scholarly journals An Herbivore-Induced Plant Volatile From Saltcedar (Tamarix spp.) Is Repellent to Diorhabda carinulata (Coleoptera: Chrysomelidae)

2020 ◽  
Vol 49 (5) ◽  
pp. 1063-1070
Author(s):  
Alexander M Gaffke ◽  
Sharlene E Sing ◽  
Jocelyn G Millar ◽  
Tom L Dudley ◽  
Daniel W Bean ◽  
...  

Abstract The leaf beetle Diorhabda carinulata Desbrochers (Coleoptera: Chrysomelidae) was introduced into the United States in 1999 for classical biological control of the exotic woody invader saltcedar (Tamarix spp. L. [Caryophyllales: Tamaricaceae]). The recent southern expansion of the range of D. carinulata in the United States has precipitated conflict between proponents of biological control of Tamarix and those with concerns over habitat conservation for avian species. Several semiochemicals that mediate aggregations by this species have been reported, but no repellent compounds have been recorded thus far. We now report a repellent compound, 4-oxo-(E)-2-hexenal, induced by adult D. carinulata feeding on saltcedar foliage. Collection of headspace volatiles, gas chromatography mass spectrometry, and electroantennographic analyses identified 4-oxo-(E)-2-hexenal as an insect-induced compound that is antennally active. Behavioral and exposure assays were conducted to test for repellency and toxicity in adults and larvae. Headspace volatiles were also collected from adult males exposed to 4-oxo-(E)-2-hexenal to determine the impact exposure might have on the emission of the aggregation pheromone. 4-Oxo-(E)-2-hexenal elicited electrophysiological responses in adults of both sexes. Behavioral responses indicated repellency across multiple doses for reproductive D. carinulata adults but not in nonreproductive adults. Exposure assays indicated altered behaviors in first instar larvae and adults, but not in third instar larvae. Collection of headspace volatiles indicated that exposure to 4-oxo-(E)-2-hexenal did not alter emission of the D. carinulata aggregation pheromone by adult males. The continued development and field deployment of this repellent compound may provide a new tool for the management of D. carinulata.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alexander M. Gaffke ◽  
Sharlene E. Sing ◽  
Tom L. Dudley ◽  
Daniel W. Bean ◽  
Justin A. Russak ◽  
...  

Abstract The northern tamarisk beetle Diorhabda carinulata (Desbrochers) was approved for release in the United States for classical biological control of a complex of invasive saltcedar species and their hybrids (Tamarix spp.). An aggregation pheromone used by D. carinulata to locate conspecifics is fundamental to colonization and reproductive success. A specialized matrix formulated for controlled release of this aggregation pheromone was developed as a lure to manipulate adult densities in the field. One application of the lure at onset of adult emergence for each generation provided long term attraction and retention of D. carinulata adults on treated Tamarix spp. plants. Treated plants exhibited greater levels of defoliation, dieback and canopy reduction. Application of a single, well-timed aggregation pheromone treatment per generation increased the efficacy of this classical weed biological control agent.


2020 ◽  
Author(s):  
Tyson Wepprich ◽  
Fritzi S Grevstad

Abstract A key knowledge gap in classical biological control is to what extent insect agents evolve to novel environments. The introduction of biological control agents to new photoperiod regimes and climates may disrupt the coordination of diapause timing that evolved to the growing season length in the native range. We tested whether populations of Galerucella calmariensis L. have evolved in response to the potential mismatch of their diapause timing since their intentional introduction to the United States from Germany in the 1990s. Populations collected from 39.4° to 48.8° latitude in the western United States were reared in growth chambers to isolate the effects of photoperiod on diapause induction and development time. For all populations, shorter day lengths increased the proportion of beetles that entered diapause instead of reproducing. The critical photoperiods, or the day length at which half of a population diapauses, differed significantly among the sampled populations, generally decreasing at lower latitudes. The latitudinal trend reflects changes in growing season length, which determines the number of generations possible, and in local day lengths, at the time when beetles are sensitive to this cue. Development times were similar across populations, with one exception, and did not vary with photoperiod. These results show that there was sufficient genetic variation from the two German source populations to evolve different photoperiod responses across a range of environmental conditions. This study adds to the examples of rapid evolution of seasonal adaptations in introduced insects.


2018 ◽  
Vol 65 ◽  
pp. 111-130 ◽  
Author(s):  
Fatemeh Ganjisaffar ◽  
Elijah J. Talamas ◽  
Marie-Claude Bon ◽  
Brian V. Brown ◽  
Lisa Gonzalez ◽  
...  

TrissolcushyalinipennisRajmohana & Narendran is an Old World egg parasitoid ofBagradahilaris(Burmeister). Its potential as a classical biological control agent in the United States has been under evaluation in quarantine facilities since 2014. A survey of resident egg parasitoids using fresh sentinelB.hilariseggs in Riverside, California, revealed thatT.hyalinipennisis present in the wild. Four cards with parasitized eggs were recovered, from which one yielded a single liveT.hyalinipennisand two unidentified dead wasps (Scelionidae), and three yielded twenty liveTrissolcusbasalis(Wollaston) and one dead wasp. Subsequently, samples from Burbank, California, collected with a Malaise trap as part of the BioSCAN project, yielded five females ofT.hyalinipennis. It is presumed that the introduction ofT.hyalinipennisto this area was accidental. Surveys will be continued to evaluate the establishment ofT.hyalinipennisas well as the presence of other resident parasitoid species.


2015 ◽  
Vol 147 (3) ◽  
pp. 300-317 ◽  
Author(s):  
Leah S. Bauer ◽  
Jian J. Duan ◽  
Juli R. Gould ◽  
Roy Van Driesche

AbstractFirst detected in North America in 2002, the emerald ash borer (EAB) (Agrilus planipennis Fairmaire; Coleoptera: Buprestidae), an invasive phloem-feeding beetle from Asia, has killed tens of millions of ash (Fraxinus Linnaeus; Oleaceae) trees. Although few parasitoids attack EAB in North America, three parasitoid species were found attacking EAB in China: the egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) and two larval parasitoids Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae). In 2007, classical biological control of EAB began in the United States of America after release of these three species was approved. In 2013, release of the larval parasitoids was approved in Canada. Research continues at study sites in Michigan, United States of America where the establishment, prevalence, and spread of O. agrili and T. planipennisi have been monitored since 2008. However, establishment of S. agrili remains unconfirmed in northern areas, and its release is now restricted to regions below the 40th parallel. In 2015, approval for release of Spathius galinae Belokobylskij (Hymenoptera: Braconidae), an EAB larval parasitoid from the Russian Far East, may be granted in the United States of America. Researchers are guardedly optimistic that a complex of introduced and native natural enemies will regulate EAB densities below a tolerance threshold for survival of ash species or genotypes in forested ecosystems.


EDIS ◽  
2006 ◽  
Vol 2006 (20) ◽  
Author(s):  
Julio Medal ◽  
William Overholt ◽  
Philip Stansly ◽  
Lance Osborne ◽  
Amy Roda ◽  
...  

Revised! ENY-824, a 4-page illustrated fact sheet by J. Medal et al., describes the status ongoing efforts in the biological control of Tropical Soda Apple (TSA) in the United States. This version updates the original 2002 publication to reflect ongoing research and activities. Published by the UF Department of Entomology and Nematology, August 2006.


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