摘要:

A means for predicting population trends of the southern pine beetleDendroctonus frontalisZimmerman was effective on spots at Morrow Mountain State Park, NC, and the Calhoun Experimental Forest, SC, and in 2 ranger districts in the Sumter National Forest, SC. The primary predictive factor was the attack:emergence ratio. Five secondary factors were also used to improve the accuracy of predictions on static spots. All but 1 of the 12 spot-trend predictions made during the fall of 1973 were accurate 12 mo later; all but one of the predictions made during 1974 were accurate 8 mo later. Beetle spots predicted to decrease in the fall continued to do so for 6–9 mo, while increases were fully realized 3–6 mo later.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.335

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Larvae of the black cutworm,Agrotis ipsilon(Hufnagel), parasitized byMicroplitis kewleyiMuesebeck and reared on an artificial diet lived up to 60 days after parasite emergence. Under greenhouse conditions, the host larvae succumbed soon after parasite emergence and cut only 32% as many corn seedlings as did nonparasitized larvae.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.343

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Three yr of sampling for overwintering boll weevils,Anthonomus grandisBoheman, in debris from habitats adjacent to cotton fields near Brownsville, TX showed a density ranking of habitats, in descending order, of hackberry trees (Celtis laevigataWilld.), granjeno bushes (C. pallida Torr.), and open grassy areas. However, more total weevils were found in grassy areas, which were the most abundant of the habitats. Populations of overwintering weevils were lowest the winter after the cotton crop had been harvested and plowed under by Aug. 31.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.345

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

To assess the impact ofMicrolarinus lareynii(Jacquilin du Val) andM. lypriformis(Wollaston) on puncturevine (Tribulus terrestrisL.), half of the plants in irrigated and non irrigated plots were dusted weekly with 10% Diazinon® insecticide to protect them from weevil attack. The mortality, flower, and seed production, and stem lengths (radii) of insecticide-treated and untreated plants in these plots were then compared throughout the 1974 growing season.Water stress apparently was the principle cause of early-season plant mortality; however, weevil attack caused a 60% reduction in flower production on surviving plants in nonirrigated subplots. Moreover, only half of the flowers on these unprotected plants in nonirrigated sub-plots produced fruit late in the growing season. The mean number of seed/fruit from August onwards also was significantly reduced by weevil attack. Stem growth was exponential during June and July in irrigated plots, but was slower and ceased 2–3 wk earlier in nonirrigated plots where the suppressing effect of weevil attack was especially evident.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.349

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Gypsy moth larvae and pupae (91,902) were collected in 1st cycle populations along the leading edge of the infestation in Pa. from 1974–1977. More than 14,600 parasites were recovered. Parasite associations with pre-culminating, culminating, and post-culminating host populations are given.B. pratensiswas recovered most frequently during the pre-culmination phase,B. intermediaduring the culmination phase andP. silvestrisduring the post-culmination phase. Relatively low rates of parasitism were observed in the pre-culmination and culmination phases. Much higher rates were detected in the post-culmination phase. Parasite effectiveness is discussed.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.355

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Pitfall traps were used to monitorCalosoma sayiDeJean (Coleoptera: Carabidae) populations in soybean fields to determine the species' seasonal history, patterns of colonization, and response to insecticides.C. sayiadults were detected from mid-July into mid-Oct. Adults of the 1st and 2nd generations were separated by ca. 4 wk. Usually only 1 generation developed annually, but a 2nd generation developed in some instances.C. sayiadults quickly established populations in most areas where noctuid larvae were plentiful. However, noC. sayiwere detected, even though abundant prey were available, in 2 relatively isolated soybean fields which had not been previously planted to soybeans.Methyl-parathion and methomyl treatments reduced the numbers ofC. sayilarvae when these insecticides were applied when these forms were active. However, applications made beforeC. sayiactivity began often resulted in higher adult and larval numbers later. Insecticide induced reductions of the beetles' biotic control agents and, more likely, a resurgence of noctuid prey in treated areas may have led to the increase in numbers ofC. sayiafter insecticide treatment.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.359

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Heliothishybrids were produced from crosses betweenHeliothis subflexa(Guenée) females andH. virescens(F.) males. Male progeny from these crosses were sterile and females were fertile. When the hybrid females were backcrossed toH. virescensmales, the sterile male trait persisted through successive backcross (BC) generations.H. virescensmoths were released in field cages with BC3and BC6moths in 1:1 and 1:5 ratios, respectively, to study infusion of the hybrid sterile male trait into theH. virescenspopulation. Egg hatch was reduced through sterile male matings and the hybrid sterile male trait infused into theH. virescenspopulations.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.364

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Populations of predatory arthropods in insecticide free cotton fields varied in number and species composition during the growing seasons of 1972, 1973, and 1974 though there were definite trends. In general, populations increased between June and July, peaked in late July or early Aug., and decreased sharply after mid-Aug. Populations usually peaked near or soon after the peak squaring of cotton. Many fields were without significant number of predators for control of bollworms,Heliothis zea(Boddie), andHeliothis virescens(F.), during the period of their peak population which begins in Aug. and may extend through Sept.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.367

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Six families of beetles (Coleoptera) were found in traps placed around slash pine trees treated with Paraquat to artificially induce lightwood formation. Scolytid beetles, represented by 4 genera, were the most abundant. Application method and Paraquat concentration significantly affected (P<0.05) trap catches of some Scolytidae and Curculionidae.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.372

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Field olfactometers were designed for presenting various stimuli to host-seeking horn flies and measuring the degree of response.The devices emitted desired levels of gases and heat, and their form was suitable for flies to orient to, land upon, and be entrapped.The temperature of the devices and CO2affected orientation of flies to the devices. The data show that the devices are suitable for assessment of the parameters involved in host location.

ISSN:1754-5692    

DOI:10.1093/ee/7.3.375

出版商:Oxford University Press    

年代:1978

数据来源: OUP