Southwestern Entomologist

Publications
Species, seasonal abundance, damage, control, and predaceous natural enemies of thrips (Thysanoptera: Thripidae) on cotton, Gossypium hirsutum L., were determined at two sites from 2005 to 2007 in the Lower Rio Grande Valley of Texas. Thrips can stunt growth and reduce yield potential. Seven species of thrips were found. When the cotton field was 0.5 km from commercial onion, Allium cepa L., the predominant species were western flower thrips, Frankliniella occidentalis (Pergande) (61.7%) and onion thrips, Thrips tabaci Lindeman (27.2%). A cotton field 50 km from a commercial onion-growing area was infested with western flower thrips (68.5%) and bean thrips, Caliothrips fasciatus (Pergande) (29.2%). At both fields, cotton seedlings from the cotyledon to 3-4-true leaf stages were most susceptible to onion thrips. Western flower thrips and bean thrips were found predominantly on 5- to 6-true-leaf stage and older cotton. Thrips were found in cotton at the beginning of the growing season and increased gradually in abundance, peaking in mid-May to late June. Predators on cotton were: minute pirate bugs, Orius spp.; lady beetles, Hippodamia spp.; green lacewing, Chrysopa rufilabris (Burmeister); bigeyed bugs, Geocoris spp.; spiders, Argiope spp., and syrphid flies, Syrphus spp. Orius spp. were the most abundant predators (69.5% on nontreated cotton). Heavy rainfall temporarily reduced abundance of thrips on cotton. The systemic insecticides thiamethoxam (Cruiser) and imidacloprid (Gaucho Grande) applied to seeds protected cotton from thrips for as long as 30 days after planting.
 
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.
 
The arundo wasp, Tetramesa romana Walker, has been permitted as a biological control agent for the invasive perennial grass, the giant reed, Arundo donax L. Evidence of adventive populations of the arundo wasp in the Lower Rio Grande Basin was confirmed with a spatio-temporal survey spanning more than 350 river miles. A total of 2,414 adult females of T. romana was collected during a 14month period of study in 2008–2009. This study documents the initial locations and regional expansion of two adventive populations of T. romana, centered around the cities of Eagle Pass and Laredo, TX. Peaks in T. romana abundance in August 2008 and June 2009 indicate a region-wide positive association between abundance of T. romana and warm summer temperatures. Correlations between site-specific abundance data and weather suggest the presence of populationspecific associations with both temperature and rainfall.
 
Impact by two potential biological control agents, Tetramesa romana Walker and Rhizaspidiotus donacis (Leonardi), on the invasive weed, giant reed, Arundo donax L., was assessed in a quarantine greenhouse before release. Tetramesa romana alone and T. romana plus R. donacis significantly damaged A. donax by suppressing leaf and stem lengths and stimulated production of side branches during a 12-week period. R. donacis plus T. romana only slightly more impacted the plant than did T. romana alone, most likely because of the longer life cycle of R. donacis that may require a longer period of time to cause measurable damage. No negative interactions were observed between the two candidate biological control agents. Therefore, based on their potential to significantly damage A. donax under greenhouse conditions and their narrow host ranges, T. romana and R. donacis are suitable candidates for biological control of this invasive reed grass in North America.
 
Survival of Eggs.and First-Instar Crawlers of Bemisia tebeci at Three Field Sites in Central Arizona, 2005.
Greenhouse and field studies were conducted to estimate survival rates of crawler stage Bemisia tabaci (Gennadius) Biotype B (=B. argentifolii Perring & Bellows) on cotton plants to enable more accurate life tables to be constructed for this important insect pest. The survival of crawlers did not differ significantly between still-air and artificial wind treatments in the greenhouse and averaged 90% overall. Over 99% of all surviving crawlers settled on the abaxial surface of leaves and 99.9% settled on the leaf where eggs were oviposited. Out of 4125 nymphs only five settled on leaves other than the leaf of origin and they all moved to leaves lower on the plant. Assuming that these individuals crawled rather than fell, the mean distance moved was at least 200 mm. Using a combination of cohort-based life table studies to measure egg mortality and recruitment studies to measure egg to settled 1st instar mortality in the field, crawler survival was estimated to average 89.2% over three study sites in Phoenix in Maricopa, AZ. Overall results suggest that crawlers move very little on cotton and that survival of the crawler stage is relatively high under both greenhouse and field conditions. Generational mortality rates estimated from previous life table studies in the field that excluded crawler mortality would increase by only 0.8% with the addition of this minor mortality component.
 
Treatment Scheme for Field Trials of Fungi for Control of the Russian Wheat Aphid.
Mycosis among Russian Wheat Aphids Collected from Plots Immediately after Treatment and Incubated 5 days in the Laboratory.
Field plots of irrigated spring and winter wheat, Triticum aestivum L., in southeastern Idaho, were infested with the Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae) and later treated with spores of Beauveria bassiana (Balsamo) Vuillemin or Paecilomyces fumosoroseus (Wize) Brown and Smith at rates of 2.5 or 5 × 1013 spores/ha. Small plots (1.4 to 6.6 m2) were treated with a backpack sprayer in 1995-1998 and large plots (470 m2) were treated using an overhead irrigation system in 1997 and 1998. In 1995, Russian wheat aphid densities rose to an average of over 120 Russian wheat aphids per tiller in control plots compared to an average of less than 30 Russian wheat aphids per tiller in all fungus-treated plots 33 days after the first treatment. Smaller, significant reductions were observed within 14 days of treatment with B. bassiana in 1996 and 1997. Low Russian wheat aphid infestation rates, averaging less than 1 Russian wheat aphid per tiller, made significant differences impossible to detect. Significant reductions in both Russian wheat aphid densities and the percentage of tiller infestation were observed in large-plot experiments two weeks after application of a high rate of B. bassiana in spring (1997) and winter wheat (1998). Fungus-treated Russian wheat aphids suffered 32-83% mycosis when field-treated tillers were incubated in the laboratory. Persistence of fungal inocula of either species, measured by estimating CFUs obtained from washed leaf segments, decreased by 10- to 1000-fold within 3 to 5 days.
 
The Russian wheat aphid, Diuraphis noxia (Mordvilko), is a severe pest of wheat, Triticum aestivum L; barley, Hordeum vulgare L; other small grains; and grasses. Although the Russian wheat aphid is a significant pest of small grains, its feeding effects on grain yield and vegetative biomass in large-scale wheat fields have not been well documented. Data were collected for 3 years in dryland and irrigated wheat fields in Texas and Oklahoma. The insect reduced grain yield 50.2 to 82.9% and biomass by 55.4 to 76.5%. These results suggested that winter wheat suffers significant economic loss from Russian wheat aphid.
 
The cycad aulacaspis scale, Aulacaspis yasumatsui Takagi, is currently found in China, Singapore, Hong Kong, Cayman Islands, Puerto Rico, U.S. Virgin Islands, Hawaii, and Florida (Germain and Hodges 2007). It was originally described from specimens collected on a Cycas sp., in Bangkok, Thailand, in 1972 (Takagi 1977). In recent years, finds have also been reported in California, Georgia, and Nevada (IUCN/SSC Cycad Specialist Group 2009). In 2006, severe outbreaks of cycad aulacaspis scale were reported in South Texas where sago palms, Cycas revoluta Thunb., adorn landscapes and are important ornamental plants for commercial nursery growers (Bográn et al. 2006). Of the more than 20 species of scale insects that occur on cycads in Florida, the most damaging species is cycad aulacaspis scale (Hodges et al. 2003).
 
Rio Grande Miles Treated and Arundo Acres Controlled with the USDA-ARS Arundo donax Biological Control Program Between San Ignacio and Del Rio, Texas, 2009-2015 a 
Annual Acre-Feet of Water Saved and Accruing to the United States with Arundo Control in the Rio Grande Basin, San Ignacio to Del Rio, Texas, 2009 through 2058 Acre-feet of water saved 
Sensitivity Analysis, Benefit-Cost Ratio of Benefits with Variations in Annual Water Consumption of Arundo and Control Rate from Beneficial Insects (Total %) using Normalized Prices, in the Texas Lower Rio Grande Valley, 2009 
Regional Economic Impact to the Texas Lower Rio Grande Valley in 2006 Dollars from the USDA-ARS, Weslaco, Texas, Arundo donax Biological 
Giant reed, Arundo donax L., is a large, bamboo-like plant native to the Mediterranean region. It has invaded several thousand hectares of the Rio Grande riparian habitat in Texas and Mexico. The United States Department of Agriculture-Agricultural Research Service (USDA-ARS) is investigating four herbivore insects as potential biological control agents for giant reed. One of the most important reasons for targeting this invasive weed is to reduce its impact on available water supplies, especially in the Rio Grande Basin. This study examined selected economic implications of this program for agricultural water users in the U.S. The research included (a) estimating the value of the water saved (to agricultural purposes) by reduction of giant reed, (b) benefit-cost analyses, (c) regional economic impact analyses, and (d) an estimate of the per-unit life-cycle cost of water saved during a 50-year planning horizon (2009 through 2058).
 
It is commonly thought that blow flies are nocturnally inactive. Blowflies are often important in helping to estimate post mortem intervals (PMI) for corpses found at death scenes. If blow flies oviposit during nocturnal hours, there could possibly be up to 12-hour discrepancies for estimates of PMI. Two blow fly species, Phaenicia eximia (Wiedemann) and Cochliomyia macellaria (F.), oviposited nocturnally on ground beef baits in 2003, during the onset of low-atmospheric pressure (an air mass with lower atmospheric pressure than that of the air surrounding it) at rural study sites near Snook (Burleson County), Texas, under artificial lighting of at least 1500 footcandles when temperatures were at 26?C or higher. Trials conducted under similar conditions during the same year without a low-pressure system moving into the area resulted in no nocturnal blow fly oviposition. Nocturnal blow fly oviposition went undetected once low-atmospheric pressure systems settled into the study area, irrespective of temperature and lighting conditions. Thus, this study illustrates that there is a connection between the onset of low-atmospheric pressure and nocturnal blow fly oviposition on baits under artificial lighting of 1500 footcandles or more when temperatures are 26 ?C or above. After concluding 2003 experiments, statistical analyses supplied evidence that woodland habitat was more favorable for blow fly oviposition than prairieland habitat throughout the 2003 study, irrespective of species or time of year. Furthermore, statistical analyses conducted on nocturnal and diurnal temperature ranges furnished evidence to support the hypothesis that 2003 nocturnal temperatures had more of an effect on daily ovipositing than diurnal temperatures for P. eximia and Cynomyopsis cadaverina (Robineau-Desvoidy).
 
Number of different stages of E. varivestis on bean crop 8 days after treatment with carbaryl and biological (formulated and unformulated B. thuringiensis) insecticides. Average of four replicates; total number per eight random plants.
Particle Size of Ingredients and Bacillus thuringiensis Spray Dried Formulations Measured with a Coulter Multisizer.
Number of Epilachna varivestisfPlant in Bean Plots Treated with Carbaryl and Biological (Formulated and Unformulated B. thuringiensis) Insecticides."
A new sprayable microgranule formulation of Bacillus thuringiensis subsp. kumomatoensis (strain C-9) was evaluated for the control of the Mexican bean beetle Epilachna varivestis Mulsant. Strain C-9 was isolated from dead E. varivestis in a Phaseolus vulgaris L. field in Durango, Mexico. A spore and crystal complex of the C-9 strain were active against E. varivestis larvae in bioassays using treated bean plants (LC50 of 642 μg/ml), and against Trichoplusia ni (Hubner) larvae using artificial diets (LC50 of 219 μg/ml). The sprayable powder (microgranule formulation), consisting of cornstarch (CS), nixtamalized corn flour (NCF), vegetable oil, powdered sugar, 2-propanol, malachite green, and formaldehyde, was prepared using a spray-dry process. Shelf life of formulated B. thuringiensis maintained over 90% of its original activity after 24 months of storage. A field test demonstrated that treatments of formulated B. thuringiensis controlled E. varivestis significantly better than treatments with unformulated B. thuringiensis. This study demonstrated that B. thuringiensis can potentially be formulated by spray drying, based on ingredients, which would help to improve its activity as a biopesticide under field conditions.
 
Novel formulations for Bacillus thuringiensis (Berliner) were tested using bioassay methods in the laboratory and greenhouse. Granular formulations were made with gelatin, pectin or cornstarch, each with and without Congo red (i.e., a solar protectant). B. thuringiensis strain GM-7 was grown under liquid culture conditions and used in all formulations. Artificial sunlight caused reduction in spore viability within 30 min of exposure. Within 1 h of exposure, formulations made with gelatin protected spores better than formulations made with starch or pectin. Insecticidal activity was not reduced as quickly, nor were differences among treatments quite so obvious. Formulations containing Congo red protected spores and insecticidal activity better than formulations without Congo red. When Trichoplusia ni (Hubner) neonates were placed on cotton plants treated with granules, no differences in defoliation occurred over three weeks among treatments containing B. thuringiensis. Plants treated with control granules or left untreated experienced 10.2% defoliation; plants treated with granules containing B. thuringiensis underwent 0.6% defoliation. Granules made with pectin generally resisted wash-off better than granules made with starch or gelatin. When granules were placed in corn whorls previously infested with Spodoptera frugiperda (J.E. Smith) larvae in the greenhouse, granules made with pectin or starch caused 94% insect mortality and the granules made from gelatin caused 72% larval mortality.
 
The effects of blastospores and conidia of Paecilomyces fumosoroseus were compared for insecticidal activity against 3-day old larvae of Mexican bean beetle (MBB), Epilachna varivestis Mulsant. Blastospores of P. fumosoroseus were produced using strain ARSEF 3581 grown in a liquid basal medium, whereas conidia were produced on potato dextrose agar. Initial insecticidal activity was demonstrated with a single-dosage dipped-leaf assay using a concentration of 1 × 108 conidia or blastospores/mL. Blastospores, conidia, and no fungus control treatments averaged 90%, 86%, and 19% larval mortality, respectively, after 3-day continuous exposure. Subsequently, a dosage response assay was completed to compare two assay conditions, dipped-leaf and topical application techniques. Five spore concentrations, 1.2×109, 2.4×108, 4.8×107, 9.6×106, and 1.9×106 spores/mL, were prepared and used for both assay techniques. For the dipped-leaf technique, 25 larvae were exposed to treated leaf disks, five larvae to each of five treated leaf disks per spore concentration. For the topical assay, 5 μL was applied directly to each of 25 larvae for each spore concentration. After 3-day incubation, blastospores of P. fumosoroseus showed higher activity than conidia, and the topical application technique was more effective (lower LC50 values and lower X 2 values) than the dipped leaf assay technique. This research demonstrates the insecticidal activity of P. fumosoroseus on MBB and provides a comparison of two basic bioassay techniques that may be useful in future research on this topic.
 
Locations in Arkansas and Mississippi at which Tarnished Plant Bugs were Collected from Weeds for Laboratory Testing to Determine Resistance to Permethrin Using Glass-Vial Bioassays.
Tarnished Plant Bug Populations with Different Levels of Pyrethroid Resistance Evaluated with Field Rates of Formulated Pyrethroid Insecticides in Spray-Chamber or Field-Cage Tests.
Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations from 21 locations in the Mississippi River Delta of Arkansas and Mississippi were tested for resistance to permethrin in 2004 and 2005. Each population was tested using permethrin in a discriminating-dose bioassay to determine percent mortality, and with a glass-vial bioassay that used dose-response regression lines to determine LC50 values for permethrin. Results from the two bioassays were compared by regression of percent mortalities with LC50 values. The regression was significant with an R2 value of 0.90 which showed that the two methods of determining resistance were closely correlated. The regression equation had a slope of −0.74 and an intercept of 72.06, which showed that the LC50 value decreased by 7.4 μg/vial for every 10% increase in mortality in the discriminating-dose bioassay. Percent mortality in the discriminating-dose bioassay and LC50 values were related to control of plant bugs in the field using four spray chamber and one field cage test. Plant bug populations in these tests were not controlled with four different pyrethroids applied at recommended field rates. Results indicated that either a LC50 value of 24 μg/vial or greater of permethrin, or 60% or less mortality in the discriminating-dose bioassay with permethrin, could be used to predict field control problems with plant bugs and pyrethroid insecticides in cotton, Gossypium hirsutum L. The discriminating-dose bioassay is a much easier bioassay to use as compared to determining LC50 values using dose-mortality curves. It could be easily used by researchers, consultants, or Cooperative Extension personnel in an insecticide resistance monitoring program for tarnished plant bugs.
 
The efficacy of novaluron (Diamond(TM) 0.83 EC) on cotton, Gossypium hirsutum L., against nymphs of different instars of field-collected southern green stink bug, Nezara viridula (L.), was investigated in a spray chamber using two nozzles, 650033 and 8002E. The nozzles delivered rates of 18.7 and 46.7 L/ha, respectively, of total water-based spray. Novaluron was applied at 0.0218, 0.0436 and 0.0654 kg active ingredient (AI) rates per ha. The 8002E nozzle produced significantly larger droplets, increased droplet density and increased spray coverage compared to the 650033 nozzle. Regardless of dosage and spray rate, the age of nymphal instars significantly influenced mortality. Mortality of small nymphs (2(nd) instars) was significantly greater than that of either 3(rd)- or 4(th)-instar nymphs. When novaluron was applied at 0.0654 and 0.0872 kg Al per ha with or without crop oil concentrate, the deposit from the 8002E nozzle significantly increased mortality of 3(rd)-instar nymphs; however, neither dosage nor addition of crop oil concentrate increased Mortality of 3(rd)-instar nymphs. Novaluron did not cause a great amount of mortality of 4(th)-instar nymphs. This study suggests that application of novaluron should be directed at 2(nd)-instar nymphs to maximize efficacy for control of southern green stink bug on cotton and that applications that produce deposits with increased droplet size and density on plants might increase efficacy.
 
The susceptibility of G. punctipes and the tarnished plant bug (TPB), L. lineolaris, to selected insecticides was determined in topical, tarsal contact, and field studies. In both topical and tarsal contact studies, L. lineolaris was more susceptible to imidacloprid and oxamyl residues than G. punctipes. However, oxamyl was more toxic to the pest than imidacloprid. Both insect species responded very similarly to fipronil, acephate, dicrotophos, and lambda-cyhalothrin, all of which were very toxic to these insects. In a field study conducted in the USA during 1996 and 1997, lambda-cyhalothrin had an equally negative impact on the populations of TPB and G. punctipes. Results from our laboratory and other field studies indicate that oxamyl and imidacloprid would be effective against TPB while conserving populations of G. punctipes for the biological control of lepidopteran larvae in cotton.
 
The pecan weevil, Curculio caryae (Horn), is a key pest of pecans, Carya illinoinensis (Wangenh.) K. Koch. The entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metschnikoff) Sorokin are pathogenic to and are being developed as microbial control agents for pecan weevil. One approach to suppressing pest populations and the resultant damage might be to apply entomopathogenic fungi when adult pecan weevils are emerging from the soil. Here we report the efficacy of B. bassiana (GHA strain) and M. anisopliae (F52 strain) applied to trees in orchards at three locations: Byron, GA, Fort Valley, GA, and Comanche, TX. At Fort Valley, treatments included B. bassiana as an oil-based spray with a UV-protective screen applied to the trunk, M. anisopliae applied as an impregnated fiber band stapled onto the trunk, and a nontreated check. At Byron, GA, we compared the B. bassiana trunk treatment to a nontreated check. Treatments at the Texas location were the B. bassiana trunk application, M. anisopliae applied as a trunk band and as a soil drench, and a nontreated check. At each location, weevils were trapped and transported to the laboratory for 15 to 17 days post-treatment to record mortality and mycosis. At both Georgia locations, B. bassiana caused ≥80% mortality and mycosis, which was significantly greater than mortality observed in the check (≤33%); mortality and mycosis in the M. anisopliae treatment at Fort Valley did not differ from that observed in the check. In Texas, due to insufficient replication in plots, statistical comparison among treatments was not possible. However, mean percentages of mortality of pecan weevils after 7 and 14 days were 38 and 55% in the check, 75 and 88% in the B. bassiana-treated plots, and 57 and 75% in the M. anisopliaetreated plots. These results indicate potential for B. bassiana trunk sprays to suppress adult pecan weevil. Future research is needed to determine if the approach contributes to economic levels of crop protection.
 
The shelf showing accumulation of pupae on the sponge wrapped in a towel. 
Stable flies, Stomoxys calcitrans L., are important pests of confined and pasture cattle. They have been reared in the laboratory to study their biology and to test new methods of control. Research on rearing modifications has concentrated on developing larval diets from materials locally abundant. Under current protocols, pupae form in the medium. Aggregations of pupae were located and removed, often with a considerable amount of extraneous material. Various methods have been developed to separate the pupae from waste material. We describe a method by which wandering larvae are enticed to leave the medium prior to pupariation. The larvae were attracted to a moist cloth on a shelf positioned at the end of the rearing pan. Almost 85% of the wandering larvae were collected on the shelf. This simplifies obtaining clean pupae and allows for collecting pupae of known age for experimental work. We also include data on the rate at which the larvae wandered onto the shelf under conditions we used in the laboratory.
 
We have used the expressed sequence tag (EST) approach to isolate new gene coding regions from the horn fly, Haematobia irritans. Seventy four unique ESTs and one complete open reading frame were sequenced from genes not previously identified in horn flies and recorded in the databases of the National Center for Biotechnology Information. Fifteen ESTs are from genes involved in metabolism, ten ESTs are from structural proteins, and 20 ESTs are from genes involved in other functions, including storage, heat shock response and transcription. Five of the ESTs have similarity to members of gene families involved in resistance to pesticides. The entire coding region from a gene involved in cell cycle regulation was obtained and the mRNA encoding the protein found to be highly expressed in early embryonic and pupal stages of the fly.
 
Pupal weight versus percentage of successful eclosion for 20,484 horn fly pupae. Data were pooled for multiple dung samples, including aged, nutrientdepleted dung and fresh dung at various larval densities.
Bioassay of Fresh Dung Mixed with Insoluble Material from Fresh Dung
Aging of bovine dung for 3–5 years under refrigeration resulted in smaller sizes of horn fly, Haematobia irritans (L.), pupae. Growth of horn fly larvae in mixtures of aged and fresh dung resulted in production of larvae and pupae stunted in proportion to the relative amount of aged dung. Reduction of size of pupae produced in aged dung was because of nutrient limitation, which was partially reversible by supplementation with a bacteriological medium or yeast extract that increased the numbers of bacteria for consumption by horn fly larvae. Similar stunting of growth and development of horn fly larvae was produced by crowding larvae in fresh bovine dung. Stunting was dependent on the amount of larval crowding, with greater larval densities resulting in smaller individuals but greater aggregate pupal weight, suggesting that stunting at great larval density resulted from phagoinhibition rather than depletion of nutrients in the fresh dung. Successful eclosion of adult horn flies was dependent (0.9578 correlation) on pupal size between 1.0 and 2.7 mg. The smaller size limit for pupae that were successful in eclosion of adult flies was about 1.0 mg, compared to an average weight for horn fly pupae of 4.2 mg. Implications for modeling and control of horn flies are discussed.
 
Effects of cotton, Gossypium hirsutum L.; green bean, Phaseolus vulgaris L.; and sweet potato, lpomoea batatas (L.) Lam.; on mortality and development of sweetpotato whitefly, Bemisia tabaci (Gennadius) biotype B; bandedwinged whitefly, Trialeurodes abutilonea (Haldeman); and greenhouse whitefly, T. vaporariorum (Westwood); and on the key biological parameters of an exotic parasitoid species, Eretmocerus mundus Mercet, and an indigenous parasitoid, Encarsia pergandiella Howard, were compared in the laboratory. Cotton was most suitable for sweetpotato whitefly, and bean was most suitable for greenhouse whitefly. No significant differences were found between these two whitefly species on sweet potato. Preimaginal mortality of sweetpotato whitefly on cotton was 35.2% versus 77.3% of greenhouse whitefly. Developmental time of sweetpotato whitefly was significantly shorter (17.5 days) than that of greenhouse whitefly (23.2 days). The mortality and developmental time of bandedwinged whitefly did not differ on the different host plants. Parasitism by Er. mundus was greatest in sweetpotato whitefly and least in greenhouse whitefly when both whiteflies were reared on cotton. Parasitism of bandedwinged whitefly was intermediate. Parasitism by En. pergandiella was significantly greater than that by Er. mundus attacking the same whitefly species reared on bean or cotton, except parasitism of sweetpotato whitefly. Emergence of Er. mundus was greatest from sweetpotato whitefly on cotton, and least for bandedwinged whitefly on bean. Emergence of En. pergandiella was significantly greater than that of Er. mundus among host plants and whitefly species except sweetpotato whitefly.
 
Citrus leafminer, Phyllocnistis citrella Stainton, is an economically important insect pest of citrus in Pakistan, Mexico, the United States and many other citrus-producing countries. Extract of Azadirachta indica A. Juss at 5 and 7% and its oil at 1 and 1.5% concentrations were tested in comparison to synthetic insecticide abamectin 1.8% EC against P. citrella in nursery plantations of Citrus reticulata L. Control of all larval instars of citrus leafminer was good with application of abamectin and A. indica oil during fall 2015 and summer 2016. Abamectin suppressed 75-90% of P. citrella larvae both seasons. A. indica oil at greater concentration (1.5%) provided the most control (65-88%) like abamectin but at less concentration (1%), control decreased slightly. Larvae of P. citrella were more sensitive to A. indica oil than to extract. Like abamectin, A. indica oil also better controlled citrus leafminer larvae and might be considered a promising tool for management of citrus leafminer. El minador foliar de los cítricos (MFC), Phyllocnistis citrella Stainton, es un insecto plaga económicamente importante de los cítricos de Pakistan, México, Estados Unidos de Norteamérica y de muchos países productores de cítricos. El extracto de Azadirachta indica A. Juss a las concentraciones de 5% y 7% y su aceite al 1% y 1.5% fueron probadas en comparación con el insecticida sintético abamectina al 1.8% CE en contra de P. citrella en plantaciones de vivero de mandarina, Citrus reticulata L. Los resultados mostraron que la tasa de control de todos los estadios larvarios del MFC fue alta con la aplicación de abamectina y el aceite de A. indica durante el otoño de 2015 y el verano de 2016. Sin embargo, el aceite de A. indica a la concentración más grande (1.5%) proporcionó el nivel de control más grande así como la abamectina, pero al disminuir su concentración (1%), la tasa de control disminuyó ligeramente. Las larvas de P. citrella fueron más sensibles al aceite que al extracto de A. indica. Además, también la abamectin y el aceite de indica también dieron mejor control de larvas del MFC; esto podría ser considerado como una herramienta promisoria para el manejo del MFC.
 
Peridomestic water containers such as livestock water troughs are considered important reservoirs of mosquito larvae. This study identified environmental factors that favored seasonal abundance and relative frequency of yellow fever mosquito (Ae. aegypti Linnaeus, 1762; Diptera: Culicidae) larvae in suburban livestock drinking-water troughs at La Paz, Mexico. Water was sampled (n = 280) each week by dipping from five water troughs and two sentinels during a 14-month (2015-2016) period. Overall frequency of Ae. aegypti in all samples was 57.5%, with a mean of 21.4 larvae per liter. Few larvae were found during summer and autumn (21.8 ± 3.8 and 29.1 ± 4.7 per liter, respectively), with fewest during winter (1.4 ± 1.0). Water samples from troughs containing Ae. aegypti larvae had significantly greater turbidity (p = 0.02), water-dissolved oxygen (p < 0.001), and total solids (p < 0.001) than did samples without mosquitoes. Average number and frequency of larvae per liter were positively and significantly (p = 0.05) correlated with water temperature. Changes in water temperature influenced the relative percentage of Ae. aegypti larvae approximately 1 month later. The model NL = - 37.27 + 0.68 WT, where NL was the number of larvae per liter and WT was water temperature explained the relationship (R² = 0.46, p = 0.03). The water troughs provided conditions that supported proliferation of mosquito larvae, especially Ae. aegyti. In water troughs where Ae. aegypti larvae were established, water temperature was most closely correlated to abundance and frequency of the larvae.
 
Imagos de las cuatro especies estudiadas. A. Zerene cesonia cesonia; B. Colias erate; C. C. eurytheme; D. C. dimera. Imagos of the four species. A. Zerene cesonia cesonia; B. Colias erate; C. C. eurytheme; D. C. dimera.  
Estructuras del corion en dos de las especies estudiadas. A,C. Corion y microrretícula de Zerene cesonia cesonia. B. Corion de Colias erate. Structures of the chorion of two studied species. A,C. Chorion and micro-rid of Zerene cesonia cesonia. B. Chorion of Colias erate.
Fotografías en el corion bajo el MEB de regiones micropilar y apical (aerópilos). A-D. Colias dimera; B-E. C. erate; C-F. C. eurytheme. Photos in chorion from SEM of the micropyl and apex region (aeropyles). A- D. Colias dimera; B-E. C. erate; C-F. C. eurytheme.  
Fotografías en el corion bajo el MEB de la zona apical y de la microrretícula a nivel ecuatorial. A-D. Colias dimera; B-E. C. erate; C-F. C. eurytheme. Photos in chorion from SEM of the apex zone and micro-rid in equator a zone. A-D. Colias dimera; B-E. C. erate; C-F. C. eurytheme.  
Etapas de la formación de la microrretícula. A. Esquema gráfico; B. Ilustraciones de observaciones con el MEB. 1. Concentración de polipéptidos dentro de las celdas macrorreticulares; 2. Rugosidad incipiente; 3. Rugosidad total; 4. Proto-microrretícula; 5. Microrretícula. Stages of formation of the micro-grid. A. Graphic scheme; B. Illustrations made of photos from the SEM. 1. Polypeptides concentration within macro-grid cells; 2. Incipient roughness; 3. Total roughness; 4. Proto micro-grid; 5. Micro-grid.  
Resumen Se estudia e ilustra la estructura coriónica de cuatro especies de dos géneros de la subfamilia Coliadinae: Colias (C. dimera, C. erate, y C. eurytheme) y Zerene (Z. c. cesonia). Se reexaminan y comparan descripciones previas de C. dimera, C. eurytheme y Z. c. cesonia, con nuevos materiales provenientes de México y Colombia. Además, por primera vez se describe el corion de C. erate y la microrretícula en tres de las cuatro especies; que se pensaba ausente en ambos géneros, por su carencia en C. dimera. Con el uso del microscopio electrónico de barrido (MEB), se efectuaron tomas fotográficas de cuatro regiones coriónicas (micropilar, perimicropilar o apical, ecuador, y base); éstas se describen, ilustran, y comparan tabularmente. Las tomas en el MEB permiten analizar y resolver que C. dimera presenta caracteres de géneros menos derivados dentro de los Coliadinae, mientras que en C. eurytheme se expresan caracteres encontrados en géneros más derivados. Sin embargo, caracteres reticulares del área basal, cantidad de ejes y su doble grosor respecto a las costillas colocan a C. dimera como una especie derivada dentro del grupo. Ambas condiciones exponen a C. dimera siendo una especie con un mosaico de caracteres coriónicos ancestrales y derivados.
 
A-C. Imago y corion de Ectima thecla thecla. A. Vista dorsal y ventral del imago; B. Vista lateral del corion; C. Vista apical del corion. A-C. Imago and chorion of Ectima thecla thecla. A. Dorsal and view; B. Lateral view of the chorion; C. Apical view of the chorion. 
A-B. Patrón triangular en el corion de Ectima thecla thecla. A. Amplificación del relieve coriónico; B. Teselación triangular en sentido al eje Y. A-B. Triangular pattern on the chorion of Ectima thecla thecla. A. Amplification of the chorionic relief; B. Triangular tessellation in the Y-axis direction. 
The chorion of Ectima thecla thecla was examined and compared with the chorionic morphology of Hamadryas spp. An illustrated glossary of the terminology used in chorionic descriptions in Ageroniina was created. The chorion of both genera was typified as globose and unique for the clade -with plesiomorphic structures in Ectima as compared to Hamadryas. The need for clearer and more detailed chorionic descriptions in Batesia and Panacea is noted, as previous publications recognized other types of chorion related to different Biblidinae subgroups, when perhaps a globular chorion would be expected for the entire Ageroniina subtribe.
 
We described and compared the macro and micro exochorionic grid of three species of the genus Colias: C. croceus, C. alfacariensis, and C. lesbia mineira, under methylene blue staining techniques and with the scanning electron microscope (SEM). The size, shapes, as well as diverse aspects of the grid in its region or zones, are different for each species. The differences occur in the micropyle, perimicropylar area, relative thickness between axes and ribs, the arrangement and number of polygons that make up the micro-grid, among other characters we detailed. All these characters are illustrated in drawings and SEM photographs. The results are compared between each species and those of earlier works. © 2018 Southwestern Entomological Society. All rights reserved.
 
We examined and described the structure of the chorion of Leucidia brephos with the methylene blue staining technique and with the use of scanning electron microscopy (SEM). Their morphological comparison includes illustrations or pictures of other chorions of the subfamily Coliadinae. Leucidia brephos' chorion has a rather generalized macro-grid within the group, in addition to an elongated shape and base with more polygonal cross-linking, which makes it plesiomorphic. The micro-grid, along with the axes and the ribs forms a relief structure in three different planes, which are quite particular. The sides of the micro-grid are of different thickness and the number of irregular polygons between the ribs is reduced, almost always less than 10. This new knowledge confirm the presence of the micro-grid in the Coliadinae, explaining its absence in some species as a secondary loss. And, together with the data previously obtained in Dismorphiinae, Coliadinae and Pierinae allow us to summarize the macro-grid tendencies on Pieridae: The tendency to form quadrangular polygons, the simplification of the axes and ribs, and the disappearance of irregular and multiple polygons toward the poles. © 2018 Southwestern Entomological Society. All rights reserved.
 
Gymnetis stellata (Latrielle, 1833) ♂ a) dorsal view; b) lateral view; c) aedeagus.
The presence of Gymnetis stellata is recorded for the first time in the state of Oaxaca, Mexico. The new report is based on a female collected by hand near a red "nanche" tree (Malpighia mexicana) at Villa Sola de Vega and a male and female pair collected on wild vegetation at Miahuatlán de Porfirio Díaz. Both sites are in the Sierra Sur region of Oaxaca at approximately 1,500 m elevation. © 2018 Southwestern Entomological Society. All rights reserved.
 
Nearest neighbor dendrogram in morphotypes of Meteorus sp. from Durango, Mexico.
Collection Data of Individuals Analyzed Taxonomically, Species to which They Belonged, and Access Code in GenBank ®
Hymenoptera parasitoids Meteorus laphygmae Viereck, 1913 and M. arizonensisMuesebeck, 1923 were analyzed genetically to identify their variability in relation to species similar to them in morphology. Because of complexity in delimitation of the species, they have polymorphisms in color of the body and distinctive color patterns in the mesosome. A fragment of the cytochrome oxidase I (COI) gene was sequenced to learn the genetic distance between individuals. Maximum distribution of variance was found when two groups were formed: Group 1: Meteorus sp. Durango (two species = nine morphotypes) and Group 2: M. laphygmae ("predominant" species in Mexico) compared with external group Homolobus truncator Say, 1829, taxonomically similar to Meteorus (in Durango). The morphotypes of Meteorus sp. at Durango were genetically in a single group (0.0005 genetic distance between them), although taxonomically they belonged to two species (M. laphygmae and M. arizonensis). Group 1 differed from Group 2 of M. laphygmae (0.118) and H. truncator (0.206). This indicated the morphological characters of the two species of Meteorus did not coincide with genetic characters, which resulted in erroneous identification.
 
Historical and new extended distribution of Peltophorus polymitus across the ecoregions of Durango State.
Consumption of mezcal in Mexico and its international exportation is increasing. Potential pests of agave, the plant distilled for this alcoholic beverage, need to be studied. Durango is the second state in mezcal production in Mexico. It is important to contribute to the knowledge of potential pests of agaves. Peltophorus polymitus (Boheman 1845) has been historically registered as pest at three municipalities in the State of Durango. However, little is known of the biology or ecology of P. polymitus, a potential pest of the agave crop. The objective of this work was to contribute to the knowledge of the distribution of the weevil of agave (P. polymitus) in Durango. Here, the distribution of P. polymitus was extended to 13 additional municipalities in an altitudinal range from 1,104-2,094 m above sea level, across all the ecoregions of the State.
 
A neotype of centipede species Scolopendra pomacea Koch, 1847 was designated based on analysis of published information and morphological examination of specimens collected in Michoacán State, Mexico.
 
Nineteen parasitoids of Cydia caryana (Fitch) were found in six pecan-growing areas of Coahuila State (Saltillo, Monclova, General Cepeda, Parras de la Fuente, Muzquiz, and Torreon). Calliephialtes grapholithae (Cresson, 1890), Phanerotoma fasciata (Provancher, 1881), Hyssopus spp. (Linnacus, 1753), and Apanteles epinotiae (Forester, 1962) were most common. Calliephialtes grapholithae parasitized 26.46% of shuckworm larvae at Saltillo and 7.04% at Parras, while P. faciata parasitized 10.05% of larvae at Saltillo and 30.99% at Parras. Parras de la Fuente was the pecan-growing area with most parasitism (53.52%), followed by Saltillo (46.93%), General Cepeda (41.38%), Monclova (24.0%), Muzquiz (17.24%), and Torreon (5.52%).
 
Acanthoderes (Pardalisia) funeraria Bates, 1861 was reported for the first time in the State of Durango, at the municipalities of Durango, Mezquital, and Vicente Guerrero. The species was reported in 19 of the 32 states of Mexico (59% of the national territory). Agave durangensis Gentry and A. parryi Engelm were reported as new hosts.
 
Caligo telamonius for Hidalgo, Mexico, Jorge Valencia-Herverth collector. Dorsal view (A), ventral view (B). Distribution of C. telamonius in Mexico and the first records for the State of Hidalgo (C). Symbols: white triangle (new record), black circle in white circle (specimen), black circle (observation), and white box (unknown).
Abstract. The pale owl butterfly, Caligo telamonius (C. Felder & R. Felder, 1867), was recorded for the first time in the State of Hidalgo, Central Mexico. This extends the known distribution of the species 115 km north of the northernmost specimen collected in eastern Mexico. Ecological data and environmental characteristics of the habitat where the species were collected were described.
 
Resumen Se examina la estructura coriónica de Orophila cardases campaspe; también se efectúan comparaciones con el corion de siete especies de la subtribu Callicorina, taxón que aquí se caracteriza. Su corion se tipifica por la presencia de ‘ventanas’ en la base de las crestas, el relieve apical en semicírculos y la ausencia parcial o total de las costillas entre los ejes. Se reconocieron las similitudes del corion entre ésta y la subtribu Epiphilina, así como la posibilidad de reducción u optimización del material que derivaría en las crestas ‘en puente’ de la subtribu Eubagina. Es indispensable una mayor exploración del corion en otras especies de Callicorina, por su posible empleo como fuente de caracteres y para contrastar la hipótesis de Freitas et al. (2014) sobre las relaciones filogenéticas entre los géneros de dicha subtribu.
 
Distribución de Synargis nymphidioides sspp. en México. Círculo vacío S. n. nymphidioides ; Círculo obscuro S. n. septentrionalis ; Triángulo S. n. praedictum ssp. nov.; Cuadrado S. nymphidioides ssp. nov.? Distribution from Synargis nymphidioides sspp. in Mexico. Empty circle S. n. nymphidioides ; Dark circle S. n. septentrionalis ; Triangle S. n. praedictum ssp. nov.; Square S. nymphidioides ssp. nov.? 
We examined and compared populations of Synargis nymphidioides (Butler, 1872) from the Pacific slope region in the Sierra Madre del Sur with others from the southern and eastern regions of Mexico. A new endemic subspecies from this region, Synargis nymphidioides praedictum ssp. nov., is described, listed and discussed too other taxa in this geographic area, making it a strong candidate for an endemism center. Such endemism center can predict other unpublished taxa characteristic from evergreen and subcaducifolious forests around the southern Sierra Madre.
 
Top-cited authors
John A. Goolsby
  • United States Department of Agriculture
Jorge Llorente
  • Universidad Nacional Autónoma de México
Adrián Emilio Flores Gallardo
  • Universidad Nacional Autónoma de México
Terán Antonio
  • INIFAP Instituto Nacional de Investigaciones Forestales Agricolas y Pecuarias
Juan D. Lopez
  • United States Department of Agriculture