Sensitivity of Bacillus thuringiensis var. thuringiensis to various insecticides and herbicides

JOURNAL

OF

INVERTEBRATE

Sensitivity

PATHOLOGY

17,

292-293

(1971)

of Bacillus thuringiensis Various Insecticides and

var. thuringiensis Herbicides’

to

appropriate insecticide or herbicide were placed aseptically on the surface of the media. Then the petri dishes were incubated at 31’C and the presence or absence of an inhibition zone was recorded at 24 hr. All controls (solvents only) and tests were performed in triplicate. The results of the Mitt. Biol. Budesanst. Land. Forstwirt. 103, l-67, 1961; C. Toumenoff and M. Lapied, tests are presented in Table 1. Ann. Inst. Pasteur Paris 8’7,370-374, 1954). The following subst’ances did not inhibit However, little information is available as B. thuringiensis var. thuringiensis: Co-Ral, DDVP, Sevin, and Baygon. Relatively poor to the sensitivity of Bacillus thuringiensis (failure to inhibit at 1O-3 M) was to various insecticides and herbicides which inhibition experimentally are being formulated to- obtained with rotenone, pyrethrin, allethrin, DDT, methoxychlor, lindane, dieldrin, malgether as a means of integrated control. thion, 2,4-D, Although there is little if any significant and 2,4,5-T. However, relationship existing between growth in- significant inhibition was obtained with Naled, parathion, and CIPC. hibition of Bacillus Lhuringiensis and the Thanite, The difference in inhibitory response with insecticidal activity of the B. t.-b-endotoxin using different already formed, a relationship is possible the same t’est material with insects that demonstrate the classical solvents was likely the result of solubility differences of the particular insecticide or Type II and III reaction described by A. M. herbicide. Heimpel and T. A. Angus (J. Insect Pathol. EDWARD M. DOUGHERTY 1, 152-170, 1959). In the Type II reaction, CHARLES F. REICHELDERFER~ the gut becomes paralyzed, feeding stops ROBERT M. FAUST shortly after the crystals are ingested, and U.S. Department of Agriculture death occurs in 45-72 hr from starvation Agricultural Research Service and septicemia caused by spores germinating Beltsville, Maryland dOYO6 in the gut and vegetative cells that invade the hemocoel. Insects that demonstrate ReceivedSeptember14, i970 the Type III reaction require both spores 1 Scientific Article No. A1623, Contribution No. and the B. t.-b-endotoxin to cause death. 4349 of the Maryland Agricultural Experiment The method of testing w-as as follows: Station, College Park, Md. 20742. Petri plates (100 X 15 mm) containing 2 Difco Laboratories, Detroit, Mich. nutrient agar2s 3 were surface inoculated 3 Mention of a company name or proprietary product does not constitute an endorsement of with Bacillus thuringiensis var. thuringiensis this product by the U. S. Department of Agricul(serotype I) spores at a concentration of ture or the University of Maryland. 7000/plat,e. Sterile paper discs (Whatman 4 Present address: University of Maryland, DeNo. 2 filter paper, 7 mm) containing the partment of Entomology, College Park, Md. The

sensitivity spectrum of Bacillus var. thuringiensis to antibiotics, sulfonamides, and other substances has been reported (C. Ignoffo, J. Insect Pathol. 5, 395-397, 1963; E. Afrikian, J. Insect Pathol. 2, 299-304, 1960; A. Krieg, thuringiensis

292

39: :

NOTES

TABLE ~ICNSITIV~TY

Pesticide

Thanite

Rotenone

Pyrethrin

Allethrin

DDT

Methoxychlor

Lindane

Dieldrin

Naled

OF Bacillt~s

thllringiensis

VAR.

Solvent

Minimum inhibitor9 response; Molar concentration

Hexane Tween DMSW Ethanol Tween DMSO Ethanol Tween DMSO Ethyl Tween DMSO Hexane Tween DMSO Hexane Tween DMSO Hexane Tween DMSO Hexane Tween DMSO Benzene Tween

thuringiensis

lo-4

80~

80

80 ether 80

80

80

80

80

80

10-S lo-2 None 10-r None 10-l None 10-l 10-l 10-Z None None 10-Z None None 10-r None None 10-i None 10-r 10-r 10-r 10-c 10-S

1 TO VARIOUS

Pesticide

Naled-Cont’d Co-Ral

Malathion

DDVPe

INSECTICIDES

AND

HERBICIDIW

Minimum inhibitor9 response; Molar concentration

Solvent

DMSO Benzene Tween 80 DMSO Benzene Tween 80 DIVE0 Benzene Tween 80 DMSO

Parathion

Baygon

2, 4-Df 2, 4, 5-P CIPCh

Tween DMSO Ethanol Tween DMSO Ethanol Tween DMYO Tween DMSO Tween DMSO Tween 1) MS0

80

80

80 80 SO 80

---

a Source of test materials was as follows: Thanite, rotenone, allethrin, DDT, DDVP, Sevin, metboxychlor, lindane, dieldren, Naled, malathion, parathion, Co-Ral, Entomological Society of America Pesticide reference st.andards, City Chem. Corp., N. Y.; Pyrethrin, Lot 2287-1, McLaughlin Gormley King Co., Minneapolis, Minn.; Baygon, Ent. 25671, USDA, Beltsville, Md.; CIPC, Technical 99% assay, Pittsburgh Plate Glass Co., Pittsburgh, Pa.; 2, 4-D, Lot 091980, Dow Chemical Co., Abbott Rd., Midland, Mich.; 2, 4, 5-T, Am. Chem., Box 33, Ambler, Pa. b Ten microliters of each dilution were applied to each disc for the insecticide or herbicide in question. In the case of DMSO only 5 ~1 was applied. The solvent was evaporated by placing the discs under a warm stream of air. An inhibitory response was considered a clearing zone of > t mm from each disc. G Tween 80 (100 mg/ml) was formulated with methylene chloride. d Dimethyl sulfoxide. 8 2,2-Dichlorovinyl dimethyl phosphate. f 2,4-Dichlorophenoxyacetic acid. g 2,4,5-Trichlorophenoxyacetic acid. h Isopropyl-N-3-chlorophenylcarbamate.