scholarly journals Laboratory Hybridization Between the Green Lacewings Chrysoperla comanche (Neuroptera: Chrysopidae) and Chrysoperla rufilabris, Predators of the Asian Citrus Psyllid

2019 ◽  
Vol 112 (4) ◽  
pp. 1575-1580
Author(s):  
Marco Gebiola ◽  
Richard Stouthamer
Keyword(s):  
The United States ◽  
Genetic Identity ◽  
Invasive Pest ◽  
Interspecific Crosses ◽  
Asian Citrus Psyllid ◽  
Postzygotic Isolation ◽  
Hybrid Fitness ◽  
Chrysoperla Rufilabris ◽  
Green Lacewings ◽  
Courtship Songs

Abstract Chrysoperla comanche (Banks) and its sibling species Chrysoperla rufilabris (Burmeister) are voracious predators of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), an invasive pest that vectors a bacterium responsible for the lethal and incurable citrus greening disease. The Comanche lacewing naturally occurs in Southern California, whereas C. rufilabris is currently one of only two commercially available green lacewing in the United States. These sister species can be separated by larval morphological traits, by differences in courtship songs, and possibly by three nuclear genes wingless, PepCK, ATPase, yet they are not distinguishable based on the mitochondrial barcode gene (COI). Releasing in a new area a biological control agent capable of hybridizing with a resident species may pose risks that range from local displacement to irreversible loss of genetic identity. Therefore, we performed no-choice laboratory crosses to assess pre- and postzygotic isolation. We show that fertile and viable hybrid progeny could be readily obtained in interspecific crosses and backcrosses and, although there is a trend toward lower hybrid fitness, postzygotic isolation is overall weak and might not prevent loss of genetic identity under natural conditions. It remains to be determined if differences in courtship songs will prevent hybridization in the wild, as shown for other green lacewings. We also report a low prevalence of Rickettsia infection in both species.

scholarly journals Geographical variation in postzygotic isolation and its genetic basis within and between two Mimulus species

2010 ◽  
Vol 365 (1552) ◽  
pp. 2469-2478 ◽  
Author(s):  
Noland H. Martin ◽  
John H. Willis
Keyword(s):  
Pollen Fertility ◽  
Genetic Basis ◽  
Interspecific Cross ◽  
Local Scale ◽  
Interspecific Crosses ◽  
Postzygotic Isolation ◽  
Hybrid Fitness ◽  
Pure Species ◽  
Geographical Scale ◽  
Germination Success

The aim of this study is to investigate the evolution of intrinsic postzygotic isolation within and between populations of Mimulus guttatus and Mimulus nasutus . We made 17 intraspecific and interspecific crosses, across a wide geographical scale. We examined the seed germination success and pollen fertility of reciprocal F 1 and F 2 hybrids and their pure-species parents, and used biometrical genetic tests to distinguish among alternative models of inheritance. Hybrid seed inviability was sporadic in both interspecific and intraspecific crosses. For several crosses, Dobzhansky–Muller incompatibilities involving nuclear genes were implicated, while two interspecific crosses revealed evidence of cytonuclear interactions. Reduced hybrid pollen fertility was found to be greatly influenced by Dobzhansky–Muller incompatibilities in five out of six intraspecific crosses and nine out of 11 interspecific crosses. Cytonuclear incompatibilities reduced hybrid fitness in only one intraspecific and one interspecific cross. This study suggests that intrinsic postzygotic isolation is common in hybrids between these Mimulus species, yet the particular hybrid incompatibilities responsible for effecting this isolation differ among the populations tested. Hence, we conclude that they evolve and spread only at the local scale.

Efficacy of five herbicide treatments for control of Pyrus calleryana

2020 ◽  
pp. 1-6
Author(s):  
James T. Vogt ◽  
David R. Coyle ◽  
David Jenkins ◽  
Chris Barnes ◽  
Christopher Crowe ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Foliar Application ◽  
The United States ◽  
Invasive Pest ◽  
Active Ingredients ◽  
Old Field ◽  
Control Efficacy ◽  
Pyrus Calleryana ◽  
Callery Pear ◽  
Cut Stump

Abstract Callery pear (Pyrus calleryana Decne.) is rapidly spreading in the United States, gaining attention in the last two decades as a serious invasive pest. Recommended control methods include foliar, basal bark, cut stump, and hack-and-squirt application of herbicides, but there are few published studies with replicated data on efficacy. Four readily available herbicidal active ingredients and a combination of two active ingredients were tested for control efficacy against P. calleryana in old-field areas and loblolly pine (Pinus taeda L.) understory. Basal bark applications (triclopyr, triclopyr + aminopyralid), foliar applications (glyphosate, imazapyr), and a soil application (hexazinone) effectively killed P. calleryana with the exception of hexazinone at one site, where rainfall may not have been optimal. Foliar application of glyphosate provided the most consistent control. Our results demonstrate efficacy of registered herbicide formulations for P. calleryana control in two geographic locations and two habitat types. The need for development of integrated pest management programs for P. calleryana is discussed.

scholarly journals Association of the invasive Haemaphysalis longicornis tick with vertebrate hosts, other native tick vectors, and tick-borne pathogens in New York City

2020 ◽  
Author(s):  
Danielle M. Tufts ◽  
Laura B. Goodman ◽  
Meghan C. Benedict ◽  
April D. Davis ◽  
Meredith C. VanAcker ◽  
...  
Keyword(s):  
United States ◽  
New York ◽  
Vector Potential ◽  
The United States ◽  
Dermacentor Variabilis ◽  
Amblyomma Americanum ◽  
Invasive Pest ◽  
Haemaphysalis Longicornis ◽  
Tick Vectors ◽  
Host Associations

AbstractHaemaphysalis longicornis, the Asian longhorned tick, is an invasive ixodid tick that has rapidly spread across the northeastern and southeastern regions of the United States since first reported in 2017. The emergence of H. longicornis presents a potential threat for livestock, wildlife, and human health as the host associations and vector potential of this invasive pest in the United States are poorly understood. Previous field data from the United States has shown that H. longicornis was not associated with natural populations of small mammals or birds, but they show a preference for medium sized mammals in laboratory experiments. Therefore, medium and large sized mammals were sampled on Staten Island, New York to determine H. longicornis host associations and vector potential for a range of human and veterinary pathogens. A total of 97 hosts were sampled and five species of tick (Amblyomma americanum, Dermacentor variabilis, H. longicornis, Ixodes scapularis, Ixodes cookei) were found feeding concurrently on these hosts. Haemaphysalis longicornis was found in the highest proportions compared to other native tick species on raccoons (55.4%), Virginia opossums (28.9%), and white-tailed deer (11.5%). Tissue, blood, and engorged larvae were tested for 17 different pathogens using a nanoscale PCR platform. Infection with five pathogens (Borrelia burgdorferi, Anaplasma phagocytophilum, Rickettsia spp., Mycoplasma haemocanis, and Bartonella spp.) was detected in host samples, but no pathogens were found in any larval samples. These results suggest that although large and medium sized mammals feed large numbers of H. longicornis ticks in the environment there is presently a low potential for H. longicornis to acquire pathogens from these wildlife hosts.HighlightsH. longicornis were sampled from seven genera of large and medium-sized mammalsRaccoons, opossums, and white-tailed deer fed a large proportion of H. longicornisH. longicornis did not acquire pathogens through co-feeding with native tick vectorsHost species were infected with a range of pathogens of human and veterinary concernHost-derived H. longicornis engorged larvae were not infected with any pathogens

Direct and residual contact toxicity of insecticides toHalyomorpha halys(Hemiptera: Pentatomidae)

2019 ◽  
Vol 151 (2) ◽  
pp. 209-218 ◽  
Author(s):  
A.E. Gradish ◽  
H. Fraser ◽  
C.D. Scott-Dupree
Keyword(s):  
United States Of America ◽  
Economic Loss ◽  
The United States ◽  
Invasive Pest ◽  
Contact Toxicity ◽  
Halyomorpha Halys ◽  
Effective Management ◽  
Management Options ◽  
Horticultural Crops ◽  
Contact Exposure

AbstractHalyomorpha halys(Stål) (Hemiptera: Pentatomidae) is a serious invasive pest of many agricultural and horticultural crops in Canada and the United States of America. To mitigate economic loss for growers, effective management options forH. halysare needed. We evaluated the efficacy of 12 insecticides (Beauveria bassiana(Balsamo-Crivelli) Vuillemin (Cordycipitaceae), boric acid, chlorpyrifos, clothianidin, flupryadifurone, λ-cyhalothrin, malathion, novaluron, sulfoxaflor, thiamethoxam, thiamethoxam + λ-cyhalothrin, and thiamethoxam + novaluron) currently used or with potential forH. halysmanagement by determining their direct and residual contact toxicity toH. halysnymphs. Each insecticide was tested at its Canadian label rate and half and twice that rate. With the exception of chlorpyrifos, nymph mortality was low (< 40%) following direct or residual contact exposure to all insecticides and rates. All surviving nymphs were severely affected (i.e., knocked down) by direct and residual contact exposure to neonicotinoids, while approximately 66% of nymphs were severely affected following exposure to sulfloxaflor residues at label and twice label rate. However, few nymphs were severely affected by all other insecticides and rates. Overall, our results suggest thatH. halysis not susceptible to many insecticides at current label rates for Canada. More research is needed to identify efficacious insecticides forH. halys.

Parallel evolution in courtship songs of North American and European green lacewings (Neuroptera: Chrysopidae)

2012 ◽  
Vol 105 (4) ◽  
pp. 776-796 ◽  
Author(s):  
CHARLES S. HENRY ◽  
STEPHEN J. BROOKS ◽  
PETER DUELLI ◽  
JAMES B. JOHNSON ◽  
MARTA M. WELLS ◽  
...  
Keyword(s):  
North American ◽  
Parallel Evolution ◽  
Green Lacewings ◽  
Courtship Songs

scholarly journals TLC-Based Bioassay to Isolate Kairomones from Tea Tree Essential Oil That Attract Male Mediterranean Fruit Flies, Ceratitis capitata (Wiedemann)

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 683
Author(s):  
Nurhayat Tabanca ◽  
Jerome Niogret ◽  
Paul E. Kendra ◽  
Nancy D. Epsky
Keyword(s):  
Essential Oil ◽  
Short Range ◽  
Ceratitis Capitata ◽  
Control Strategies ◽  
The United States ◽  
Rapid Screening ◽  
Detection Methods ◽  
Invasive Pest ◽  
Vegetable Production ◽  
Tea Tree

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) poses a major threat to fruit and vegetable production in the United States and throughout the world. New attractants and detection methods could improve control strategies for this invasive pest. In this study, we developed a method that combined thin-layer chromatography (TLC) of tea tree essential oil (TTO) (Melaleuca alternifolia) with short-range bioassays to isolate attractive kairomones for male C. capitata. After development, the TLC chromatogram indicated that TTO separated into five major spots, designated as zones 1 to 5. When the TLC plate was exposed to flies, zones 1 and 3 were strongly attractive to male C. capitata. To confirm activity, the developed TLC plate was cut into five zones which were then tested in short-range bioassays. Again, flies were observed to aggregate around zones 1 and 3, which corresponded with Rf values of 0.93 and 0.59. In addition, zones 1 to 5 were separated using preparative-TLC, and olfactory responses to volatile emissions from the five fractions were quantified by electroantennography (EAG). Highest amplitude EAG responses were recorded with fractions 1 and 3, further supporting the bioactivity of these samples. In conclusion, a TLC-based bioassay system can provide an effective, rapid screening protocol for initial isolation of insect kairomones from complex mixtures such as essential oils or plant extracts. Further analysis of TTO fractions 1 and 3 is needed to identify the specific constituents attractive to male C. capitata.

scholarly journals Assortative mating in hybrid zones is remarkably ineffective in promoting speciation

2019 ◽  
Author(s):  
Darren E. Irwin
Keyword(s):  
Assortative Mating ◽  
F1 Hybrids ◽  
Secondary Contact ◽  
Hybrid Zones ◽  
Mating Types ◽  
Postzygotic Isolation ◽  
Small Reduction ◽  
Hybrid Fitness ◽  
Prezygotic Isolation ◽  
Two Populations

AbstractAssortative mating and other forms of partial prezygotic isolation are often viewed as being more important than partial postzygotic isolation (low fitness of hybrids) early in the process of speciation. Here I simulate secondary contact between two populations (‘species’) to examine effects of pre- and postzygotic isolation in preventing blending. A small reduction in hybrid fitness (e.g., 10%) produces a narrower hybrid zone than a strong but imperfect mating preference (e.g., 10x stronger preference for conspecific over heterospecific mates). This is because, in the latter case, rare F1 hybrids find each other attractive (due to assortative mating), leading to the gradual buildup of a full continuum of intermediates between the two species. The cline is narrower than would result from purely neutral diffusion over the same number of generations, largely due to the frequency-dependent mating disadvantage of individuals of rare mating types. Hybrids tend to pay this cost of rarity more than pure individuals, meaning there is an induced postzygotic isolation effect of assortative mating. These results prompt a questioning of the concept of partial prezygotic isolation, since it is not very isolating unless there is also postzygotic isolation.

scholarly journals Dispersion Patterns and Sample Size Estimates for Egg Masses of Spotted Lanternfly (Hemiptera: Fulgoridae)

2020 ◽  
Vol 49 (6) ◽  
pp. 1462-1472
Author(s):  
J Keller ◽  
J Rost ◽  
K Hoover ◽  
J Urban ◽  
H Leach ◽  
...  
Keyword(s):  
Sample Size ◽  
Life Stage ◽  
Spatial Arrangement ◽  
The United States ◽  
Egg Laying ◽  
Sampling Unit ◽  
Invasive Pest ◽  
Dispersion Pattern ◽  
Egg Masses ◽  
Individual Trees

Abstract The spotted lanternfly, Lycorma delicatula (White), is a new invasive pest in the United States. To quantify spotted lanternfly population abundance, one must understand this pest’s dispersion pattern, that is, the spatial arrangement of individuals within a population. Spotted lanternflies overwinter in egg masses from late fall to May, making this life stage suitable for population assessments. We measured the dispersion pattern of egg masses at two types of sites: a suburban housing development, where we used individual trees as the sampling unit, and rural woodlots, where we used individual trees and also plots with 5.64 m radius as sampling units. Plots were the same size as those recommended for monitoring the gypsy moth, a well-studied pest with similar egg laying habit to the spotted lanternfly. Egg masses in both sampling units were counted up to a height of 3 m. With trees as the sampling unit, egg masses were aggregated in 12 of 20 rural sampling universes, randomly dispersed at 6, and completely absent at 2. Similar patterns were seen when using the 5.64-m radius rural sampling units and for suburban sampling universes. We calculated sample size requirements for a range of mean densities at a precision of 25 and 30%. Additionally, the vertical distribution of egg masses was characterized on the invasive tree of heaven [Ailanthus altissima (Mill.) Swingle], a preferred host for spotted lanternflies. For small trees, there was a positive relationship between number of egg masses in the bottom 3 m of the tree and the total count.

Sign in / Sign up

Export Citation Format

Share Document