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Vinegar flies (Diptera: Drosophilidae) are well known to be associated with yeasts, which provide important nutrients and emit attractive semiochemicals. Drosophila suzukii (Matsumura) has become a major pest of berries and cherries around the world, requiring intensive management to maintain fruit quality. Although insecticides remain a dominant control approach, disruption of fly–yeast–host interactions remains a promising avenue for reducing the economic impact of this pest. We conducted field and laboratory experiments to explore whether a crop sterilant (peroxyacetic acid and hydrogen peroxide) developed for disease control can affect D. suzukii. In 2 yr of field tests in highbush blueberries, we found significantly lower infestation by D. suzukii in plots treated with the crop sterilant, both alone and in a rotation program with zeta-cypermethrin. When shoots from treated plots were tested in no-choice bioassays, crop sterilant treatments did not affect adult mortality or oviposition, but they reduced infestation. To explore the mechanisms in the laboratory, we found that the crop sterilant did not affect adult mortality, nor oviposition on treated fruit under no-choice settings, but adult flies settled and oviposited less on treated fruit in choice settings. When the crop sterilant was applied to colonies of Hanseniaspora uvarum (Niehaus) (Saccharomycetales: Saccharomycodaceae) and Issatchenkia terricola (Van der Walt) (Saccharomycetales: Saccharomycetacea) yeasts that are attractive and provide nutrition to D. suzukii , there was a dose-dependent inhibition of their growth. We highlight the potential for microbial management as a component of integrated pest management programs and prioritize research needs to incorporate this approach into control programs. [ABSTRACT FROM AUTHOR]

Two isolates of Beauveria bassiana (Balsamo) Vuillemin, including the commercial strain GHA and the Mississippi Delta native NI8 strain, and two emulsifiers, Tween-80 and a starch-based sprayable bioplastic, were evaluated in the laboratory and field for pathogenicity and infectivity against the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae). The effect on fruit damage based on within-season cotton plant mapping was also examined. The highest mortality 10 d after treatment was found with insects caged on cotton terminals sprayed with NI8 + Tween-80, followed by those exposed to NI8 + bioplastic. Similarly, sporulation was shown to be higher in NI8 + Tween-80 than in other treatments. Plots sprayed with B. bassiana showed at least a twofold decrease in tarnished plant bug adults 3 d after treatment compared with control plots. Little to no variation was observed in tarnished plant bug nymph populations between treated and untreated plots. Within-season plant mapping provided clear evidence of damage to cotton caused by tarnished plant bug. The highest percentage retention of all first position fruiting structures was observed in plots treated with NI8 + Tween-80 (93.41 ± 1.51) followed by NI8 + bioplastic (90.25 ± 1.52). Both treatments were significantly different when compared with GHA + Tween-80 (82.89 ± 2.26) and GHA + bioplastic (70.48 ± 3.19), and both GHA formulations did not differ from the control (63.61 ± 2.96). Overall, these results indicated that B. bassiana application resulted in >50% mortality of tarnished plant bug regardless of the isolates by direct spray or by contact. However, the superior performance of the Mississippi Delta native NI8 strain was observed in all treatment applications and evaluation times. [ABSTRACT FROM AUTHOR]

Autodissemination and foliar sprays of PFR-97 (Certis Inc. Columbia, MD) microbial insecticide, a blastospore formulation of Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), were evaluated for control of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), on residential citrus. Seasonal trials on dooryard trees in South Texas evaluated: 1) pathogenicity of I. fumosorosea (Ifr) spores on autodisseminators (dispensers) deployed up to 3 wk on grapefruit trees; 2) psyllid control on several citrus species by dispensers and sprays; 3) infection range of the dispenser. Decline in spore pathogenicity over time was similar among dispensers during fall, winter, or spring and decreased by 30% after 1 d, 59% after 7 d, 81% after 14 d, and 100% after 21 d. Dispensers or sprays were equally effective for psyllid control on heavily infested lime trees from fall to spring and reduced mean reproduction (cumulative eggs) by 90% and mean attack intensity (cumulative psyllid-days) of adults by 76% and nymphs by 82%. Dispensers or sprays were also equally effective for psyllid control on lightly infested lime trees from spring to mid-summer and on orange or grapefruit trees from fall to winter. Very light infestations on grapefruit trees from spring to mid-summer were not significantly reduced by dispensers or sprays. Psyllid control was not improved by combining dispensers and sprays. Adult psyllids infected by Ifr were recovered in trees located 3–4 m away from trees with dispensers but not at greater distances. PFR-97 dispensers could be a treatment option for D. citri in settings where chemical control is problematic. [ABSTRACT FROM AUTHOR]

The insect pest complex in U.S. pulse crops is almost an “orphan” in terms of developed microbial control agents that the grower can use. There are almost no registered microbial pest control agents (MPCA) for the different pulse pests. In some cases, a microbial is registered for use against specific pests, e.g., grasshoppers, but not in pulse crops. In most cases, best-use practices for any of the microbials are not defined for pulses. Thus, there are ample research opportunities in this area. This review discusses what is actually or potentially available to manage each of the pulse crop pests and identifies research needs to make microbial control measures a reality. [ABSTRACT FROM AUTHOR]

An isolate of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) was tested for its ability to reduce survival and reproduction of spruce beetle, Dendroctonus rufipennis (Kirby) (Coleoptera: Scolytinae), under laboratory and field conditions. Conidial suspension applied directly to adults or to filter papers that adults contacted had a median survival time of 3–4 d in laboratory assays and beetles died more rapidly when exposed to conidial suspension than when treated with surfactant solution only. In the field, conidial suspension was applied to the surface of felled and pheromone-baited Engelmann spruce (Picea engelmannii) trees using a backpack sprayer. Mortality of colonizing parent beetles (F0), reproduction (abundance of F1 offspring in logs), and emergence of F1 beetles from logs was compared between treated and nontreated logs. Application of spore suspension increased mortality of F0 adults by 36% on average. Total F1 reproduction was reduced by 17% and emergence from logs was reduced by 13% in treated logs, but considerable variability in reproduction and emergence was observed. Viable spores were re-isolated from treated logs up to 90 d after application, indicating that spores are capable of long-term persistence on the tree bole microhabitat. Subsequent in vitro tests revealed that temperatures below 15°C and exposure to spruce monoterpenes likely limit performance of B. bassiana under field conditions, but exposure to low-intensity light or interactions with spruce beetle symbiotic fungi were not strongly inhibitory. It is concluded that matching environmental tolerances of biocontrol fungi to field conditions can likely improve their usefulness for control of spruce beetle in windthrown trees. [ABSTRACT FROM AUTHOR]

Rice water weevil (Lissorhoptrus oryzophilus Kushel) is the most damaging insect pest of rice in the United States. Larval feeding on the roots stunt growth and reduce yield. Current pest management against the weevil in California relies heavily on pyrethroids that can be damaging to aquatic food webs. Examination of an environmentally friendly alternative biopesticide based on Bacillus thuringiensis spp. galleriae chemistry against rice water weevil larvae showed moderate levels of activity in pilot studies. We further examined the performance of different formulations of Bt.galleriae against the leading insecticide used in California rice, λ-cyhalothrin. The granular formulation performed as well as the λ-cyhalothrin in use in California in some of our greenhouse and field studies. This is the first reported use of B. thuringiensis spp. galleriae against rice water weevil. [ABSTRACT FROM PUBLISHER]

The brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae), is a destructive invasive pest and has become one of the most economically-important rice pests in China. Effective control measures are desperately needed. Entomopathogenic fungi, such as Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Clavicipitaceae) and B. brongniartii (Saccardo), have shown great potential for the management of some sucking pest species. In this study, to explore alternative strategies for sustainable control of the sucking pest population, nine isolates of Beauveria from different pests were bioassayed under the concentrated standard spray of 1000 conidia/mm2 in laboratory. The cumulative mortalities of adults ranged from 17.2 to 79.1% 10 days after inoculation. The virulence among all tested isolates exhibited significant differences (at p = 0.05). The highest virulent isolate was Bb09, which killed 79.1% of the treated insects and had a median lethal time of 5.5 days. Its median lethal concentration values were estimated as 134 conidia/mm2 on day 10. The chitinase activities of nine isolates were also assayed. The results showed that the chitinase activity (18.7 U/mg) of isolate Bbr09 was the highest among all tested isolates. The biological characteristics of these strains, including growth rate, sporulation, and germination rate, were further investigated. The results showed that strain Bbr09 exhibited the best biological characteristics with relatively higher hyphal growth rate, the highest spore production, and the fastest spore germination. The isolate of Bbr09 had strong pathogenicity and exhibited great potential for sustainable control of N. lugens. [ABSTRACT FROM AUTHOR]

The susceptibility of preimaginal and adult olive fruit fly, Baetrocera oleae (Gmelin) (Diptera: Tephritidae), to a strain of the mitosporic aseomycete Metarl2izimn brmmeum (Peteh) (Hypocreales: Clavicipitaceae) and the insecticidal activity of its crude extract to olive fruit fly adults were investigated. Strain EAMb 09/01-Su caused 60% mortality to B. oleae adults, with average survival time (AST) of 8.8 d. In soil treatments against pupariating third-instar larvae, preimaginal B. oleae mortality reached 82.3%, whereas preimaginal mortality targeting puparia was 33.3%. The crude extract of EAMb 09/01-Su strain caused 80.0% adult mortality when administered per os, with AST of 27.7 h. The crude extract was demonstrated to be quite thermostable and photoresistant. These results indicate that M. brunneum EAMb 09/01-Su strain mad its crude extract show potential to be used in an integrated pest management olive fruit fly management strategy targeting both adults and preimaginals. [ABSTRACT FROM AUTHOR]

We screened 85 isolates of Bacillus thuringiensi$ (Berliner), making up 57 different subspecies, and two isolates of Bacillus sphaericus (Meyer and Neide) for activity against immature horn flies, Haematobia irritans (L.), and stable flies, Stomoxys calcitrans (L.). The majority of B. thuringiensis and the B. sphaericus isolates had little or no activity against horn fly and stable fly. Approximately 87% of the isolates caused <50% mortality of horn fly larvae and 64% caused <25% mortality. For stable fly, 95% of the isolates caused <50% mortality, and 93% caused <25% mortality. Five isolates were highly toxic to horn fly and stable fly immatures. These isolates were B. t. tolworthi 4L3, B. t. darmstadiensis 4M1, B. t. thompsoni 4O1, B. t. thuringiensis HD2, and B. t. kurstaki HD945. The LD2 values ranged from 2.2 to 7.9 x 106 spores per g manure for horn fly and from 6.3 to 35 X 106 spores per g media for stable fly. These were consistently more toxic compared with the B. t. israelensis isolates examined. All had DNA that hybridized with crylAa, crylAb, and crylAc toxin probes, three hybridized with a cryiB probe, and two hybridized with a cry2A probe. These may have potential for use in integrated management of pest flies. [ABSTRACT FROM AUTHOR]

The insecticidal activity after field exposure of an aluminum–carboxymethylcellulose microencapsulated formulation of Bacillus thuringiensis i.sraelensis (Bti) spore–toxin complex, with malachite green as photoprotective agent, was evaluated using third–instar Aedes aegypti (L.) larvae in laboratory bioa.ssays in Veraci–uz, Mexico. Four insecticide treatments and an untreated control were compared at low and high doses over 96 d of field exposure under full sun or full shade conditions: 1) microencapsulated Bti spore–toxin complex, 2) nonmicroencapsulated Bti spore–toxin complex, 3) a commercial Bti formulation, 4) a commercial formulation of temephos, and 5) an untreated control. The low and high doses corresponded to the LC50 and LC90 concentrations for the Bti insecticides and to 0.5 and 1.0mg⁄liter for temephos; the corresponding values for the microencapsulated Bti and commercial Bti, estimated in this study, were 0.061 and 0.14 mg⁄ml and 0.13 and 0.30 mg/mI, respectively. Overall, the study demonstrated that microencapsulation with aluminum–carboxymeth–ylcellulose improved the activity against Ae. aegypti larvae of B. t. israelensis spore–toxin complex over that of a nonmicroencapsulated spore–toxin complex and that the improvement was particularly important under full sun and high dose. Moreover, insecticidal activity of the microencapsulated B. thuringiensis israelensis spore–toxin complex was superior to that of a commercial B. thuringiensis israelensis formulation and comparable to that of the chemical insecticide temephos. Finally, it was suggested that the microencapsulated B. thuringiensis israelensis formulation should be evaluated for field use in Veracruz because its activity against Ae. aegypti larvae remained high through 31 d and this would allow halving of the current insecticide application frequency. [ABSTRACT FROM AUTHOR]

ABSTRACT Codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), a serious pest of pome fruit, is a threat to exportation of apples (Malus spp.) because of the possibility of shipping infested fruit. The need for alternatives to fumigants such as methyl bromide for quarantine security of exported fruit has encouraged the development of effective fumigants with reduced side effects. The endophytic fungus MuscodDr albus Worapong, Strobel and Hess (Ascomycota: Xylariales) produces volatile compounds that are biocidal for several pest organisms, including plant pathogens and insect pests. The objectives of our research were to determine the effects of M. albus volatile organic compounds (VOCs) on codling moth adults, neonate larvae, larvae in infested apples, and diapausing cocooned larvae in simulated storage conditions. Fumigation of adult codling moth with VOCs produced by M. albus for 3 d and incubating in fresh air for 24 h at 25°C resulted in 81% corrected mortality. Fourand 5-d exposures resulted in higher mortality (84 and 100%, respectively),but control mortality was also high due to the short life span of the moths. Exposure of neonate larvae to VOCs for 3 d on apples and incubating for 7 d resulted in 86% corrected mortality. Treated larvae were predominantly first instars, whereas 85% of control larvae developed to second and third instars. Exposure of apples that had been infested for 5 d, fumigated with M. albus VOCs for 3d, and incubated as described above resulted in 71% corrected larval mortality. Exposure of diapausing cocooned codling moth larvae to VOCs for 7 or 14 d resulted in 31 and 100% mortality, respectively, with negligible control mortality. Our data on treatment of several stages of codling moth with M. albus VOCs indicate that the fungus could provide an alternative to broad spectrum chemical fumigants for codling moth control in storage and contribute to the systems approach to achieve quarantine security of exported apples. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the susceptibility of the strawberry crown moth, Synanthedon bibionipennis (Boisduval) (Lepidoptera: Sesiidae) larvae to two species of entomopathogenic nematodes. The entornopathogenic nematodes Steinernema carpocapsae (Weiser) strain Agriotos and Heterorhabditis bacteriophora (Steiner) strain Oswego were evaluated in laboratory soil bioassays and the field. Both nematode species were highly infective in the laboratory bioassays. Last instars were extremely susceptible to nematode infection in the laboratory, even in the protected environment inside the strawberry (Fragaria × ananassa Duch.) crown. Infectivity in the laboratory was 96 and 94% for S. carpocapsae and H. bacteriophora, respectively. Field applications in late fall (October) were less effective with S. carpocapsae and H. bacteriophora, resulting in 51 and 33% infection, respectively. Larval mortality in the field from both nematode treatments was significantly greater than the control, but treatments were substantially less efficacious than in the laboratory. Soil temperature after nematode applications in the field (11°C mean daily temperature) was below minimum establishment temperatures for both nematode species for a majority of the post-application period. It is clear from laboratory data that strawberry crown moth larvae are extremely susceptible to nematode infection. Improved control in the field is likely if nematode applications are made in late summer to early fall when larvae are present in the soil and soil temperatures are more favorable for nematode infection. [ABSTRACT FROM AUTHOR]

Aims: To PCR-amplify the full-length genomic-encoding sequence for one chitinase from the facultative fungal pathogen Paecilomyces lilacinus, analyse the DNA and deduced amino acid sequences and compare the amino acid sequence with chitinases reported from mycopathogens, entomopathogens and nematopathogens. Methods and Results: The encoding gene (designated as PLC) was isolated using the degenerate PCR primers and the DNA-Walking method. The gene is 1458 bp in length and contains three putative introns. A number of sequence motifs that might play a role in its regulation and function had also been found. Alignment of the translation product (designated as Plc, molecular mass of 45·783 kDa and pI of 5·65) with homologous sequences from other species showed that Plc belongs to Class V chitinase within the glycosyl hydrolase family 18. The phylogenetic and molecular evolutionary analysis usingmega (Molecular Evolutionary Genetics Analysis) indicated that these chitinases from mycopathogens, entomopathogens and nematopathogens, the majority of which belong to glycosyl hydrolase family 18, were clustered into two well-supported subgroups corresponding to ascomycetes fungal and nonfungal chitinases (bacteria, baculoviruses). Conclusions: Our study showed that chitinases from mycoparasitic, entomopathogenic and nematophagous fungi are closely related to each other and reaffirmed the hypothesis that baculovirus chitinase is most likely to be of a bacterial origin – acquired by gene transfer. Bacterial and baculoviral chitinases in our study are potential pathogenicity factors; however, we still cannot ascribe any specific function to those chitinases from the fungi. Significance and Impact of the Study: To our knowledge, this is the first report describing the chitinase gene and its translation product from Paecilomyces lilacinus, which constitutes the largest number of formulated biological nematicides reported so far, this is also the first study to analyse and resolve the phylogenetic and molecular evolutionary relationships among the chitinases produced by mycopathogens, entomopathogens and nematopathogens. [ABSTRACT FROM AUTHOR]

We examined the amount of maturation feeding and transmission of pinewood nematodes, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (Nematoda: Parasitaphelenchidae), to healthy pine (Pinus spp.) trees by pine sawyer Monochanius alternatus Hope (Coleoptera: Cerambycidae) adults infected with Beanveria hassiana (Balsamo) Vuill. (Deuteromycotina: Hyphomycetes). Inoculated beetles fed less than noninoculated beetles, probably because feeding by inoculated beetles began to decrease at about 4 d postinoculation and inoculated beetles ceased to feed for several days before their death. In inoculated beetles carrying >1,000 nematodes, some beetles died before nematode departure. The remaining heavily nematode-infested beetles lived until the beginning of nematode departure, but they had stopped feeding, preventing the nematodes from entering pine twigs. We suggest that microbial control of pine sawyer adults by B. bassiana may be effective in preventing transmission of pine wilt disease to healthy pine trees. [ABSTRACT FROM AUTHOR]

Aims: To produce more thermotolerable conidia of Beauveria bassiana, a well-known fungal biocontrol agent, by optimizing the medium components and culture conditions. Methods and Results: The conidia produced on media including 0·5–6% glucose, sucrose or starch as carbon source and 50–300- μg ml−1 Cu2+, Zn2+, Mn2+ or Fe3+ as additive to Sabouraud dextrose medium at 15–30°C, pH 4–8 or KCl-adjusted water availabilities were exposed to 30-min wet heat stress at 48°C. The medium components for conidial production with greatly enhanced thermotolerance included 4% glucose as optimum or 1% starch as alternative for the carbon source and ⩽50- μg ml−1 Mn2+ for the metal additive. The culture conditions were optimized as 25°C and pH 5–6. Conidial thermotolerance decreased remarkably when sucrose and Fe3+ or Cu2+ were used in the cultures, but altered slightly when 50–200- μg ml−1 Zn2+ were included. Conclusions: The tolerance of B. bassiana conidia to the thermal stress was significantly affected by the medium composition and culture conditions under which the conidia were produced. Significance and Impact of the Study: Proper treatment of small grains as mass production substrates for more glucose release and supplement of glucose or ⩽50- μg ml−1 Mn2+ are possible means to enhancing conidial thermotolerance and field persistence for improved insect control. [ABSTRACT FROM AUTHOR]

Agrotis ipsilon multiple nucleopolyhedrovirus (family Baculoviridae, genus Nucleopolyhedrovirus, AgipMNPV), a naturally occurring baculovirus, was found infecting black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), on central Kentucky golf courses. Laboratory, greenhouse, and field studies investigated the potential of AgipMNPV for managing black cutworms in turfgrass. The virus was highly active against first instars (LC50) = 73 occlusion bodies [OBs] per μl with 2-μl dose; 95% confidence intervals, 55-98). First instars that ingested a high lethal dose stopped feeding and died in 3-6 d as early second instars, whereas lethally infected fourth instars continued to feed and grow for 4-9 d until death. Sublethal doses consumed by third or fifth instars had little or no effect on subsequent developmental rate or pupal weight. Horizontal transmission of AgipMNPV in turfgrass plots was shown. Sprayed suspensions of AgipMNPV (5 × 108-6 × 109OB/s/m2) resulted in 75 to >93% lethal infection of third or fourth instars in field plots of fairway-height creeping bentgrass, Agrostis stolonifera (Huds.), and on a golf course putting green collar. Virus spray residues (7 × 109OBs/m2) allowed to weather on mowed and irrigated creeping bentgrass field plots significantly increased lethal infection of implanted larvae for at least 4 wk. This study, the first to evaluate a virus against a pest in turfgrass, suggests that AgipMNPV has potential as a preventive bioinsecticide targeting early instar black cutworms. Establishing a virus reservoir in the thatch and soil could suppress successive generations 1 that key pest on golf courses and Sport fields. [ABSTRACT FROM AUTHOR]

Female alates of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), infected with Thelohania solenopsae Knell, Allen, and Hazard (Microsporidia: Thelohaniidae) were found to be significantly less likely to be among the early alates to initiate a mating flight. If a flight was initiated, the infected females were significantly more likely to initiate the flight later in comparison with uninfected alates. In addition, many infected female alates seemed not to fly as a significantly greater proportion of the remaining females. Furthermore, infected females exhibited a significantly reduced body weight and a significantly reduced lipid titer, in comparison with uninfected individuals. However, there was no difference between the infected and uninfected alates in the amount of soluble protein. These results suggest that the low-weight late riving-infected females may be less likely to reach a male mating swarm and less likely to outcompete uninfected females in mating and dispersing. Last, if mated or not, upon landing, the infected females may less likely have the needed energy to initiate a colony. [ABSTRACT FROM AUTHOR]

p. makridis, s. martins, t. vercauteren, k. van driessche, o. decamp and m.t. dinis. 2005.The aim of this study was to evaluate the effect of six bacterial strains on gilthead sea bream larvae (Sparus aurata).Six bacterial strains isolated from well-performing live food cultures were identified by sequencing fragments of their 16s rDNA genome to the genus level asCytophagasp.,Roseobactersp.,Ruergeriasp.,Paracoccussp.,Aeromonassp. andShewanellasp. Survival rates of gilthead sea bream larvae transferred to seawater added these bacterial strains at concentrations of 6 ± 0·3 × 105 bacteria ml−1 were similar to those of larvae transferred to sterilized seawater and showed an average of 86% at 9 days after hatching, whereas, survival rates of larvae transferred to filtered seawater were lower (P < 0·05), and showed an average of 39%, 9 days after hatching.Several bacterial strains isolated from well-performing live food cultures showed a positive effect for sea bream larvae when compared with filtered seawater.The approach used in this study could be applied as anin vivoevaluation method of candidate probiotic strains used in the rearing of marine fish larvae. [ABSTRACT FROM AUTHOR]

a.t. de souza liberal, e.a. da silva filho, j.o.f. de morais, d.a. simões and m.a. de morais jr. 2004.The present work focuses on the possibility to use conserved primers that amplify yeast ITS1-5·8S-ITS2 ribosomal DNA locus (rDNA) to detect the presence of non-Saccharomyces cerevisiaeyeast in fermentation must of bioethanol fermentation process.Total DNA was extracted from pure or mixed yeast cultures containing different cell concentrations and different contaminant/fermenting yeast concentrations and submitted to PCR. Upon improvement of detection limits and DNA extraction protocol, must samples of distillery were checked for the presence of contaminant yeast. Contaminant rDNA bands were detected only in industrial samples during contamination episodes, but not in noncontaminated must.The method described here could detect the presence of contaminant yeast from industrial must in eight hours after sampling.The improved procedure may help to avoid severe contamination episodes at fermentation industries by decreasing the detection time from 5 days to 8 h and possible quantification of contaminant yeasts that can impose economical loss to the process. [ABSTRACT FROM AUTHOR]

Microbial control of red imported fire ant, Solenopsis invicta Buren, by the entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin, has been inconsistent. Therefore, fungal isolates and precisely controlled soil moisture and composition were investigated as possible limiting factors. For each experiment, ant colonies were collected from the field and placed into 19-liter buckets at room temperature. Fungal inoculation in all experiments was by point-source placement of B. bassiana growing in a single 100 by 15 mm petri dish into the colony; data were collected for 8-10 wk on percentage infection and on ant numbers by a stake-count method and by a population-index rating. Two fungal isolates did not differ in efficacy, and both were inferior to GardStar (permethrin) in killing the ants. B. bassiana reduced ant numbers more effectively in -0.2 bar soil than in -0.5 bar soil, which in turn was better than 0 bar (wet) or -1.0 bar (dry) soil moisture. Even in dry soil (-1.0 bar), however, up to 22.5% of the ants were infected. According to all three parameters, B. bassiana killed more ants in silt (70:15:15, silt:sand:clay) and in sandy soil (15:70:15) than in clay (15:15:70). Results with B. bassiana in clay did not differ significantly from the control. [ABSTRACT FROM AUTHOR]

Glutinous broomcorn millets from the crop Panicum miliaceum were first used as substrate to produce granular cultures of Pandora neoaphidis, an obligate fungal pathogen specific to aphids. Carrying a water content of 36.5% after being steamed in a regular autoclaving procedure, millet grains of each 15 g (dry weight) in a 100-ml flask were mixed with 3 ml modified Sabouraud dextrose broth containing half a mashed colony of P. neoaphidis grown on egg yolk milk agar and then incubated at 20°C and a light/dark cycle of 12 h/12 h for 21 days. Based on individually monitoring conidial production potential of 20 millet grains sampled from an arbitrarily taken flask at 3-day intervals, the millet cultures incubated for 6–15 days were capable of producing 16.8–23.4×104 conidia per millet grain with conidial ejection lasting for up to 6 days. The cultured millet grains individually produced significantly more conidia than apterous adults of Myzus persicae killed by P. neoaphidis (8.4×104 conidia per cadaver) and sporulated twice longer. The modeling of time–dose–mortality data from bioassays on M. persicae apterae exposed to conidial showers from the cultured millet grains and the mycelial mats produced in liquid culture resulted in similar estimates of LC50 (millets: 21.4, 7.3, and 4.9 conidia mm−2 on days 5–7 after exposure; mycelial mats: 22.1, 10.6, and 7.7 conidia mm−2) although the LT50 estimated at a given conidial concentration was slightly smaller for the millet cultures than for the mycelial mats. This indicates that the millet grains cultured with P. neoaphidis produced conidia as infective as or slightly more infective to M. persicae than those from the mycelial mats. Based on the sporulation potential, infectivity, and ease and cost of the millet cultures, the method developed in this study highly improved in vitro cultures of P. neoaphidis and may adapt to culturing other entomophthoralean fungi for microbial control of insect pests. [Copyright &y& Elsevier]

Abstract Aims: To investigate the thermal biology of entomopathogenic fungi being examined as potential microbial control agents of Varroa destructor , an ectoparasite of the European honey bee Apis mellifera . Methods and Results: Colony extension rates were measured at three temperatures (20, 30 and 35°C) for 41 isolates of entomopathogenic fungi. All of the isolates grew at 20 and 30°C but only 11 isolates grew at 35°C. Twenty-two isolates were then selected on the basis of appreciable growth at 30–35°C (the temperature range found within honey bee colonies) and/or infectivity to V. destructor , and their colony extension rates were measured at 10 temperatures (12·5–35°C). This data were then fitted to Schoolfield et al . [J Theor Biol (1981)88:719–731] re-formulation of the Sharpe and DeMichele [J Theor Biol (1977)64:649–670] model of poikilotherm development. Overall, this model accounted for 87·6–93·9% of the data variance. Eleven isolates exhibited growth above 35°C. The optimum temperatures for extension rate ranged from 22·9 to 31·2°C. Only three isolates exhibited temperature optima above 30°C. The super-optimum temperatures (temperature above the optimum at which the colony extension rate was 10% of the maximum rate) ranged from 31·9 to 43·2°C. Conclusions: The thermal requirements of the isolates examined against V. destructor are well matched to the temperatures in the broodless areas of honey bee colonies, and a proportion of isolates, should also be able to function within drone brood areas. Significance and Impact of the Study: Potential exists for the control of V. destructor with entomopathogenic fungi in honey bee colonies. The methods employed in this study could be utilized in the selection of isolates for microbial control prior to screening for infectivity and could help in predicting the activity of a fungal control agent of... [ABSTRACT FROM AUTHOR]

Methods are described for the in vivo production of the nematode Thripinema nicklewoodi (Siddiqi), an obligate parasite and potential biological control agent of western flower thrips Frankliniella occidentalis (Pergande). Nematode infection is not lethal but causes sterilization of adult female hosts. Both fertilization and horizontal transmission of T. nicklewoodi is achieved in 1.5-ml microcentrifuge tubes (infection arenas), in the presence of 100% humidity, a temporary food source and preferably a damp substrate. Following exposure to infection arenas, F. occidentalis are reared on excised bean leaves Phaseolus vulgaris (L.) in polypropylene containers for 2 wk at 25°C to allow the reproduction and development of a single generation of nematodes within infected hosts’s abdominal cavity. To identify infected hosts after this incubation period, thrips are isolated in microcentrifuge tubes and monitored for free-living nematodes being released along with frass. Infected thrips are reintroduced back into infection arenas to inoculate further thrips to maintain the culture. We documented the output of the rearing procedure using a standard method and following simple manipulation of several individual parameters of the infection technique. The standard method was the most efficient, and resulted in an increased (output/input) ratio of infected thrips of ≈2; i.e., the number of infected thrips approximately doubles each generation. Monitoring infected thrips revealed that nematodes were first released between 12–14 d postinfection and for an average of 7.9 d at 25°C; highlighting the potential to reuse infective thrips between infection arenas. The possibility of using T. nicklewoodi as an inoculative agent against F. occidentalis infesting floricultural crops is discussed. [ABSTRACT FROM PUBLISHER]

The red imported fire ant, Solenopsis invicta Buren, is an important pest in the southern United States, in part because few natural enemies exist. Beauveria bassiana is an entomopathogenic fungus that holds great promise as a biological control agent against S. invicta. In previous studies, B. bassiana was effective in laboratory trials, but field applications were less effective. In the current study, we compared the efficacy of different application methods of B. bassiana mycelia encapsulated in alginate pellets against S. invicta in heavily infested areas. Direct insertion of pellets into S. invicta mounds caused some reduction in activity rating. However, observations of ants removing pellets from mounds shortly after insertion led to the development of a bait system to encourage pellet retention in the mounds. Broadcast applications and individual mound treatments of B. bassiana alginate pellets coated with peanut oil reduced activity ratings of S. invicta populations. [ABSTRACT FROM PUBLISHER]

Imidacloprid and the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin are both used to control the whitefly Bemisia argentifolii Bellows & Perring. We tested whether the two control strategies acted additively, synergistically, or antagonistically when combined for whitefly control. We found antagonism in that B. bassiana inhibited the effectiveness of imidacloprid. When B. bassiana was combined with imidacloprid, insect response was either less than or similar to (depending on B. bassiana rates) that when imidacloprid was used alone. Adding imidacloprid to B. bassiana treatments always increased mortality, but the increase was less than additive. Beauveria bassiana spore germination and colony formation were not inhibited by imidacloprid in vitro, and B. bassiana did not adsorb or degrade imidacloprid in a tank mix. We hypothesize that B. bassiana caused a behavioral response that reduced insect feeding and uptake of imidacloprid. [ABSTRACT FROM PUBLISHER]

The article discusses a study which examines the impact of D-erythro-C14-Sphingosin (C14-Sph) on the infection time between conidial adhesion and insect invasion in Nomuraea rileyi. Findings of the study reveal that the activation of conidia by C14-Sph could reduce the infection time. It concludes that C14-Sph could be an effective adjuvant for fungal pesticide in Nomuraea rileyi.

Tlulohania solenopsae Knell, Allen, & Hazard is an entomopathogenic microsporidium that infects imported fire ants. We documented artificially initiated transmission of T. solenopsae among colonies of the red imported fire ant, Solenopsis invicta Buren. Microsporidian transmission was initiated by providing colonies with brood (mixture of eggs, larvae, and pupae) from infected S. invicta colonies. Inoculated laboratory colonies of S. invicta had significantly less brood and adults than control colonies; after 23-29 wk, there was at least 88% less brood in the inoculated colonies. Lower egg laying rates, queen weights, and queen survivorship was also documented from infected colonies. Thus, T. solenopsae slowly debilitates an S. invicta queen so that reproductive capacity diminishes and early death results. Artificial inoculations resulting in infection and spread of T. solenopsae among red imported fire ant colonies under field conditions was also demonstrated for the 1st time. [ABSTRACT FROM AUTHOR]

Virulence ofMetarhizium anisopliae (Metschnikoff) Sorokin strain ESC-1 against the German cockroach, Blattella germanica (L), was determined using 5 concentrations ranging from 8 x 107 to 2 x 109 spores per milliliter. The calculated LD50 value was 4.18 by 108 spores per milliliter (4.18 x 105 spores per cockroach). In vitro study was conducted to determine the compatibility of M. anisopliae strain ESC-1 with chlorpyrifos, propetamphos, and cyfluthrin. Insecticides did not affect conidial germination but did adversely affect the growth and sporulation of M. anisopliae strain ESC-1. The growth of M. anisopliae colonies on mediaamended only with 50 and 500 ppm of chlorpyrifos and 500 ppm of propetamphos treatments at 3, 6, and 9 d was significantly inhibited compared with the control. Similarly, sporulation was significantly reduced in treated colonies exhibiting partial colony growth. The coloniescultured on SDAY media amended with 50 ppm of chlorpyrifos had significantly reduced sporulation compared with the control and no sporulation was observed in colonies cultured on media amended with 500 ppm of chlorpyrifos; and propetamphos. [ABSTRACT FROM AUTHOR]

In Southern California, populations of the western grapeleaf skeletonizer, Hanisina brillians Barnes & McDunnough, appear to be maintained at low levels of abundance by tile combined activitv of Harrisina brilliam granulovirus (HbGV) and the parasitoid Arnetadoria mi.wlla (Wulp). In contrast, outbreaks of H. brillians were common in central California in the late 1970s and 1980s. We investigated field populations of H. brillians in Fresno and nearby Madera Counties from 1992 to1995 to determine the prevalence and impact of both natural enemies.A double antibody sandwich enzyme-linked immunosorbent assay (ELISA)employing polyclonal antibodies to HbGV was developed to detect virus in field samples. The sensitivity of the ELISA was = 10 ng of viralprotein (equivalent to 100 ng/ml in the assay) detecting granulovirus in infected H. brill ions larvae 72 h after infection. The ELISA did not cross react with the multicapsid nucleopolyhedrovirus Autographa californica MNPV at concentrations as high as 10's ng/ ml, but did cross react with another granulovirus Cydia pomonella GV at concentrations >103 ng/ml. H. brillians pupae were collected from 4 vineyards.Both natural enemies were abundant at all sites, and the total mortality of host pupae ranged from 53 to 98%. Granulovirus accounted for as much as 97% mortality, whereas parasitism by A. nn~sella ranged from 12 to 33% as estimated by marginal death rate analysis. These dataindicate that both natural enemies cause significant mortality of H.brillians and that, contrary to earlier reports, A. misella is established in central California. Additionally, up to 47% of H. brilliansadults eclosing from overwintering pupae tested positive for granulovirus by ELISA, indicating that host adults are an important mechanism of intergenerational and interseasonal persistence of the virus in host populations. [ABSTRACT FROM AUTHOR]