EFFECT OF BACILLUS THURINGIENSIS VAR. ISRAELENSIS ON A GENETICALLY-DEFINED POPULATION OF BLACK FLIES (DIPTERA: SIMULIIDAE) AND ASSOCIATED INSECTS IN A MONTANE NEW HAMPSHIRE STREAM

1984 ◽  
Vol 116 (7) ◽  
pp. 975-981 ◽  
Author(s):  
Lawrence A. Pistrang ◽  
John F. Burger

AbstractA small, undisturbed stream in central New Hampshire was treated for 1 min with a 10 ppm suspension of Bacillus thuringiensis var. israelensis (B.t.i.) to determine the effect on an outlet-breeding black fly population and associated nontarget aquatic insects. The black fly larval population was eliminated and susbsequent adult black fly biting activity reduced near the treatment site although weather conditions may also have contributed to an observed decrease in biting activity. Some Chironomidae were killed by B.t.i. but they were not abundant enough to adequately assess impact on their populations. Temporary increases in the drift of two Ephemeroptera and two Trichoptera species were observed following treatment. Increase in rate of drift was inversely related to increase in distance from the treatment point. Slight increases in observed drift of three Plecoptera species could not be attributed directly to the B.t.i. treatment. No direct mortality caused by B.t.i. was observed in any stream insects studied except black fly larvae and some Chironomidae.

1991 ◽  
Vol 123 (1) ◽  
pp. 179-185 ◽  
Author(s):  
Richard W. Merritt ◽  
Mark S. Wipfli ◽  
R.S. Wotton

AbstractThe effects of Bacillus thuringiensis var. israelensis de Barjac (B.t.i.) on the feeding habits of two black fly predators, Nigronia serricornis (Say) and Acroneuria lycorias (Newman), and a detritivore, Prostoia completa (Walker), were examined. We assessed whether B.t.i.-killed and hot water-killed black fly larvae were less or more desirable to these consumers than live larvae. Nigronia larvae showed no significant differences in predation on larvae within the three categories. Acroneuria nymphs consumed more live than dead prey. Experiments with the detritivore, Prostoia, showed that they preferred dead black fly larvae to live ones. Bacillus thuringiensis var. israelensis treatment may have little direct effect on nontarget organisms, but these studies indicate that there still may be consequences for predators and detritivores when a viable population of larval black flies is transformed into dead organic matter.


1981 ◽  
Vol 113 (4) ◽  
pp. 281-293 ◽  
Author(s):  
R. J. Sebastien ◽  
W. L. Lockhart

AbstractTwo formulations of methoxychlor were compared with regard to toxicity and availability to aquatic organisms. A particulate formulation was less toxic than an emulsifiable formulation to chironomid larvae, stonefly nymphs, and fish. Similarly the particulate methoxychlor was less rapidly accumulated from water by those same animals than was the emulsified methoxychlor. With black fly larvae, the only filter-feeding animal used, the two formulations were about equal in toxicity, but the particulate formulation was accumulated more readily than emulsified material. Both formulations induced larvae to detach from substrate but emulsifiable methoxychlor acted more quickly. At the time of detachment, larvae exposed to the particulate formulation contained an average of 68 times more methoxychlor than larvae exposed to the emulsion.


1960 ◽  
Vol 92 (10) ◽  
pp. 745-754 ◽  
Author(s):  
A. S. West ◽  
A. W. A. Brown ◽  
D. G. Peterson

The results reported in this paper are part of a study of the biology and control of black flies in the forests of Eastern Canada conducted on the north shore of the St. Lawrence River, near Baie Comeau, Quebec, during 1954, 1955, and 1956. Reference to this study is made in a review by Peterson and Wolfe (1958). The identification and biology of the black flies of this region has been reported on by Wolfe and Peterson (1959) who also describe the topography of the region. The important feature of this rugged area is an abundance of fast-flowing streams which provide highly suitable environments for the development of black-fly populations.


1978 ◽  
Vol 56 (7) ◽  
pp. 1608-1623 ◽  
Author(s):  
Daniel C. Kurtak

Larvae of nine species of black flies were exposed to synthetic particles in the laboratory. Sizes and concentrations of particles were chosen to simulate natural conditions. Smaller particles (diameter 5–10 μm) were offered at a rate of 50–100/cephalic fan area per second, and larger ones (diameter approximately 150 μm) at 0.3–1.0/cephalic fan area per second. Experiments were conducted at water velocities of 30, 50, and 70 cm/s.In all the laboratory experiments, only a small percentage of the particles passing through an area equal to that of the cephalic fans of a single larva were ingested. Particles larger than the spacing between the fan rays were ingested more efficiently than smaller ones. At 50 cm/s, the mean percentage ingested for all species was 1.6% (0.14–8.3%) of particles 150 μm in diameter and 0.094% (0.0026–0.76%) of particles 5–10 μm in diameter. The percentage of material ingested decreased at higher concentrations and water velocities. There were significant differences among the species.Experiments were done with one of the species in the field with similar results.Based on this work, an individual black fly larva in nature probably ingests 1–10% by weight of the material passing through its cephalic fans.


1994 ◽  
Vol 51 (2) ◽  
pp. 295-314 ◽  
Author(s):  
John K. Jackson ◽  
Bernard W. Sweeney ◽  
Thomas L. Bott ◽  
J. Denis Newbold ◽  
Louis A. Kaplan

The microbial pesticide Bacillus thuringiensis var. israelensis (B.t.i.) was applied aerially to suppress larval black fly populations in the Susquehanna River, Pennsylvania. We quantified (1) the passage and retention of B.t.i. spores through a 1.5-km reach and (2) changes in black fly and nontarget macroinvertebrate abundances in the drift and benthos. B.t.i. exposure in the treatment riffle was 1.16 × 105 min-spores/mL or 16 min-mg/L in 1989 and 5.20 × 104 min-spores/mL or 4.4 min-mg/L in 1990. Retention of B.t.i. within the reach was low. While black fly drift from the treatment riffle increased markedly, B.t.i. appeared to have little effect on drift densities of most nontarget macroinvertebrates during the 48-h period following application. Similarly, benthic densities of black flies in the treatment riffle decreased significantly 1 d after the B.t.i. application whereas benthic densities of most nontarget taxa in the treatment riffle and depositional zone appeared unaffected 1, 7, and 28 d following B.t.i. application. Responses potentially related to B.t.i. exposure were observed for the aquatic lepidopteran Petrophila and the chironomid Polypedilum. These results suggest that the application of B.t.i. on the Susquehanna River markedly reduces black fly populations, but does not negatively affect most nontarget macroinvertebrates.


1961 ◽  
Vol 93 (6) ◽  
pp. 419-428 ◽  
Author(s):  
J. G. Chillcott

The genus Roederioides was erected by Coquillett in 1901 for the single species juncta Coquillett, described from Saranac Inn, New York. The species has since been recorded only from Mt. Washington, New Hampshire. A second species has been described from the Madeiras by Frey. This paper describes five new species from North America and presents a revised description of the genus.The type of the genus, juncta, was collected in association with black flies, and recent collections have been made from black fly swarms. It is possible that juncta, and possibly other species of the genus, are predators of black flies, both as adults and as larvae.


2000 ◽  
Vol 78 (2) ◽  
pp. 199-218 ◽  
Author(s):  
R W Palmer ◽  
D A Craig

A conceptual model that uses labral-fan structure to predict the distribution of black fly species within a catchment is proposed. The model is based on water flow, seston availability, and the structure of the primary labral fans of mature black fly larvae from southern Africa. The model predicts that black fly larvae found in fast-flowing (>1.0 m/s) seston-rich (>50 mg/L) water will tend to have strong fans with a porous ray structure, whereas larvae found in slow-flowing (<0.5 m/s) seston-poor (<10 mg/L) water will tend to have weak fans with a complex structure and larvae found in water with moderate water velocities and moderate seston levels will tend to have a standard fan structure. The model was tested against black flies from other parts of the world, particularly Polynesia, and provides a useful framework for predicting the distribution of black fly species within a catchment. Exceptions to the model were found among phoretic species. The model should predict changes in black fly species in areas where anthropogenic changes to watersheds are occurring.


1960 ◽  
Vol 92 (9) ◽  
pp. 714-719 ◽  
Author(s):  
D. G. Peterson ◽  
A. S. West

A study of the biology and control of black flies in the forests of Eastern Canada was conducted on the north shore of the St. Lawrence River, near Baie Comeau, Quebec, from 1954 to 1956. Reference was made to this study by Peterson and Wolfe (1958). Details on the identity of species, and studies on their life histories and habits were reported by Wolfe and Peterson (1959), while the control of black-fly larvae by aircraft spraying was described by West, Brown, and Peterson (in press). Experiments on the control of adult black flies by aircraft spraying are reported in this paper.


1984 ◽  
Vol 116 (8) ◽  
pp. 1085-1096 ◽  
Author(s):  
M. H. Colbo ◽  
H. O'Brien

AbstractA pilot black fly control program using Bacillus thuringiensis var. israelensis on a small stream system near St. John's, Newfoundland resulted in a 70% or greater population reduction of adult black flies from the previous year. The species present in the system were Prosimulium mixtum, Stegopterna mutata, Eusimulium vernum, Simulium tuberosum, S. venustum/verecundum complex, and S. vittatum. The formulation used was Teknar® flowable concentrate (Sandoz Inc.) rated at 600 ITU/mg which proved effective against the larval stages of all black fly species at a dose of 10 ppm for 1 min. The results indicated that this agent will be effective if applied at the appropriate locations and times. The 1-min dose was practical except in very cold water (0°–7 °C) where a 5-min or longer dose may be required. The unpredictable relief pattern of the northern streams resulted in a highly variable downstream carry for the B.t.i. Therefore application sites must be determined by a stream survey and not just from discharge characteristics.


2012 ◽  
Vol 42 (8) ◽  
pp. 1335-1340 ◽  
Author(s):  
Carla Pedroso de Moraes ◽  
Luis Amilton Foerster

Plutella xylostella L. is the most important worldwide pest of cruciferous plants and indiscriminate use of insecticides has led to the resistance of the species to different groups. This research was conducted to compare the toxicity and persistence of two strains of Bacillus thuringiensis to P. xylostella larvae. Concentrations between 125 and 500g 100L-1 of water of the commercial products were evaluated and compared to the insect growth inhibitor diflubenzuron and to the neurotoxic pyrethroid deltamethrin. The efficacy of the insecticides was compared between treated plants kept indoor greenhouse and outdoor. Third instar larvae were more susceptible to B. thuringiensis than first instar ones. Agree and Dipel showed similar control rates of third instars until 10 days after treatment, but on the 15th day, Agree was significantly more efficient than Dipel. Both B. thuringiensis formulations showed a reduction in mortality after 10 days when the treated plants were exposed to natural weather conditions in comparison to the same treatments kept inside greenhouse. Dimilin (100g 100L-1 of water) and deltamethrin (30ml of commercial product 100L-1 of water) were not efficient to control third instar larvae of P. xylostella. This inefficiency cannot be attributed to a resistant population of P. xylostella since the larval population used in the experiments was not subjected to insecticide pressure, once the crop was organically cultivated all year round. The results showed that both formulations of B. thuringiensis are sound alternatives for the control of the diamondback moth in organically conducted cruciferous crops, considering the high residual control provided under subtropical weather conditions.


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