MAJOR FACTORS IN SURVIVAL OF THE IMMATURE STAGES OF HYLEMYA BRASSICAE (DIPTERA: ANTHOMYIIDAE) ON CABBAGE

1971 ◽  
Vol 103 (5) ◽  
pp. 717-728 ◽  
Author(s):  
M. K. Mukerji
Keyword(s):  
Sampling Error ◽  
Pupal Stage ◽  
Density Dependent ◽  
Mortality Process ◽  
Key Factor ◽  
Pupal Parasitism ◽  
Hylemya Brassicae ◽  
Table Data ◽  
Cabbage Maggot ◽  
Major Factors

AbstractStudies on the population dynamics of the cabbage maggot, Hylemya brassicae (Bouché), on cabbage were carried out at two locations in Ontario from 1967 to 1970. Analysis of life-table data for nine generations showed that extensive mortalities occurred during the following age intervals: (1) egg stage; (2) between hatching and the second moult; (3) third-instar larvae; (4) pupal stage. Density dependent mortality occurred only during the latter period. The analysis of age interval survivals and graphical key factor analysis showed that "misadventure" of the larvae between hatching and the second moult was the key factor. The overall mortality process from egg to adult eclosion was density dependent, revealing the importance of pupal parasitism as a stabilizing factor. A predictive model based on density relationships was found to explain 62% of the variance in generation survival. The remainder of the variance is unexplained and may be due to sampling error and/or the influence of factors not measured.

Major Factors in Survival of the Immature Stages of Pieris rapae (L.)

1966 ◽  
Vol 98 (6) ◽  
pp. 653-662 ◽  
Author(s):  
D. G. Harcourt
Keyword(s):  
Population Dynamics ◽  
Survival Rate ◽  
Pieris Rapae ◽  
Pupal Stage ◽  
Population Data ◽  
Life Tables ◽  
Immature Stages ◽  
Mortality Factors ◽  
Key Factor ◽  
Major Factors

AbstractDetailed studies on the population dynamics of the imported cabbageworm, Pieris rapae (L.), have been carried out at Merivale, Ontario, since 1959. A method for preparing life tables is described and a mean life table is presented for 18 generations of the species on cabbage. Population data for the preadult period show that there are three age intervals during which extensive mortality may occur: (1) between hatching and the second moult, (2) instars three to five, and (3) during the pupal stage. The analysis of successive age-interval survivals in relation to generation survival showed that the latter is largely determined by the survival rate for (2). Examination of the life tables revealed that a granulosis of the larvae caused by a capsule virus is the key factor in generation survival. Major mortality factors include rainfall and parasites.

SPATIAL PATTERN OF THE IMMATURE STAGES OF HYLEMYA BRASSICAE ON CABBAGE

1970 ◽  
Vol 102 (10) ◽  
pp. 1216-1222 ◽  
Author(s):  
M. K. Mukerji ◽  
D. G. Harcourt
Keyword(s):  
Spatial Pattern ◽  
Poisson Distribution ◽  
Negative Binomial ◽  
Immature Stages ◽  
Expected Number ◽  
Chi Square ◽  
Binomial Series ◽  
Binomial Parameter ◽  
Hylemya Brassicae ◽  
Cabbage Maggot

AbstractCounts of the cabbage maggot, Hylemya brassicae (Bouché), on cabbage did not conform to the Poisson distribution, there being an excess of uninfested and highly infested plants over the expected number. But when the negative binomial series was fitted to the observed distribution, the discrepancies were not significant when tested by chi-square. The negative binomial parameter k tended to increase with density. Using a common k, the distribution of the various stages may be described by expansion of (q − p)−k, when values of k are as follows: egg 0.78, larva 0.71, pupa 0.84. Three different transformations are offered for stabilizing the variance of field counts.

DIAPAUSE IN THE CABBAGE MAGGOT, HYLEMYA BRASSICAE (DIPTERA: ANTHOMYIIDAE)

1967 ◽  
Vol 99 (8) ◽  
pp. 890-893 ◽  
Author(s):  
D. G. R. McLeod ◽  
G. R. Driscoll
Keyword(s):  
Hylemya Brassicae ◽  
Cabbage Maggot

AbstractThe cabbage maggot, Hylemya brassicae, has a facultative diapause induced by the appropriate conditions of light and temperature: 16 hours of light per 24 hours at 20 °C produce nondiapause pupae while 12 hours of light per 24 hours at 20 °C produce diapause pupae. Diapause can be terminated if the pupae are exposed to temperatures from 0 to 5 °C for 4–5 months. Discrepancies in the literature with regard to the foregoing facts are explained.

HOST SELECTION BY THE ADULT CABBAGE MAGGOT, HYLEMYA BRASSICAE (DIPTERA: ANTHOMYIIDAE): EFFECT OF GLUCOSINOLATES AND COMMON NUTRIENTS ON OVIPOSITION

1976 ◽  
Vol 108 (10) ◽  
pp. 1021-1030 ◽  
Author(s):  
K. S. S. Nair ◽  
F. L. McEwen
Keyword(s):  
Host Selection ◽  
Plant Material ◽  
Wheat Germ ◽  
Casein Hydrolysate ◽  
Allyl Isothiocyanate ◽  
Mustard Oil ◽  
Wheat Germ Oil ◽  
Hylemya Brassicae ◽  
Cabbage Maggot

AbstractIn Hylemya brassicae (Bouché) little oviposition occurred when access to host plant material was denied. The mustard oil, allyl isothiocyanate (AITC), stimulated the flies into greater activity and attracted them to its source. Sinigrin and four other glucosinolates (mustard oil glucosides) tested induced oviposition. AITC by itself did not induce, oviposition, but in the presence of a glucosinolate, small concentrations of AITC caused an increase in the number of eggs laid. Glucose, sucrose, casein, wheat germ oil, and a mixture of B-vitamins did not influence oviposition at the concentrations tested, but casein hydrolysate inhibited it. The role of glucosinolates and common nutrients in host selection by H. brassicae is discussed.

Density dependent ambient ammonium as the key factor for optimization of stocking density of common carp in small holding tanks

Aquaculture ◽  
2006 ◽  
Vol 261 (3) ◽  
pp. 952-959 ◽  
Author(s):  
J.K. Biswas ◽  
D. Sarkar ◽  
P. Chakraborty ◽  
J.N. Bhakta ◽  
B.B. Jana
Keyword(s):  
Common Carp ◽  
Stocking Density ◽  
Density Dependent ◽  
Key Factor ◽  
Small Holding

POPULATION DYNAMICS OF THE CEREAL LEAF BEETLE, OULEMA MELANOPUS (COLEOPTERA: CHRYSOMELIDAE): A MODEL FOR AGE SPECIFIC MORTALITY

1972 ◽  
Vol 104 (6) ◽  
pp. 797-814 ◽  
Author(s):  
Robert G. Helgesen ◽  
Dean L. Haynes
Keyword(s):  
Pupal Stage ◽  
Leaf Beetle ◽  
Fourth Instar ◽  
Egg Survival ◽  
Density Dependent ◽  
Cereal Leaf Beetle ◽  
Density Dependent Mortality ◽  
Oulema Melanopus ◽  
First Instar ◽  
Dependent Mortality

AbstractThe cereal leaf beetle, Oulema melanopus (L.), has rapidly increased its numbers and range since it was discovered in Michigan in 1962. We have shown in this report that intraspecific density-dependent mortality is the major constraint on survivorship. We have attempted to quantify survival within a generation from the egg stage to the adult.Larval mortality varies among populations. Density-dependent mortality, caused by intraspecific competition, accounts for most of the variation of within-generation survival of the cereal leaf beetle in wheat and oats. Mortality in the first instar on oats and the fourth instar on wheat and oats is a linear function of the logarithm of total egg density. Establishment of the first instar on oats appears to become more difficult as density increases because leaf surface disturbance and interference with larger larva increases. Competition for food accounts for the increase in mortality of the fourth instar in both wheat and oats as density increases. Egg survival, survival of the first instar on wheat and in the second, third, and pupal stage in both crops are constants with respect to density. These constants can be expected to change with respect to other environmental parameters however, e.g. host variety, planting date, rainfall, etc.

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