Aethina tumida Murray (Coleoptera: Nitidulidae) is an invasive parasite species in populations of honey bees, Apis mellifera L. Aiming toward substitution of chemical control, we here identified a naturally occurring fungal pathogen of adult A. tumida from its endemic range in South Africa [Metarhizium anisopliae (Metschnikoff) Sorokin variety anisopliae strain FI-203]. The susceptibility of adult beetles (n = 400) to this fungus and to three other generalist entomopathogenic fungal isolates [Metarhizium anisopliae, Beauveria bassiana (Balsamo) Vuillemin, and Hirsutella illustris Minter & Brady] was assessed using spore suspension bioassays. The data revealed significantly increased mortality in the B. bassiana (74.00 ± 8.94%) and M. anisopliae variety anisopliae (28.00 ± 16.43%) tests but not in the H. illustris (2.00 ± 4.47%) and M. anisopliae (12.00 ± 8.37%) groups. The results indicate a potential for entomopathogenic fungi as an alternative control of A. tumida.

Workers of the honey bee subspecies Apis mellifera capensis (Eschscholtz) produce female offspring by thelytokous parthenogenesis and can parasitize colonies of other subspecies. In 1990, translocation of 400 colonies of A. m. capensis into the distribution area of A. m. scutellata by a commercial beekeeper triggered a dramatic parasitic phenomenon. Parasitized colonies died within a few months of infestation, and this resulted in the loss of tens of thousands of colonies by commercial beekeepers in the A. m. scutellata range in South Africa. To deal with the problem and to identify methods that would limit the impact of the social parasite, we investigated the link between beekeeping management and severity of parasitic infestations in terms of colony mortality and productivity. We demonstrate that colonies from apiaries subjected to migrations are very susceptible to infestation and consequently show dramatic mortality. Their productivity is also inferior to sedentary colonies and those in isolated apiaries in terms of honey yield and brood quantity. Furthermore, by concentrating hives in small areas and often in the vicinity of other beekeepers, cross-infestations can easily occur. This can undermine previously parasite-free beekeeping businesses. As a result of our surveys, we propose beekeeping practices based on locally trapped bees, reduced migration, and better control of parasite spread, thus promoting the conservation of these pollinators. If followed by all the South African beekeepers, these measures should limit the spread of the parasite until it is eliminated within a few years, after which full migratory beekeeping practices could resume.

The article presents the results of bioassaying 39 samples of TM Biocontrol-1, a viral insecticide, from 10 different lots and various sizes of vacuum-sealed packages that were stored at −10°C for 5–15 yr. This is the first study to present potency data for a registered virus product stored for this length of time. Laboratory bioassays in insects from the same colony from which the TM Biocontrol-1 was produced showed that the stored viral insecticide is still effective, although it lost ≈30% of its effectiveness during storage. A direct correlation of this loss with the length of time in storage is not apparent. Bioassays also showed that there are significant differences in the susceptibility of Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), larvae from different geographic regions to OpMNPV (family Baculoviridae, genus Nucleopolyhedrovirus) infection. Package size did not affect the potency of stored TM Biocontrol-1. There were no clear, significant differences in the effectiveness among lots of TM Biocontrol-1 processed by different organizations.

Hydrophobic and hydrophilic kaolin-based particle films are effective for control of insect pests in certain agricultural crops. How these products interact with potential biological control agents is not well documented. This study was conducted to evaluate the effects of the hydrophobic (M96-018) and hydrophilic (Surround WP) kaolin-based particle films (Engelhard Corporation, Iselin, NJ) on pea aphid, Acyrthosiphon pisum (Harris), on peas (Pisum spp.), and on the fungal aphid pathogen Pandora neoaphidis (Remaudière and Hennebert) Humber. Over two field seasons (2001 and 2002) in northern Idaho, applications of M96-018 significantly reduced the rate of pea aphid increase on pea, but Surround WP, tested only in 2001, did not reduce aphid population growth rate. Neither particle film treatment was as effective as a standard application of esfenvalerate (DuPont Asana). In the laboratory, particle films suppressed pea aphid populations by up to 30%. M96-018 seemed to have some repellent activity based on aphid distributions after treating plants. When applied along with P. neoaphidis conidia, M96-018 but not Surround WP caused higher percentage of infection mortality of pea aphids by P. neoaphidis than occurred on controls treated only with P. neoaphidis conidia. P. neoaphidis conidia deposited on glass slides coated with M96-018, produced more germ tubes and secondary conidia than those deposited on untreated glass slides or slides treated with Surround WP. This result suggests that greater infection of pea aphids on plants treated with M96-018 is in part a result of a direct enhancement of fungal germination by the particle film.

Irradiation studies were conducted with three sweet potato, Ipomoea batatas (L.) Lam., pests to determine an effective dose for quarantine control. Dose–response tests indicated that the most radiotolerant stage occurring in roots was the pupa of sweetpotato vine borer, Omphisa anastomosalis (Guenee), and the adult of West Indian sweetpotato weevil, Euscepes postfasciatus (Fairmaire), and sweetpotato weevil, Cylas formicarius elegantulus (Summers). In large-scale confirmatory tests, irradiation of 60,000 C. formicarius elegantulus adults, 62,323 E. postfasciatus adults, and 30,282 O. anastomosalis pupae at a dose of 150 Gy resulted in no production of F₁ adults, demonstrating that this dose is sufficient to provide quarantine security.

Atmospheric pressure plasma discharge (APPD) has been applied to a number of industrial applications, including the bacterial sterilization of medical equipment of bacteria. APPD may also have applications in insect control. A positive correlation was found between exposure time to APPD and mortality of western flower thrips, Frankliniella occidentalis (Pergande); tobacco thrips, Frankliniella fusca (Hinds); Asian tiger mosquito, Aedes albopictus (Skuse); twospotted spider mite, Tetranychus urticae Koch; and German cockroach, Blattella germanica (L.), with the level of mortality also increasing with time after treatment. Cockroaches exposed to APPD for 60, 90, 120, and 180 s lost on average 7.5 ± 0.8, 8.1 ± 0.6, 8.7 ± 0.4, and 10.1 ± 1.1 (±1 SEM) mg of water weight, respectively, which was an increase over that of the controls. The metabolic rate of cockroaches exposed to plasma for 180 s increased from 0.79 ± 0.03 to 1.07 ± 0.04 ml of oxygen consumed mg-cockroach⁻¹ h⁻¹ at standard temperature and pressure. The level of cuticular hydrocarbons identified by electron impact gas chromatography-mass spectrometry were not significantly affected by plasma exposure in the green peach aphid, Myzus persicae (Sulzer), German cockroach, and citrus mealybug, Planococcus citri (Risso), except for a reduction in n-tritriacontane in the latter. However, changes in the behavior of cockroaches after plasma exposure, including the loss of photo-, vibro-, and thigmotropic responses, inability to right themselves, and hyperexcitatory symptoms, suggest that the site of action of APPD in insects is the nervous and/or neuromuscular system.

The cerambycid Dectes texanus texanus LeConte that infests soybean, Glycine max (L.) Merr., is thought to be the same Dectes that damages sunflower, Helianthus annuus L. However, morphometric characteristics and mating compatibility between individuals from soybean and sunflower fields have not been assessed. Eight hundred eighty stalks of soybean and sunflower residues infested with Dectes were collected from Texas and Kansas. Outside stalk diameter of sunflower (22.6 mm) was 3.2 times greater than that of soybean. Diameters of tunnels by Dectes in sunflower and soybean were 7.0 and 3.4 mm, respectively. Widths of head capsules and pronotums were ≈1.3 times greater for Dectes larvae from sunflower than soybean. Larval, pupal, and adult Dectes from sunflower were ≈2.5 times heavier and 1.3 times longer than from soybean. Adults reared from residues of soybean and sunflower were paired to evaluate mating compatibility. Although individuals collected and reared from different crop residues differed significantly in size, percentage of mating success by Dectes from the two crops (26.2%) did not differ significantly from that by adults from the same kind of crop (34.9%). Results indicated that Dectes that infest soybean and sunflower are the same species and reconfirmed that farmers should not plant soybean and sunflower in rotation or in adjacent fields.

Management for twospotted spider mite, Tetranychus urticae Koch, populations in peanut, Arachis hypogaea L., relies on acaricides. The outcomes of acaricide applications are most predictable when complete information on their toxicity and specificity is available. Specifically, the degrees to which acaricides impact different stages of T. urticae and natural enemies combined determine the overall efficacy of an acaricide application. The objectives of this study were to determine stage-specific direct and residual efficacies of three acaricides (fenpropathrin, etoxazole, and propargite) against T. urticae, and the direct and residual toxicity of the acaricides to Orius insidiosus (Say) adults. Direct toxicity of acaricides to T. urticae was measured on peanut cuttings. All acaricide treatments caused significant mortality to a mixed stage population of T. urticae, and mortality did not differ among the acaricides 7 d after treatment. When toxicity to eggs was tested, the proportion of eggs that hatched for all acaricide treatments was significantly lower than the control, with etoxazole and propargite causing 100% mortality. Exposure to acaricide residues caused <30% mortality of T. urticae adults 1 and 2 d after treatment and was not significantly different from the control. Fenpropathrin and propargite caused 100% mortality and etoxazole caused >50% mortality of O. insidious adults after direct exposure to the acaricides. Residual toxicity of acaricides to O. insidiosus adults varied but remained toxic to O. insidiosus longer than to T. urticae. Fenpropathrin had the longest residual effect on O. insidiosus adults, causing >95% mortality after 14 d; etoxazole and propargite caused <30% mortality after 14 d.

The soybean aphid, Aphis glycines Matsumura, is a newly invasive species of aphid in North America. Previous studies disagree as to whether soybean, Glycine max (L.) Merr., plant stage has an impact on aphid intrinsic rate of increase. Therefore, the growth rate of soybean aphids on soybean plants of different stages was examined at two different scales in the field. A planting date experiment was used to measure the population growth of soybean aphids on plants of different stages. Clip-cages were used to measure life history characteristics of individual aphids on plants of different stages. No differences were found in the population growth or dynamics of soybean aphids in the planting date experiment. The life history characteristics of individual aphids also showed no significant difference when feeding on different growth stages of soybean plants. The impact of these findings on soybean aphid management is discussed and the possible reasons why the results differ from previous estimates of the aphid growth–plant stage relationship are considered.

We characterized the level of risk of boll weevil, Anthonomus grandis grandis Boheman, reintroduction to an eradication zone posed by dispersal from cotton modules during and after transport to the gin. Mark–release-recapture experiments in August and September in Texas indicated that most weevils disperse rapidly from the module surface, temperature permitting, unless confined under a module tarp, where most died. Nevertheless, 1–5% of released weevils were recovered alive after 24 h on the side and top surfaces of modules, representing potential dispersants. Mortality of boll weevils caged on the top surface of a module was 95–100% after 1–4 d when maximum air temperatures were ≥33°C and 72–100% when minimum temperatures were −7°C or lower, but a few survived even after experiencing a minimum daily temperature of −12°C. Under warm (daily maximum temperatures ≥25°C) and cold (daily minimum temperatures ≤0°C) weather conditions, survival was higher under the tarp than on the open surface of the module (20 versus 7% and 42 versus 26%, respectively), but mortality was 100% in both locations when temperatures reached 34°C. Our results indicate that although the threat to an eradication zone posed by boll weevil dispersal from an infested module is very low under most environmental conditions, it is probably greatest when 1) a module is constructed and transported from an infested zone during weather too cool for flight, followed by warm weather favorable for flight at the gin yard; or 2) such a module is transported immediately after construction in moderate-to-warm weather.

After greenhouse and outdoor microplot experiments, a critical density of two third instars per microplot for third instars of European chafer, Rhizotrogus (Amphimallon) majalis (Razoumowsky), in corn, Zea mays L., was derived. On average, the number of missing or damaged plants increased ≈8% from zero to two larvae per 900 cm². Furthermore, 23 fields in 2 yr were sampled for larvae along transects by using a golf cup cutter as the sampling tool and the critical density of 0.2 larva per sampling unit as the critical density. The sampling unit was one golf cup cutter with a diameter of 10.8 cm or 91.4 cm² (10 sampling units ≈ 900 cm² ≈ 1 foot²). Fieldwide means and variation were modeled to Taylor’s power law, a = 1.42 and b = 1.47, and 20 of 23 fields fit the negative binomial probability distribution. Wald’s formula for a sequential sampling plan was most accurate and least time-consuming, according to the operating characteristic and the average sample number function, relative to Iwao’s and converging lines formulae. Percentage of sand, topography, soil bulk density, and proximity to trees were measured as potential predictors of areas with high larval density. Percentage of sand and soil bulk density were significant predictors, and topography and proximity to trees were not significant predictors. Field areas where the percentage of sand is high and the soil bulk density is low to moderate or where the percentage of sand is moderate and the soil bulk density is low should be chosen as sampling locations.

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is one of the most serious nonnative invasive forest insects discovered in North America in recent years. A. glabripennis is regulated by federal quarantines in the United States and Canada and is the subject of eradication programs that involve locating, cutting, and chipping all infested trees. Other control methods are needed to aid in eradication and to form an integrated management program in the event eradication fails. We conducted laboratory bioassays to determine the toxicity of two systemic insecticides, azadirachtin and imidacloprid, for potential control of A. glabripennis and the cottonwood borer, Plectrodera scalator (F.) (Coleoptera: Cerambycidae), a closely related native cerambycid. Larvae of both cerambycid species were fed artificial diet with dilutions of azadirachtin or imidacloprid for 14 wk. Both insecticides exhibited strong antifeedant effects and some toxicity against A. glabripennis and P. scalator larvae. For A. glabripennis, the highest larval mortality at the end of the bioassay was 60% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (1.6 ppm). For P. scalator, the highest larval mortality at the end of the bioassay was 100% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (160 ppm). At 14 wk, the LC₅₀ values for P. scalator were 1.58 and 1.78 ppm for azadirachtin and imidacloprid, respectively. Larvae of both species gained weight when fed diet treated with formulation blanks (inert ingredients) or the water control but lost weight when fed diet treated with increasing concentrations of either azadirachtin or imidacloprid. In a separate experiment, A. glabripennis adults were fed maple twigs treated with high and low concentrations of imidacloprid. A. glabripennis adult mortality reached 100% after 13 d on twigs treated with 150 ppm imidacloprid and after 20 d on twigs treated with 15 ppm imidacloprid. There was no visible feeding by A. glabripennis adults on twigs treated at the higher imidacloprid rate, and feeding was significantly reduced for adults placed on twigs treated at the low imidacloprid rate compared with adults on untreated twigs. In summary, imidacloprid and azadirachtin had both antifeedant and toxic effects against A. glabripennis and P. scalator and have potential for use in management programs. Based on our results, the delivery of high and sustained insecticide concentrations will be needed to overcome the antifeedant effects and lengthy lethal time for both larvae and adults exposed to these insecticides.

We evaluated the efficacy of the systemic insecticides dinotefuran, emamectin benzoate, fipronil, and imidacloprid for preventing attacks and brood production of southern pine engraver beetles (Coleoptera: Curculionidae: Scolytinae) and wood borers (Coleoptera: Cerambycidae) on standing, stressed trees and bolt sections of loblolly pine, Pinus taeda L., in eastern Texas. Emamectin benzoate significantly reduced the colonization success of engraver beetles and associated wood borers in both stressed trees and pine bolt sections. Fipronil was nearly as effective as emamectin benzoate in reducing insect colonization of bolts 3 and 5 mo after injection but only moderately effective 1 mo after injection. Fipronil also significantly reduced bark beetle-caused mortality of stressed trees. Imidacloprid and dinotefuran were ineffective in preventing bark beetle and wood borer colonization of bolts or standing, stressed trees. The injected formulation of emamectin benzoate was found to cause long vertical lesions in the sapwood–phloem interface at each injection point.

Biorational foliar sprays and a novel application method of soaking transplants in imidacloprid were evaluated for control of adult and larval cottonwood leaf beetle, Chrysomela scripta F., on hybrid poplar, with emphasis on conservation of coccinellid predators. Foliar sprays of four biorational insecticides killed adult and larval C. scripta: Bacillus thuringiensis (B.t.) variety tenebrionis (Novodor), B.t. variety kurstaki (Raven), spinosad (Conserve SC), and azadirachtin (Azatin XL) (larvae only) but did not kill two species of coccinellids, Hippodamia convergens Guérin-Meneville and Harmonia axyridis (Pallas). Only imidacloprid (Admire 2) and carbaryl (Sevin XLR Plus) killed two species of coccinellids and adult and larval C. scripta. We evaluated a novel stick soak method for systemically applying imidacloprid by soaking poplar sticks in Admire 2 solutions of 3 and 6 ml/liter for 48 h before planting. The imidacloprid in the sticks was translocated to the leaves and reduced survivorship of adult and larval C. scripta for 10 mo without any symptoms of phytotoxicity. The novel stick soak method did not kill two species of coccinellids when foraging on leaves.

Regularly applied sprays of a particle film, Surround WP, greatly enhanced the growth of citrus trees on a poorly drained Winder soil at Fort Pierce, FL. After 3 yr of applications every 3 or 4 wk, Surround-treated trees had at least 5 times the mass, 6 times the canopy volume, and ≈4 times the cross-sectional area of the tree stems at the graft union compared with untreated trees. The larger Surround-treated trees attracted a higher number of adult weevil Diaprepes abbreviatus (L.) and to a lesser extent citrus root weevil, Pachnaeus litus (Germar), per tree, but there was an equivalent number of egg masses per tree compared with the control trees. The number of egg masses per female weevil oviposited on Surround-treated trees was significantly less than either the control trees or trees treated biannually with an entomopathogenic nematode, BioVector. The number of larvae per tree recovered from the roots of excavated trees was greater from trees treated with Surround once every 3 wk compared with control trees. The data suggest that Surround particle film greatly enhanced the growth of citrus trees grown in a poorly drained soil. The reduction in oviposition by D. abbreviatus was insufficient to significantly reduce the number of root weevil larvae per tree feeding on the roots. However, the more vigorous trees resulting from Surround applications may be more resistant or tolerant to root weevil feeding.

The midge Contarinia nasturtii (Keiffer), a serious gall-forming insect pest of cruciferous plants in Europe and southwestern Asia, was first reported in the United States in summer 2004. It had not been recorded in North America until its discovery in Ontario, Canada, in 2000. Efficacy of 20 insecticides belonging to 12 different classes was evaluated by using a foliar spray, soil drench, or seed treatment method. The broccoli cultivar ‘Packman’ was used in all tests at the suitable stage of four to five true leaves. Results indicated that foliar sprays of λ-cyhalothrin, acephate, acetamiprid, chlorpyrifos, and methomyl reduced C. nasturtii larval populations by 96.7–100%. Except for acetamiprid, the other four insecticides also were effective against adults and provided 100% mortality after 24 h. When applied by drench, acetamiprid, imidacloprid, and thiamethoxam provided 100% control of C. nasturtii larvae, and the duration of efficacy lasted at least 7 wk. When applied as seed treatment, clothianidin and thiamethoxam provided 100% control of larvae and did not significantly affect seed germination. Imidacloprid also provided 100% control but the percentage of germination after treatment was only 62% (96.9% in check). These results indicate that several insecticides may significantly reduce midge populations. The nicotinoid class of insecticides, which has strong systemic activity, is likely to be the first choice. It is necessary to explore and develop other control methods such as cultural control and host resistance to develop an effective integrated pest management system.

To identify subterranean termite species, we designed a pair of common primers that amplified 381-bp fragments from cDNAs encoding the endo-β-1,4-glucanases (EGases) of Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe). cDNAs from C. formosanus and R. speratus, and genomic DNA from R. speratus, were amplified by polymerase chain reaction (PCR) by using this primer pair and then cloned and sequenced. Sequences amplified from C. formosanus cDNA displayed 97–99% identity to cDNA encoding the EGase of C. formosanus (CfEG), and 92–94% identity to cDNA encoding the EGase of R. speratus (RsEG). By contrast, cDNA from R. speratus displayed 99–100% identity to RsEG cDNA and 93–94% identity to CfEG cDNA. CfEG and RsEG cDNAs can therefore be used as markers for the identification of these termite species. This is the first report of the successful identification of termite species by using cDNA and genomic DNA sequences of termite origin.

Monomorium orientale Mayr (Hymenoptera: Formicidae) is a common structure- and food-infesting ant in Asia. There is only limited information on the biology and habits of this species, especially on the preferred foods and distribution of nutrients in colonies. We conducted a laboratory study on the distribution of carbohydrates, proteins, and lipids, which were represented by respective food sources, in M. orientale colonies. Three colony conditions were applied: normal, with a balanced ratio of castes, queenless (only workers and brood), and broodless (only queens and workers). Food sources were stained to track the flow of the respective food in the colonies. Results revealed that carbohydrates had rapid distribution, with >60% of the colony indicated in 24 h, in all colony conditions. Queens in all colonies did not feed on protein. Protein showed a more delayed distribution in the brood in all colony conditions; <10% of the colony fed on protein by 24 h. Only queens in broodless colonies showed signs of feeding on lipid, with <10% indicated in 24 h. Workers in all colonies fed on lipid as soon as it was delivered, whereas the brood only began to reveal feeding response after 24 h.

[¹⁴C]Noviflumuron uptake, clearance, rate of excretion, and transfer from treated to untreated termite workers were evaluated at 15, 19, 23, and 27°C. Feeding units were constructed from plastic containers provisioned with washed sand, distilled water, [¹⁴C]noviflumuron-treated feeding discs (0.05 or 0.5% [AI]), and Reticulitermes flavipes (Kollar) workers. Feeding units were held in environmental growth chambers preset at 15, 19, 23, and 27°C. The amount of [¹⁴C]noviflumuron present within R. flavipes was measured by scintillation counting and subsequently quantified. Uptake of noviflumuron by R. flavipes workers at 15°C was ≈2.8 times less than at 19 or 23°C and ≈4.4 times less than at 27°C. The highest uptake of [¹⁴C]noviflumuron occurred at 27°C and 144 h. Most transfer of [¹⁴C]noviflumuron from treated to untreated termite workers occurred between 19 and 27°C. [¹⁴C]Noviflumuron had a half-life in R. flavipes workers of ≈31–45 d, dependent on temperature. A higher amount of [¹⁴C]noviflumuron was lost through excretion at ≥19°C (≈15–22%) compared with 15°C (0.27%). Results indicated that increased uptake, transfer, and clearance of noviflumuron by R. flavipes occurred at warmer temperatures (19–27°C), and all of these processes were significantly lower at 15°C.

Homalodisca coagulata Say , adults from three locations in California were subjected to insecticide bioassays to establish baseline toxicity. Initially, two bioassay techniques, petri dish and leaf dip, were compared to determine the most useful method to establish baseline susceptibility data under laboratory and greenhouse conditions. Comparative dose-response data were determined by both techniques to endosulfan, dimethoate, cyfluthrin, and acetamiprid. Toxic values were similar to some insecticides with both techniques but not for all insecticides, revealing susceptibility differences among the three populations of H. coagulata. In subsequent tests, the petri dish technique was selected to establish baseline susceptibility data to various contact insecticides. A systemic uptake bioassay was adapted to estimate dose-mortality responses to a systemic insecticide, imidacloprid. A 2-yr comparison of toxicological responses showed all three populations of H. coagulata to be highly susceptible to 10 insecticides, including chlorpyrifos, dimethoate, endosulfan, bifenthrin, cyfluthrin, esfenvalerate, fenpropathrin, acetamiprid, imidacloprid, and thiamethoxam. In general, two pyrethroids, bifenthrin and esfenvalerate, were the most toxic compounds, followed by two neonicotinoids, acetamiprid and imidacloprid. The LC₅₀ values for all insecticides tested were lower than concentrations used as recommended field rates. Baseline data varied for the three geographically distinct H. coagulata populations with the petri dish technique. Adult H. coagulata collected from San Bernardino County were significantly more susceptible to select pyrethroids compared with adults from Riverside or Kern counties. Adults from San Bernardino County also were more sensitive to two neonicotinoids, acetamiprid and imidacloprid. The highest LC₅₀ values were to endosulfan, which nonetheless proved highly toxic to H. coagulata from all three regions. In the majority of the tests, mortality increased over time resulting in increased susceptibility at 48 h compared with 24 h. These results indicate a wide selection of highly effective insecticides that could aid in managing H. coagulata populations in California.

The population dynamics of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in the Murrumbidgee Valley, Australia, has been characterized using five highly variable microsatellite loci. In the 2001–2002 growing season, there were very high levels of migration into the Murrumbidgee Valley with no detectable genetic structuring, consistent with previous analyses on a national scale. By contrast, there was significant genetic structuring over the 2002–2003 growing season, with three distinct genetic types detected. The first type corresponded to the first two generations and was derived from local individuals emerging from diapause and their progeny. The second genetic type corresponded to generation 3 and resulted from substantial immigration into the region. There was another genetic shift in generation 4, which accounts for the third genetic type of the season. This genetic shift occurred despite low levels of immigration. During the third generation of the 2002–2003 growing season, different population dynamics was characterized for H. armigera on maize, Zea mays L., and cotton Gossipium hirsutum L. Populations on cotton tended to cycle independently with very little immigration from outside the region or from maize within the region. Maize acted as a major sink for immigrants from cotton and from outside the region. If resistance were to develop on cotton under these circumstances, susceptible individuals from maize or from other regions would not dilute this resistance. In addition, resistance is likely to be transferred to maize and be perpetuated until diapause, from where it may reemerge next season. If low levels of immigration were to occur on transgenic cotton, this may undermine the effectiveness of refugia, especially noncotton refugia.

Susceptibilities of bollworm, Helicoverpa zea (Boddie) and tobacco budworm, Heliothis virescens (F.) to Cry1Ac were measured via a diet-incorporated assay with MPV II at the University of Arkansas during 2002–2004. Lethal concentration–mortality (LC₅₀) estimates of five laboratory, seven laboratory-cross, and 10 field populations of H. virescens varied 12-fold. Pooled susceptibilities of H. virescens across all laboratory and field populations varied five-fold. The LC₅₀ estimates for H. virescens were higher than those reported by previous research before the introduction of transgenic crops. However, the ratio of susceptibility of laboratory and field populations was similar, suggesting no change in overall species susceptibility. Individual LC₅₀ estimates of five laboratory, nine laboratory-cross, and 57 field populations of H. zea varied over 130-fold. Pooled susceptibilities across laboratory and field populations varied widely. Among the field populations, colonies from non-Bacillus thuringiensis (Bt) crops were generally more susceptible than those from Bt crops. Across the Bt crops expressing Cry protein, colonies from Bollgard (Monsanto Company) cotton had lower susceptibility to Cry1Ac than those from Bt corn and those from non-Bt crops.

Six to nine populations of the diamondback moth, Plutella xylostella (L.), were collected annually from fields of crucifer vegetables in the United States and Mexico from 2001 to 2004 for baseline susceptibility tests and resistance monitoring to spinosad, indoxacarb, and emamectin benzoate. A discriminating concentration for resistance monitoring to indoxacarb and emamectin benzoate was determined based on baseline data in 2001 and was used in the diagnostic assay for each population in 2002–2004 together with a discriminating concentration for spinosad determined previously. Most populations were susceptible to all three insecticides, but a population from Hawaii in 2003 showed high levels of resistance to indoxacarb. Instances of resistance to spinosad occurred in Hawaii (2000), Georgia (2001), and California (2002) as a consequence of a few years of extensive applications in each region. The collaborative monitoring program between university and industry scientists we discuss in this article has provided useful information to both parties as well as growers who use the products. These studies provide a baseline for developing a more effective resistance management program for diamondback moth.

Commercially available air curtain units were used to create air barriers to prevent mosquitoes and house flies from entering a simulated aircraft doorway together with passengers. Two assemblies of simulated passenger bridge and aircraft were constructed, and airflow measurements were recorded to confirm airflow characteristics for several combinations of commercial units. Three mosquito species were selected for different host-seeking characteristics, and house flies were selected to represent a large, strong-flying insect. Batches of 20 or 200 insects of four species were released into the passenger bridge just before 25 persons passed through the assembly, then insects that entered the aircraft cabin were recovered. Results showed that horizontal plus vertical or vertical-mounted air curtain units with the airflow directed at a 45° angle into the passenger bridge excluded 95–99% of the mosquitoes and 95–100% of the house flies, respectively. Airflows were measured and estimated to be effective if the mean was >4 m/s in the critical area in the center of the converging airflows. The study validates the concept that air barriers can effectively prevent the passage of flying insects into an aircraft.

One field strain each of the European corn borer, Ostrinia nubilalis (Hübner); southwestern corn borer, Diatraea grandiosella Dyar; and sugarcane borer, Diatraea saccharalis (F.); were collected from cornfields in northeastern Louisiana. Susceptibilities of the field strain and a corresponding laboratory strain of the three borer species to Cry1Ab protein in DK69-70 Bacillus thuringiensis (Bt) corn hybrid were determined by exposing neonates to intact leaf tissues from whorl stage plants or by feeding neonates or third instars on a meridic diet treated with different concentrations of Cry1Ab protein extracted from Bt corn leaves. Mortality and growth of larvae were evaluated after 2 and 4 d posttreatment in the bioassays by using intact leaf tissues or after 7 d in the bioassays by using diet incorporating Cry1Ab protein. D. saccharalis was the least susceptible species to Cry1Ab protein among the three species, followed by D. grandiosella, whereas O. nubilalis was most susceptible. The 2-d mortality of D. saccharalis neonates on intact Bt leaf tissues was lower than that of O. nubilalis and D. grandiosella. All neonates of O. nubilalis were killed on the diet treated with Cry1Ab protein at 0.5 and 1 mg/kg. The mortality of D. grandiosella was >75% at 1 mg/kg, but it was <6% for D. saccharalis at 1 mg/kg. The LC₅₀ values of D. saccharalis were 3- and 11-fold higher than those of D. grandiosella and O. nubilalis, respectively. The LC₉₀ values of D. saccharalis were 8- and 32-fold higher than those of D. grandiosella and O. nubilalis, respectively. Larval growth of the three species on Cry1Ab-treated diet was inhibited, but the inhibition was greater for O. nubilalis and D. grandiosella than for D. saccharalis. The lower susceptibility of D. saccharalis to Cry1Ab protein suggests that it is necessary to verify if a high-dose Bt corn for O. nubilalis and D. grandiosella is also a high dose for D. saccharalis.

Chinch bugs are common pests of many agronomic and horticulturally important crops and turfgrasses. The extensive overlap of plant hosts and geographic distribution of Blissus leucopterus leucopterus (Say), Blissus leucopterus hirtus Montandon, Blissus insularis Barber, and Blissus occiduus Barber underscores the importance of identifying resistant germplasm. Cool- and warm-season turfgrasses and sorghum, Sorghum bicolor (L.) Moench, were evaluated for resistance to chinch bugs in the Blissus complex, and the presence of multiple resistance was documented. Greenhouse studies established that B. occiduus-resistant (‘Prestige’, formerly NE91-118) and -susceptible (‘378′) buffalograsses, , Buchloë dactyloides (Nuttall) Engelmann, were susceptible to all other chinch bug species. KS94 sorghum exhibited resistance to both B. occiduus and B. l. leucopterus, whereas B. insularis-resistant St. Augustinegrass, Stenotaphrum secundatum (Walter) Kuntze (‘Floratam’), was also resistant to B. occiduus. B. l. leucopterus-susceptible sorghum (‘Wheatland’) and B. insularis-susceptible St. Augustinegrasses (‘Raleigh’ and ‘Amerishade’) were highly resistant to B. occiduus. Endophyte-free and -enhanced fine fescues (Festuca spp.) were moderately to highly susceptible to B. l. hirtus but moderately to highly resistant to B. occiduus. The results of this research showed the buffalograsses evaluated, including B. occiduus-resistant Prestige, are moderately to highly susceptible to the three other chinch bug species. In contrast, B. occiduus did not cause considerable damage to any of the turfgrasses or sorghum cultivars evaluated, other than buffalograss, irrespective of whether or not they are resistant to another chinch bug species. This information is increasingly important as various grasses become adapted to regions that may possess chinch bug species other than those with which they are typically associated. These levels of Blissus resistance should be included when selecting resistant germplasm for managing Blissus species pests.

Chinch bugs are common pests of many agronomic and horticulturally important crops and turfgrasses. Previous research has indicated that some grasses exhibit resistance to multiple chinch bug species, whereas others are resistant to only one species. The objectives of this research were to document differences in the probing frequencies and locations among Blissus species as well as differences in mouthpart morphology as a first step in understanding the differential responses of grasses to chinch bug feeding. Scanning electron microscopy detected differences in the total lengths of proboscises as well as individual mouthpart segments among the four species studied. Blissus occiduus Barber probed significantly more often on buffalograss, Buchloë dactyloides (Nuttall) Engelmann, than any other plant material. Probing locations of B. occiduus and Blissus leucopterus leucopterus (Say) were similar on both B. occiduus-resistant and susceptible buffalograsses and KS94 sorghum, Sorghum bicolor (L.) Moench (B. occiduus-resistant, B. l. leucopterus-resistant). However, on ‘Wheatland’ sorghum (B. occiduus-resistant, B. l. leucopterus-susceptible), stylet tracts of B. l. leucopterus most often terminated in the bundle sheath cells, whereas those of B. occiduus generally terminated in the vascular tissues.

The impact of Blissus occiduus Barber feeding on resistant (‘Prestige’) and susceptible (‘378’) buffalograsses, Buchloë dactyloides (Nuttall) Engelmann, was evaluated through measurement of carbon exchange rate, light and carbon assimilation (A-C_i) curves, chlorophyll a fluorescence, and nonstructural carbohydrates. No significant differences in carbon exchange rates were observed between infested and control plants for 378 at 5 and 10 d after infestation; however, at 20 d after chinch bug introduction, significant differences in carbon exchange rates between infested and control 378 plants were detected. Carbon exchange rates were similar between infested and control Prestige plants at 5, 10, and 20 d after infestation, suggesting that resistant plants can allocate energy for recovery from chinch bug injury. Significant differences in the photochemical efficiency of photosystem II (PSII) and the apparent photosynthetic electron transport ratio were observed between infested and control 378 plants, whereas, no significant differences in the photochemical efficiency of PSII and the electron transport ratio were detected between control and infested Prestige plants. Blissus occiduus-infested 378 and Prestige plants consistently had similar or higher levels of nonstructural carbohydrates compared with their respective control plants. These data suggest that both resistant and susceptible buffalograsses increase levels of nonstructural carbohydrates in response to B. occiduus feeding. This research also suggests compensatory photosynthesis takes place in Prestige but not in 378.

Laboratory bioassays were conducted to evaluate the effect of the diatomaceous earth (DE) formulation SilicoSec (Biofa GmbH, Münsingen, Germany), against two stored-product mite species, Tyrophagus putrescentiae (Shrank) and the predator Cheyletus malaccensis Oudemans. For this purpose, DE was applied in wheat, oat, rye, and maize, at the dose rates 0, 0.5, 1, and 2 g/kg grain. The mortality of the exposed mites was assessed after 24 h, 48 h, 7 d, and 14 d of exposure in the treated substrate. After this interval, the treated grains were checked for oviposition or progeny. The tests were conducted at 80% RH and at two temperatures, 20 and 25°C. Generally, for both species, mortality was higher at 25°C than at 20°C. For T. putrescentiae, at both temperatures, the mortality in grains treated with the highest DE rate was 100% after only 24 h of exposure, with the exception of maize at 20°C, where mortality was 91.7%. The mortality of C. malaccensis after 24 h of exposure to the treated grains, in the absence of prey, did not exceed 29% at any of the temperature–grain–dose combinations, whereas no mites were dead in rye and maize treated with 0.5 and 1 g of DE. Even after 14 d of exposure at the highest DE rate, mite mortality did not reach 100%. The presence of T. putrescentiae individuals as prey in the treated substrate enhanced C. malaccensis survival. Hence, after 14 d of exposure, the mortality of C. malaccensis, in wheat, oat, rye, and maize treated with the highest DE rate was 51.7, 59.7, 70, and 36.9, respectively. No progeny production was recorded in the treated substrate for T. putrescentiae; in contrast, oviposition and F₁ progeny were recorded for C. malaccensis. Our results suggest that the use of C. malaccensis with low doses of DE may be an appealing integrated pest management (IPM) approach against T. putrescentiae, and probably against other stored-grain mite species.

Effects of temperature, adult feeding, and host instar on life table parameters of Venturia canescens Gravenhorst (Hymenoptera: Ichneumonidae) parasitizing larvae of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were studied in the laboratory. Experimental adults lived under various regimes of temperature (15, 20, 25, and 30°C), food supply (with or without access to honey), and host instar (second, third, fourth, and fifth). Temperature increase resulted in higher values of the intrinsic rate of natural increase (r_m), the net reproductive rate (R_o), the finite capacity of increase (λ), and the gross reproductive rate (GRR), whereas it was followed by decrease of the mean generation time (G) and the doubling time (DT) values. Feeding on honey caused remarkable increase of r_m, R_o, and GRR, whereas r_m and λ reached their maximum when full-grown hosts (fifth instar) were parasitized. This is the first time life table parameters of V. canescens have been studied. The findings of the current study are discussed on the basis of improving V. canescens performance as a biological agent against moth pests of stored products.

A geophone system was used to monitor activity of subterranean termites and ants in a desert environment with low vibration noise. Examples of geophone signals were recorded from a colony of Rhytidoponera taurus (Forel), a colony of Camponotus denticulatus Kirby, and a termite colony (undetermined Drepanotermes sp.) under attack by ants from a nearby C. denticulatus colony. The geophone recordings were compared with signals recorded from accelerometers in a citrus grove containing Solenopsis invicta Buren workers. Because of their small size, all of these insects produce relatively weak sounds. Several different types of insect-generated sounds were identified in the geophone recordings, including high-frequency ticks produced by R. taurus and C. denticulatus, and patterned bursts of head bangs produced by Drepanotermes. The S. invicta produced bursts of ticks with three different stridulation frequencies, possibly produced by three different-sized workers. Overall, both systems performed well in enabling identification of high-frequency or patterned pulses. The geophone was more sensitive than the accelerometer to low-frequency signals, but low-frequency insect sound pulses are more difficult to distinguish from background noises than high-frequency pulses. The low cost of multiple-geophone systems may facilitate development of future applications for wide-area subterranean insect monitoring in quiet environments.