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Two trapping systems were compared in a study in Guatemala during the wet season, May through Dec 2001. Trap/lure combinations consisting of green or yellow-based plastic McPhail-like traps baited with a synthetic 2-component lure (putrescine and ammonium acetate) and 300 mL of propylene glycol antifreeze as a preservative were compared to the traditional glass McPhail baited with torula yeast/borax and 300 mL of water. Both systems captured several key Anastrepha species including Anastrepha ludens Loew, A. obliqua, Macquart, A. serpentina Weidemann, A. striata Schiner, A. distincta Greene, A. fraterculus Weidemann as well as Ceratitis capitata Weidemann. Additionally, 13 other Anastrepha spp. were captured with the synthetic lure. The plastic traps captured more key flies than the McPhail trap except for A. distincta where there were no significant differences between the yellow-based plastic trap and the McPhail trap and no significant differences between any trap and lure for trapping A. frat...

beta-Exotoxin (thuringiensin) was found in high titers in centrifugation supernatants and acetone/lactose powders produced from centrifugation pellets of strains Guat 1 and HD 2 of Bacillus thuringiensis (Berliner). Diets containing powders of either strain were toxic, diets containing Guat 1 supernatant were not toxic, diets containing HD 2 supernatant were slightly toxic, and diets containing powders or supernatants from uninoculated culturing medium spiked with beta-exotoxin were not toxic. Most mortality occurred within 3 d when flies fed on powders but not until 6-7 d when flies fed on HD 2 supernatant. These results indicated that the primary toxic principals of the powders were endotoxins/spores and that beta-exotoxin alone was not toxic to adult flies at the concentrations found in the supernatants or powders.

Centrifugation pellets obtained from an isolate of Bacillus thuringiensis subspecies darmstadiensis (Guat 1) cultured from a Guatemalan soil sample were found to be toxic to Anastrepha ludens (Loew) adults in the laboratory. We developed a bioassay diet that consisted of a mixture of the bacterium, a protein source, and sugar. A pH of 4.1 of the mixture was needed to obtain maximum adult mortality. One meal of the diet, which lasted from 30 s to 4 min, was enough to cause >70% mortality of both fed or starved adults. Mortality of fed adults was 70-75% following a feeding period of 60 min and mortality of starved adults was 80-90% following a feeding period of 30 min. The isolate was toxic to adults from 1 to 21 d old.

The toxicity of 55 isolates of Bacillus thuringiensis (Berliner) was tested on larvae of Mexican fruit fly, Anastrepha ludens (Loew). The 7 isolates that were most toxic to larvae as centrifugation pellets were tested against adult flies as either pellets or acetone/lactose precipitates made from resuspended pellets. The 5 isolates most toxic to adult flies were an unidentified Guatemalan isolate, and 4 isolates from larvae that died after eating pellets from isolates HD 565 (serovar5a5c; subsp. Canadensis ), HD 199(serovar 10;subsp. darmstadiensis ), HD 567 (serovar 14; subsp. israelensis ), and HD 1 (serovar 3a3b; subsp. kurstaki ). These 5 isolates killed 65-80% of adults in 10 d after feeding on them for 2 d, compared with 2.7% mortality in controls. The other two isolates (an isolate from a larva that died after eating pellets from HD 146 [serovar 10; darmtadiensis ] and a second unidentified Guatemalan isolate) killed 40% of adults in the same experiment. Isolates that were most toxic to larvae were not necessarily most toxic to adults and vice versa. The toxic principals were characterized as endotoxins based on their water insolubility and heat lability.

An analysis was performed to identify the volatile components of a supernatant derived from a bacterial (Klebsiella pneumoniae, ATCC 13883, American Type Culture Collection) fermentation of a trypticase soy broth. The bacteria-produced supernatant (BPS) was comparable to a 30% solution of NuLure in attractiveness to mixed sexes of adult Mexican fruit flies, Anastrepha ludens (Loew), in a laboratory bioassay. The volatile components of BPS, most resulting from bacterial metabolism, were identified by a combination of capillary GC and GC-MS techniques. A total of 21 compounds were identified, including 7 alcohols (2 sulfur containing), 8 alkyl-substituted pyrazines, 2 ketones, 2 acids, 1 ketoalcohol, and phenol. The five most abundant compounds, in decreasing order of abundance, were 3-methyl-1-butanol, phenethyl alcohol, 2,5-dimethylpyrazine, 2-methyl-1-propanol, and 3-(methylthio)-1-propanol. One or more unidentified, low molecular weight amines were also present in the mixture of volatiles.

The effects of cyromazine on the adult Mexican fruit fly, Anastrepha ludens (Loew), include mortality and reduced fecundity and survival of the F1 generation. Dosage-dependent mortality was recorded for concentrations from 0.125 to 16%. Neonate to 2-d-old females fed an artificial diet with 5% cyromazine were incapable of laying eggs in fruit with a resistance of penetration >11 newtons. Laboratory observations showed that treated females could not insert their ovipositor into grapefruit rind. When the same females were given a soft substrate (parafilm membrane), they laid significantly fewer eggs than control females. The F1 generation of treated females developed significantly less in an artificial larval diet and in grapefruit in the field. A field test showed that grapefruit from treatments made with 5% cyromazine-NuLure mixture had significantly fewer larvae per fruit than the control. This difference did not occur with fruit from a 5% malathion treatment.

One- to two-day-old Mexican fruit fly adults, Anastrepha ludens (Loew), were not deterred from feeding continuously or Jor periods of 1, 3, and 5 d on diet containing either 1 x 103 or 1 x 104 ppm cyromazine. Although flies behaved normally after feeding, egg production was significantly reduced. Cyromazine did not appear to affect males. Those females fed a single meal containing >1.5 x 103 ppm cyromazine had significantly fewer eggs compared with the control.

A bacterium isolated from the mouthparts of a laboratory-culture female Mexican fruit fly, Anastrepha ludens (Loew), was highly attractive to sugar-fed, protein-starved, 4–16-d-old male and female laboratory-cultured Mexican fruit flies. The bacterium was identified as a strain of Staphylococcus (RGM-1) matching most closely to S. aureus . This is the first report of a Staphylococcus attractive to a tephritid species. Four S. aureus strains purchased from the American Type Culture Collection were as attractive to A. ludens as RGM-1. Tryptic soy broth cultures of RGM-1 were compared with torula yeast-borax, a standard bait for Anastrepha , for attractiveness to Mexican fruit flies. Bacterial preparations generally were less attractive or at best equally attractive as torula yeast-borax when baits were tested in pairs of competing McPhail traps in a greenhouse flight chamber and in a grapefruit orchard.

Filtrates of 11 bacteria representing 4 higher taxonomic categories were attractive to Mexican fruit flies, Anastrepha ludens (Loew) (Diptera: Tephritidae) in laboratory bioassays. All bacterial filtrates were more attractive at pH 9 than at pH 5 although filtrates at pH 5 were more attractive than water controls. The effects of pH on attractiveness of filtrates were consistent with an hypothesis that attractive principals of bacterial filtrates were various nitrogen-containing compounds and carboxylic acids that became more volatile at specific pH's resulting in increased attractiveness. Volatiles produced by the bacteria were sampled by solid-phase microextraction and identified by GC and GC-MS. Attractive principals identified were ammonia, aliphatic amines, pyrazines, imines, and acetic acid. Relative amounts of most of the chemicals were not closely tied to bacteria taxonomy.

Bacteria isolated from the Mexican fruit fly, Anastrepha ludens Loew, were identified and found to be similar to bacteria isolated from other fruit fly species. Bacteria of the same species as those identified from A. ludens were obtained from the American Type Culture Collection (ATCC). These bacteria were cultured and attractiveness to A. ludens adults was determined for the whole beer, and for filtered and autoclaved supernatants in laboratory bioassays. All bacterial cultures were attractive to A. ludens, and some were significantly more attractive than others. Autoclaved supernatants were significantly more attractive than the whole beer or filtered supernatants. Two strains of Bacillus thuringiensis (serovars finitimus and kurstaki), not previously reported to attract fruit flies, were attractive to A. ludens. In field studies, metabolites from bacterial fermentation of two cultures (ATCC #8090 and #13883) captured as many A. ludens adults as Torula yeast/borate pellets. Metabolites from these two cultures caught nearly twice as many females as males compared to about equal numbers of males and females captured by Torula yeast/borate pellets and Nulure@^R. Consistent with laboratory bioassays, metabolites from RGM-1 caught significantly fewer A. ludens adults than the metabolites from #8090 and #13883.

The addition of chlortetracycline hydrochloride to bioassay diets increased the LC50S of the HD-1 isolate of Bacillus thuringiensis 2.4–67.1 times when bioassayed against 4-day-old larvae of Trichoplusia ni, Heliothis virescens, and Ostrinia nubilalis. There were no significant differences in LC50 s when bioassays were conducted with neonate larvae in the presence or absence of antibiotic, nor were there any highly significant differences between the LC50 s for HD-1 when neonate larvae were used in the presence or absence of antibiotic or when 4-day-old larvae were used in the absence of antibiotic. Viable counts of B. thuringiensis did not increase over time in any of three bioassay diets. There were no differences in activity of pure chlortetracycline hydrochloride and veterinary grade Aureomycin. There was a direct correlation between amount of antibiotic and elevation of HD-1 LC50 s when 4-day-old larvae were used. LC50 elevation in presence of antibiotic first appeared in 2-day-old larvae.

Polyhedral inclusion bodies of the nuclear polyhedrosis virus of the cabbage looper, Trichoplusia ni, were precipitated from concentrated suspensions in 4–6% solutions of lactose by adding acetone. In this procedure, the lactose precipitates along with the polyhedra and helps to obtain a dry product with minimum clumping that is easily resuspended in water. The polyhedra may be precipitated directly from crude suspensions of larvae that have been macerated in water and coarse-filtered to remove body parts. In this case, lactose is dissolved in the suspension to the desired concentration. Greater purity can be obtained by first centrifuging the polyhedra and then resuspending them in the lactose solution. Yields of 80% were obtained. The product has proved to be a useful replacement for the usual lyophilized preparation.

Although the spore-crystal complex of Bacillus thuringiensis can be precipitated from concentrated aqueous suspensions derived from fermentation beers by the addition of acetone, the spores and crystals in the resulting products have a strong tendency to clump, and they are difficult to resuspend in water. Clumping can be reduced by suspending the concentrated complex in 4–6% lactose solutions and precipitating the lactose along with the complex by the addition of 4 vol of acetone. The precipitate is then easily recovered as a dry, stable preparation that is not difficult to resuspend in water. Yields of over 70% were obtained, and the ratios of spores to crystals did not change during the process. A new term, the diet dilution unit, was defined and used to express potencies and calculate yields.