Spectral preferences of Lycorma delicatula (Hemiptera: Fulgoridae)

Many insects prefer lights with certain spectral properties, and such preferences may be associated with behavioral contexts such as mating, host finding or dispersal. Lycorma delicatula (Hemiptera: Fulgoridae) is a newly invasive species in Korea and is spreading rapidly. It is diurnal and may rely on visual cues for orientation. We conducted a series of three phototaxis experiments to understand spectral preferences in L. delicatula: light/dark choice, UV/white light choice, and color preference experiments. Nymphs of the third and final stages as well as adults were used for these experiments. In the light/dark choice, the orientation of L. delicatula was bimodal between the white light and darkness, for all stages and both sexes. In a choice of UV (395–410 nm wavelengths) vs. white light, L. delicatula of both sexes and all stages preferred the UV light. In the color preference experiment where insects had a choice of four colors in a circular arena, L. delicatula stayed significantly longer in the blue light than in white, yellow or green lights. Overall, nymphs and adults of L. delicatula oriented toward lights with shorter wavelengths, and this orientation was consistent throughout all stages, regardless of sex. It is necessary to investigate the behavioral contexts under which L. delicatula prefers the UV and blue lights.     

Orientation of flight for physically disturbed spotted lanternflies,Lycorma delicatula, (Hemiptera,Fulgoridae)

The spotted lanternfly, Lycorma delicatula, (Hemiptera, Fulgoridae) is an invasive pest to Korea and the United States, originating from China or Southeast Asia. Immature L. delicatula feed on a wide range of plants, but the adults are more host-selective, often preferring the tree of heaven, Ailanthus altissima. We performed field studies to evaluate adult movement in relation to A. altissima after disturbance. The Ailanthus trees were in a mixed suburban forested situated at the southern border of an open grassy field. Female adult lanternflies were manually disturbed from feeding on the trunks of large A. altissima trees. In the first experiment, insects were disturbed directly from the tree using a ballpoint pen to simulate a predatory attack. These insects usually flew initially southward away from the tree line toward a sunlit field, but turned northward back toward the tree line. In the second experiment, to simulate an initially successful predatory attack, they were manually taken from trees, and allowed to escape. The females immediately opened their wings in an apparent aposematic display. They then either immediately flew toward the sunlit open field, or remained with their wings splayed open for a prolonged period.     

斑衣蜡蝉雌性生殖系统超微结构

【目的】明确斑衣蜡蝉Lycorma delicatula雌成虫生殖系统整体形态及超微结构特征,为蜡蝉总科昆虫分类及系统发育探讨提供更多形态学证据。【方法】采用光学显微镜与透射电子显微镜,观察斑衣蜡蝉雌成虫生殖系统整体形态和各主要器官的超微结构。【结果】斑衣蜡蝉雌成虫生殖系统主要包括1对卵巢、1个中输卵管、1个交配囊、1个交配囊管、1个前阴道、1个后阴道、1个受精囊、1个受精管和2根受精囊附腺。卵巢为端滋式,由14根卵巢小管组成,卵室由固有膜、滤泡细胞和卵细胞组成,卵巢小管中的滋养细胞清晰可见;中输卵管位于前阴道基部,由中输卵管腔、上皮细胞、肌肉鞘和基膜组成;交配囊膨大呈圆球状,囊壁由上皮细胞、肌肉层和基膜组成;交配囊管呈圆柱状,连接交配囊和后阴道,由肌肉鞘、上皮细胞层和管腔组成;前、后阴道超微结构相似,主要由肌肉鞘、基膜、上皮细胞和管腔组成,但后阴道上皮细胞细胞核周围存在分泌颗粒,且管腔内有大量微绒毛,而前阴道壁内包含有大量囊泡结构;受精管从中输卵管末端延伸至受精囊,由基膜、厚层肌肉鞘和管腔组成;受精囊为受精管近末端略膨大的囊状结构,由肌肉鞘、基膜、上皮细胞和囊腔构成;雌性受精囊附腺着生于受精囊末端,为均匀的螺旋管状,主要由肌肉层、上皮细胞层和附腺中心管腔组成。【结论】斑衣蜡蝉雌性生殖系统与已报道的蜡蝉总科其他类群的雌性生殖系统结构相似,但卵巢小管数目有差异;蝉亚目中不同总科雌成虫雌性附腺与受精囊附腺的形态特征存在明显区别;斑衣蜡蝉雌性生殖系统超微结构与叶蝉总科和沫蝉总科昆虫也存在部分差异。这些差异是否可以作为头喙亚目高级阶元的划分依据仍有待于进一步研究。     

Agonistic interactions between nymphs of Lycorma delicatula (Hemiptera: Fulgoridae)

The nymphs of Lycorma delicatula typically aggregate on tree branches for feeding. We studied agonistic interactions between nymphs in the field and investigated the effects of prior residence and body size on contest outcome. Resident nymphs maintained positions on tree branches and engaged in feeding, whereas intruding nymphs moved along tree branches. When an intruder approached, the resident typically raised its front legs as a threat posture. The intruder would either move away or palpate the resident, and the resident often lowered its body when palpated. The intruder would then attempt to shake the resident back and forth, with the number of attempts varying from one to several. The resident either maintained its position or fled. After a contest, the winner was determined to be the one occupying the contested position on the branch. The resident nymphs won 84.2% of the agonistic encounters, and the nymphs with larger body size won 63.2% of the agonistic encounters. Logistic regression analysis revealed that prior residence was a significant factor for the contest outcome, but body size was not. We discuss the hypotheses for the dominance of the residents in agonistic interactions between nymphs of L. delicatula.     

Impact of minimum winter temperature on Lycorma delicatula (Hemiptera: Fulgoridae) egg mortality

Climate change, especially winter temperature increase, may be a factor the recent occurrence and range expansion of Lycorma delicatula (White) in South Korea. Egg mortality increased as minimum winter temperature decreased. Egg mortality was highest (93.32%) in Chuncheon, where the mean minimum winter temperature was lowest. The temperature that induced complete mortality of fulgorid eggs was estimated to be ?3.44 °C on the basis of mean daily temperatures from December 2009 to February 2010 and ?12.72 °C on the basis of mean daily minimum temperatures in January 2010. Mean winter temperatures during the last 30 years have gradually increased to above the temperature for 100% mortality of the fulgorid egg. This suggests that the winter temperature increase may contribute to the successful settlement of the fulgorid in South Korea and its subsequent outbreak and expansion.     

Molecular comparison of Lycorma delicatula (Hemiptera: Fulgoridae) isolates in Korea,China, and Japan

Lycorma delicatula (White) was recently introduced in Korea, acting as a grape insect pest. Since the introduction of this invasive insect, it initially spread rapidly throughout central and southern Korea, and is now distributed throughout the mainland. Here we developed new mitochondrial markers from NADH dehydrogenase subunit 2 and NADH dehydrogenase subunit 6 regions, and analyzed the regional isolates of L. delicatula collected from original locations in China, as well as invasive locations in Korea and Japan. All Korean and Japanese isolates were found to be genetically identical to those from Beijing, Tianjin, Qingdao, and Shanghai, China. Further isolates, from Zhejiang province, China, had two additional haplotypes.     

Predicting potential current distribution of Lycorma delicatula (Hemiptera: Fulgoridae) using MaxEnt model in South Korea

Lycorma delicatula (Hemiptera: Fulgoridae) is an invasive insect in Korea which causes plant damages by sucking and sooty molds. Lycorma delicatula was first detected in South Korea in 2004, where its introduction and spreading possibly were affected by human activity-related factors. Here, we used MaxEnt to describe current distribution of L. delicatula in Korea and tried to find out the impact of human influences on distribution. We used 143 sites of occurrence data, 19 bioclimatic variables, duration of temperature below −11 °C, average daily minimum temperature in January, cumulative thermal unit variable, the distribution of grape orchard variable and human footprint to create models. These models were estimated by two sets of 24 candidates with feature combinations and regularization multipliers. In addition, these two sets were created as models with and without footprint to assess human influence on distribution. Model selection for optimal model was performed by selecting a model with a lowest sum of each rank in small sample-size corrected Akaike’s information criterion and difference between training and test AUC. Model of LQ10 parameter combinations was selected as optimal models for both model sets. Consequently, both of distribution maps from these models showed similar patterns of presence probability for L. delicatula. Both models expected that low altitude regions were relatively more suitable for L. delicatula than mountain areas in Korea. Footprint might be limited for the distribution and L. delicatula might already occupy most of available habitats. Human-related factors might contribute to spread of L. delicatula to uninfected areas.     

Discovery of an egg parasitoid of Lycorma delicatula (Hemiptera: Fulgoridae) an invasive species in South Korea

Anastatus sp. (Hymenoptera: Eupelmidae) is reported as the first chalcidoid wasp which parasitizes eggs of Lycorma delicatula, an invasive species spreading rapidly in South Korea. The wasp appears to be a solitary endoparasitoid. The present paper also describes its oviposition and host feeding behaviour.     

A review of biology and management of Lycorma delicatula (Hemiptera: Fulgoridae), an emerging global invasive species

Lycorma delicatula (White) (Hemiptera: Fulgoridae) is an invasive species inflicting damage to agricultural and forest systems. This species is native to China, Taiwan, and Vietnam. Lycorma delicatula was accidentally introduced into South Korea and Japan, with outbreaks reported since mid-2000s. More recently, this pest was found in Pennsylvania, USA, and its geographical distribution has steadily expanded since the introduction with increasing population densities in the USA. This species is univoltine in invaded regions and overwinters in the egg stage. Lycorma delicatula is known to attack at least 65 host plants, and so-called preferred host plants such as Ailanthus altissima and Vitis vinifera are present in all invaded countries. This species threatens grape industries in China, South Korea, and USA, with the impact on other crops still unknown, at least in the USA. For monitoring this pest, light or pheromone traps have not yet been developed, but using sticky tree bands may serve as a promising tool. To date, visual survey is the primary means for detecting L. delicatula and studying their population dynamics. To control L. delicatula, several studies evaluated conventional insecticides. Under field conditions, chlorpyrifos, dinotefuran, etofenprox, and etofenprox + diazinon yielded high levels of mortality against this pest. In general, environmentally-friendly materials, registered as Environmentally-Friendly Agricultural Material in South Korea, resulted in lower insecticidal efficacy against L. delicatula compared with conventional chemicals. Natural enemies of L. delicatula such as egg parasitoids in the genus Anastatus and Dryinus are promising candidates as a long-term solution for management.     

Adhesive properties of the arolium of a lantern-fly, Lycorma delicatula (Auchenorrhyncha, Fulgoridae)

The arolium in Lycorma delicatula is shaped as a truncated pyramid, tapering proximally. The base or the terminal area is corrugated, forming parasagittal wrinkles (period 1.5-5.0 microm), which are supported from inside by cuticular dendrites. Side faces of the arolium are made up of sclerotized dorsolateral plates. When claws slip on a smooth substrate and pronate, the dorsolateral plates diverge and expand the sticky terminal area. The real contact area with the glass plate was recognized by light reflection on its periphery. This area was measured and shown to be smaller when the leg was pressed perpendicularly to the substrate (0.02 mm(2)) than when it was sheared in a direction parallel to the substrate (0.05 mm(2)). Attachment forces were measured with the aid of dynamometric platforms during pulling of active insects from horizontal or vertical glass surfaces. Normal adhesive force (about 9-12 mN) was much less than friction force during sliding with velocity of 6-17 mm/s (50-100 mN); however, when expressed in tenacity per unit contact area the difference was less pronounced: 170 and 375-625 mN/mm(2), respectively. Sliding of the arolium during shear displacement was shown to be oscillatory in frame-by-frame video analysis. Relaxative oscillations consisted of periodical sticks-slips of the arolium along the glass surface.     

Repellency of lavender oil and linalool against spot clothing wax cicada,Lycorma delicatula (Hemiptera: Fulgoridae) and their electrophysiological responses

This study was performed to investigate the repellent effect of 5 μl doses of ten essential oils (bergamot, chamomile, clary sage, fennel, lavender, lemongrass, majoram, peanut, pennyroyal, and peppermint) against Lycorma delicatula 4th nymphs using an olfactometer. Only lavender oil exhibited significant repellency. We then tested 10, 5, 2.5, and 1 μl doses of lavender oil against the nymphs and females of L. delicatula. The oil showed significant repellency at 10 and 5 μl, although the latter is less potent to 1st instar nymphs. At the lavender oil dose of 2.5 μl, only 3rd and 4th instar nymphs and females were significantly affected. None of the stages tested were affected by 1 μl. Chromatographic and mass spectrometric analyses of lavender oil detected linalool (42.2%), linalyl acetate (49.4%), terpinen-4-ol (5.0%), and caryophyllene oxide (3.4%). Among the four main components, only linalool showed repellency to all instar nymphs and females. No synergism was detected. Antennae of all instar nymphs and females showed electrophysiological responses only to linalool. In field studies using linalool, 4th nymphs and adults were highly repelled at a dose of 30 μl of lavender oil. The effect differed according to test plot and treatment dose.     

斑衣蜡蝉若虫寄生蜂地理种群遗传差异及早期快速检测

【目的】明确不同地理种群斑衣蜡蝉Lycorma delicatula若虫寄生蜂种群遗传差异,实现若虫被寄生早期的快速准确检测,以评估其对斑衣蜡蝉种群的控制作用。【方法】利用DNA条形码技术获得不同地理种群斑衣蜡蝉若虫寄生蜂COI和28S rDNA序列,利用K2P模型计算不同地理种群间的遗传距离,以邻接(neighbor-joining, NJ)法构建系统发育树;基于COI序列设计种特异性PCR(SS-PCR)引物,利用SS-PCR对斑衣蜡蝉若虫DNA进行扩增,测定其体内是否有中华螯蜂Dryinus sinicus寄生;利用目测法观察和PCR扩增测定寄生蜂对不同采样点斑衣蜡蝉若虫的寄生率。【结果】经鉴定,不同地理种群斑衣蜡蝉若虫寄生蜂为中华螯蜂,该寄生蜂COI序列共检测到16个单倍型,28S rDNA序列共检测到4个单倍型。不同地理种群间中华螯蜂遗传距离在0.00691～0.01310之间。邻接法构建的系统发育树显示不同地理种群中华螯蜂均聚于一枝。基于COI序列设计的SS-PCR引物对中华螯蜂成虫、幼虫均具有良好的扩增效果,最低检测阈值为0.000005 ng/μL DNA。利用SS-P...     

Thermal adaptation in North American cicadas (Hemiptera: Cicadidae)

We determine and summarize the thermal responses for 118 species and subspecies of North American cicadas representing more than 50 years of fieldwork and experimentation. We investigate the role that habitat and behavior have on the thermal adaptation of the North American cicadas. There are general patterns of increasing thermal responses in warmer floristic provinces and increasing maximum potential temperature within a habitat. Altitude shows an inverse relationship with thermal responses. Comparison of thermal responses of species emerging early or late in the season within the same habitat show increases in the thermal responses along with the increasing environmental temperatures late in the summer. However, behavior, specifically the use of endothermy as a thermoregulatory strategy, can influence the values determined in a particular habitat. Subspecies generally do not differ in their thermal tolerances and thermal tolerances are consistent within a species over distances of more than 7600 km.     

Bad side of a good beetle: the North American experience with Harmonia axyridis

The multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is a generalist predator of aphids and other soft-bodied insects and has been utilized in biological control programs around the world. Over the last two decades, this species has spread throughout much of the continental USA and southern Canada. Despite the benefits it offers as a biological control agent, H. axyridis is perhaps most well known for its adverse impacts. In this paper we provide a review of the North American experience with H. axyridis, focusing on these adverse impacts, which can be classified into three general categories: impacts on non-target arthropods, impacts on fruit production and impacts as a household invader. The impacts of H. axyridis on non-target arthropods and, to lesser extent, the impacts as a household invader possibly could have been anticipated, due to its generalist feeding preferences and overwintering behavior in Asia. However, it is unlikely that the impacts on fruit production could have been anticipated. Therefore, even in retrospect, it is difficult to predict the potential impacts that an introduced natural enemy might have in its adventive range.     

Impending extinctions of North American freshwater mussels (Unionoida) following the zebra mussel (Dreissena polymorpha) invasion

1. Freshwater mussels (Order Unionoida) are the most imperiled faunal group in North America; 60% of described species are considered endangered or threatened, and 12% are presumed extinct. Widespread habitat degradation (including pollution, siltation, river channelization and impoundment) has been the primary cause of extinction during this century, but a new stress was added in the last decade by the introduction of the Eurasian zebra mussel, Dreissena polymorpha , a biofouling organism that smothers the shells of other molluscs and competes with other suspension feeders for food. Since the early 1990s, it has been spreading throughout the Mississippi River basin, which contains the largest number of endemic freshwater mussels in the world. In this report, we use an exponential decay model based on data from other invaded habitats to predict the long-term impact of D. polymorpha on mussel species richness in the basin.
2. In North American lakes and rivers that support high densities (>3000 m⁻²) of D. polymorpha , native mussel populations are extirpated within 4–8 years following invasion. Significant local declines in native mussel populations in the Illinois and Ohio rivers, concomitant with the establishment of dense populations of D. polymorpha , suggest that induced mortality is occurring in the Mississippi River basin.
3. A comparison of species loss at various sites before and after invasion indicates that D. polymorpha has accelerated regional extinction rates of North American freshwater mussels by 10-fold. If this trend persists, the regional extinction rate for Mississippi basin species will be 12% per decade. Over 60 endemic mussels in the Mississippi River basin are threatened with global extinction by the combined impacts of the D. polymorpha invasion and environmental degradation.     

Cyclic Behavior of <Emphasis Type="Italic">Lycorma delicatula</Emphasis> (Insecta: Hemiptera: Fulgoridae) on Host Plants

Lycorma delicatula is an invasive insect species in Korea, and its populations are increasing. It sucks plant sap and can cause withering of the whole trees. To prevent damage to fruit trees, it is important to determine the behavioral characteristics of L. delicatula. We monitored migration patterns and host plant preferences, from the egg mass on the tree bark, through egg hatching to egg laying. Most eggs hatched between 0500 h and 0800 h. The nymphs ascended trees until they reached the leaves. They often fell to the ground because of physical factors, such as wind, but then ascended the trees again on the upper sides of the branches. Their falling-ascending cycle became longer as their arolia developed. The host preference changed over the course of its growth, from a broad range of plant species at the early nymph stage to a few plant species, such as Ailanthus altissima at the adult stage. We summarize the life cycle behavior as follows. Initially, there is a short-term cycle of falling and ascending, which becomes longer as the nymphs age. The other cycle is a yearly cycle of host plant preferences, with broad host preference in the early nymph stage and a narrower host preference in the adult stage. Knowledge of this cyclic behavior can be used to prevent the rapid expansion of L. delicatula populations in orchards.     

Discovery of cryptic species among North American pine‐feeding Chionaspis scale insects (Hemiptera: Diaspididae)

Cryptic species are present in many animal groups and they may be best detected through large sample sizes collected over broad geographic ranges. Fine‐scale local adaptation has been hypothesized to occur in armoured scale insects (Hemiptera: Diaspididae) and a consequence of this process may be multiple cryptic species. We estimate species diversity of pine‐feeding Chionaspis scale insects across North America by inferring species boundaries using genealogical concordance across allele genealogies of two nuclear loci and one mitochondrial locus. Our ingroup sample includes 366 individual insects from 320 localities and 51 host species within the Pinaceae. We also conducted a morphological survey of all insect specimens and assigned them as either one of the two currently recognized pine‐feeding species, Ch. heterophyllae, Ch. Pinifoliae, or with undescribed morphology. Using maximum likelihood allele genealogies in a majority‐rule consensus to assess congruence, we conservatively detect ten species in this group. Most of these species are robust to alternative methods of genealogical inference (Bayesian inference, maximum parsimony) and a few are robust to the use of strict consensus to assess congruence. Species show both narrow and more widespread ranges where almost half of the individuals sampled belong to a single very widespread polyphagous species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 47–62.     

Analysis of Anemotactic Flight Tendencies of the Spotted Lanternfly (Lycorma delicatula) during the 2017 Mass Dispersal Flights in Pennsylvania

Journal of Insect Behavior - Video-recordings were made of adult spotted lanternflies, Lycorma delicatula, taking flight from apple trees in an orchard in northeast Pennsylvania in September, 2017...