Insecticidal properties of powdered boldo, Peumus boldus Molina, were evaluated against larvae of fall armyworm, Spodoptera frugiperda (J. E. Smith), and corn earworm, Helicoverpa zea (Boddie). Bioassays assessed development, feeding preferences, and mortality of neonate and third instars. For both species, most mortality (65 and 67.5%, respectively) was obtained with 8% boldo concentration incorporated into an artificial insect diet, and the LC₅₀ and LC₉₀ for fall armyworm were 6.8 and 25.9 g boldo kg^-1 diet and 3.8 and 35.6 g boldo kg^-1 diet for corn earworm. With increased concentration of boldo, larvae were shorter, weighed less, and had anatomical abnormalities, and fewer pupated. Concentrations of 4 and 8% boldo resulted in fewer adults of both species. In feeding preference tests, neonates selected the diet with the least concentration of boldo powder, and larvae fed less with higher concentrations. In tests for insect preference, the greatest concentrations of boldo resulted in the greatest indexes of feeding inhibition and growth, while the least indexes resulted in increases in larval weight and greater efficiency of conversion of ingested food in the diet percentage used to produce new larval biomass.

Southern green stink bug, Nezara viridula (Linnnaeus), feeds on developing seeds of soybean, Glycine max (L.) Merrill, and is an important pest of the crop in the southern US. Sixteen soybean lines were evaluated for resistance by caging adult southern green stink bugs on pods in an insectary. The resistant standard, IAC-100, had the fewest feeding punctures per seed which was not significantly different from the number for genotypes V00-0742, V00-0842, or V99-1685. When exposed to southern green stink bug, the seed weight for IAC-100 was not significantly different from that of the genotypes PI 558040, V00-0870, or PI 588053A. The percentage of seed weight loss for IAC-100 was not significantly different from that of seed weight loss of PI 558040 or V00-0870 when exposed to feeding by southern green stink bug. The genotypes IAC-100, V00-0742, V00-0842, and V99-1685 are resistant to feeding by southern green stink bug based upon a reduction in feeding punctures, while genotypes IAC-100, PI 558040, and V00-0870 may provide a source of genetic traits for resistance by minimizing seed weight loss caused by feeding by southern green stink bug.

The beet leafhopper, Circulifer tenellus (Baker), transmits curtoviruses that cause disease losses to several crops and many weeds in the western United States. While the host plants, life history, and possible migrations have been studied for many years, little is known about differences between leafhopper populations from different areas. Therefore, beet leafhopper populations from California and New Mexico were compared as to their morphology, feeding behavior, and genetics. The crown, wing venation, and male genitalia were indistinguishable among the leafhoppers collected from different locations. Four synonymous mutations were detected in the nucleic acid sequences of the mitochondrial cytochrome oxidase (mtcoi) region of leafhoppers between the states, but not among specimens collected from New Mexico. Feeding preferences of the leafhoppers from the two states differed when presented with cafeteria-style choice tests. With a 20-day feeding period, most (87.5%) of California leafhoppers were found on sugarbeets, Beta vulgaris L., while New Mexico leafhoppers were more evenly distributed on a variety of hosts such as Kochia sp. (46%); sugarbeets (18%); Russian thistle, Salsola tragus L. (15.3%); and red root pigweed, Amaranthus retroflexus L. (12.3%). With a 2-day feeding period, leafhoppers from both states equally chose sugarbeets, reflecting their willingness to settle on sugarbeets over most other hosts. The results suggested that while the beet leafhopper populations were similar morphologically, they showed difference in genetics and host feeding preferences.

Homalodisca liturata Ball, commonly known as “smoke tree sharpshooter”, transmits Xillela fastidiosa Wells bacterium, which causes Pierce's disease and severe damage to many U.S. and Mexican orchards. This is the first observation of variation in host preference among populations of H. liturata in Mexico. Plants preferred by H. liturata were studied during 2007 and 2008 in an experimental field of a community of sarcocaulescent shrub plants in southern Baja California Peninsula. Thirty-one species of plants were associated with the insect, but only 26 where host plants, with a marked preference for Yucca valida Brand. and Prosopis articulate S. Watts, on which greater numbers of insects were found; fewer insects were observed on Lysiloma candida Brand., Cyrtocarpa edulis Brand., and Bursera microphylla A. Gray. Most insects were observed in March and April, and the insect was generally absent in the summer between July and September when temperatures were warmest. Y. valida is a host with potential commercial importance because it contains saponins, but H. liturata should be managed to be able to use Y. valida commercially.

Leaves from cotton, Gossypium hirsutum L., plants containing transgenic traits (Bollgard®, Bollgard II®, and WideStrike™) were assayed for bioactivity against bollworm, Helicoverpa zea (Boddie); beet armyworm, Spodoptera exigua (Hübner); fall armyworm, Spodoptera frugiperda (J. E. Smith); and cabbage looper, Trichoplusia ni (Hübner); in a laboratory. Fifty leaves from the middle of the plants were collected every 20 days, starting at 40 days and until 120 days after cottons were planted. The leaves were fed to 15 first-instar larvae of each insect pest until they died or pupated. Most larvae died when fed Bollgard II or WideStrike. At the end of the season (100–120 days after planting), more larvae died when fed Bollgard II than WideStrike. Conclusions from the results are that (1) mortality was not significantly different when the larvae were fed dual Bt cotton leaves of different ages; (2) survival duration depended on consumption of the amount of endotoxin that caused larval mortality; (3) biological characteristics of surviving lepidopterans (pupal weight, emergence, and developmental time) were significantly better on non-Bt cotton.

Spiders were sampled in fall 2000 and spring 2001 from two areas (upper bajada and basin) of native grassland invaded by Lehmann lovegrass (Eragrostis lehmanniana Nees) on the Jornada del Muerto, Doña Ana County, NM. Sampling involved three amounts (dominant, intermediate, and minimal) of invasion by Lehmann lovegrass. Spiders were sampled in 5 × 5 m plots with three replications of the amounts of lovegrass infestation to determine if spider diversity was affected by an increase in invading grass. However, the prevalence of lovegrass did not seem to play an influential role in the numbers of species or individual spiders collected. Spider biodiversity and abundance are primarily influenced by prey availability and geometrical complexity of habitat, allowing proper hiding and building of web sites, and apparently Lehmann lovegrass compared to native grassland does not adversely affect either factor.

Arthropods were sampled from branches of saltcedar, Tamarix spp., and willow trees, Salix spp. using a new funnel bucket technique. This is a modification of the beat-bucket design. The funnel bucket was compared to results found by using a traditional 5-gallon bucket, sweep net, and beat sheet. Each method was assessed for effectiveness of arthropod capture. Sixteen saltcedar trees and 16 willow trees were sampled with each method for 10 seconds per compass side of the tree. The means, standard errors, and n needed for a 90% confidence interval are provided for each technique. The funnel bucket method collected numbers of arthropods comparable to the other sampling techniques tested. This technique may be another option for sampling in trees and shrubs, especially for arthropod predators.

A new species of meniscus midge is reported from western Michigan. Adults of Dixella fraxina Taber appear in spring in tussock sedge, Carex stricta Lamarck, understory of black ash, Fraxinus nigra Marshall, swamp. No new species of this genus have been discovered in the United States in the last 40 years. Dark wing coloration suggests a close relationship to Dixella marginata (Loew) but characters in both sexes distinguish this fly from that species and from its other 18 congeners occurring in the United States, half of which occur in the western and southwestern states.

Little was known about the Lepidoptera fauna at White Sands National Monument or Carlsbad Caverns National Park, both in the Chihuahuan Desert of southern New Mexico, before 2006 when the National Park Service initiated studies of the Lepidoptera, especially moths. Many species of moths were captured in black-light traps. Cisthene perrosea (Dyar) (Erebidae), Schinia intrebilis (Smith) (Noctuidae), and Tolype meyelisae Franclemont (Lasiocampidae), recorded from New Mexico for the first time, represent significant range extensions.

This is the first record of Celliphore grahemi (Aldrich 1930) in Mexico since it was first reported in the United States of America in 1929. Specimens were collected in spring 2008 and 2009 from carcasses of pigs, Sus scrofa L., in a semidesert area in Saltillo, Coahuila, Mexico.

The abundance and species richness of Orthoptera fluctuate throughout time. The dynamics of species abundance can be influenced by seasonal climatic factors. Here we report the species richness, and nymph and adult abundance of Orthoptera species, throughout a year of sampling at Parque Nacional El Cimatario, Querétaro state, in México. These three phenologic variables (species richness, nymph and adult abundance), using non-parametric analyzes were related to the monthly temperature and relative humidity averages, and with the monthly total precipitation recorded during the sampling year. We tested the immediate effects of climatic factors, and their delay from the phenologic variables of one, two, and three months. Moreover, we determined diverse groups of species with similar adult and nymph phenology. A total of 38 species from 31 genera was found. Seventy-nine percent of the species belonged to the Caelifera suborder. The most abundant species was Dichopetala n. sp. “cercus I teuriformis” (Phaneropterinae), followed by Phoetaliotes nebrascensis (Melanoplinae), Dichopetala serrifera, Schistocerca cohni (Cyrthacantacridinae), and Amblytropidia mysteca (Gomphocerinae). We found some correlations between the species, the nymph and the adult numbers with the climatic factors without and with delay from one to three months. Among a selection of the 18 most abundant species, we found diverse phenologic groups of species in the sampled year. This study contributes to the knowledge of the Orthoptera diversity of Querétaro and its relation with climate.

An updated review has been made on the potential of “white grubs” as beneficial insects for increasing soil fertility. Historically white grubs have been considered economic pests because they cause damage in diverse agricultural crops. However, many species of white grubs also consume plant residues in the decaying process. According to the written literature, white grubs may promote fertility in agricultural soils mainly through decomposition of organic matter, rendering humic substances in a similar way as earthworms do. Main activities in which white grubs are considered as soil engineers that may increase soil fertility are that: 1) white grubs may act as earthworms because they may positively affect soil physical functions through increasing soil pore space and improve drainage and aeration; 2) white grubs may affect soil chemical functions either by nutrient immobilization, nutrient distribution, mineralization and/or humification in a dynamic way acting like biological facilitators, and 3) white grubs may stimulate soil biological activities by increasing microbiological decomposition of organic matter and regulating soil biotic composition and exporting aboveground soil nutrients contained in the adult beetle. All of these activities may give us a different vision of the problem caused by white grub when it is regarded as a soil engineer and may inspire possible solutions for their management.

An update of the current status of corn earworm, Helicoverpe zea (Boddie), the tobacco budworm, Heliothis virescens (Fabricius), and other heliothine pests in the Southern United States and Mexico is presented. A brief description of the damage caused to their host plants, their host range, geographic distribution, susceptibility to chemical and biological pesticides, development of resistance to pesticides, and the role of the new hybrids carrying one or multiple Bt toxins in their IPM are discussed.

This paper identifies knowledge and knowledge gaps in biology and ecology, and migratory flight of corn earworm, Helicoverpa zee (Boddie). The paper focuses on results from studies of corn earworm population dynamics and migration in Texas during a period of substantial irrigated maize, Zee meys L., production in the Lower Rio Grande Valley, which prevailed before planted acres decreased due to drought, expansive land development, and the introduction of Bt corn. Because overwintering survival of corn earworm in the U.S. is generally accepted to be limited to areas south of 40° N latitude, much of the maize-growing area in the north-central U.S. would not be infested by corn earworm if not for migration. Overwintering emergence contributes to infestations by corn earworm, but it is difficult to separate the contributions of overwintering emergence and immigrants on local populations. We emphasize three critical elements affecting the timing and extent of corn earworm migration: period of emergence of adult corn earworm, availability of fruiting maize as a host, and availability of suitable atmospheric conditions for transport. Knowledge of corn earworm migration will be especially useful in devising and utilizing novel control tactics in the northern tier of states where insecticides are applied extensively to control immigrant corn earworm in sweet corn; seed corn; snap beans, Pheseolus vulgeris L.; and other high-value crops. This is particularly important to the abundance, geographical range, and management of corn earworm relative to potential climate change and use of transgenic crops tolerant of drought and heat conditions.

The tobacco budworm, Heliothis virescens (F.), is thought to be a pest that migrates each year from warmer southern latitudes to colder areas where it cannot survive cold temperatures during the winter. Although northwestern Mississippi is south of 40° N latitude, which is recognized as the upper boundary for overwintering survival of the insect, it is commonly believed that increasing abundance during the spring in this area is because of migration of moths from the south. In this study we used a 10-year set of captures of tobacco budworm male moths from pheromone traps and air temperatures from the area, as well as data on development of tobacco budworm in incubators at a range of constant temperatures. Results indicated that moths that produced eggs before the 258^th day of the year have time to accumulate the necessary degree days to produce the last generation of that year, while moths that produced eggs between days 258 and 277 give raise to the first spring generation. Moths re productively active after day 277 will not, under the hypothesis of no larval overwintering survival, produce a generation the following year in northwestern Mississippi. Moths reproductively active between days 80 and 124 will produce the generation observed between days 136 and 162; there is a gap between generations, and this gap will separate generations all year. Because we observed generations overlapping in the data from the pheromone traps, there is a possibility that larval overwintering survival might explain the dynamics of the insect in this area.

Females of the tobacco budworm, Heliothis virescens (F.), exhibit distinct geographical and temporal variation in sex pheromone composition, but the causes and significance of this variation are largely unexplored. Here we assessed whether 1) female pheromone variation was related to the host plants of origin, and 2) pheromone lures with varying amounts of Z9–14:Ald or 16:Ald were differentially attractive to males. Variation in female pheromone did not seem to be related to the host plants from which the eggs or larvae were collected, which may be because field-collected larvae were reared for three to five larval stages on artificial diet. By varying the concentration of Z9–14:Ald within the range in the female pheromone gland, we found males were more attracted as the amount increased from 1 to 10% relative to Z11–16:Ald, but significantly less with the highest concentration of 25%. In contrast, with 16:Ald, similar numbers of tobacco budworm males were caught in all traps where 16:Ald ranged from 0 to 200%. These results show that variation in Z9–14:Ald but not 16:Ald is evolutionary significant and likely subject to stabilizing selection in the field.

Transgenic crops expressing one or more Becillus thuringiensis Berliner (Bt) toxins are being commercialized worldwide, primarily because of their efficacy against several economically-important lepidopteran pests. However, the risk of insects developing resistance to Bt toxins concerns organic growers, farmers, and seed producers. Because of the ecology and migratory ability of several lepidopteran pests, the USA and Mexico share geographical overlap with cropping systems that include Bt maize, Zee meys L.; and Bt cotton, Gossypium hirsutum L.; that impact these pest species. With mobile pests and concern for the development of proactive resistance management programs, scientists from both countries have organized meetings and workshops since 2003. This manuscript summarizes the achievements of the USA and Mexico collaborations in surveying Bt-expressing crops and pest dynamics from 2003 to 2010.

The Cry proteins produced by Bacillus thuringiensis Berliner are effective bioinsecticides against different insect pests. The primary threat to their long-term use is evolution of resistance by pests. Cry toxins are produced as protoxins activated in larval-gut lumen. The toxins bind to receptors that induce oligomerization and insertion into the membrane forming ionic pores that kill the cells and the larvae. The Cry1AMod toxins were created by genetic engineering of Cry1A by the deletion of the N-terminal end. These proteins kill resistant insects, in particular, those that have eliminated or modified one of the toxin receptors. Cry1AMod toxins could have potential to be used to control insect resistance. However, for the future use of these proteins in the field, it is important to demonstrate their mechanism of action is similar to the wild-type Cry1A toxins. Here we summarize results regarding the mode of action of CryMod toxins showing they have a similar mechanism as wild-type Cry toxins.

Bacillus thuringensis Berliner Cry1A toxins are three-domain proteins that show insecticidal activity to certain important lepidopteran insect pests. Transgenic plants, Bt-maize, Zea mays L.; or Bt-cotton, Gossypium hirsutum L.; expressing Cry1Ab or Cry1Ac toxins have been planted worldwide and are efficient in insect control. Here, we revise recent data on the mode of action of Cry1Ab toxin. After activation by proteases in the midgut, Cry1Ab toxin binds to the more abundant but low affinity glicosylphophatidylinositol (GPI)-anchored proteins alkaline phosphatase or aminopeptidase-N (ALP and APN, respectively) through domain II loop 3 and domain III ß16. This binding event concentrates the toxin in the microvilli membrane where it then binds to Cadherin receptor with high affinity. After binding to Cadherin, an extra proteolytical cleavage is produced and oligomers are formed. Oligomers gain a 200 higher binding affinity to both GPI-anchored proteins through domain II loop 2. The binding of Cry1Ab oligomers to GPI-anchored proteins facilitates insertion into the membrane and pore formation. This binding mechanism was named ping-pong because it involves going from GPI-anchored proteins to Cadherin and back to GPI-anchored proteins before membrane insertion. We also show the ALP receptor has a greater role in toxicity than does APN.

Results from conventional resistance monitoring and F₂ screens have found no evidence of major resistance alleles to Cry1Ac in the bollworm, Helicoverpa zea (Boddie), in US cotton, Gossypium hirsutum L., fields. Furthermore, sentinel field plot results show no changes in field performance of Cry1Ac cotton despite 14 years of commercial use. Although insecticide-resistant management practices such as refugia, insecticide oversprays, and pyramided traits in Bt cotton have likely contributed to the lack of observed resistance development and changes in field efficacy, fitness costs associated with the development of Cry1Ac resistance in bollworm probably also have contributed to this outcome. This paper discusses various fitness costs associated with Cry1Ac resistance in bollworm and concludes with a discussion of how exclusive use of diet-based laboratory bioassays may underestimate their role in delaying development of resistance to Bt.

Transgenic crops that produce toxins from Bacillus thuringiensis Berliner (Bt) to control insects are grown widely, but rapid evolution of resistance by pests could nullify the benefits of Bt. Cotton bollworm, Helicoverpa ermigere Hübner, is an economically important lepidopteran pest that has experienced intense selection for resistance to Bt-Cry1Ac cotton in China since 1997. Since 2002, changes in the frequency of alleles for resistance and the quantitative shifts in tolerance to Cry1Ac were monitored for 7 years using bioassays of F₁ and F₂ offspring of isofemale lines of larvae of H. armigera from the field in Xiajin County of Shandong Province (an intensive Bt cotton planting area) and Anci County of Hebei Province (a multiple-crop system including maize, Zee mays L.; soybean, Glycine max L.; peanut, Arechis hypogaea L.; and Bt cotton, Gossypium hirsutum L.) in Northern China. Here, we summarized the monitoring data from Xiajin and Anci regions during 2002–2008. The monitoring results during this period indicated that the frequency of alleles for resistance has remained low in both regions of China. The results suggested that natural refugia may be part of an effective management strategy for delaying the evolution of resistance in H. armigera to Bt cotton in Northern China.

The corn earworm or cotton bollworm, Helicoverpa zea (Boddie), is an economically important pest throughout much of North America, but particularly in the southern U.S., where many crops are vulnerable to damage. Although transgenic cotton, Gossypium hirsutum L., expressing selected insecticidal toxins of Bacillus thuringiensis Berliner (Bt) has been available since 1996 in the southern states, the Cry1Ac toxin in cotton and Cry1Ab in maize, Zea meys L., are not known to cause consistent mortality in H. zea. Consequently, long-term areawide suppression would not be expected. However, with the advent of pyramided Bt events for cotton and field corn, and in the absence of the evolution of field-level resistance to Bt toxins, the potential exists for these crops to suppress H. zea. Simulation modeling predicted the initial decrease in abundance to be rapid, illustrating the impact of an immediate adoption of the two Bt crops, with high efficacy. Abundance of H. zea remained low and approximated an 85% reduction from baseline. This decrease or areawide suppression effect was proportional to the 80 and 90% Bt use rates for maize and cotton, respectively. The residual population that remains is largely the result of the net influx of moths via annual migration from outside Mississippi. These results are discussed within the context of resistance management and alternative migration and crop composition scenarios.

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is one of the most important insect pests on the American continent. Its control has relied primarily on multiple applications of insecticides that can amount to 1,000 g of active ingredient per hectare on some of approximately 30 crops the insect damages. The use of genetically engineered crops that express Bacillus thuringiensis (Bt) Berliner toxins, Bt-corn, Zee meys L.; and Bt-cotton, Gossypium hirsutum L.; are other ways to control this insect. However, fall armyworm is one of the Lepidoptera species least susceptible to Bt proteins, and a case of high tolerance to Bt-corn has already being reported. We found the susceptibility to Cry1Ac and Cry1Fa proteins of Bt in 133 isofamilies from five regions of three countries was similar to the susceptibility of two Bt-susceptible laboratory colonies to these proteins. Four isofamilies from Puerto Rico were very tolerant to Cry1Fa and not so tolerant to Cry1Ac. Two of the four isofamilies were backcrossed with a Bt-susceptible laboratory colony and their progeny was as susceptible to both Bt proteins as was the Bt-susceptible colony, indicating that resistance to Bt is a recessive trait.

Some field populations of bollworm, Helicoverpa zea (Boddie), in the southeastern U.S. have evolved resistance to Bacillus thuringiensis Berliner (Bt) toxins Cry1Ac and Cry2Ab produced by transgenic cotton, Gossypium hirsutum L. Decreased susceptibility to Cry1Ac, the toxin in first-generation Bt cotton (Bollgard), was detected in laboratory diet bioassays and was associated with increased survival on Bollgard plant tissues and control problems in the field. Bollgard cotton is no longer registered in the U.S. and has been replaced primarily by Bt cotton that produces Cry1Ac and Cry2Ab (Bollgard II). Laboratory diet bioassay results showed that the percentage of field populations resistant to Cry2Ab increased from 0% in 2002 to 50% in 2005. In bioassays from 2003 to 2006, 14 field-derived strains of bollworm had <50% mortality at 150 µg Cry2Ab per milliliter of diet, the highest toxin concentration tested. As with the recently reported resistance of pink bollworm, Pectinophora gossypiella (Saunders), to Bollgard cotton in India, laboratory diet bioassays provide the critical data documenting genetically based decreases in susceptibility of bollworm field populations to Bt toxins Cry1Ac and Cry2Ab. Resistance to Bt toxins linked with increased damage to Bt crops in the field has now been documented in at least four target lepidopteran pests. Systematic analyses of these cases, as well as the many cases in which pests remain susceptible to Bt crops, can provide knowledge useful for increasing the durability of current and future generations of transgenic insecticidal crops.

The pink bollworm, Pectinophora gossypiella (Saunders), is a primary pest of cotton, Gossypium hirsutum L., in Mexico. Baseline and diagnostic concentration bioassays were used to determine the susceptibility of this pest to Becillus thuringiensis (Berliner) toxins Cry1Ac and Cry2Ab in different cotton-growing regions of Mexico, during 1998–2006. The LC₅₀ values varied depending on the region and collection date or generation of insect. Pink bollworm populations from the Mexicali Valley, Baja California, were the most susceptible. In general, results obtained showed no indication of resistance by this insect in Mexico.

Transgenic crops producing Becillus thuringiensis (Bt) Berliner (Bacillales: Bacillaceae) toxins target key insect pests in cotton, Gossypium hirsutum L., and maize, Zea mays L., cropping systems. The pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), is currently the target of an area-wide eradication program with the purpose to eliminate pink bollworm from cotton-producing areas of the U.S. and adjacent areas of northern Mexico. Transgenic Bt cotton is a key component of the program. Evolution of resistance to Bt cotton could jeopardize the eradication program and diminish success of long-term control of pink bollworm populations. Molecular monitoring for known resistance alleles and bioassays indicated that pink bollworm resistance to Bt cotton in the U.S. remains rare. However, recent discovery of field-evolved resistance to Bt cotton in India emphasizes the need for diligent resistance monitoring and stewardship of the Bt transgenic technology. Resistance to Cry1Ac in laboratory-selected strains of pink bollworm may involve at least two resistance mechanisms, based on characterization of cadherin-based resistant strains and a newly selected Bt4R strain. In all previous resistant strains of pink bollworm, resistance involved mutations in a cadherin gene encoding for a functional Cry1Ac toxin receptor. Selection of the Bt4R strain using Bt cotton bolls and Cry1Ac in diet revealed a novel mechanism of resistance that differs from previously described Cadherin mutations.

The pink bollworm, Pectinophora gossypiella (Saunders), first invaded Arizona in 1926 and has been a key pest of cotton, Gossypium hirsutum L., since the early 1960s. A broad range of tactics has been developed to manage this pest including a variety of cultural methods, mating disruption via pheromones, sterile insect release, and plant resistance. Transgenic cotton producing the insecticidal proteins of Bacillus thuringiensis Berliner (Bt) was introduced in 1996 and was rapidly and widely adopted by producers in Arizona. Adoption rose to approximately 86% by 2006 and has been more than 93% since 2007 when the state was granted a U.S. Environmental Protection Agency exemption to eliminate required refuge plantings as part of a regional eradication program. The deployment of Bt cotton for selective control of caterpillars led to dramatic regional reductions in abundance of pink bollworm, and associated crop damage and insecticide use. Bt cotton has also been a key technology enabling more selective and biologically-based control approaches for sweetpotato whitefly, Bemisia tabaci (Gennadius), and western tarnished plant bug, Lygus hesperus Knight, two other keys pests of cotton in Arizona. Overall insecticide use (statewide average number of sprays per hectare) in cotton has dropped 88% since 1995. Some challenges ahead include re-invasion of eradicated zones, maintaining susceptibility of pink bollworm to Bt cotton, the economics of Bt cotton use in a post-eradication future, and a rapidly changing agroecosystem.

In my first three years as an extension specialist at the Louisiana State University AgCenter, I responded to the detections of six invasive species. I have learned by experience the process of appropriately responding to the report of an invasive species. This manuscript identifies the eight key steps I follow to streamline the response of my extension program and avoid communication failures with the media, fellow university faculty, and regulatory agencies. I also describe a number of groups affected by species introductions, where Land Grant University extension faculty can assist in the response, and the final result of these team efforts.

In recent years, leafhopper-transmitted phytoplasma diseases of potato, Solanum tuberosum L., have become increasingly important in many production areas worldwide. Serious epidemics of purple top disease of potato, caused by phytoplasma infections, have occurred in North and Central America and Central and Eastern Europe. Countries severely affected by phytoplasma diseases of potato include the United States, Mexico, Guatemala, Russia, and Romania. These emerging potato diseases are causing significant yield losses and a reduction in tuber and seed quality. Accurate identification of phytoplasmas involved in the disease and their insect vectors, in addition to a better understanding of disease epidemiology and vector population dynamics, are essential to effective management of phytoplasma diseases in potatoes. A case study of identification, epidemiology, and management of leafhopper-transmitted phytoplasma disease of potatoes in the Pacific Northwest of the United States is presented herein.

The southern green stink bug, Nezara viridule L., is a member of the stink bug complex that has become more economically important in cotton, Gossypium hirsutum L., production in recent years. A disease of cotton bolls, identified as South Carolina boll rot, seemed coincidental to the increase in abundance of stink bugs. The relationship between the occurrence of the cotton disease and the southern green stink bug is discussed here. This review documents: the identification and description of the disease; potential causal agents and insect vectors; conclusive identification of Pentoea egglomerans (Ewing and Fife) Gavini et al. as the causative agent of the disease; establishment of southern green stink bug as a model insect based on ingestion, retention, and transmission of the disease to cotton bolls; determination of vulnerability of bolls of different ages to disease; and, transmission of other disease agents by southern green stink bugs. Future research needs also are discussed.

The potato psyllid, Bactericera cockerelli (Sulc), is an insect pest of solanaceous plants and has recently become of interest because of its association with zebra chip, an immerging potato disease in the US. Genomic information on the potato psyllid is limited but could be used to develop novel management strategies for the insect and disease. To that end, cDNA libraries were prepared for the 5 instar and adult life stages. Structural and muscular, neurological and reproductive developmental processes, stress response and primary metabolism sequences were recovered. Metagenomic sequences aligning to microbial, viral and fungal symbionts or pathogens were also identified. Additionally, general housekeeping, life stage, and gender-specific targets were selected for RNAi-based knockdown experiments.

The Asian citrus psyllid, Diaphorina citri Kuwayama, was detected in Orleans Parish, LA, in May 2008. Soon after detection, the tree upon which the Asian citrus psyllid had been found tested positive for citrus greening (or huanglongbing). In response to these detections, personnel from the Louisiana State University AgCenter worked with representatives of the Louisiana Department of Agriculture and Forestry and USDA-APHIS-PPQ to respond to the situation. Pest control recommendations were developed for nursery, commercial, and backyard citrus production. This information was distributed to stakeholders via traditional extension channels (publications, media, Internet sites, and in-person presentations). County field faculty worked with inspectors to identify locations to survey. The efforts culminated in the implementation of an area-wide management approach in Plaquemines Parish, the largest citrus-producing region of Louisiana. To date, huanglongbing has not been detected in Plaquemines Parish and Asian citrus psyllid has been suppressed by carefully timed applications of insecticide. We continue to work with USDA-APHIS-PPQ and the Louisiana Department of Agriculture and Forestry to monitor the situation.

Psyllids (Hemiptera: Psylloidea) are important pests of agricultural crops worldwide. These insects may cause damage to plants by direct feeding and/or vectoring plant pathogens. Psyllid-transmitted bacterial diseases are increasingly becoming important in perennial and annual crops. Several reports have shown that the fastidious bacterium ‘Candidatus Liberibacter’, vectored by at least four psyllid species, is associated with newly-emerging and economically important diseases of crops, including Huanglongbing or citrus greening disease in Citrus spp. and zebra chip in potatoes, Solanum tuberosum L. Huanglongbing is vectored by the Asian citrus psyllid, Diaphorina citri Kumayama, and the African citrus psyllid, Trioza erytreae Del Guercio, whereas zebra chip is vectored by the potato/tomato psyllid, Bactericera cockerelli Sulc Recently, ‘Ca. Liberibacter’ has been associated for the first time with the carrot psyllid, Trioza apicalis Förster, and carrot, Daucus carota L. subsp. sativus, plants affected by this insect in northern Europe. An overview of psyllid species vectoring bacterial diseases to annual crops, with emphasis on potato psyllid and carrot psyllid, is presented herein.

Xylella fastidiosa Wells et al. is a gram-negative bacterial plant pathogen spread by sharpshooter insect vectors including the glassy-winged sharpshooter, Homoladisca vitripennis (Germar). Pierce's disease of grapevines, Vitis vinifera L., is the result of the grape strain of the bacterium, X. fastidiosa subsp. fastidiosa growing in the xylem of the plant. Pierce's disease typically results in vine death within 1 to 2 years. Several X. fastidiosa subsp. fastidiosa isolates have been sequenced from California, but to understand the evolutionary history of the bacterium and pathogenicity differences between populations, it was the goal of this project to sequence a genome of the Texas grape strain, GB514. Whole genome shotgun titanium pyrosequencing was performed and resulting data assembled, yielding two primary contigs one of which was 2.49 megabases and represented what is predicted in this version 1 assembly to be a complete Xylella chromosome. A second notable fragment did not assemble as part of the chromosome and could represent a possible low copy number plasmid or linear extrachromosomal DNA content. For the region that did not assemble, 39 novel genes have been identified with known functions. A BLASTn analysis of this gene collection found 94% query coverage and 98% identity to the recently uploaded plasmid pXF-RIV25 from mulberry isolate (X. fastidiosa subsp. multiplex). However, plasmid isolations of GB514, thus far, have not resulted in any detectable plasmid. Of the 39 genes identified, 11 genes code for the components of a functional Type IV secretion pathway (critical for many bacteria-infecting eukaryotic hosts). The presence of these Type IV genes integrated into the Texas grape strain or on a plasmid in two subspecies suggests it may have a critical role in virulence.