Prosapia bicincta (Hemiptera: Cercopidae) abundance, plant associations, and impacts on groundcover in Hawai'i Island rangelands.

The twolined spittlebug, Prosapia bicincta (Say), is a major economic pest of forage grass and turfgrass. Prosapia bicincta was first detected in rangelands on Hawai'i Island in 2016 and has since spread to an estimated 72,000 ha in the North and South Kona districts. This study aimed to quantify P. bicincta abundance, plant associations, and impacts on groundcover over time. Monthly surveys of P. bicincta nymphs and adults were conducted from February 2018 to September 2022 along 17 established 100-m transects at 4 ranches located in Kona, Hawai'i Island, spanning an elevation gradient from 519 to 1,874 m above sea level (a.s.l.). Monitoring revealed P. bicincta occurs from 519 to 1,679 m a.s.l., primarily in Kikuyu grass (Cenchrus clandestinus (Hochst. ex Chiov.)) Morrone (Poales: Poaceae) pastures. Peaks in P. bicincta abundance coincided with the wet season, with most activity occurring from April to October and little to no activity between November and March. Mid elevation (1,000-1,300 m) transects had significantly higher mean P. bicincta abundance (126 nymphs/m2) relative to low (500-999 m) (64 nymphs/m2) and high elevations (>1,300 m) (20 nymphs/m2). Sites with the highest abundance of P. bicincta were also associated with the greatest decrease in mean grass cover (30%) and were replaced by forbs, bare ground, and shrubs. Grasses accounted for 72% of the total P. bicincta detections, with the remaining plants comprised of legumes (16%), sedges (6%), and forbs (6%). Twenty new P. bicincta plant associations were found. This information will help improve the effectiveness of management to suppress populations below economic thresholds.

Host plant resistance of cool-season (C3) turfgrasses to above- and belowground feeding by Tipula paludosa (Diptera: Tipulidae).

Feeding on above- and belowground plant tissues by Tipula paludosa Meigen during the period of rapid growth from second to forth instars is highly damaging to cool-season (C3) turfgrasses. It may be possible to reduce this damage by identifying grass genotypes that increase host plant protection. This study examined the impacts of plant genotype, endophyte infection, and plant ontogeny on host plant and insect responses during whole-plant feeding by T. paludosa. A series of no-choice greenhouse trials were conducted with third instar crane flies to determine 1) host plant tolerance in terms of reductions to above- and belowground plant biomass, 2) antixenosis resistance impacting insect behavior (emigration), and 3) antibiosis resistance impacting insect growth. Results showed that insect infestation level was the primary factor influencing plant biomass reductions. Belowground tissues were more tolerant to feeding than were aboveground tissues, with tall fescues, Festuca arundinacea Schreber, being most resistant to aboveground biomass reduction. Host plant associations with intercellular fungal endophytes (E+) decreased insect weight gain and decreased insect movement, but did not increase host plant tolerance. Plant ontogeny affected this response with insect weight gain significantly decreased on young (28 d) growth E+ grasses but not on old (90 d) growth E+ grasses, however. Host plant genotype and plant ontogeny can have significant impacts to host plant tolerance and insect physiology for T. paludosa larva. Furthermore, plant-endophyte associations have apparent sublethal effects that impact insect fitness and may further enhance host plant protection.

First record of the scarab beetle, Phyllophaga lissopyge from South America, with descriptions of adult seasonal activity and male response to sex attractants.

Phyllophaga lissopyge (Bates) (Coleoptera: Scarabaeidae: Melolonthinae) is reported for the first time from South America. Male sex pheromone response is described for P. lissopyge and two other co-occurring Phyllophaga species. Adults of P. lissopyge and P. menetriesi (Blanchard) flew to traps baited with methyl 2-(methylthio) benzoate whereas adults of P. obsoleta (Blanchard) flew irregularly to four different pheromone compounds. Adult seasonal activity is described from males captures in Rionegro, Antioquia, Colombia.

Sex pheromone of the scarab beetle Phyllophaga (Phytalus) georgiana (horn).

The sex pheromone of Phyllophaga (Phytalus) georgiana was characterized as valine methyl ester, tentatively the L-enantiomer. This is the first sex pheromone identified from the Phyllophaga subgenus Phytalus. The pheromone was extracted from female glands, the active component isolated by coupled gas chromatography-electroantennogram detection analysis, characterized by mass spectrometry, and shown to be active in field tests. The seasonal flight pattern was determined for P. georgiana as well as for three other species, P. anxia (both northern and southern genitalic forms), P. gracilis, and P. postrema. The latter three species were captured in traps baited with L-isoleucine methyl ester.

Invasive Tipula (Diptera: Tipulidae) in turfgrass of the northeast United States: geographic distribution and local incidence three years after detection.

Two species of invasive crane flies are damaging pests of turfgrass in the Great Lakes region after their inadvertent introduction and establishment. In New York, where Tipula paludosa Meigen and Tipula oleracea L. (Diptera: Tipulidae) were first detected in 2004, baseline data on the extent of establishment is needed to monitor range expansion, make predictions about pest status, and guide management efforts. The incidence of both species was therefore addressed at two spatial scales to ascertain how widespread they were across the state and across sites of recent local establishment. Based on divergent natural history, T. oleracea was predicted to be more widespread both geographically and locally than T. paludosa. To delimit the current area of occurrence, surveys were conducted from 2004 to 2006. T. paludosa was detected in four counties and T. oleracea in 12 counties. In western New York, T. oleracea was established in more than a six-fold greater area than T. paludosa. T. oleracea was additionally detected on Long Island, shown to be a geographically disjunct area of establishment. To measure local incidence, putting greens and tee boxes were scouted on golf courses. Contrary to predictions, 56-97 and 22-56% of those surfaces were already infested by T. paludosa and T. oleracea, respectively, within one or two seasons after initial detection. Because damage thresholds are relatively high, scouting for the insect, rather than its injury, will promote earlier detection. Given the impact of invasive Tipula across diverse turf habitats, continued range expansion will have serious repercussions for regional turfgrass management.

Patterns of variation in the seasonal dynamics of Listronotus maculicollis (Coleoptera: Curculionidae) populations on golf course turf.

Listronotus maculicollis (Kirby) is a burgeoning pest of Poa annua L. in the northeast United States. To develop an understanding of its spatial and temporal association with golf course landscapes, we described the patterns of variation in certain population parameters across site (Fayetteville and Ithaca, NY), year (2004-2006), and management habitat (fairway, intermediaterough, rough). In weekly surveys along fairway transects, we sampled larvae (identified to instar) by soil core extraction and adults (identified to sex and maturation)by hand collection. Five instars were confirmed based on head capsule width measurements; there was no overlap among instars. Sex ratio was significantly male-skewed on the rough versus the fairway. Insect load, a measure of population size based on cumulative insect-days, varied from 3.0- to 18.5-fold across sites and years and averaged 8.7- and 8.0-fold greater on the fairway than rough for larvae and adults, respectively. Visual assessment of stage-specific population fluctuation curves revealed no divergence in adult males and females, i.e., no evidence of protandry. Variation was greater by year than by site in terms of overall shape of the fluctuation curves, relative abundance of overwintered to spring and summer adults, population synchrony, and number of generations (two to three). Evidence of bimodal spring generations showed that early season population synchrony may be linked to the pattern of adults transitioning from overwintering to developmental habitats. The magnitude of variation in population dynamics underscores the relevance of decision-making strategies and has implications for improving both the spatial and temporal targeting of intervention tactics.

Application timing and efficacy of alternatives for the insecticidal control of Tipula paludosa Meigen (Diptera: Tipulidae), a new invasive pest of turf in the northeastern United States.

BACKGROUND: Two invasive crane flies, Tipula paludosa Meigen and Tipula oleracea L. (Diptera: Tipulidae), were detected in New York State for the first time in 2004. Both are damaging pests of turfgrass and other horticultural systems in North America where establishment has already been documented. To develop management recommendations for the Northeast and define opportunities for preventive (autumn) and curative (spring) control, four insecticide trials targeting T. paludosa larvae were conducted over a 2 year period. RESULTS: The most efficacious (>or=70% control in both trials) products against early instars in autumn were bifenthrin, carbaryl, chlorantraniliprole, clothianidin and trichlorfon. Results varied for azadirachtin, Beauveria bassiana, cyfluthrin, dinotefuran, imidacloprid, imidacloprid + bifenthrin and indoxacarb. Clothianidin and dinotefuran were most efficacious against fourth instars in spring; results varied for imidacloprid, indoxacarb and trichlorfon. CONCLUSION: Several insecticides offer alternatives for preventive and curative control of T. paludosa, but, because there is little overlap with application windows for scarab larvae pests, management may entail an entirely new insecticide treatment window, implying new economic and environmental burdens to the turfgrass industry. Moreover, curtailing the impact and spread of these invasives may be severely hampered because the best performing alternatives (clothianidin, dinotefuran) are not registered in New York.

Imidacloprid as a contact arrestant for larvae of the European chafer, Amphimallon majale.

BACKGROUND: Manipulative studies of the behavioral response of soil-dwelling insects to insecticides and other antagonists are stymied by the difficulties of observing and interpreting interactions played out below ground. Six experiments were carried out using X-ray radiography to quantify the movement of the European chafer, Amphimallon majale (Razoumowsky), larvae in response to imidacloprid and how this was affected by host plant cues and cold temperature. RESULTS: The movement of third instars was arrested in imidacloprid-treated soil at ≥ 0.6 ppm concentration. At ≥ 0.8 ppm, the arrestant effect of imidacloprid was stronger than the attraction cue posed by germinating grass seed. There was a less disruptive effect on dispersal distance in vertical versus lateral panels. In vertical panels, there was a less disruptive effect on downward movement under a cold temperature treatment that simulated overwintering conditions. CONCLUSION: Larvae of A. majale do not remotely detect imidacloprid in the soil; they neither evade contact, nor are repelled after contact. Imidacloprid thereby acts as a contact arrestant to disrupt grub movement. This finding might help to explain the synergistic effect of imidacloprid in combination with other biological agents for white grub control, and its effects on grub overwintering behavior.

Variation in the laboratory susceptibility of turf-infesting white grubs (Coleoptera: Scarabaeidae) to biological, biorational and chemical control products.

BACKGROUND: White grubs are the most widespread and damaging pests in turfgrass habitats of the northeast USA, and their management is highly dependent on chemical pesticides. Because this complex includes at least eight species, opportunities for pest management would be enhanced by understanding how susceptibility to control products varies across taxa. The objective of this laboratory study was to measure variation in the susceptibility of four species to 18 biological, biorational and chemical insecticides used as curative controls. RESULTS: Across species, the most efficacious biological and chemical insecticide alternatives were Steinernema scarabaei and chlorpyrifos respectively. For biorational and chemical insecticides, the European chafer [Amphimallon majale (Razoumowsky)] was the least susceptible species. For biologicals, the Japanese beetle (Popillia japonica Newman) was the least susceptible. Considering all control products, the oriental beetle [Anomala orientalis (Waterhouse)] was the most susceptible. CONCLUSION: The magnitude of variation in susceptibility supports the idea that a single product will not reliably suppress populations of all taxa, and highlights the need for pest management practitioners to identify white grub species before intervention. This differential susceptibility could have broader consequences for grub management if a numerically dominant target species is more completely suppressed than a co-occurring species.

Dinámica poblacional y fenología del salivazo de los pastos Zulia carbonaria ( Lallemand ) ( Homoptera: Cercopidae ) en el valle geográfico del río Cauca, Colombia / Population dynamics and phenology of the pasture spittlebug Zulia carbonaria ( Lallemand ) ( Homoptera: Cercopidae ) in the Cauca river Valley, Colombia

Se estudió la fluctuación poblacional de ninfas, adultos, huevos y enemigos naturales de Zulia carbonaria (Lallemand) (Homoptera: Cercopidae) asociado con pastos de Brachiaria dictyoneura en el valle geográfico del río Cauca, Colombia. El objetivo de este trabajo fue describir la fenología de Z. carbonaria bajo las condiciones estacionales de precipitación bimodal (marzo-mayo y septiembre-noviembre). Semanalmente, durante dos años, se cuantificaron las poblaciones del salivazo y ciertos enemigos naturales mediante pases de jama (adultos) y conteos de ninfas en masas de espuma. Para obtener huevos y estudiar su desarrollo, semanalmente se recolectaron adultos hembras que se pusieron a ovipositar en cajas de petri con papel filtro húmedo en su interior. En ambos años de muestreo se documentaron 3-4 generaciones de Z. carbonaria con un ciclo de vida promedia de 66 días. Las poblaciones fueron más abundantes en el primer semestre y disminuyeron dramáticamente en el transcurso del segundo semestre, aún en los meses lluviosos (septiembre-noviembre). Se encontró muy bajo número de huevos diapáusicos (0.5 por ciento). Los enemigos naturales encontrados fueron la mosca depredadora de las ninfas Salpingogaster nigra Schiner (Diptera: Syrphidae), ácaros parasitarios de los adultos (Acari: Erythraeidae) y hongos de varios géneros. Aunque Z. carbonaria sincroniza su ciclo de vida con las lluvias del primer semestre, no se detectó un papel de la diapausa en los huevos como es común en otras especies de salivazo en zonas bajo condiciones unimodales de precipitación. Se discuten posibles explicaciones por esa sincronización y por la escasez del insecto bajo las condiciones lluviosas del segundo semestre.

Economic damage caused by spittlebugs (Homoptera: Cercopidae) in Colombia: a first approximation of impact on animal production in Brachiaria decumbens pastures / Dano econômico da cigarrinha-das-pastagens (Homoptera: Cercopidae) na Colômbia: primeira aproximação do impacto na produção animal em pastagens de Brachiaria decumbens

Usando um modelo de simulação como ferramenta de análise, quantificou-se o impacto econômico da cigarrinha-das-pastagens em termos de produção animal na Colômbia. Três níveis de infestação (10, 25, 50 adultos/m²) e de área infestada (25, 50, 100 por cento) foram avaliados usando dados obtidos no Brasil com Notozulia entreriana (Berg) em Brachiaria decumbens Stapf. O modelo considerou sistemas de produção de duplo propósito em dois ecossistemas contrastantes: (1) trópico-seco, caracterizado por seis meses bem definidos de estação chuvosa e (2) trópico-umido, caracterizado por distribuição uniforme de chuva durante o ano. Comparada com as pastagens não infestadas, a carga animal e a produtividade de leite e carne tiveram um decréscimo de 1-8, 8-34 e 38-54 por cento, respectivamente, aos níveis de infestação baixo, intermediário e alto, dependendo da área da fazenda infestada. O custo de produção de leite e carne aumentou 0-4, 3-16 and 18-30 por cento nos mesmos níveis de infestação, causando redução no lucro da ordem de 3-16, 17-69 e 67-100 por cento. Em nível regional, o dano econômico nos 1.140.000 ha plantados com pastagens suscetíveis à cigarrinha-das-pastagens nos trópicos úmidos da Colômbia variou de US$7-25, 28-36 e 39-47 milhões/ano. Nos 4.720.000 ha de pastagens suscetíveis no trópico-seco, o prejuízo econômico foi de US$33-118, 132-175 e 228-273 milhões/ano. O investimento requerido para desenvolver variedades resistentes à cigarrinha-das-pastagens e adaptadas a solos de baixa a média fertilidade (US$6 milhões em 12 anos) é baixo quando comparado com o dano econômico causado pelas cigarrinhas-das-pastagens na Colômbia constituindo-se, assim, grande incentivo ao apoio as pesquisas em melhoramento de variedades e manejo da cigarrinha-das-pastagens.

Using a simulation model as an analysis tool, the economic impact of spittlebugs in pastures of Colombia was quantified in terms of animal production. Three levels of abundance (10, 25, 50 adults/m²) and farm area affected (25, 50, 100 percent) were evaluated using data obtained in Brazil for Notozulia entreriana (Berg) on Brachiaria decumbens Stapf. The model considered dual-purpose production systems in two contrasting ecosystems: (1) the dry tropics, characterized by a well defined, 6-month rainy season and (2) the humid tropics, characterized by uniform rainfall distribution throughout the year. Compared to healthy pastures, stocking rate, milk and meat productivity decreased 1-8, 8-34 and 38-54 percent, respectively, at low, intermediate and high abundance levels, depending on farm area infested. The cost of producing milk and meat increased 0-4, 3-16 and 18-30 percent at the same infestation levels, causing net income to decrease 3-16, 17-69 and 67-100 percent. At the regional level, economic damage in the 1,140,000 ha sown to grasses susceptible to spittlebugs in the humid tropics of Colombia ranged from US$7-25, 28-36 and 39-47 million/yr. In the 4,720,000 ha of susceptible grasses in the dry tropics, economic damage was US$33-118, 132-175 and 228-273 million/yr. The investment required to develop grass varieties resistant to spittlebugs and adapted to soils with low to intermediate fertility (US$6 million over 12 yr) is low compared with the economic damage caused by spittlebugs in Colombia, and therefore presents a major economic incentive for support of research on varietal improvement and spittlebug management.

Alternative methods for rearing grass-feeding spittlebugs (Hemiptera: Cercopidae) / Métodos alternativos para a criação das cigarrinhas-das-pastagens (Hemiptera: Cercopidae)

Duas metodologias para criação de cigarrinhas-das-pastagens são relatadas e avaliadas, utilizando-se Aeneolamia varia (Fabricius) sobre Brachiaria ruziziensis Germ. & Evrard. Desenvolveuse uma nova unidade de criação em pequena escala para manter a cigarrinha nos seus diferentes estágios de desenvolvimento, e assim promover estudos biológicos dos insetos. A unidade possui uma bandeja de plantas com raízes, que são os locais de alimentação e desenvolvimento das ninfas, junto com uma gaiola para emergência dos adultos contendo plantas e substrato para oviposição eobtenção de ovos. Para produção em larga escala, aperfeiçoou-se um método de criação massal, reduzindo-se os insumos e agilizando-se a produção. A principal característica é uma caixa coberta com raízes e condições de microclima adequados para o desenvolvimento de ninfas. A eficiência de produção de adultos a partir de ovos foi de 45,1%, produzindo 1002 adultos/m2 por geração, com um período de desenvolvimento ninfal de 36,1 dias. A emergência de adultos foi de 70,5% em uma semana. Esse método para produção massal é uma ferramenta efetiva para produção de cigarrinhas em larga escala, podendo ser utilizado para estudos como de controle com fungos entopatógenos, resistência da plantahospedeira e outros. São discutidas as possibilidades e necessidades futuras para se melhorar a técnica e ajustá-la a outras espécies de cigarrinhas.

Two methodologies for rearing grass-feeding spittlebugs are described and were evaluated with Aeneolamia varia (Fabricius) on Brachiaria ruziziensis Germ. & Evrard. To promote biologicalstudies, a new small-scale rearing unit was developed to maintain spittlebug life stages in the greenhouse year round. This unit features a plant tray established with roots as feeding sites for nymphal development alongside an adult emergence cage with plants and oviposition substrate for egg collection. For largescale production, an improved mass-rearing colony was designed to reduce inputs and streamline production. The major feature was a covered box with root and microclimate conditions adequate for nymphal development. Efficiency of adult production from eggs was 45.1%, yield 1002 adults/m2 pergeneration, nymphal development time 36.1 d, and adult emergence 70.5% in a 1-wk period. This massrearing method is a more effective tool for reliable and high-level production of spittlebugs for massive screening required for the evaluation of control tactics such as fungal entomopathogens and host plantresistance. The possibilities for further improving these designs and tailoring them to other spittlebug species are discussed.