摘要:

Field cage experiments were conducted to identify predators which feed on eggs and early stage larvae ofHeliothisspp.,Pseudoplusia includens(Walker) andAnticarcia gemmatalisHübner. Isotope labeled (32p) eggs, 1st-, 2nd-, and early 3rd-stage larvae were exposed to possible predators. Predaceous arthropods which obtained the label were identified by autoradiography. A total of 349 individual arthropods from 25 species obtained radioactive labels when exposed to lepidopterous eggs or early stage larvae.Major predators identified in this study wereNabis roseipennisReuter,Geocoris punctipes(Say), andOxyopes salticusHentz.Nabis roseipenniswas the most frequently labeled predator of eggs and larvae. Spider species encountered in this study were not labeled when eggs were provided as prey. A high percentage of the carabids found in the foliage such asLebia analisDejean,Callida decora(F.) andColliuris pennsylvanicus(L.) was labeled. Other foliage dwelling beetles which contained the isotope wereColeomegilla maculata(DeGeer) adults and larvae andNotoxus monodon(F.). Several tettigoniids,Conocephalus fasciatus(Forster), also were labeled. Predation upon primary predators was demonstrated when labeled nymphs ofG. punctipesandN. roseipenniswere exposed to the indigenous predator complex.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.199

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Certain fungi were found to be valuable dietary supplements for stored-product beetles.Penicilliumspp. were compared with brewer's yeast as nutritional supplements in wheat flour diets forTribolium confusum.Only 3 fungal isolates of 20 tested added no nutritional value to autoclaved wheat flour (P. purpurogenum, P. rubrum,andP. oxalicum.) P. chrysogenumandP. viridicatumallowed excellent larval growth, minimal development time and low mortality. More progeny were produced onP. chrysogenumdiets than on control diets. Some other isolates were toxic or repellent.P. purpurogenumandP. rubrumwere poor growth media, increased development time and caused high mortality (99% for one isolate ofP. purpurogenum).Growth of these 2 species on wheat resulted in physical characteristics (hardened kernels, oily texture) which may have deterred insect feeding. Extracts revealed only small quantities of mycotoxins present in these fungal cultures.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.204

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Whole wheat flour, autoclaved wheat flour and fungal cultured (Penicilliumspp) wheat flour were offered toTribolium confusumadults in a choice chamber. Whole wheat flour was the preferred medium. No preference was shown for autoclaved wheat flour even over no flour at all. Behavioral responses ofT. confusumto various isolates ofPenicilliumwere compared to life history data forT. confusumfrom previously published feeding trials. In general,T. confusumwas attracted to those fungal isolates with nutritional benefit and repelled by those containing growth inhibitors. One mycotoxin, citrinin, was repellent toT. confusumwhen offered in whole wheat flour.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.213

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The mycotoxins ochratoxin A, citrinin, rubratoxin B, patulin, penicillic acid and oxalic acid were fed toTribolium confusum, Lasioderma serricorneandAttagenus megatomain whole wheat flour. Penicillic and oxalic acids were not toxic to these insects at any concentration tested. Ochratoxin A and citrinin inhibited larval growth ofA. megatomaat 10 and 1000 ppm, respectively, but rubratoxin B had no effect. Citrinin and rubratoxin B inhibited larval growth ofT. confusumandL. serricorneat 1000 ppm only. Patulin inhibited growth ofT. confusumat 1000 ppm both with and without yeast supplementation of the diet.L. serricornelarval growth slowed when patulin (at all concentrations) but no yeast was in the diet. Larval development time was increased whenever larval growth rates were inhibited. Reproduction ofT. confusumwas decreased by citrinin, patulin and ochratoxinA. L. serricornereproduction was affected only by citrinin.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.217

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The seasonal trends ofDendroctonus frontalisZimmermann attack on, and survival in, pines were studied. Estimates of beetles attacking, egg gallery length, 3rd and 4th instars, pupae, and beetles emerging were obtained for a total 113 loblolly pines,Pinus taedaL. The estimates were used to calculate the percentages of each of the following: eggs that survived to become 3rd and 4th instars, SE; 3rd and 4th instars that survived to become pupae, SL; pupae that survived to emerge as beetles, SP; and, eggs that survived to emerge as beetles, SG. The sizes and seasonal trends of SE, SL, SP, and SG changed during the 3-yr period studied. SE, SL, SP, and SG all decreased during the summer, but SL decreased most predictably. Trends in SG followed the trends in SL most closely.Indices of temperature and rainfall were calculated from the daily records of weather stations. Only SL and SG were associated with temperature and rainfall indices. The most useful indices in regression equations describing SL and SG were day-degree accumulation, DD, and the proportion of the infestation period when 0.6 cm or more of rain fell per day, PR. Increases in DD and PR were associated with decreases in SL and SG. It is suggested that DD and PR were the most useful indices because they measure both the size and the duration of temperature or rainfall.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.222

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

A total of 29 species of wild bees in 4 families (Hymenoplera: Apidae, Anthphoridae. Megachilidae, Halictidae) was collected from soybeans from 3 regions of the United States. Twenty-two species were taken in Delaware from 14 varieties of soybeans. Soybean pollen was recovered from 6 of these species. Seven species were collected in Wisconsin and 10 in Missouri.Melissodes bimaculata(Lepeletier) andHalictus confususSmith were found in all 3 regions.Megachile rotundata(F.),Megachile mendicaCresson, andDialictus testaceus(Robertson) were the most abundant pollen carriers. The highest density of wild bees was 0.36 individuals/m2on ‘Essex’ beans. The highest single species density was 0.24 individuals/m2forCeralina calcarataRobertson on ‘Columbus’ beans.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.230

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The scelionid egg parasite,Telenomus sphingisAshmead, effectively parasitizedErinnyis elloeggs in cassava,Manihot esculentaCrantz, in the Dominican Republic. In the 1st year of a 2-yr study,T. sphingisresponded well to increases inE. elloegg density. A time lag between the beginning of an intense oviposition period of the host and the action of the parasite resulted in larval population increases. During the 2nd year of the study,T. sphingiseffectively prevented the increase of large larval populations and no time lag between the action of the parasite and intense oviposition byE. ellowas found. OtherE. ellonatural enemies identified in the study wereApanteles americanus(Hymenoptera: Braconidae),Polistes major, P. crinitus(Hymenoptera: Vespidae) andBubulcus ibis(Aves: Ardeidae).

ISSN:1754-5692    

DOI:10.1093/ee/9.2.233

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Distribution of eggs of cotton fleahopper,Pseudatomoscelis seriatusamong wild host plants in a field study area was found to be related to the species and phenology of the plants. On a per plant basis, horsemint,Monarda punctata, accounted for the highest proportion of eggs until mid-July. After July 29 allP. seriatuseggs in the study area were found onCroton capitatus. Other aspects of the distribution of eggs among host plants in the field were investigated. Laboratory studies showed that floweringMonarda punctata, and floweringCroton capitatuswere favored over other host species and other phenological stages as oviposition sites. Significantly more eggs were deposited in a pubescent cotton variety than in a glabrous variety.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.236

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

We evaluated annual glandular-haired diploids (Medicago blancheanaBoiss., andM. disciformisDC.) and tetraploids (M. rugosaDesr. andM. scutellata(L.) Mill.) for resistance to adult alfalfa weevils,Hypera postica(Gyllenhal) in growth chambers.In no-choice and free-choice tests, adult weevils reared onM. sativaL. laid fewer eggs in stems ofM. blancheana, M. rugosaandM. scutellatathan in stems ofM. sativa. Similar results were obtained in no-choice tests when weevils were reared from eclosion on the test species (M. blancheana, M. rugosaandM. sativa). Stem size was not related to oviposition resistance in the annual species.Adults preferredM. sativato the glandular-haired species for feeding; adults confined to the glandular-haired species preferred stems to leaves. In contrast, leaves were readily accepted when the adults were confined toM. sativa.In no-choice tests, total adult mortality at 45 days was 65, 20, and 5%, respectively, forM. rugosa, M. blancheana,andM. sativa.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.241

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Developmental rates for the immature stages ofKeiferia lycopersicella(Walsingham) are presented. Laboratory development from oviposition to adult takes 456C°-days at a threshold temperature of 9.5°C. Greenhouse development requires from 444 to 495C°-days based on the 9.5°C threshold.

ISSN:1754-5692    

DOI:10.1093/ee/9.2.245

出版商:Oxford University Press    

年代:1980

数据来源: OUP