Pea leafminer Liriomyza huidobrensis (Diptera: Agromyzidae) uses vibrational duets for efficient sexual communication

The pea leafminer (Liriomyza huidobrensis) is a notorious pest of vegetables and ornamental plants worldwide. Despite a large number of studies on its biology and ecology, the courtship behavior and sexual communication of this species remain unclear. Here, we studied vibrational communication in the sexual interaction of the pea leafminer. On host plant leaves, females and males behaviorally displayed the bobbing-quivering alternation, which finally led to copulation. Moreover, records of laser vibrometry revealed threesignal duets underlying the behavioral alternation. Sexually mature males spontaneously emitted calls (MCs) to initiate the duets. The females rapidly responded to MCs by emitting replies (FRs) that are longer in duration. The FRs further triggered male replies (MRs) in their search for potential partners. Leafminer-produced vibrational signals convey efficient information to partners and generate pair formation on stretched substrates, such as plant leaves and nylon mesh, but cannot elicit responses on dense substrates, such as glass and plastic. Vibrational playbacks of both MCs and FRs can elicit replies in females and males, respectively. This study completely characterizes substrate-borne vibrational duets in a dipteran insect. The discovery of vibrational sex signals in the pea leafminer provides new insights for the development of novel approaches to control the pest and its relative species.     

Substrate-borne vibrational signals and stridulatory organs for sexual communication in leafminer,Liriomyza sativae (Diptera: Agromyzidae)

The vegetable leafminer (Liriomyza sativae [Burgess]) is a highly polyphagous pest that threatens vegetables and horticultural plants. Although sexual communication is a key component of the animal behavioral repertoire, the mechanism underlying sexual communication in L. sativae remains to be elucidated. Here, we used laser vibrometry to characterize the vibrational signals emitted by L. sativae during pair formation. By emitting trains of vibrational pulses (male calling) the male initiated communication on the host plant. The female then became immobile and responded to the male calling by emitting replies (female replies), which in turn triggered male replies consisting of a rapid series of chirps and trills. If the female replied, a continuous exchange of male and female replies ensued, representing a duet. In playback trials, a playback signal caused responses from the opposite sex. Moreover, scanning electron microscopy revealed vibration-producing stridulatory organs in both male and female individuals. The files in males were more developed than those in females, and older male specimens had more signs of abrasion. The results provide new insight into the mating biology of L. sativae.     

Genetic control of Plutella xylostella in omics era

Diamondback moth, Plutella xylostella (L.), is a specialist pest on cruciferous crops of economic importance. The large‐scale use of chemical insecticides for the control of this insect pest has caused a number of challenges to agro‐ecosystems. With the advent of the omics era, genetic pest management strategies are becoming increasingly feasible and show a powerful potential for pest control. Here, we review strategies for using transgenic plants and sterile insect techniques for genetic pest management and introduce the major advances in the control of P. xylostella using a female‐specific RIDL (release of insects carrying a dominant lethal gene) strategy. Further, the advantages of gene drive developed in combination with sex determination and CRISPR/Cas9 systems are addressed, and the corresponding prospects and implementation issues are discussed. It is predictable that under the policy and regulation of professional committees, the genetic pest control strategy, especially for gene drive, will open a new avenue to sustainable pest management not only for P. xylostella but also for other insect pests.     

Notonomus gravis (Chaudoir) (Coleoptera: Carabidae) predation of Deroceras reticulatum Müller (Gastropoda: Agriolimacidae), an example of fortuitous biological control

The increasing use of pesticides in broad-acre cropping in South eastern Australia is suspected to have reduced native carabid beetle populations which fortuitously control potential pest populations. Slugs are increasingly becoming an establishment pest of canola, which is often attributed to stubble retention introduced to arable farming systems. Exclusion enclosures were employed to test the effect of the native carabid Notonomus gravis on the exotic pest slug Deroceras reticulatum. The native predatory species limited D. reticulatum populations and this was further supported by a negative field association between the predator and slug numbers. However, while N. gravis contributed to control of slug populations, enclosure experiments suggest that slug damage was not reduced below economic thresholds by this predator alone. Although N. gravis provides a “lying in wait” pest control option for slugs, multiple predators and environmental interactions need to be considered in developing robust integrated pest management guidelines.     

The invasive gall wasp Quadrastichus erythrinae (Hymenoptera: Eulophidae) in South America: is classical biological control needed?

The invasive gall wasp Quadrastichus erythrinae, a pest of Erythrina plants, is recorded for the first time in South America in Espírito Santo, Brazil. Research on Q. erythrinae and its potential natural enemies in this region is required to determine the need for classical biological control of this invasive pest.     

世界性害虫葡萄花翅小卷蛾入侵我国的风险分析

【目的】葡萄花翅小卷蛾是我国禁止进境的检疫性害虫,一旦入侵我国,将会给葡萄产业和林果业造成严重损失。开展葡萄花翅小卷蛾入侵我国的风险分析可为该虫的检疫和预警提供依据。【方法】介绍了葡萄花翅小卷蛾的形态特征和生物学特性,并参照通用的有害生物风险评估方法,从该虫在国内外的发生情况、潜在的经济危害性、受害作物的经济重要性、传播扩散的可能性及风险管理的难度等方面,对其入侵风险进行了定性和定量分析。【结果】葡萄花翅小卷蛾是一种对我国有很大潜在威胁的有害生物,其风险值为2.14,属高度危险性有害生物。【结论】建议新疆等口岸比较多的省、自治区口岸检疫部门加强对该害虫的检疫力度,杜绝其传入我国。     

Invasion biology,ecology, and management of Frankliniella occidentalis in China

Frankliniella occidentalis is an economically important invasive pest worldwide, which can damage various horticultural crops and ornamental plants. F. occidentalis was first intercepted in Kunming, Yunnan province in 2000, and first reported to establish a population in Beijing, China in 2003. Since then, this pest is currently distributed across tens of provinces in mainland China and cause increasingly serious damage and loss. To control this pest, invasion biology, monitoring, and integrated pest management have been generally and intensively studied for 15 years in China. Furthermore, western flower thrips (WFT) as an important invasive insect pest, the research achievements on WFT has contributed to the promotion of technological innovation and development for invasive alien species management strategies and techniques in China. This review provides an overview for research on the biology, ecology, prevention, and management of this pest during 15 years in China. Meanwhile, China's “4E action” strategy on F. occidentalis is also discussed in this review.     

Neoseiulus Californicus (Acari: Phytoseiidae) as a Potential Control Agent of Tetranychus Urticae (Acari: Tetranychidae): Effect of Pest/Predator Ratio on Pest Abundance on Strawberry

Neoseiulus californicus (McGregor) is a promising agent for successful Tetranychus urticae Koch control through conservation techniques, in strawberry crops in La Plata (Buenos Aires, Argentina). In prey–predator interaction, initial relative densities have an important effect on system dynamics. The economic threshold level (ETL) used for this pest in the present study was 50 active mites per leaflet. In our laboratory experiments, initial T. urticae to N. californicus ratio had a significant effect on the population abundance of T. urticae at a 7-day period. When pest/predator ratio was 5/1 (at initial pest densities from 5 to 15 females/leaflet) the final number of active T. urticae/leaflet was significantly lower than the ETL, while at 20 females/leaflet this number did not differ from the ETL. At 7.5/1 ratio, the final number of active T. urticae/leaflet, at initial pest densities from 5 to 15 females/leaflet, reached the ETL without surpassing it. At 10/1 and 15/1 ratios, pest densities exceeded the ETL only at 15 initial T. urticae/leaflet. Most greenhouse and field observations were consistent with the predictions of a graphical model based on experimental results. This predator was very effective in limiting pest densities at a 7-day period and within the range of pest–predator ratios and absolute densities used in this study. Conservation of N. californicus promoting favorable pest/predator ratios may result in early control of T. urticae.     

Using life stage-structured matrix models to determine natural enemy:pest release ratios for augmentative biological control

Augmentative biological control (ABC) is crucial for the integrated pest management (IPM) of greenhouse pests. The proper calculation of natural enemy:pest release ratio (NEPRR) stands out among the various challenges of ABC. Often, most NEPRR calculations only take into account the predation/parasitism efficiency of natural enemies, while disregarding pest population growth capacity, population structure and/or economic thresholds. In a model system consisting of Trichogramma pretiosum Riley parasitizing eggs of Tuta absoluta (Meyrick) on greenhouse tomatoes, we investigated whether a stage-structured Lefkovitch matrix could be used to determine suitable NEPRRs. The results suggested that these matrix models can potentially provide more precise and realistic predictions of NEPRRs since they account for differential pest population growth over time as a response to natural enemy action. The matrix models could also allow us to choose an adaptable NEPRR based on parameters such as the period the grower wishes to keep the pest population below economic threshold.     

Biological control: lessons from a study of California red scale

A 20-year study of suppression of California red scale, a world-wide pest of citrus, by the parasitoid Aphytis melinus has established that the interaction is dynamically stable and that the mechanisms leading to control and stability operate at a local scale: spatial processes are not important. Key features appear to be an invulnerable class in the pest and rapid development of the parasitoid compared with the pest, as well as the fact that the parasitoid is an in situ specialist on the pest. Although another parasitoid species and two predator species are also present, they play at most a negligible role in pest control. These features—long-term persistence, suppression by a single natural enemy, an invulnerable stage in the pest and rapid development in the natural enemy—appear to be common in other coccid pest systems. By contrast, in temporary crops where the pest and enemy populations are open (i.e., sustained over the long run mainly by immigration) and non-persistent locally, as is frequently found in aphid pests, we expect that multiple generalist enemies are required for control and, of course, that spatial processes are important. There are very few well-studied examples of such systems, but these support our expectations. In these cases, it also appears that neither rapid enemy development nor an invulnerable pest stage is important for successful control.     

Exotic wildland weeds serve as reservoirs for a newly introduced cole crop pest,Bagrada hilaris (Hemiptera: Pentatomidae)

The role of wildland weeds that serve as alternate hosts for insect pests has not been directly examined for the potential to sustain pest populations or facilitate pest outbreaks. The development of weed biological control programmes is also complicated by weed species that are closely related to economically important or native plants, especially rare or special status species. In recent surveys in southern California, USA, we found a newly introduced insect pest of cole crops, Bagrada hilaris Burmeister (Bagrada bug), feeding on Brassicaceae weeds in riparian areas adjacent to agricultural fields where cole crops are routinely grown. Insect populations grew to levels well over action thresholds and caused severe damage to populations of the invasive weed, Lepidium latifolium (perennial pepperweed). The numerical response of B. hilaris on L. latifolium and other Brassicaceae weeds in natural areas may pose a significant challenge to effectively managing pest populations in crops. However, the accidental introduction of this insect provides the opportunity to examine plant–insect interactions with important implications for development of biologically based control methods for weeds.     

Ein Winzling lehrt das Fürchten

The invasive Spotted Wing Drosophila – a significant pest The Spotted Wing Drosophila (Drosophila suzukii), native in South-East Asia, is an invasive pest belonging to the small fruit fly family of Drosophilidae, also named vinegar flies. Apparently displaced by global trade to the USA and Europe, this pest was able to disperse enormously over the continents since 2008. Ideal preconditions for this spread were suitable climatic conditions, the availability of a wide variety of host plants and the use of an ecological niche, namely healthy ripening and ripe fruits. In addition, D. suzukii is highly reproductive and owns excellent overwintering strategies. The Spotted Wing Drosophila is difficult to control and causes enormous damage.     

First finding of a quarantine pest,Atherigona (Acritochaeta) orientalis Schiner (Diptera: Muscidae), in Korea

The invasive quarantine pest fly, Atherigona (Acritochaeta) orientalis Schiner, is observed for the first time in tomato greenhouses in Gyeongsangbuk‐do, Korea. The genus Atherigona Rondani is also newly added to Korean fauna. Allium tuberosum is listed as a new host crop for this species. Some morphological characteristics for accurate identification and host lists are given to provide plant quarantine information for pest management.     

葡萄花翅小卷蛾抗药性研究进展

葡萄花翅小卷蛾是葡萄上的重要害虫,具有多食性、多化性等生物学特点,抗逆能力极强。该虫起源于欧洲,现已入侵全球多个国家。葡萄花翅小卷蛾主要以幼虫取食葡萄花序、幼果和成熟果实,给葡萄生产造成重大损失;其危害有利于真菌的侵入,导致灰霉病、白粉病等病害大量发生,从而造成葡萄腐烂。由于该虫入侵风险极高,已被我国列为重要的进境检疫性有害生物。国外对葡萄花翅小卷蛾的防治主要采用化学杀虫剂,由于长期大量且不合理地使用化学杀虫剂,葡萄花翅小卷蛾已对多种不同类型的杀虫剂产生了抗药性。本研究总结了葡萄花翅小卷蛾的抗性测定方法、抗性现状及其抗性机理,同时结合国外葡萄花翅小卷蛾抗性和防治相关研究,提出该虫抗性治理策略,并对我国预防该虫的入侵提出建议。     

Mating interference of glassy‐winged sharpshooters,Homalodisca vitripennis

Animal communication is a complex behavior that is influenced by abiotic and biotic factors of the environment. Glassy‐winged sharpshooters (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), primarily use vibrational signaling for courtship communication. Because GWSS is a major pest, transmitting the plant pathogenic bacterium Xylella fastidiosa Wells et al., interruption of communication is a possible avenue for control. Playback of white noise, pre‐recorded female signals, and artificial female noise (continuously overlapping female signals) significantly reduced mating of GWSS when compared to silent control mating trials. Furthermore, to begin to determine the mechanism underlying playback control, female signaling activity was recorded in the presence of stimuli. In response to playback of female signals, females signaled (duet‐like) more often than females tested in the absence of playback. After the first playback, almost two‐thirds of females signaled a response within 3 s. Additionally, one‐third of the females signaled within 1 s after cessation of white noise, and significantly more in the time periods following noise termination. Results highlight how GWSS responds to differing competitive disturbances in the environment and lays important ground work that possibly could be used to develop pesticide‐free control methods.     

A review of the damage caused by invasive wild mammalian herbivores to primary production in New Zealand

ABSTRACT

Wild mammalian herbivores can compete with domestic livestock and damage other types of production systems. We reviewed damage by wild mammalian herbivores, excluding rodents, to primary production in New Zealand and assessed whether primary producers alter stocking rates in response to changes in forage availability following pest control. Given the dearth of information on the damage caused by wild mammalian herbivores to many production systems, we primarily focused on their damage to agriculture. With the exception of the substantial damage that brushtail possums (Trichosurus vulpecula) and European rabbits (Oryctolagus cuniculus) cause, there are no quantitative estimates of pasture depletion by other wild mammalian herbivores on New Zealand farmland. Estimates of dry matter consumption by wild mammalian herbivores, converted to stock unit equivalents, suggest that several species can substantially reduce stocking rates when they occur on farmland. Quantitative data on the damage they cause to horticulture and silviculture are lacking, but damage to coniferous seedlings has been recorded for possums, wallabies (Notamacropus spp.), and some species of deer (Cervus spp., Rusa spp., and Dama dama). The process that primary producers use to decide whether to control wild mammalian herbivores includes complex social and economic factors, but quantitative information is important for weighing up the expected costs and benefits of pest control. However, it is unclear how primary producers manage livestock in response to increases in forage availability following pest control. The paucity of quantitative data on wild mammalian herbivore damage to production assets is a substantial knowledge gap. Key research priorities are (i) understanding how damage varies with pest density (critical information for effective pest management) and (ii) and how primary producers alter stocking rates following reductions in pest density.     

First record of the quarantine pest Atherigona (Atherigona) oryzae Malloch (Diptera: Muscidae) in Korea

Occurrence of the invasive quarantine pest fly, Atherigona (Atherigona) oryzae Malloch, is hereby recorded for the first time in Gyeongsangbuk‐do Province, Korea. Morphological characteristics for accurate identification of the species, a list of hosts, and damage patterns are described to provide plant quarantine information for pest management.