Chipping to Destroy Egg Masses of the Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae).

A chipping study was conducted during the winter of 2015 in Berks County, Pennsylvania, to determine efficacy against field collected egg masses of the spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae). Infested Ailanthus altissima Swingle (Sapindales: Simaroubaceae) trees in eastern Pennsylvania were felled and egg masses were counted. Sections were either chipped or allowed to remain intact as controls. Chipped material and intact wood controls were placed in screened barrels and monitored for emergence. No L. delicatula nymphs were found in the chipped treatment, as opposed to hundreds of nymphs per barrel in the intact control treatment. We conclude that mid-winter chipping, using the standard 1-inch in 2-dimension chip size, is a quarantine safe mitigation method suitable for treating wood infested with L. delicatula egg masses.

PCR Multiplexes Discriminate Fusarium Symbionts of Invasive Euwallacea Ambrosia Beetles that Inflict Damage on Numerous Tree Species Throughout the United States.

Asian Euwallacea ambrosia beetles vector Fusarium mutualists. The ambrosial fusaria are all members of the ambrosia Fusarium clade (AFC) within the Fusarium solani species complex (FSSC). Several Euwallacea-Fusarium mutualists have been introduced into nonnative regions and have caused varying degrees of damage to orchard, landscape, and forest trees. Knowledge of symbiont fidelity is limited by current identification methods, which typically requires analysis of DNA sequence data from beetles and the symbionts cultured from their oral mycangia. Here, polymerase chain reaction (PCR)-based diagnostic tools were developed to identify the six Fusarium symbionts of exotic Euwallacea spp. currently known within the United States. Whole-genome sequences were generated for representatives of six AFC species plus F. ambrosium and aligned to the annotated genome of F. euwallaceae. Taxon-specific primer-annealing sites were identified that rapidly distinguish the AFC species currently within the United States. PCR specificity, reliability, and sensitivity were validated using a panel of 72 Fusarium isolates, including 47 reference cultures. Culture-independent multiplex assays accurately identified two AFC fusaria using DNA isolated from heads of their respective beetle partners. The PCR assays were used to show that Euwallacea validus is exclusively associated with AF-4 throughout its sampled range within eastern North America. The rapid assay supports federal and state agency efforts to monitor spread of these invasive pests and mitigate further introductions.

Antennal Sensitivity of Spotted Lanternflies, Lycorma delicatula: Differential Electrophysiological Responses of Males and Females to Compounds Derived from Host Plants and Conspecifics.

In herbivorous insects, antennae play a crucial role in chemical communication and orientation when locating host plants and mates. To evaluate antennal sensitivity in response to odor stimuli, electroantennography (EAG) has been a practical technique. In the current study of the invasive spotted lanternfly (SLF), Lycorma delicatula (Hemiptera: Fulgoridae), we evaluated and compared their antennal sensitivity to a series of volatile chemicals collected from their bodies, honeydew, and host plants. To do this, we exposed the antennae of SLF fourth-instar and adult males and females to individual chemicals at a fixed dose of 50 ng. Further, a series of dose-response tests were carried out within a range of 0.5 to 100 ng. Although the amplitude of antennal responses varied among stages and sexes, adult males generated the strongest antennal responses in both experiments. In dose-response experiments, increased doses of chemicals up to 50 ng revealed the saturation points except in adult females which required a higher dose (100 ng) to reveal the saturation point. Although EAG does not provide any information on behavioral responses, our results are consistent with the olfactory bioassays in previous publications in which adult males, not females, were attracted to natural volatiles of their conspecifics. EAG indicated a higher sensitivity of adult male antennae to odor stimuli, particularly conspecific volatiles, than female antennae and highlighted sexual differences in the perception of chemical cues in SLF.

Spotted Lanternflies Respond to Natural Pheromone Lures for Mate-Finding and Oviposition.

Using semiochemicals collected from spotted lanternflies Lycorma delicatula (Hemiptera: Fulgoridae) (SLF) and deployed in the field with circle traps, we demonstrated that SLF responded to SLF pheromones: in particular, this was the case for males while seeking mates and for females while ovipositing. The attractants consisted of SLF body extract emitted from diffuser lures and SLF honeydew on burlap ribbons, collected from heavily infested locations. Traps with attractants were deployed in field sites with very light SLF infestations to avoid competing signals of pre-existing aggregations. The number of SLF equivalents emitted by each diffuser per trapping period was used in a dose-response analysis. Three trees per block received either (1) a control hexane lure and a clean ribbon, (2) a lure containing SLF extract and a clean ribbon, or (3) a lure containing SLF extract and a honeydew-laden ribbon. Ten blocks were sampled three times per week for twelve weeks. We found a significant positive dose-response by males to SLF body extract only in the presence of SLF honeydew, indicating a synergistic effect between honeydew volatiles and body volatiles. This dose-response occurred for five weeks after mating started, after which males no longer responded. Subsequently, females had a significant positive dose-response to SLF extract only in the presence of honeydew when oviposition was their primary activity, continuing for two weeks, suggesting that females may use pheromones to aggregate for oviposition. The extract in the absence of honeydew did not result in a positive dose-response, nor did the hexane control. These findings suggest that SLF respond synergistically to the combination of pheromones present in both SLF honeydew and SLF bodies. Thus, combining key components from both sources may aid the development of semiochemical lures for SLF.

Behavioral responses of two dengue virus vectors, Aedes aegypti and Aedes albopictus (Diptera: Culicidae), to DUET and its components.

Ultralow volume droplets of DUET, prallethrin, and sumithrin at a sublethal dose were applied to unfed (nonbloodfed) and bloodfed female Aedes aegypti L. and Aedes albopictus (Skuse) in a wind tunnel. Control spray droplets only contained inert ingredients. Individual mosquitoes were videotaped before, during, and after spraying and various behaviors analyzed. During the spray periods of all three pesticide treatments, mosquitoes spent a greater percentage of time moving, and the distance moved was greater than for mosquitoes in the control treatments. In the postspray period, the percent of time moving increased for mosquitoes exposed to all pesticide treatments compared with the controls. After treatment, all females spent more time walking compared with controls, with unfed Ae. aegypti females walking more after exposure to DUET and sumithrin than after exposure to prallethrin and the control. Pesticide exposure increased flying in both species. Sumithrin exposure increased activity and velocity of unfed mosquitoes more than bloodfed mosquitoes. DUET and sumithrin treatments enhanced activity of Ae. aegypti females more than Ae. albopictus females.

Factors Guiding the Orientation of Nymphal Spotted Lanternfly, Lycorma delicatula.

A mark-release-recapture experiment was conducted to evaluate the orientation of spotted lanternfly (SLF) Lycorma delicatula White (Hemiptera: Fulgoridae) nymphs when released equidistant between two trees. The experiment was repeated weekly for eight weeks in a heavily infested area with mature tree-of-heaven Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) planted in rows as ornamental street trees in Beijing, China. One tree in each pair received a methyl salicylate lure, and the lure was rotated between trees every week as it aged. Two additional independent variables for each tree were also analyzed: size and SLF population density. Marked-released SLF significantly chose trees with higher SLF population density over trees with lower density populations, and they also chose larger trees significantly more than smaller trees. Population density and tree size were better predictors of attraction than lures, but when those factors were controlled, SLF significantly chose trees with methyl salicylate lures over control trees for the first 4 weeks of lure life. Wild SLF distribution was assessed weekly, revealing strong aggregation in first and second instars that diminished with development to the third and fourth instars. Thus, nymphal SLF aggregate, and orientation is strongly guided by the presence of other SLF and tree size.

Investigating Photo-Degradation as a Potential Pheromone Production Pathway in Spotted Lanternfly, Lycorma delicatula.

Since its discovery in North America in 2014, the spotted lanternfly (SLF), Lycorma delicatula, has become an economic, ecological, and nuisance pest there. Developing early detection and monitoring tools is critical to their mitigation and control. Previous research found evidence that SLF may use pheromones to help locate each other for aggregation or mating. Pheromone production necessitates specific conditions by the insects, and these must be investigated and described. A chemical process called photo-degradation has been described as a final step in the production of pheromones in several diurnal insect species, in which cuticular hydrocarbons were broken down by sunlight into volatile pheromone components. In this study, photo-degradation was investigated as a possible pheromone production pathway for SLF. Extracts from SLF mixed-sex third and fourth nymphs and male or female adults were either exposed to simulated sunlight to produce a photo-degradative reaction (photo-degraded), or not exposed to light (crude), while volatiles were collected. Behavioral bioassays tested for attraction to volatiles from photo-degraded and crude samples and their residues. In third instars, only the volatile samples from photo-degraded mixed-sex extracts were attractive. Fourth instar males were attracted to both crude and photo-degraded residues, and volatiles of photo-degraded mixed-sex extracts. Fourth instar females were attracted to volatiles of crude and photo-degraded mixed-sex extracts, but not to residues. In adults, only males were attracted to body volatiles from crude and photo-degraded extracts of either sex. Examination of all volatile samples using gas chromatography coupled with mass spectrometry (GC-MS) revealed that most of the identified compounds in photo-degraded extracts were also present in crude extracts. However, the abundance of these compounds in photo-degraded samples were 10 to 250 times more than their abundance in the crude counterparts. Results from behavioral bioassays indicate that photo-degradation probably does not generate a long-range pheromone, but it may be involved in the production of a short-range sex-recognition pheromone in SLF. This study provides additional evidence of pheromonal activity in SLF.

Radio Telemetry and Harmonic Radar Tracking of the Spotted Lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae).

Lycorma delicatula (White) (Hemiptera: Fulgoridae), spotted lanternfly (SLF), is an invasive pest that feeds and oviposits on numerous woody and herbaceous plants important to agricultural, forest, ornamental, and nursery industries. Describing and understanding SLF movements is key to implementing surveillance and control strategies for this pest and projecting population spread. We used radio telemetry (RT) and harmonic radar (HR) to track the movements of individual SLF at field sites in eastern Pennsylvania and northwestern New Jersey. SLF equipped with HR or RT tags were tracked in 2019 and 2020 from adult emergence until oviposition time, and their movements are described. Although the bulkier RT tags disproportionately affected the distance traveled by males, which are smaller than females, both males and females were more likely to be lost due to signal attenuation when affixed with the lighter-weight HR tags. Females were tracked moving longer distances than males, with maximum distances of 434 m by a single female and 57 m by a single male. A significant positive relationship was found between their height in trees and the distance of subsequent movement. Adult SLF were found in trees predominantly at heights between 6-9 m high. For the fraction of SLF found at eye level, males, but not females, significantly moved above eye level in the weeks prior to mating, likely resulting in the observed sex ratio shift that defines the Early-2 stage. During mating time, tracked SLF were significantly higher than 8 m and oriented to trees where tight aggregations of SLF were present. This orientation towards tight aggregations started when mating began and peaked in the following 2.5 weeks for males in Late-1 and the beginning of Late-2 (after oviposition began), whereas females started this orientation behavior a half-week after males, and this activity peaked for two weeks. Male and female SLF adults exhibited slight differences in host preference, and strong preferences for wild grape, black walnut, sweet birch, and tree-of-heaven were observed. The HR-tagged nymphs moved up to 27.6 m over a five-day period in a cornfield. Nitinol wire HR tags performed better than Wollaston process or tungsten wire tags. SLF movement parameters in the field are described.

Male-produced pheromone in the European woodwasp, Sirex noctilio.

A male-produced pheromone that attracts both males and females was identified for the European woodwasp, Sirex noctilio, a serious pest of pine trees. Males displayed excitatory behaviors when placed in groups, and were attracted to the odors from males that were 2-5-d-old, but not to odors from males that were 0-1-d-old. An unsaturated short-chain alcohol, (Z)-3-decen-1-ol, was discovered in samples collected on SuperQ filters over groups of males and identified by using micro-derivatization reactions and gas chromatography coupled with mass spectrometry (GC-MS). The compound was not detected in volatile samples from females. Gas chromatography coupled electroantennographic detection (GC-EAD) of antennae from males exposed to male headspace odors produced strong antennal responses to the main peak of (Z)-3-decen-1-ol, as well as to an unknown minor component that had a similar retention time. Antennae from both males and females responded to synthetic (Z)-3-decen-1-ol. Several different synthetic candidates for the GC-EAD active minor components were selected based on GC-MS and GC-EAD responses to male headspace collections. These synthetic compounds were tested for antennal activity using GC-EAD, and those that produced strong responses were blended with the major component and tested for male attraction in the Y-tube olfactometer at different concentrations and ratios. Males tested in the Y-tube olfactometer were attracted to a synthetic blend of (Z)-3-decen-1-ol and (Z)-4-decen-1-ol at a ratio of 100:1. Whereas the addition of some suspected minor compounds reduced attraction, the addition of a third compound found in male emanations that produced strong male antennal responses, (E,E)-2,4-decadienal (at a ratio of 100:1:1), resulted in attraction of both males (Y-tube and wind tunnel) and females (wind tunnel).

Male-produced pheromone of Spathius agrili, a parasitoid introduced for the biological control of the invasive emerald ash borer, Agrilus planipennis.

The braconid wasp, Spathius agrili, has been released in the U.S. as a biocontrol agent for the invasive emerald ash borer (Coleoptera: Buprestidae: Agrilus planipennis), a destructive pest of ash trees (Fraxinus spp.). We identified and synthesized seven male-specific volatile compounds. Three of these, dodecanal, (4R,11E)-tetradecen-4-olide, and (Z)-10-heptadecen-2-one, were the key behaviorally active components in flight tunnel bioassays. Male specificity was demonstrated by gas chromatographic comparison of male and female volatile emissions and whole body extracts. Identifications were aided by coupled gas chromatographic-mass spectrometric (GC-MS) analysis, microchemical reactions, NMR, chiral GC analysis, and GC and MS comparison with authentic standards. Both the racemic and chiral forms of the γ-lactone, as well as both E- and Z-isomers were synthesized. Flight tunnel behavioral tests showed positive male and female S. agrili responses to both natural pheromone and synthetic blends, with upwind flight and landing on the source. Large field-cage tests, using yellow sticky traps baited with pheromone, captured approximately 50% of the released male and female wasps in 24-h periods. The use of pheromone-baited traps in the field could simplify the current detection method for determining parasitoid establishment (i.e., laboriously felling and peeling ash trees for recovery of S. agrili from infested EAB larvae).

Communication disruption of Epiphyas postvittana (Lepidoptera: Tortricidae) by using two formulations at four point source densities in vineyards.

Light brown apple moth [Epiphyas postvittana (Walker)] is now established as an economic and quarantine pest in California, and new technologies are being investigated to increase options for its management. Two new organic formulations for mating disruption, SPLAT LBAM HD-O and organic Hercon Biotie (biodegradable) were field tested at four point source densities (25, 72, 322, and 500/ha) and compared with the standard Isomate LBAM Plus (500/ha, as a positive control) and an untreated (negative) control. Assessment involved trapping using synthetic lures and virgin females. In total, 175,776 male light brown apple moths were caught to both the caged females and synthetic lures, from 10 February to 19 May 2011. The light brown apple moth catch dramatically decreased from baseline measurements after the treatments were applied, with the highest density treatments reducing catch to below 10% of the catch in the untreated controls within the first week (> 90% disruption). In synthetic lure traps, the SPLAT and Biotie treatment performed similarly well over all rates (P = 0.317 for posttreatment percentage communication disruption), but SPLAT performed better at disrupting virgin female traps (P = 0.045). There was a significant increase in disruption with an increasing number of points/ha (P < 0.001). Disruption of communication was similar for all three technologies (SPLAT, Biotie and Isomate) at 500 points/ha for both types of trap (P > 0.74). Disruption of this species in vineyards is thus highly feasible.

Responses of adult spotted lanternflies to artificial aggregations composed of all males or females.

Spotted lanternflies (SLF) Lycorma delicatula are economically important invasive planthoppers discovered in North America in 2014. SLF are gregarious, but how they locate each other, or who finds whom and when, is poorly understood. Here we describe adult SLF behavior and phenology on their preferred host, Ailanthus altissima, under field conditions, in the context of both aggregation and mate-location, since SLF demonstrated aggregation prior to mating. We documented aggregation behavior of adults and found we could manipulate free-living SLF populations in both number and sex ratio by the placement of confined populations of SLF males or females on trees. Trap capture of arriving SLF was significantly higher on trees with confined SLF aggregations than on control trees, and was corroborated with photographic data, demonstrating the manipulation of attraction and aggregation behavior. Sex ratios of trapped SLF arrivals were significantly more male-biased on trees with confined males and more female-biased on trees with confined females, evidence that the male- and female-biased sex ratios observed on trees naturally can be explained by sex-specific conspecific signals. SLF sex ratios shifted over time in the same pattern over two consecutive years. A mark-release-recapture study over time found that 1) SLF behavior is density dependent and strongly influenced by natural populations, 2) released females were captured significantly more on trees with caged females, particularly prior to mating, and 3) released males were captured significantly more on trees with caged females starting at mating time. Photographic data revealed that most clustering behavior (a measure of courtship) of free-living SLF began on trees with caged females during mating time, but not on trees with caged males or controls. We describe adult male and female SLF phenology whereby 1) aggregation behavior occurs, 2) males and females arrive at different times, 3) females began to aggregate several weeks prior to mating, 4) males subsequently joined aggregations at the time of mating, and 5) aggregation continued into oviposition. Population density and aggregation behavior were found to be key factors in their natural history which can be manipulated, providing a foothold for future research. Possible mechanisms for future exploration are discussed.

Evidence of Receptivity to Vibroacoustic Stimuli in the Spotted Lanternfly Lycorma delicatula (Hemiptera: Fulgoridae).

The spotted lanternfly Lycorma delicatula White (Hemiptera: Fulgoridae) is a polyphagous insect pest that invaded the United States in 2014, in Berks County, Pennsylvania. It has since spread to several northeastern states and poses a significant threat to northeastern grape production. Most studied species of Hemiptera are known to communicate intraspecifically using some form of substrate-borne vibrational signals, although such behavior has not yet been reported in L. delicatula. This report demonstrates that adult and fourth-instar L. delicatula were attracted towards broadcasts of 60-Hz vibroacoustic stimuli directed to a laboratory arena and test substrate, which suggests that both adults and fourth instar nymphs can perceive and respond to vibrational stimuli.

The Attractiveness of α-Copaene to Members of the Euwallacea fornicatus (Coleoptera: Curculionidae) Species Complex in California and Taiwan.

Species belonging to the Euwallacea fornicatus Eichhoff (Coleoptera: Scolytinae) species complex have invaded the continental U.S. since at least 2003. Three species of this complex are known to have established, two in California (E. fornicatus; and Euwallacea kuroshio), and a third in Florida (Euwallacea perbrevis). Their native ranges are spread across southern and southeast Asia. In Taiwan, all three species occur in sympatry. They attack healthy trees of widely varied species and cause severe damage and death to the trees. The attractant quercivorol is commonly used to promote their detection by passive trapping. Recent studies in Florida have shown that trapping of E. perbrevis can be further improved by adding a synergist, α-copaene, alongside the quercivorol lure. Thus, we were interested in testing the effectiveness of α-copaene for trapping the other invasive members of the complex in California and in an area of Taiwan where all three species co-occur. We found that α-copaene marginally enhanced the trapping of E. perbrevis in Taiwan, but had no effect on the trapping of E. fornicatus or E. kuroshio in either California or Taiwan. We conclude that any enhancing effect of α-copaene is specific to E. perbrevis. This highlights the economic importance of accurate species identification in developing and implementing an efficient, and yet cost-effective, monitoring program for the management of E. fornicatus and E. kuroshio in California and elsewhere.

Volatiles from male honeydew excretions attract conspecific male spotted lanternflies, Lycorma delicatula (Hemiptera: Fulgoridae).

The spotted lanternfly (SLF), Lycorma delicatula (Hemiptera: Fulgoridae), is a generalist phloem feeder that produces copious amounts of honeydew, which in turn coats the understory. These insects form large aggregations covering the trunks of some trees, while similar trees nearby mysteriously seem unattractive. We investigated whether volatiles from SLF honeydew are attractive to conspecifics by collecting honeydew from the field and testing it for SLF attraction in a two-choice olfactometer. We found that honeydew excreted by adult male SLF was significantly attractive to male SLF, but not female SLF. Although the honeydew excreted by adult female SLF did not significantly attract male or female SLF, both sexes showed a positive trend towards attraction in response to female honeydew in the olfactometer. Analysis of the headspace volatiles of honeydew was conducted, and numerous semiochemicals were identified. Five of which, 2-heptanone, 2-octanone, 2-nonanone, benzyl acetate, and 1-nonanol, were tested in two-choice behavioral assays against a blank control. Benzyl acetate and 2-octanone were attractive to both sexes, whereas 2-heptanone was only attractive to males, and 2-nonanone only to females. The remaining compound, 1-nonanol, repelled females, but not males. Although honeydew has been reported as a source of kairomones for some natural enemies, this may be the first report of sex-specific attractants for conspecific insects found in the honeydew volatiles of a planthopper.

Prallethrin-induced excitation increases contact between sprayed ultralow volume droplets and flying mosquitoes (Diptera: Culicidae) in a wind tunnel.

Female Culex quinquefasciatus Say (Diptera: Culicidae) mosquitoes were exposed to sublethal amounts of prallethrin, sumithrin, and piperonyl butoxide applied as ultralow volume (ULV) droplets in a wind tunnel. Mosquitoes were video recorded before, during, and after treatment, and the number and size of droplets on their bodies were later determined using a compound microscope. A positive correlation was found between mosquitoes that spent more time flying during the time of spraying and number of droplets on their bodies. Excitation, in the form of increased speed and duration of flight, was immediate in mosquitoes exposed to prallethrin, whereas exposure to sumithrin did not increase their exposure to the ULV droplets. The location of droplets on mosquitoes, the effects of droplet volume, and subsequent mortality are discussed.

Developing Traps for the Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae).

The spotted lanternfly, Lycorma delicatula (White), an invasive, phloem-feeding fulgorid generalist, was recently discovered in the United States. Current trapping methods include placing glue-covered sticky bands around trunks of host trees to exploit the lanternfly's behavior of climbing up tree trunks. These bands are messy and need to be replaced often as they become covered in both target and nontarget insects and debris. Fourth instar nymphs and adults have also shown an ability to escape from traditional tree bands or avoid capture. A promising commercially available tree band (BugBarrier) design that faces inward to the trunk and targets larger developmental stages was tested. A modified pecan weevil trap (circle trunk trap) was also compared with tree bands. This design does not require the use of insect-trapping adhesive. Circle trunk traps caught more third and fourth instar and adult L. delicatula than BugBarrier bands. Flight intercept traps caught fewer adult L. delicatula than trunk-based tree bands. In a separate comparison, more spotted lanternflies were caught on adhesive-coated 'tree mimicking' traps placed along the edges of Ailanthus altissima Swingle (Sapindales: Simaroubaceae) stands than away from hosts in an open field. Circle trunk traps are recommended for their effectiveness at capturing L. delicatula as well as their relative ease-of-use and reusability.

Plant Volatiles Help Mediate Host Plant Selection and Attraction of the Spotted Lanternfly (Hemiptera: Fulgoridae): a Generalist With a Preferred Host.

Host plant volatiles play a key role in mediating plant-herbivore interactions. How an array of host plant volatiles guides host preference and attraction in the invasive polyphagous Lycorma delicatula (White), the spotted lanternfly (SLF), is largely unknown. A pernicious phloem feeder, SLF feeds on over 70 species of plants, some with high economic impact. To aid the development of detection and monitoring tools for SLF, we used a two-choice olfactometer to compare 14 host plant species for attraction, first to a blank control, and then to their preferred host Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae), tree-of-heaven. SLF were significantly attracted to seven host plants compared to a blank control, but no host plant was more attractive than tree-of-heaven. We then used electroantennographic detection (EAD) to screen select host plants for EAD active compounds, hypothesizing that EAD-active plant volatiles act as kairomones and mediate SLF attraction to host plants. Out of 43 unique antennal responses, 18 compounds were identified and tested individually for attraction in a two-choice olfactometer against a blank control and then against methyl salicylate, the current best attractant. Eleven compounds were significantly attractive, and one, sulcatone, was more attractive than methyl salicylate. Blends of kairomones were then tested for attraction, revealing five blends that were significantly more attractive than methyl salicylate, and could be developed into lures for field testing. The presence of these kairomones in volatile profiles of 17 plant species is described. These findings support the hypothesis that the identified volatiles act as kairomones and function in attraction to host plants.

Distribution, Survival, and Development of Spotted Lanternfly on Host Plants Found in North America.

Studies were conducted from 2015 to 2018 to evaluate spotted lanternfly (SLF) distribution and developmental suitability of different plant species in the U.S. Tree bands on 283 trees spanning 33 species captured 21,006 SLF in 2 yr. More SLF per tree were trapped on tree-of-heaven Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) than on other species, on average, and most adults were captured on tree-of-heaven. Frequency of detection of adult SLF was higher on tree-of-heaven than on other species but was actually equal or lower on tree-of-heaven than on all other species combined for younger SLF stages in 2015. An enclosed choice test between tree-of-heaven and black walnut Juglans nigra L. (Fagales: Juglandaceae) revealed nymphs showed little consistent preference, whereas adults consistently and significantly preferred tree-of-heaven. No-choice field sleeve studies evaluated SLF survivorship on 26 host plant species in 17 families. Ten plant species supported SLF for an average of ≥45 d, with the rest unable to support SLF for >30 d. Eight species were able to support development from first instar to adult: black walnut, chinaberry Melia azedarach L. (Sapindales: Meliaceae), oriental bittersweet Celastrus orbiculatus Thunb. (Celastrales: Celastraceae), tree-of-heaven, hops Humulus lupulus L. (Rosales: Cannabaceae), sawtooth oak Quercus acutissima Carruthers (Fagales: Fagaceae), butternut Juglans cinerea L, and tulip tree Liriodendron tulipifiera L. (Magnoliales: Magnoliaceae). The ability of SLF to develop to adult on hosts other than tree-of-heaven may impact pest management decisions.

Effects of different pyrethroids on landing behavior of female Aedes aegypti, Anopheles quadrimaculatus, and Culex quinquefasciatus mosquitoes (Diptera: Culicidae).

Mosquitoes from three genera, Aedes aegypti L., Anopheles quadrimaculatus Say, and Culex quinquefasciatus Say, were tested for facultative landing and resting behavior on pyrethroid-treated surfaces paired with adjacent untreated surfaces. The three pyrethroids tested were bifenthrin, deltamethrin, and lambda-cyhalothrin. Landing and resting behavior was video recorded and quantified using Observer XT software. Untreated control treatments were tested to show behavior in the absence of insecticides. In controls, the three species had different activity levels, with An. quadrimaculatus being the most active and Cx. quinquefasciatus being the least active. The three species had unique responses to different compounds tested. Landing frequency on adjacent untreated and treated filter papers did not differ for any compound or species at any time during the experiment. However, landing frequencies did differ between treatments and over time. Differences between treated and untreated sides were largely caused by changes in the length of time mosquitoes rested on each side. An. quadrimaculatus had a unique response to the presence of deltamethrin compared with the other species or compounds in which it spent an increased amount of time in contact with both treated and adjacent untreated surfaces. Cx. quinquefasciatus avoided all three compounds by the end of the experiment and rested longer on untreated sides. In most cases, modification of landing and resting behaviors occurred only after mosquitoes had the opportunity to come into contact and acquire a dose of pyrethroid. Bifenthrin had the fastest TK50 for all species. Other differences between compounds for each species are described. The term excito-repellency has produced confusion in the literature, and it is revisited and discussed with respect to the results, which justify the use of alternative terminology. The term "locomotive stimulant" is offered as an acceptable alternative.