摘要:

The probability of capture of male Mediterranean fruit flies,Ceratitis capitata(Wiedemann), by trimedlure in a trap is described by an exponential curve derived with a good fit from 22 replications at each of six different distances. Not all males are responsive on any one day. There is a high probability of capture of nearby males which decreases rapidly to only a few percent at 240 m (800 ft).

ISSN:1754-5692    

DOI:10.1093/ee/15.1.71

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Oviposition habits ofEoreuma loftini(Dyar) were examined in sugarcane in the Lower Rio Grande Valley of Texas. Moths oviposited in cryptic sites located on dead, dry leaves and whorls. Plant samples indicated that 96.0% of the total number of eggs collected were located in the basal portion (between ground level and 80 cm height) of the sugarcane plant. Early in the growing season (June to July), initial oviposition was predominantly on dead leafblades (73%), but as dead shoots became more abundant (August to November) oviposition shifted to whorls of dead shoots (84%). Overall, eggs were predominately laid on leaves and whorls of dead shoots (89.4%) as opposed to dead leaves attached to green plants (10.6%). Several egg masses were found parasitized byTrichogramma retorridum(Girault).

ISSN:1754-5692    

DOI:10.1093/ee/15.1.75

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Banks grass mite (BGM),Oligonychus pratensis(Banks), density was monitored on corn plants of various growth stages that were differentially irrigated. Treatments were designed to create different levels of plant stress by combining factors associated with leaf senescence with stress due to moisture deficits. Plants that showed severe stress symptoms and those without stress symptoms became infested with low BGM numbers. Plants with intermediate stress levels became infested with the most BGM. Plant-canopy temperature measurements indicated that higher temperatures were associated with more mature, water-stressed plants, and canopy temperatures were significantly correlated with BGM numbers. The combined effect of adequate host quality and high microenvironmental temperatures may account for rapid BGM density increases during plant stress episodes.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.79

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Oryctes rhinoceros(L.) breeding and survival in decaying coconut wood was studied in 53 plots (each 9 ha) in southern Luzon, Philippines. Compared with stumps and coconut trunks on the ground, dead standing palms were preferred for breeding and contained baculovirus-infected larvae 5- to 15-fold more frequently. The percentage of baculovirus-infected breeding sites increased with density of dead standing palms up to about five dead palms per hectare, but then decreased again. Larva mortality was higher in dead standing palms and stumps than in trunks on the ground. Rainfall was also a significant mortality factor. Palm damage due toO. rhinocerosincreased with density of stumps and trunks on the ground but not with density of dead standing palms. It is concluded that in the Philippines dead standing palms can play an important role in spread of baculovirus and regulation ofO. rhinocerospopulations.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.84

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

The red pine cone beetle (Conophthorus resinosae) and the webbing cone worm (Dioryctria disclusa) compete for cones of red pine (Pinus resinosa) on a first-come, first-served basis. As a result, numbers of cones attacked by the cone beetle are often negatively correlated with those attacked by the cone worm. Moreover, when populations of both insects are high, each will attack cones already occupied by the other species. Different environmental conditions may permit one or the other to be competitively superior.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.88

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Nilaparvata lugens(Stål) populations on very early and early maturing rice cultivars with growth durations of 94–103 days from sowing to harvest were much lower than those on ‘IR20’, a medium-duration (120 days) cultivar, on which populations reached a peak in the third generation. The very early and early maturing cultivars, which were nearing harvest and were apparently unsuitable to the insects at the time of their final buildup, escaped damage.N. lugens/predator ratios were lower in the very early and early cultivars than in ‘IR20’.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.93

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Liriomyza trifolii(Burgess) larva distribution was dependent upon pepper plant development. During the initial 2–3 weeks of seedling growth, significantly greater mean numbers of larvae per leaf were noted on cotyledons. Afterwards, mature leaves had consistently greater mean numbers of larvae per leaf than newly emerged leaves. Plant stratification studies conducted after plants reached 75 mm in height indicated that mature leaves in the middle linear ⅓ of the plant supported significantly moreL. trifoliilarvae per leaf than leaves in other parts of the plant.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.96

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Biology and life cycle ofAnaphes sordidatus(Girault), an egg parasitoid of the carrot weevil,Listronotus oregonensis(LeConte), are reported. Adult longevity ranged from 1.4 ± 0.9 (SD) days for adults from host eggs in which four parasitoids developed at 29°C to 9.6 ± 3.7 days for singly emerged adults at 17°C. Fecundity was 49.4 ± 29.3 offspring for singly emerged females and 33.2 ± 19.7 for females that emerged from host eggs in which two or more parasitoids developed. Mating status had no significant effect on fecundity. Most oviposition (79%) occurred within 3 days of adult emergence. Development time (egg-to-adult emergence) was strongly influenced by temperature (8.7 and 17.6 days at 29 and 17°C, respectively). Adult emergence from the host egg occurred primarily during the first 2 h of daylight. Implications ofA. sordidatusbiology and life cycle for its effectiveness in the field are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.100

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

The oviposition site selection by the European corn borer and the within-field pattern of egg mass distribution were studied on field corn in western Virginia. Nearly all egg masses were found on the lowest six leaves of the plant. The within-field distribution of egg masses was found to be a random distribution, as interpreted from the variance/ mean ratio, the method of Taylor and Green's coefficient of dispersion.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.106

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Seasonal occurrence of corn rootworm,Diabrotica virgifera virgiferaLeConte andD. barberi(Smith and Lawrence), larvae and pupae was monitored in a total of eight corn-planting dates from 1980 to 1982, while adult emergence was characterized in a total of 11 planting dates from 1979 to 1982. Delayed planting was associated with a proportionate delay in occurrence of larvae, pupae, and adults. After adjusting for the effects of corn-planting date, population phenologies were described as functions of calendar date and heat-unit (HU) accumulations. The first predictable event was peak occurrence of second instars. Seasonal occurrence of third instars, pupae, and adults appeared equally consistent and predictable with respect to calendar date and soil HU (base, 11°C). Models based on air HU (base, 16°C) were judged to have little applicability. Simple linear models for predicting the occurrence of larvae, pupae, and adults based on calendar date or soil HU are presented. The similarities in predictability between the calendar date and soil HU models indicated that relating phenology to Julian date may provide the simplest and best estimates of the seasonal occurrence of corn rootworms. Quantifying the effects of other factors that directly or indirectly affect soil temperature and development of corn rootworms (e.g., soil type, moisture, and tillage) might increase the utility of soil-HU models.

ISSN:1754-5692    

DOI:10.1093/ee/15.1.109

出版商:Oxford University Press    

年代:1986

数据来源: OUP