J. Steven McElfresh

Bio: J. Steven McElfresh is an academic researcher from University of California, Riverside. The author has contributed to research in topics: Sex pheromone & Pheromone. The author has an hindex of 27, co-authored 56 publications receiving 1579 citations. Previous affiliations of J. Steven McElfresh include University of California.

Development and optimization of methods for using sex pheromone for monitoring the mealybug Planococcus ficus (Homoptera: Pseudococcidae) in California vineyards.

Abstract: The sex pheromone of the vine mealybug Planococcus ficus Signoret has been identified as a single component, lavandulyl senecioate. Racemic lavandulyl senecioate was as attractive to male mealybugs as the insect-produced (S)-enantiomer, indicating that the unnatural enantiomer is not inhibitory. Lavandulol, which also was found in extracts from virgin females, antagonized attraction of males at higher doses. Rubber septum lures loaded with 10- to 1,000-μg doses of the pheromone were equally attractive, and lures loaded with 100 μg of racemic pheromone remained attractive for at least 12 wk under field conditions. Delta traps were more effective than double-sided sticky cards and minimized captures of nontarget insects. Pheromone-baited traps had an effective range of at least 50 m. Comparison of visual sampling methods and sampling of males with pheromone-baited traps revealed that trap catches were significantly correlated with the results from visual sampling methods, and with economic damage.

Using generic pheromone lures to expedite identification of aggregation pheromones for the cerambycid beetles Xylotrechus nauticus, Phymatodes lecontei, and Neoclytus modestus modestus.

Abstract: Males of several species of longhorned beetles in the subfamily Cerambycinae produce sex or aggregation pheromones consisting of 2,3-hexanediols and/or hydroxyhexanones. We tested the hypothesis that this diol/hydroxyketone pheromone motif is highly conserved within the subfamily, and the resulting prediction that multiple cerambycine species will be attracted to compounds of this type. We also tested the concept that live traps baited with generic blends of these compounds could be used as a source of live insects from which pheromones could be collected and identified. Traps placed in a mature oak woodland and baited with generic blends of racemic 2-hydroxyhexan-3-one and 3-hydroxyhexan-2-one captured adults of both sexes of three cerambycine species: Xylotrechus nauticus (Mannerheim), Phymatodes lecontei Linsley, and Phymatodes decussatus decussatus (LeConte). Odors collected from male X. nauticus contained a 9:1 ratio of two male-specific compounds, (R)- and (S)-3-hydroxyhexan-2-one. Field trials with synthetic compounds determined that traps baited with (R)-3-hydroxyhexan-2-one (94% ee), alone or in blends with other isomers, attracted similar numbers of X. nauticus of both sexes, whereas (S)-3-hydroxyhexan-2-one (94% ee) attracted significantly fewer beetles. Phymatodes lecontei and P. d. decussatus also were caught in traps baited with hydroxyhexanones, as well as a few specimens of two other cerambycine species, Neoclytus modestus modestus Fall (both sexes) and Brothylus gemmulatus LeConte (only females). Male N. m. modestus produced (R)-3-hydroxyhexan-2-one, which was not present in extracts from females. Neoclytus m. modestus of both sexes also responded to lures that included (R)-3-hydroxyhexan-2-one as one of the components. The only male-specific compound found in extracts from P. lecontei was (R)-2-methylbutan-1-ol, and adults of both sexes were attracted to racemic 2-methylbutan-1-ol in field bioassays. Surprisingly, P. lecontei of both sexes also were attracted to (R)- and (S)-3-hydroxyhexan-2-ones, although neither compound was detected in extracts from this species. Males of all five beetle species had gland pores on their prothoraces that were similar in structure to those that have been associated with volatile pheromone production in other cerambycine species. The attraction of multiple cerambycine species of two tribes to (R)-3-hydroxyhexan-2-one in this study, and in earlier studies with other cerambycine species, suggests that this compound is a widespread aggregation pheromone component in this large and diverse subfamily. Overall, the attraction of multiple species from different cerambycine tribes to this compound at a single field site supports the hypothesis that the hydroxyketone pheromone structural motif is highly conserved within this subfamily.

Geographic variation in the pheromone system of the saturniid mothhemileuca eglanterina

Abstract: The common sheep moth,Hemileuca eglanterina (Boisduval), appears to have at least two distinct pheromone types. Male moths from the population in the San Gabriel Mountains of southern California are attracted optimally to a blend ofE10,Z12-hexadeca-10,12-dien-1-yl acetate (acetate);E10,Z12-hexadeca-10,12-dien-1-ol (alcohol); andE10,Z12-hexadeca-10,12-dienal (aldehyde), whereas males from the population at Robinson Summit, northwest of Ely, Nevada, are attracted to the two-component blend of alcohol and aldehyde. Populations along the eastern edge of the Sierra Nevada Mountains are composed of individuals of both pheromone types and a type intermediate between the two. Antennae from male moths from the different pheromone types give distinctly different electroantennographic responses when challenged with blends of the pheromone components, with San Gabriel Mountains males showing a large response to acetate and lesser responses to alcohol and aldehyde. In contrast, antennae from Robinson Summit males, which are attracted to lures containing only alcohol and aldehyde, exhibit a large response to alcohol, a smaller response to aldehyde, and minimal or no response to acetate. Male moths from the eastern Sierra Nevada Mountains give antennal responses similar to those of either San Gabriel Mountains or Robinson Summit males. However, eastern Sierra populations also contain an intermediate type that does not occur in areas where the major pheromone types do not occur together. This third type may be a hybrid between the two other pheromone types, and it is attracted in approximately equal numbers to synthetic pheromone lures with and without acetate. The antennae of male moths in all populations tested responded toE10,E12-16:Ac, a major pheromone component of the congenerH. nuttalli, which is sympatric with someH. eglanterina populations, and in mostH. eglanterina populations tested, the addition ofE10,E12-16:Ac antagonized responses to otherwise attractive lure blends. Overall, the existence of different pheromone types in the differentH. eglanterina populations may represent a case of reproductive character displacement.

Response of the Woodborers Monochamus carolinensis and Monochamus titillator (Coleoptera: Cerambycidae) to Known Cerambycid Pheromones in the Presence and Absence of the Host Plant Volatile α-Pinene

Abstract: In recent years, several attractant pheromones have been identified for cerambycid beetles, including 2-(undecyloxy)-ethanol (hereafter monochamol) for Monochamus galloprovincialis (Olivier), M. alternatus Hope, and M. scutellatus (Say). This study screened eight known cerambycid pheromones or their analogues (including monochamol) as potential attractants for M. carolinensis Olivier and M. titillator (F.), in the presence and absence of the host volatile α-pinene. Monochamol attracted M. carolinensis in the presence and absence of α-pinene, whereas M. titillator was only attracted to the combination of monochamol and α-pinene. (2R*,3R*)-2,3-Hexanediol also attracted both M. carolinensis and M. titillator, but only in the presence of α-pinene. Subsequent coupled gas chromatography—mass spectrometry and gas chromatography—electroantennogram detection analyses of extracts of volatiles collected from both sexes demonstrated that male M. carolinensis and M. titillator release monochamol, and that ant...

Phoracantha semipunctata (Coleoptera: Cerambycidae), a Serious Pest of Eucalyptus in California: Biology and Laboratory-Rearing Procedures

Abstract: Procedures are described for establishing a laboratory colony of the eucalyptus longhorned borer, Phoracantha semipunctata F., and rearing the adult beetles on a continual basis. Adult beetles reared from naturally infested Eucalyptus logs were caged and provided with oviposition substrates (folded sheets of plastic). Techniques for handling and caring for eggs and neonate larvae are discussed. Larvae were individually transferred into shallow incisions in the bark of fresh logs. Total survivorship from neonate larvae to adult was ≈35%. Our procedures yielded an average of 63 adult progeny for every adult female, with a generation time of ≈2 mo during the summer. Beetle colonies were protected from pyemotid mites by dusting rearing logs with sulfur and from ants with granular diazinon. An experiment on adult beetle diet showed that the provision of sucrose water greatly increased longevity and fecundity over a distilled water control, but increasing the concentration of sucrose >5% did not significantly improve beetle performance.

Sex pheromones and their impact on pest management.

Abstract: The idea of using species-specific behavior-modifying chemicals for the management of noxious insects in agriculture, horticulture, forestry, stored products, and for insect vectors of diseases has been a driving ambition through five decades of pheromone research. Hundreds of pheromones and other semiochemicals have been discovered that are used to monitor the presence and abundance of insects and to protect plants and animals against insects. The estimated annual production of lures for monitoring and mass trapping is on the order of tens of millions, covering at least 10 million hectares. Insect populations are controlled by air permeation and attract-and-kill techniques on at least 1 million hectares. Here, we review the most important and widespread practical applications. Pheromones are increasingly efficient at low population densities, they do not adversely affect natural enemies, and they can, therefore, bring about a long-term reduction in insect populations that cannot be accomplished with conventional insecticides. A changing climate with higher growing season temperatures and altered rainfall patterns makes control of native and invasive insects an increasingly urgent challenge. Intensified insecticide use will not provide a solution, but pheromones and other semiochemicals instead can be implemented for sustainable area-wide management and will thus improve food security for a growing population. Given the scale of the challenges we face to mitigate the impacts of climate change, the time is right to intensify goal-oriented interdisciplinary research on semiochemicals, involving chemists, entomologists, and plant protection experts, in order to provide the urgently needed, and cost-effective technical solutions for sustainable insect management worldwide.

Biology of mosquitoes.

Abstract: 日本には約110種の蚊が産する。その中で医学的に重要なのは, 幼虫(ボウフラ)が人里近くの水域に発生し, 雌成虫がヒトから好んで吸血する種である。西日本ではアカイエカ(南西諸島ではネッタイイエカにおきかわる), チカイエカ, コガタアカイエカ, ヒトスジシマカなどが最も重要である。これらの種は生態がことなるので, その被害に対する効果的対策もことなる。雌成虫が吸血源となる動物を発見して完了するまでの過程は複雑で, わかつていない点もある。

Exotic bark- and wood-boring Coleoptera in the United States: recent establishments and interceptions

Abstract: Summary data are given for the 25 new species of exotic bark- and wood-boring Coleoptera first reported in the continental United States between 1985 and 2005, including 2 Buprestidae (Agrilus plan...

Influence of the larval host plant on reproductive strategies of cerambycid beetles

Abstract: ▪ Abstract This investigation into the natural history and behavior of 81 species of cerambycid beetles suggests that reproductive behavior is correlated with the condition of the larval host: Adults of species whose larvae attack living trees tend to show behavioral differences from those that attack dying or dead hosts. Behavioral differences among species that are associated with larval host condition include: (a) choice of adult food source and whether adults feed at all; (b) mechanisms of mate location and the role of long-range pheromones; (c) vagility and dispersal behaviors of adults; (d) location of the mating site; and (e) duration of copulation.

On the scent of speciation: the chemosensory system and its role in premating isolation.

Abstract: Chemosensory speciation is characterized by the evolution of barriers to genetic exchange that involve chemosensory systems and chemical signals. Here, we review some representative studies documenting chemosensory speciation in an attempt to evaluate the importance and the different aspects of the process in nature and to gain insights into the genetic basis and the evolutionary mechanisms of chemosensory trait divergence. Although most studies of chemosensory speciation concern sexual isolation mediated by pheromone divergence, especially in Drosophila and moth species, other chemically based behaviours (habitat choice, pollinator attraction) can also play an important role in speciation and are likely to do so in a wide range of invertebrate and vertebrate species. Adaptive divergence of chemosensory traits in response to factors such as pollinators, hosts and conspecifics commonly drives the evolution of chemical prezygotic barriers. Although the genetic basis of chemosensory speciation remains largely unknown, genomic approaches to chemosensory gene families and to enzymes involved in biosynthetic pathways of signal compounds now provide new opportunities to dissect the genetic basis of these complex traits and of their divergence among taxa.