JOINT ACTION OF A JUVENILE HORMONE ANALOGUE WITH BENZOYLPHENYLUREAS INGESTED BY WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS (LEPIDOPTERA: TORTRICIDAE)

1984 ◽  
Vol 116 (8) ◽  
pp. 1063-1068 ◽  
Author(s):  
Jacqueline L. Robertson ◽  
Kimberly C. Smith ◽  
Jeffrey Granett ◽  
Arthur Retnakaran
Keyword(s):  
Simple Model ◽  
Juvenile Hormone ◽  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Independent Action ◽  
Western Spruce Budworm ◽  
Hormone Analogue ◽  
Juvenile Hormone Analogue ◽  
Response Range ◽  
Bay Sir 8514

AbstractMixtures of the juvenile hormone analogue (JHA) methoprene and each of three benzoylphenylureas (BPUs) were fed to sixth-instar western spruce budworm, Choristoneura occidentalis Freeman. The BPUs tested were diflubenzuron, BAY SIR 8514 (N-[(trifluoromethoxy)phenyl]carbamoyl-2-chlorobenzamide), and EL-127063 (N-[[[5-(4-bromphenyl)-6-metnyl-2-pyrazinyl]amino]carbonyl]-2-chlorobenzamide). Mixtures consisted of JHA:BPU combined in 1:9 proportions. Ingestion of methoprene combined with BAY SIR 8514 or diflubenzuron resulted in significantly lower mortality than expected under a simple model of uncorrelated, independent action. Ingestion of the mixture of methoprene and EL-127063, however, resulted in significantly enhanced toxicity over the upper response range (> 50% mortality).

EFFECT OF BODY WEIGHT ON LETHAL EFFECTIVENESS OF A JUVENILE HORMONE ANALOGUE APPLIED TO MALE AND FEMALE WESTERN SPRUCE BUDWORM (CHORISTONEURA OCCIDENTALS) (LEPIDOPTERA: TORTRICIDAE)

1982 ◽  
Vol 114 (11) ◽  
pp. 1063-1068 ◽  
Author(s):  
Jacqueline L. Robertson
Keyword(s):  
Body Weight ◽  
Juvenile Hormone ◽  
Spruce Budworm ◽  
Ethyl Carbamate ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Hormone Analogue ◽  
Juvenile Hormone Analogue ◽  
Relevant Variables

AbstractExperiments were performed to determine the role of body weight in the response of last instar western spruce budworm, Choristoneura occidentalis Freeman, to a topically applied juvenile hormone analogue (JHA), Ro 13-5223 (Ethyl [2-(p-phenoxyphenoxy)ethyl] carbamate). The response of males in weight classes from 50 to 130 mg was not proportional to their body weight; susceptibility increased drastically in heavier larvae. The susceptibility of females increased in proportion to their body weight. The results of these experiments suggest that future investigations of JHA effectiveness in last instar Lepidoptera should consider both weight and sex as possible relevant variables. Age of the last instar may not, in itself, be an adequate measure by which to quantify JHA effects.

EFFECTS OF INSECT GROWTH REGULATORS ON THE WESTERN SPRUCE BUDWORM (CHORISTONEURA OCCIDENTALIS) (LEPIDOPTERA: TORTRICIDAE): II. FECUNDITY AND FERTILITY REDUCTION FOLLOWING LAST INSTAR TREATMENTS

1979 ◽  
Vol 111 (12) ◽  
pp. 1369-1380 ◽  
Author(s):  
Jacqueline L. Robertson ◽  
Richard A. Kimball
Keyword(s):  
Simple Model ◽  
Reproductive Factors ◽  
Female Parent ◽  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Insect Growth Regulators ◽  
Fertility Reduction ◽  
Reproductive Effects ◽  
Population Reduction

AbstractThe fecundity and fertility of parent adult western spruce budworm, Choristoneura occidentalis Freeman, which survived treatment with IGRs in their last larval stage was assessed. With few exceptions, IGR treatment significantly reduced both reproductive factors regardless of whether the male or female parent had been treated. A simple model estimating population reduction in the F1-generation based on lethal and reproductive effects on the parents is described. If IGRs were applied at a dosage of 154 g/ha (ca. 2 oz/acre), the estimated percentages of F1 reduction which would result ranged from 74.6 (ZR-515) to 99+ (ZR-512 and Ro 10-3108 (oil)).

VARIABLES AFFECTING THE PRACTICAL USE OF JUVENILE HORMONE ANALOGUES FOR CONTROL OF THE WESTERN SPRUCE BUDWORM (CHORISTONEURA OCCIDENTALIS) (LEPIDOPTERA: TORTRICIDAE)

1981 ◽  
Vol 113 (9) ◽  
pp. 827-844 ◽  
Author(s):  
Jacqueline L. Robertson ◽  
Richard A. Kimball
Keyword(s):  
Juvenile Hormone ◽  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Stage Of Development ◽  
Reproductive Effects ◽  
Direct Exposure ◽  
Juvenile Hormone Analogues ◽  
Laboratory Bioassays ◽  
Residual Effectiveness

AbstractVariables affecting the efficacy of seven juvenile hormone analogues on western spruce budworm, Choristoneura occidentalis Freeman, were examined in laboratory bioassays. Those tested were epofenonane, hydroprene, kinoprene, methoprene, triprene, ZR-587, and ZR-1662. Selected intrinsic variables—stage of development, sex, and extent of direct contact with sprays—were examined in bioassays involving direct exposure of third instars, direct applications to three pupal age classes, and indirect applications to sixth instars. An extrinsic variable, persistence in the environment, was assessed by determining the residual effectiveness of each juvenile hormone analogue to sixth instars. Sixth instars, rather than third instars, appeared to be the target of choice for two reasons. First, less active ingredient would be required for equivalent mortality by the time of adult eclosion. Second, greater, more consistent, deleterious reproductive effects coupled with a lower incidence of sexual variation in lethal effectiveness, would occur. Pharate pupae and untanned pupae were very susceptible to most of the chemicals and may provide a secondary target for the primary target, sixth instars. The importance of direct chemical-insect contact in achieving maximum reproductive inhibition suggests that these chemicals might be used most effectively in ways such that contact can be maximized, as in ground applications. Finally, some juvenile hormone analogues such as epofenonane and ZR-1662 appeared to persist long enough to permit flexibility with respect to instar distribution in a population.

HORMONAL INDUCTION OF SUPERNUMERARY INSTARS IN THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1973 ◽  
Vol 105 (3) ◽  
pp. 459-461 ◽  
Author(s):  
Arthur Retnakaran
Keyword(s):  
Juvenile Hormone ◽  
Choristoneura Fumiferana ◽  
Larval Instar ◽  
Spruce Budworm ◽  
Hormone Analogue ◽  
Larval Instars ◽  
Juvenile Hormone Analogue ◽  
Hormonal Induction

AbstractInduction of supernumerary larval instars in the spruce budworm, Choristoneura fumiferana Clemens, by applying ZR-515, a potent juvenile hormone analogue, is explained in terms of larval differentiation. Application to the early sixth instar where structures are relatively indeterminate results in the formation of a supernumerary larval instar, whereas treatment of the late-larva wherein many structures are committed to differentiate towards the pupa, results in a larval–pupal mosaic.

Chemistry and field evaluation of the sex pheromone of western spruce budworm,Choristoneura occidentalis, Freeman

1982 ◽  
Vol 8 (2) ◽  
pp. 339-350 ◽  
Author(s):  
H. T. Cory ◽  
G. E. Daterman ◽  
G. D. Daves ◽  
L. L. Sower ◽  
R. F. Shepherd ◽  
...  
Keyword(s):  
Sex Pheromone ◽  
Spruce Budworm ◽  
Field Evaluation ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm
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