摘要:

The main concepts of several multivariate statistical methods used for analyzing and classifying stored-grain infestation data observed during a decade's ecological studies is presented briefly in non-mathematical language with simple diagrams to encourage their use by stored-product entomologists. The mathematical assumptions and limitations of cluster analysis, multiple regression analysis, principal component analysis, factor analysis, canonical correlation analysis and discriminant analysis are given. Original examples of application and interpretation of principal component analyses to insect- and mite-infested wheat and rapeseed bulks on western Canadian farms are given, as this method was found to be the most useful hypothesis-formulating tool.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.185

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Varying levels (0.029-12.12 ppm) of mirex (dodedaclorooctahydro-1,3,4-metheno-1H-cyclobuta[cd]pentalene) were found in nontarget ants after aerial applications of mirex bait to control the red imported fire ant,Solenopsis invictaBuren, in Grimes and Brazos Counties, TX. Fourteen species of ants were monitored in the 2 plots. A fall treatment to the Brazos Co. area just recently invaded byS. invictahad the most pronounced effect. Those ants that are generally omnivorous and highly predacious were the first to be affected and were eliminated within 2 wk: these species includedS. invicta, Solenopsis geminata(F.),Monomorium minimum(Buckley),Pheidole dentataMayr, as well as a fungus-growing ant,Trachymyrmex septentrionalis(McCook). The highest levels of mirex were observed inPogonomyrmex barbatus(F. Smith) andConomyrma insana(Buckley). After 8 wk, only 2 species could be found in the Brazos Co. study plot,P. barbatusandCamponotus pennsylvanicus(DeGeer), and samples of both contained mirex. The population ofP. barbatusandC. pennsylvanicuswas fairly stable both pre and posttreatment.Populations ofS. invictawere reestablishing in the Brazos Co. plot 7 mo posttreatment as wereC. insanaandLeptogennys elongataMayr. Fourteen mo posttreatment,C. insanaandS. invictawere the most prolific reinvaders reaching populations based on mound numbers and mound size much greater than pretreatment populations. Populations ofM. minimum, Iridomyrmex pruinosumandP. dentatawere reduced a year later over pretreatment levels.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.193

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

In 2 trials, TLm96values of 43 and 78 ppm Bayer 73 were recorded for non-fed 1st instar larvae ofS. fuscipennis. TLm96values of 30 and 33 ppm sodium pentachlorophenate were recorded for non-fedS. fuscipennislarvae. Larvae that had been fed prior to testing were far less resistant to both molluscicides. The TLm48value for non-fed 1st instar larvae ofDictyasp. was 35.5 ppm Bayer 73.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.198

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Seasonal distribution of the lesser peachtree borer,Synanthedon pictipes(Grote and Robinson), was monitored from 1967–1975 in central Georgia by counting the pupal skins found on trees and by recording male captures in sticky traps baited with synthetic pheromone in peach orchards. Counts of pupal skins on selected trees in the same orchard over 3 yr revealed that the population of borers increased substantially between 1967 and 1970, even though insecticides were being used. Insecticides, however, were not directed towards lesser peachtree borers but to fruit insect pests. Orchards with both high and low populations could be indexed by using the pupal skin counts and the captures of males in traps baited with synthetic pheromone. However, only high populations provided adequate data to confirm 2 peaks of adult eclosion with either sampling method. The spring (1st) peak always occurred in May; a 2nd peak was usually evident in August or September. However, a 2nd peak occurred in late July (1974) at Zenith, Georgia, and there were indications of a third peak during September. In this same orchard, captures of males in sticky traps baited with synthetic pheromone were very similar to the eclosion pattern made from pupal skin counts.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.203

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

The life cycle of the greenhouse whitefly,Trialeurodes vaporariorumWestwood, consists of an egg stage, 4 nymphal instars, and an adult. It is convenient to divide the 4th stage into 3 substages: the “early” 4th instar, the transitional substage, and the unemerged pharate adult.The developmental rate of 2nd, 3rd, and “early” 4th whitefly nymphal instars, parasitized byEncarsia formosaGahan, does not differ significantly from that of unparasitized hosts. However, developing parasites arrest whitefly development during the transitional and pharate adult substages of the 4th stage.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.207

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Field-collected female alfalfa weevils,Hypera postica(Gyllenhal), from an area with a low population (New Jersey) produced an average life total of nearly 4200 eggs, while weevils from areas with high populations (Kentucky arid Indiana) produced somewhat fewer eggs (ca. 3100 and 3250 eggs). It is thus unlikely that the much smaller populations of weevils in New Jersey are caused by a lower fecundity of the alfalfa weevil; they are probably a result of the much higher levels of parasitism there. The average daily production per female weevil was 48 eggs. Most eggs were laid during the 1st 60 days of the experiment.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.211

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

The distribution and abundance of house dust mites,Dermatophagoidesspp., were studied in August, October, and December, 1975 in 4 different climatic zones in southern California. During these months, a total of 15 houses were sampled in each climatic zone. Ninety-three percent of the coastal houses were infested with mites, whereD. pteronyssinus(Trouessart) dominated (78%) overD. farinaeHughes. Sixty percent of the Riverside (inland valley) houses sampled were infested, whereD. farinaewas dominant (67%). A 3rd species,D. evansiFain, Hughes and Johnson, commonly occurring in birds' nests, was found once in a coastal and Riverside house. Densities of bothD. pteronyssinusandD. farinaewere considerably higher in coastal than in Riverside houses. Live mites were not found in the lightly mite infested houses sampled in the desert (54% positive) and mountains (27% positive). Relative humidity, which varied in houses located in different climatic zones of southern California, was noted to be the principal limiting factor influencing the distribution and abundance ofD. pteronyssinusandD. farinaein these zones. Temperatures did not appear to be an important factor influencing distribution and abundance of these mites in the study zones.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.213

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Releases of as few as 1400 virgin female tobacco budworms,Heliothis virescens(F.), sterilized with CO60produced a 322-m barrier zone around a given area by intercepting and copulating with 91% of the native males. The released females dispersed well over the zone, positioned themselves on the upper portions of the canopy of various types of plants, and began calling (secreting pheromone) at ca. 2 h after sundown. No males passed through the barrier before 3 AM (COT), when the supply of available females (unmated) in the barrier had been depleted.The mating response of males inside and outside the barrier was compared by placing clipped-wing females on mating tables. One-day-old females appeared to form a better barrier than 2- to 5-day-old females stored at 13.3°C. Female barriers might be used in behavioral studies. Encapsulated sex pheromones or sterile hybrids might be substituted for barrier females in population suppression of the tobacco budworm.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.217

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Rhinocyllus conicusexhibited ovipositional preference forCarduus nutansoverC. acanthoidesin cage studies both in the field and the greenhouse. Field observations of an established weevil colony also showed that oviposition was better synchronized withC. nutansthan withC. acanthoidesat a site where both thistles were present.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.222

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Blacklight traps were placed in soybean fields in 3 central Iowa counties during late April and early May 1975. Traps were tended every third day, with the number and sex of the collected green cloverworm adults recorded. Females were dissected to determine the number of times each had mated and were classified according to their reproductive status.Green cloverworms showed a distinct seasonal variation in mating and reproductive status. Seasonal variation culminates in nonfecund females during autumn.Male green cloverworms were collected in greater numbers in blacklight traps than were females. The sex ratio was weighted toward males when the population numbers were at high levels.

ISSN:1754-5692    

DOI:10.1093/ee/6.2.225

出版商:Oxford University Press    

年代:1977

数据来源: OUP