摘要:

Cereal leaf beetle,Oulema melanopus(L.), prepupae, pupae, and adults in pupal cases were subjected to regimes of 4 temperatures and 5 relative humidities to determine mortality at each developmental stage. Temperatures ranged from 26.7 to 35.0°C and relative humidities from 13 to 71%. Mortality was greatest at the higher temperatures and lower relative humidities. These findings suggest that high soil temperatures with low soil moisture might limit cereal leaf beetle survival in the warm, dry Great Plains states.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.58

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Twelve species of field-collected arthropod predators suspected of feeding on alfalfa weevilHypera postica(Gyllenhal) (Coleoptera: Curculionidae) larvae were studied in the laboratory. Most experiments used weevil instars III and IV. In one type of test, weevil larvae were the only prey; the other type permitted a choice of weevil larvae,Lygusspp. nymphs and pea aphid adultsAcyrthosiphon pisum(Harris).Hippodamia convergens(Guérin) (larvae and adults),Coccinella transversoguttata(Faldermann) (adults),Nabisspp. (adults), andChrysopa oculata(Say) (larvae) preferred aphids. In the absence of aphids, the coccinellids were active weevil predators. The spidersTibellus oblongus(Walckenaer) andXysticussp.;Collops vittatus(Say),Collops bipunctatus(Say) andForficula auriculariaLinn. (all adults), appeared to be opportunistic feeders. The latter ranked among the more effective weevil predators.Agullasp. (adults) ate very few weevil larvae. Instar IV prey were too large for some smaller predators.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.62

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Host-parasitoid-pathogen interactions amongPieris rapae(L.),Apanteles glomeratus(L.), and the granulosis Virus (GV) ofP. rapaewere studied using laboratory and field populations. Survival ofA. glomeratusin GV-infectedP. rapaedepended on the time between oviposition by the parasitoid in a larva ofP. rapaeand ingestion of GV by the larva; parasitoids did not survive in host larvae exposed to GV on or before 4 days after oviposition at 25°C. Survival ofA. glomeratuswas less inP. rapaein which the GV disease was severe than in lightly infected larvae.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.65

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Thirty-three species of parasites were reared from four species of lepidopterous larvae. Larvae collected from insect resistant and susceptible soybeans showed no differences in insect parasitism. Hosts and parasitism levels for 1976 and 1977 respectively were: green cloverworm,Plathypena scabra(F.), 11.2 and 8.5%; corn earworm,Heliothis zea(Boddie), 1.2 and 5.7%; soybean looper,Pseudoplusia includensWalker, 9.7 and 16.0%; and velvetbean caterpillar,Anticarsia gemmatalisHubner, 0.4 and 1.9%. The most prevalent parasite reared fromP. scabra,H. zeaandP. includenswasApanteles marginiventris(Cresson).P. includenswas a new host record forA. marginiventris.Meteorus autographae(Vier.) was the most prevalent parasite ofA. gemmatalis.P. scabrawas the only host exhibiting lower population levels in the insect resistant ED73-37l than in the susceptible soybean variety ‘Bragg’.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.69

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Sameodes albiguttalis(Warren), a South American pyralid, was released at 20 sites in Florida for the biological control of waterhyacinthEichhornia crassipes(Mart.) Solms. It has become established at or near 16 of these sites and has begun to disperse throughout the state. All release methods proved satisfactory, but, in south Florida, establishment was best when 1st instar larvae were released October through March. Populations established more readily on young plants with luxuriant growth as opposed to older plants or those with poor growth.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.75

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

In greenhouse and field experiments, more than half of all 4-to 8-day-old, square-infesting, bollworm larvae,Heliothis zea(Boddie), were found on squares<6mm in diameter (measured at widest point on calyx). In terminal shoots from plants grown in the field in New Mexico, more than half of all 4-to 8-day-old larvae were found in squares<4 mm in diameter. Heavily damaged squares were nearly always<2 mm. In addition to the larvae in the squares, 25.6% of all larvae were found on leaves. Much of the heavy damage occurred as hollowed out squares which quickly dried out and were shed by the plant. Lighter damage was more evenly distributed across a range of square sizes. All parts of the square were consumed by bollworm larvae. Anthers and filaments suffered the heaviest damage.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.81

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Larvae, pupae and adults of the smaller elm bark beetle,Scolytus multistriatuswere infected and killed by the entomogenous nematodes,Neoaplectana carpocapsaeWeiser andHeterorhabditis bacteriophora.The nematodes multiplied within the host cadavers and began leaving parasitized beetle larvae 14 days after initial infection. Each beetle larva produced an average of 4, 131 and 4,238 infective stages ofN. carpocapsaeandH. bacteriophora, respectively. This is equivalent to one mg of host larva tissue producing approximately 1,620–1,660 infective stage juveniles ofN. carpocapsaeandH. bacteriophora.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.85

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

A mark and recapture system is described for estimating the population sizes of adult stable flies,Stomoxys calcitrans(L.). Flies are marked with fluorescent powders and recaptured on fiberglass panels treated with adhesive. The theoretical model used for estimating population sizes from recapture data includes adjustments for the mortality and emigration of marked flies and allows for continuous trapping of flies during time periods of unequal length. Results of field tests indicated that general trends in wild populations are adequately measured with the system, but weather changes may affect the trapping efficiency of the fiberglass panels.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.88

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Damage to corn from artifical infestations was not as severe with eggs from a non-diapause strain ofDiabrotica virgiferaLeConte as from infestations with eggs from field-collected beetles in an adjacent study. Damage was probably reduced because (1) the non-diapause eggs lost viability after infestation in the field, whereas eggs from field-collected beetles did not, and (2) the non-diapause eggs hatched 6 days earlier than those from field-collected beetles. Hatch occurred when the corn plants were still quite small; perhaps this kept many of the larvae from becoming established on the plants. Non-diapause eggs would probably not be useful for field infestations at planting time but might be useful in determining pest/host plant relationships with post-planting infestations.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.94

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

As compared to water loss from eggs of several other species, eggs of range caterpillar,Hemileuca oliviaeCockerell, are quite resistant to desiccation. Range caterpillar eggs lack aeropyles, and gas exchange apparently occurs through the micropyle. Loss of water from eggs is stimulated by exposure to low vapor densities or to high temperatures. Temperature stimulates embryonic development, and vapor densities as low as 7.6 g/m3stimulate eclosion.A higher proportion of variation in water loss occurs among egg masses than within masses. Egg size contributes to this variation, with small eggs losing water at a significantly higher rate than large eggs. Weight of larvae eclosing from eggs is inversely proportional to water loss, but larval survival does not seem to be affected by water loss. Eclosion was obtained from eggs losing 33 to 57% of their water.

ISSN:1754-5692    

DOI:10.1093/ee/10.1.97

出版商:Oxford University Press    

年代:1981

数据来源: OUP