phromone acting as a sex attractant for conspecific males and—in synergistic combination with tactile stimuli—as an assembling scent for conspecific females (Figs. 1 a, b, 2 and Table 1), females of the short-lived and feedingAntbrenus verbasci, Attagenus megatoma andAtt. elongatulus produce a sex pheromone for conspecific males, while females of the long-lived and feedingAn. scrophulariae emit a sex pheromone which lures conspecific males.Males of the long-lived and non-feeding bruchid speciesAcanthoscelides obtectus release a sex pheromone which attracts conspecific females. Androconial pheromones are discharged during courtship from the alar scales and abdominal tufts found in males of several microlepidopteran species (Phycitidae) includingAnagasta kuebniella, Cadra cautella, Ephestia elutella andPlodia interpunctella (Fig. 6 b–c); those aphrodisiac pheromones are known to enhance the specific responsiveness of the females to their mates. Electrophysiological recordings revealed that aggregation pheromones elicit considerable receptor potentials in the antennal olfactory sensilla of both sexes, whereas sex pheromones induce high receptor potentials in the antennal olfactory sensilla of one sex only. It was assumed that aggregation pheromones may be the evolutionary precursors of sex pheromones.Pheromone-producingexocrine glands are essentially groups of modified epidermals cells which are found in different body regions of male and/or female storage insect species. A simple pheromone gland, consisting of a single layer of adjacent secretory cells beneath the endocuticle of the 5th visible abdominal sternite, occurs in femaleTrogoderma granarium (Fig. 3 a). A more complex design, comprising an intra-abdominal semiglobular pheromone gland with numerous secretory cells being connected to tubuli which lead to an invaginated cuticular cribellum, is available in maleDermestes maculatus (Figs. 3 c, d and 4 c). The cribellum, provided with a caudally curved brush of fluted brisles, occurs in the centre of the 4th visible abdominal sternite (Figs. 4 a, b and 7 b). An apodemous exocrine gland is found in the lumen of the second abdominal segment of femaleLasioderma serricorne (Fig. 3 b). This lobate gland comprises many secretory cells, being connected by numerous tubuli to a sheath-like conical duct enveloping a V-shaped skeletal apodeme, which terminates in the abdominal tip. In maleTribolium castaneum, the secretory cells of both pheromone glands are connected by tubuli to two cribella, being densely covered by fluted bristles, and found in the femora of both forelegs (Fig. 7 a). Females of the phycitid speciesAnagasta kuebniella, Cadra cautella, Ephestia elutella andPlodia interpunctella are equipped with an intersegmental pheromone gland, situated between the 8th and 9th abdominal segment near the genital opening. The exocrine gland of the four moth species consists of a single layer of columnar secretory cells, lined by a spongy cuticle which seems to be permeable to the sex pheromone (Fig. 6 a). The latter is disseminated by calling females (Fig. 5 a, b) while their exocrine glands are widely exposed. Males of the above phycitid species are furnished with alar and abdominal androconia which become exposed during courtship and discharge aphrodisiac pheromones. The base of each of the androconial bristles and scales is immersed to an underlying unicellular, pheromone-producing gland (Fig. 6 d, e). The aphrodisiac pheromones, being secreted by the above glandular cells, are passing the lumen and walls of the bristles and scales, and evaporate from the surface of the latter. For example, malePlodia interpunctella possess 2 pairs of scent tufts (a small and a large one) on both sides of the 8th abdominal tergiet as well as 2 pairs of scent tufts (a small and a large one) near the base of the costal margin of the forewings (Fig. 6 b, c). Females of several phycitid species respond to the aphrodisiac pheromone of conspecific males by a pronounced readiness to mate.In the course of time, about 3 dozens of insect species (3/4 coleopteran and 1/4 lepidopterous species) have undergone sympatric speciation by sharing desiccated food in stores as a common habitat. Fertile matings between such heterogeneous species are often prevented by morphological and anatomical incompatibilities as well as physiological and behavioural barriers. Most of the species living in the storage habitat are reproductively isolated due to the molecular structure and blend composition of their pheromones (Table 2). Interestingly, some species (listed below) deviate from the majority by sharing the structure of their main pheromone components (mentioned in parenthesis), and are thus poorly separated: the curculionidsSitophilus oryzae andS. zeamais ((4S,5R)-5-hydroxy-4-methyl-3-heptanone), the tenebrionidsTribolium castaneum andT. confusum ((4R,8R)-dimethyldecanal) as well as the dermestidsTrogoderma inclusum andT. variabile ((R,Z)-14-methyl-8-hexadecenal). Theinsufficient reproductive isolation of the above species is compensated, i.a., by additional availability of a sex pheromone in femaleTribolium confusum, by different calling periods and emission rates of (R,Z)-14-methyl-8-hexadecenal in females of the forementionedTrogodema species.Trogoderma glabrum andT. granarium areincompletely isolated by sharing (R,E)-14-methyl-8-hexadecenal as a pheromone component; they are indeed capable of cross-mating, but produce sterile hybrids. Moreover, maleOryzaepbilus mercator andO. surinamensis incorporate (Z,Z)-3,6-dodecadien-11R-olide as a common chiral component to their aggregation pheromones. The females of 5 phycitid species share (Z,E)-9,12-tetradecadien-1-yl acetate as their main pheromone component, while they are reproductively separated by additional emission of (Z)-9-tetradecen-1-yl acetate and (Z,E)-9,12-tetradecadien-1-ol as secondary pheromone components, by the production of different androconial pheromones in conspecific males as well as different circadian calling activities.In the course of their research engagement on pheromones of storage insect and mite species (during the past 2.5 decades), the authors enjoyed fruitful collaboration with several renowned investigators working in Athens, Berlin, Hamburg, New York, Pantnagar, Tiantsin, Tokyo, Wisconsin, Yokohama and Zürich (chapter 6).Motto ...In addition to the amazing range of physiological activities of which it is capable during the process of moulting and cuticle formation, the epidermal cell is potentially an embryonic cell, with latent powers of differentiating in several different directions. The ordinary epidermal cell may divide to give rise to a pair of oenocytes. It may divide into four and produce a dermal gland cell with associated cells that form the glandular duct. Or the four daughter cells may differentiate into the bristle-forming and socket-forming cells which give rise to the sensillum and into the sense cell with its neurilemma cell both of which grow inwards to become a part of the central nervous system ...V B. Wigglesworth, 1959With 2 tables and 7 figuresDedicated to the memory of Prof. Dr. Sir Vincent BrianWigglesworth who died on February 12th, 1994.     

AN OBSERVATION STUDY ON BIOLOGICAL CHARACTERS AND MATING BEHAVIOR OF DAHURIAN CASEBEARER(COLEOPHORA DAHURICA FLKV.)ADULTS

Through rearing tests and observations under laboratory conditions,biologicalcharacters and mating behavior of Dahurian casebearer(Coleophora dahurica Flkv.)adultswere studied in this paper.Results discovered that the time of emergense of male adultswas 24h to 36h earlier than that of female adults.The peak of sex pheromone secretion ofthe female adults appeared of 24h to 42h after the emergence.The reaction of male adultson the sex pheromone was most sensitive during 30h to 48h after emerged,so the earlieremergence of the male adults was favorable to mating.The phenomenon of repeatedmating did not exist in female adults,but the male adults could mate for several times,with maximum of 4 times.There was a definite behavioral reaction during the matingperiod of male and female adults,and the certain period of feeding and mating times couldaffect the adults longervity to a certain degree.     

天牛信息素的研究进展

天牛是对林木健康生长最具破坏力的重要蛀干害虫之一,对天牛信息素的研究是探索基于化学生态学和行为特性的防治技术的重要方面。雌雄二性天牛受寄主植物挥发物,特别是幼虫危害诱导的寄主挥发物的吸引,聚集在取食地点附近。雌雄二性天牛都可释放性信息素吸引异性。雄性在触角接触雌性天牛后,对雌性产生的接触信息素产生反应,识别雌性后才试图和雌性进行交配,雌性天牛表皮蜡质层的烃类或雌雄二性表皮中相对含量比较多的物质成为特有的信号物质。雄性天牛产生聚集信息素吸引雌雄二性。随着对天牛信息素的深入研究,使用信息素复合技术将有利于提高天牛林间诱捕量,对监测天牛种群动态和无公害防治天牛具有极其重要的意义。     

Development of natural waxes dispensers for pheromones and use in mating disruption of the ambrosia beetle <Emphasis Type="Italic">Megaplatypus mutatus</Emphasis> in poplar (<Emphasis Type="Italic">Populus</Emphasis> spp) plantations

Megaplatypus mutatus (= Platypus mutatus) (Chapuis) is an ambrosia beetle native to South America that attacks live trees, mining deeply into the xylem through large tunnels. This activity weakens the structural integrity of the tree, causing severe stem-breakage and mortality. Attacks are initiated by pioneer males that select a host tree and build short nuptial galleries, to which they attract females using a sexual pheromone. Previously, we showed the potential for the strategy of pheromone-mediated mating disruption of M. mutatus in commercial poplar and hazelnut plantations in South America and Europe using polyethylene reservoir dispensers for pheromones. In the present work we replaced the polymeric reservoir dispensers by monolithic dispensers made by dispersion of the pheromone in natural waxes and the addition of kaolin and we found that: prior to pheromone deployment, the mean number of galleries per tree did not differ significantly between the control and treated plots and the same was observed after the mating disruption treatment for the control plot but not for treated plots, where the mean number of galleries were reduced. These findings confirm that mating disruption is a viable tool for management of M. mutatus in poplar plantations. Using natural wax dispensers has obvious advantages from an environmental point of view.     

For sex and more: attraction of the tephritid parasitoid Psyttalia concolor (Hymenoptera: Braconidae) to male sex pheromone of the olive fruit fly,Bactrocera oleae

The braconid parasitoid Psyttalia concolor foraging for larvae of Bactrocera oleae (Diptera: Tephritidae) uses olfactory cues from the larval microhabitat. However, it could rely on the sex pheromones of adults of its host, since B. oleae mating leks usually occur on olive plants and a high number of infested fruits can be easily located in their close proximity. We quantified the behavioural responses of P. concolor towards different doses of the two major sex pheromone components of B. oleae, the female-borne 1,7-dioxaspiro[5.5]undecane (DSU) and the male-borne (Z)-9-tricosene (ZT). Results showed that P. concolor females and males were attracted only to the highest amounts of ZT (10 B. oleae male equivalents), regardless of the mating status. Wasps remained longer on the surfaces treated with high ZT amounts over the control. P. concolor females could exploit the ZT produced by lekking olive fruit fly males as a foraging kairomone. This could allow them to rapidly track B. oleae-infested olive plants, thus raising their chances to locate host larvae during their lifespan. On the other hand, the perception of ZT by P. concolor males could raise their chances to locate receptive females emerging from parasitised B. oleae pupae or also ovipositing in olive fruits. This study increases the knowledge of the reproductive biology of P. concolor, highlighting a case of chemical espionage in which a sex pheromone component from adult stages of the host is exploited both as a foraging kairomone by female parasitoids and as a sexual kairomone by male wasps.     

天牛类昆虫交配行为研究进展

天牛是一类在我国危害严重且防治难度较大的林木蛀干害虫.虽然其种类众多,经济和生态价值大,但国内外较少有对天牛繁殖交配行为的总结报道.梳理国内外对天牛交配行为的研究,发现天牛交配行为可分为求偶、性冲动、交配前准备、交配四个阶段,每个阶段都不可缺少,且有其阶段特征性的行为.在交配后,一些雄性天牛会表现出配后保护行为.天牛交...     

Testing mating disruption of the horse chestnut leafminer <Emphasis Type="Italic">Cameraria ohridella</Emphasis> (Lepidoptera: Gracillariidae) in field tents

Since the beginning of the invasion of the horse chestnut leafminer, Cameraria ohridella Deschka and Dimic 1986 (Lepidoptera: Gracillariidae), into Europe over 20 years ago the damage to white flowering horse chestnut trees, Aesculus hippocastanum L (Sapindales: Hippocastanaceae) has remained extensive. This study evaluates the possible use of pheromone mating disruption as a control option against the horse chestnut leafminer. The heterogeneous distribution of ornamental trees in parks and gardens requires a different approach to evaluate pest control than in homogeneous crop fields, orchards or plantations where mating disruption is usually applied. For this reason we set up field experiments with host trees of the same age and size in field tents with a defined number of leafminers in two different densities. In the first experiment the effective quantity of newly developed C. ohridella pheromone dispensers was tested by recapturing males using traps baited with virgin females. Ninety-five percent less males were captured if three or more dispensers were positioned at a 4 m radius around the outside of an experimental tent. This set up was then used in the second experiment where male and female leafminers were released into field tents in order to assess the effect of pheromone on the reduction of leaf mining damage. Surprisingly, the pheromone dispensers were found to have no effect on the number of leaf mines at either low or high leafminer densities. Mating sites of the horse chestnut leafminer, multiple matings and distribution of pheromone dispenser are discussed as possible factors influencing the outcome in this study.     

Transfer of inoculum of Metarhizium anisopliae between adult Glossina morsitans morsitans and effects of fungal infection on blood feeding and mating behaviors

The transfer of conidia of Metarhizium anisopliae between tsetse flies Glossina morsitans and the effects of fungal inoculation on mating and blood meal feeding behaviors were investigated in the laboratory. Male or female flies were inoculated with fungal conidia (“donors“) and allowed to pair with fungus-free mate of opposite sex (“recipients”) at 1-day-interval up to three mates. Fungus-treated male or female “donor” flies as well as their mates “recipients” died from fungal infection. However, mortality in male “recipient” flies declined with successive mating, from 82.5 to 32.5 %. Fungus-treated males readily located female flies and mating was successful in most cases comparable to the controls. There were no significant differences (P > 0.05) in mean duration of mating, number of jerking movements between fungus-treated and fungus-free males for all the mating lines, except in the number of jerking movements when male flies mated with the 3rd line female flies. Fungus-treated and fungus-free female flies previously mated with treated and non-treated males showed refractoriness during subsequent pairings. The number of fertile female flies was higher (P < 0.05) in fungus-free than in fungus-treated treatments, thus producing more pupae. High concentration of fungus (3.0 × 10⁶ conidia ml^?1) significantly (P < 0.05) reduced blood meal intake of flies. This study has shown that fungal infection does not affect the mating behavior of tsetse flies and fly-to-fly contamination does occur during matings. These are important attributes if entomopathogenic fungi have to be used in auto-dissemination strategy and be integrated into sterile insect technique.     

Challenges of pheromone-based mating disruption of <Emphasis Type="Italic">Cydia strobilella</Emphasis> and <Emphasis Type="Italic">Dioryctria abietella</Emphasis> in spruce seed orchards

Seed orchards function as the primary source of high-quality seeds for reforestation in many European countries, but their seed yields can be severely reduced due to seed- and cone-feeding insects. We evaluated various parameters of pheromone-based mating disruption for control of the moths Cydia strobilella and Dioryctria abietella, which are major pests in European Picea abies seed orchards. We applied different types of pheromone dispensers (rubber septa or wax droplets) at different densities and heights, and with different amounts of active components, covering whole orchards or part of an orchard. The efficacy of the treatment was evaluated by analysing male captures in pheromone-baited assessment traps, and presence of larvae in cones. A dramatic decrease (94–100%) in capture of males in traps occurred in all pheromone-treated plots compared to control plots for both moth species. In contrast, a subsequent reduction in larval numbers in cones was only achieved when wax droplets were used as the dispensing formulation at high density and at the highest pheromone dose tested, and only in half of the trials for each pest species. Electrophysiological recordings using antennae of male C. strobilella indicated elevated pheromone concentrations in a treated plot versus a control plot. Our results show that mating disruption has potential to reduce cone damage in spruce seed orchards caused by C. strobilella and D. abietella, but optimisation of the technique is required to achieve consistent and efficient population suppression of these pests.     

Calling behaviour and male response towards sex pheromone of poplar moth <Emphasis Type="Italic">Condylorrhiza vestigialis</Emphasis> (Lepidoptera: Crambidae)

The calling behaviour of virgin females Condylorrhiza vestigialis Guenée, 1854 (Lepidoptera: Crambidae) and the female pheromone gland extract activity were studied under laboratory conditions. Most of the females started calling from their first scotophase period after emergence. Maximum calling occurred between the seventh and tenth hours of the scotophase period. The length of the calling increased with age until the fourth scotophase, but the onset of calling time did not differ with age. The number of calling bouts increased significantly with age, but the mean duration of each calling bout (20.8 min) did not vary with age. Extracts of pheromone glands evaluated in a Y-tube olfactometer attracted significantly more males than control, 70 and 30%, respectively. Gas chromatographic–electroantennogram detection (GC–EAD) analysis of these extracts indicated the presence of a single EAD-active peak, the putative sex pheromone of the species. This pheromone compound may be suitable for monitoring populations densities of C. vestigialis, and for detection of the onset of the seasonal flight period. An efficient pheromone is of importance also with respect to current attempts to develop new control methods for this important pest of Populus spp. in Brazil.     

The effect of grape vine cultivars on <Emphasis Type="Italic">Lobesia botrana</Emphasis> (Lepidoptera: Tortricidae) population levels

The European vine moth Lobesia botrana Denis & Schiff. (Lepidoptera: Tortricidae) is a key pest in the vineyards of Israel and Europe. Traps baited with the female sex pheromone are commonly used to monitor the pest population. However, the role of the vine cultivars on monitoring the moth population using pheromone-baited traps was not yet studied. The present study aimed to identify the effect of grape cultivars on L. botrana adult distribution patterns in the field, in order to achieve a better understanding of the monitored data in respect to male and female’s host preference. The 3-year study in commercial vineyards used four cultivars: Carignan, Emerald Riesling, French Colombard, and Cabernet Sauvignon. The moth population of each generation was estimated from male counts in pheromone traps; three generations were observed in all experimental orchards, each year. Female host choice was studied by monitoring freshly deposited eggs and newly hatched larvae on vines. The study showed a significant effect of cultivar on numbers of trapped males in most years, and a cultivar effect on female host choice. For both males and females and for all phenological stages of the grapes, Carignan and French Colombard attracted the most and Cabernet Sauvignon the fewest specimens. The results show that cultivar blend within the vineyard can affect the distribution pattern of the pest. Knowledge of the expected choice of the female moth, and of the timing of its decision could lead to an improved monitoring system, with the preferred cultivar as an indicator.     

Male multiple matings and reproductive success in commodity-adapted strains of <Emphasis Type="Italic">Sitophilus oryzae</Emphasis>

Multiple matings occur in many species of stored-grain insect pests, such as the rice weevil Sitophilus oryzae (L.), with both female and male mating more than once and with more than one partner. Multiple female mating in S. oryzae increased lifetime fecundity by extending the period of time progeny were produced, but consequences of multiple male mating in S. oryzae were not yet studied although it is likely to increase male fitness by increasing offspring production. Here, the effects of polygynous mating on male mating behavior, success, and fitness were assessed in two strains of S. oryzae, one adapted to barley and another to wheat. Two insect strains were considered because they may differ in response depending on the host grain, which present distinct nutritional value to the insects. Mating by pairs formed between the two strains did not impact mating success, but wheat-adapted females exhibited longer mating duration, which was positively correlated with progeny production. Wheat-adapted males exhibited higher fertility than barley-adapted males. When male multiple matings were considered in successive polygynous matings, late matings led to lower non-cumulative values of progeny production, but higher cumulative performance, and wheat-adapted S. oryzae always performed better. Thus, male fitness and grain losses in wheat are higher than in barley, even when S. oryzae was adapted to the latter.     

Courtship and mating behaviour in the fruit fly parasitoid <Emphasis Type="Italic">Psyttalia concolor</Emphasis> (Szépligeti) (Hymenoptera: Braconidae): the role of wing fanning

Psyttalia concolor is a parasitoid of fruit flies (Tephritidae) which is used to control the olive fruit fly (Bactrocera oleae). Detailed knowledge of its reproductive biology is required to optimise mass rearing conditions and use in biological control. In this study, the mating behaviour of P. concolor was investigated in order to understand the factors that can influence the success of male mating, using both high-speed video and biological assays. P. concolor males were more likely to be successful in mating during the early morning as opposed to the afternoon, and their courtship behaviour was not affected by the female mating status (i.e. virgin or mated). Wing fanning and copulation attempts were also frequently displayed among males, but male mating status did not influence male–male courtship behaviour. Video data revealed that during wing fanning, male wings were kept raised and moved rhythmically in a dorsoventral fashion. Frequency, pulse duration and interpulse interval of the fanning males during female courtship differed significantly in successful mating attempts compared to unsuccessful ones. Wingless males had significantly lower mating success compared to winged males, suggesting that wing fanning increases the likelihood of attracting a mate. Overall, the study increases the knowledge of the reproductive biology of P. concolor and suggests the importance of fanning behaviour among the range of sensory modalities used by this parasitoid in intra-specific communication.     

Geographic variation in pheromone component ratio and antennal responses,but not in attraction,to sex pheromones among fall armyworm populations infesting corn in Mexico

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is one of the most important pests of corn in Latin America. This insect presents two strains with behavioural and genetic differences. In Mexico, both strains are present, and at least two different FAW populations have been reported within the corn-strain. The objective of this study was to gather evidence of whether pheromonal communication varies among different S. frugiperda populations infesting corn in Mexico. First, we investigated any qualitative or quantitative difference in the composition of sex pheromones among populations; second, we studied whether male antennal responses to pheromone components vary among populations; and, finally, we investigated whether males from a region can discriminate between a synthetic pheromone blend characteristic of their region and blends formulated with the ratio of pheromone compounds emitted by females from other populations. Sex pheromone components were sampled by solid-phase microextraction and identified by gas chromatography coupled to mass spectrometry. Females from all populations consistently released three compounds: (Z)-9-tetradecenyl acetate (Z9-14:OAc), (Z)-11-hexadecenyl acetate (Z11-16:OAc) and (Z)-7-dodecenyl acetate (Z7-12:OAc). Our results showed that Z9-14:OAc and Z7-12:OAc evoked the highest and most variable antennal responses among the populations studied compared to Z11-16:OAc. However, males did not discriminate between local pheromone blends and those formulated from other populations in a field test. These results show that although there is geographic variation in the ratio of pheromone components and in the peripheral reception of them, males were not differentially attracted to different pheromone blends in the field.     

A review： chemical ecology of Ips typographus （Coleoptera, Scolytidae）

Chemical ecology of the spruce bark beetle lps typographus （L.） was reviewed. The outbreak of 1.typographus in central Europe triggered extensive research on chemical ecology, Males initiate host location and produce semiochemicals which attract both males and females, A successful mass attack must first overcome the resistance of the host tree. Pioneer I. typographus evolved to use the resin flow of host trees as kairomones in host location, and synthesized semiochemicals initially to detoxify the resin. If small bark beetle populations infest healthy trees, mass attack is prevented by host resistance, Nine monoterpene alcohols were found in male hind-guts, including cis-verbenol （cV） and 2-methyl-3-buten-2-ol （MB） which are regarded as primary aggregation pheromones, and a low proportion of lpsdienol （ld） which increases attractiveness of cV and MB, Verbenone （Vn） and Ipsenol （le） are anti-aggregation pheromones, that play important roles in adjusting attack density and insect density under the bark. Non-host volatiles are repellent to L typographus, so that beetles do not waste energy boring into non-host trees. The relationship between host resistance, pheromone compounds and behavior, non-host volatiles, bioassays and mass trapping are reviewed, Results of field bioassays stressed that traps baited with specific pheromones could be used as a reasonable protection measure.