摘要:

Solenopsis invictaBuren colonies were shown to significantly alter chemical properties of soils. Ant mounds in clay and loam soils contained significantly greater concentrations of phosphorus than adjacent nonmound areas. Mounds had increasedpH and decreased organic matter. Potassium was concentrated in mounds on loam soil but not on clay. Grass growing on mounds contained significantly higher concentrations of protein, carotene, and phosphorus as compared to that growing in nonmound areas.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.160

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Conditions modifying expression of resistance of maize kernels to the maize weevil,Sitophilus zeamaizMotschulsky, were investigated in the laboratory. Sample size, moisture equilibration, and kernel aging did not modify resistance, whereas germination increased susceptibility. Earlier findings that resistance is mainly located in the undamaged pericarp were confirmed. More progeny developed on susceptible than on resistant lines after pericarp was damaged. Adding flour or dough to kernels significantly increased progeny numbers. A brief extraction of kernels in ethyl ether also increased progeny numbers significantly. The data suggested that resistance was due to nonpreference and was based on lack of feeding stimulants in resistant kernels, the undamaged pericarp acting primarily as a barrier against feeding and subsequent oviposition.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.163

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Magicicadaspp. of 17–yr cicadas laid 20–27 eggs/nest in twigs of 11 genera of deciduous trees in northern Ohio in 1965 and 1968. Less than 16 eggs/nest were found in grape, peach, poison ivy, and sour cherry.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.169

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The synergistic effect of various host factors on the response of in-flight populations ofDendroctonus ponderosaeHopkins emerging fromPinus ponderosaLaws. to the aggregation pheromonetrans-verbenol was quantified in a series of replicated field bioassays. Synthetic formulations oftrans-verbenol, although largely inactive alone, attracted beetles when deployed with certain host terpenes, particularly myrcene and terpinolene. Freshly extracted ponderosa pine oleoresin in combination withtrans-verbenol was significantly more attractive to beetle populations, particularly to females, than were pheromone complexes containing single monoterpenes or the composite monoterpene fraction of oleoresin (distilled oil), When tested withtrans-verbenol on traps without replacement, fresh resin samples lost their superior attractiveness within 1 day; the numbers and sex ratios of beetle catches on exposed resin-trans-verbenol treatments paralleled those on pheromone traps baited with distilled oils. The qualitative monoterpene composition of fresh resin, however, did not appear to change with short term exposure or during the steam distillation process. In combination, these findings suggested the presence of host-produced chemical messengers other than monoterpenes in oleoresin which are disproportionately attractive to ♀D. ponderosae, the host selecting sex. Analysis of resin samples by gas chromatography and mass spectrometry led to the constituent which may contribute to the superior field attractiveness of fresh resin. The need to further investigate the role of non-terpene host volatiles in bark beetle host selection is stressed.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.171

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Acclimated adult alfalfa weevils, in envelope cages, were placed in alfalfa fields and along their borders near Ithaca during early December. Subsequently cages were collected at 3-wk intervals through March. Total overwintering survival in all sites was 25%. There was no consistent difference in survival between sites or fields. The rate of survival was not constant through the winter period, but decreased markedly in late January and February.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.180

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Three ♂ German shepherds were trained to located disparlure treated objects and egg masses of gypsy moth,Porthetria dispar(L.). Field detection of egg masses on stones, wood and bark were made by utilizing the dogs in different searching patterns. Egg mass detection up to 2 m away by domestic canines was achieved which suggests that this technique might be used for quarantine inspection of vehicles or to detect suspect infestations ofP. dispar. There was a direct correlation between actual egg mass density in 0.01 ha plots and the number of masses found by the dog in 10 min directed searches. These results indicate that canines can be employed to estimate egg mass density by relating the number found in a prescribed search period to actual field density. This study is the 1st recorded use of dogs for detectmg an insect.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.183

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The predatory behavior and distribution on unsprayed apple leaves ofZetzellia mali(Ewing) was studied to determine its role as a predator ofPanonychus ulmi(Koch) andAculus schlechtendali(Nal.).Z. malifeed on egg stages ofP. ulmi. Occasionally the predator attacked resting and nymphal stages. Adults were not attacked. Female predators consumed a maximum of 1P. ulmiegg/day. The predator fed on active stages ofA. schlechtendali. Female predators consumed a maximum of 15A. schlechtendaliadults/day.The predator occurred only on the underside of the leaf, particularly along the midrib. Therefore, the prey on top of the leaf were immune to attack. Also,Z. malioccurred primarily on short side branches or spur growth whereasA. schlechtendalioccurred primarily at the tip of the branches containing terminal leaves.Segments of the prey population were always immune to attack because of their local distribution on widely scattered parts of the leaves and trees. In other words, spatial heterogeneity was too great for effective predator control of the prey. This coupled with the fact that adult ♀P. ulmiare not attacked suggests thatZ. malialone cannot maintain the population of its prey below economic damage levels. The practical worth ofZ. mali, however should be determined only in conjunction with actual spray practice and in association with other predators.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.187

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

A significant negative correlation coefficient and linear regression (Y = 80.9−201.0X) was found between concentration of gossypol and the toxicity of methyl parathion applied topically to larvae of the tobacco budworm,Heliothis virescens(F.), when they had been reared on diet containing 5 concentrations of gossypol. All sizes of larvae tested were affected similarly. Significant regressions were not obtained in similar tests with endrin or FMC-33297 (3-phenoxybenzylcis-trans-(±)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate).

ISSN:0046-225X    

DOI:10.1093/ee/5.1.192

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Laboratory-reared ♂ tobacco budworms,Heliothis virescens(F.), released in cotton entered the native mating population at a rate only 4.5% of that expected. Even when laboratory-reared males and females were released together, the laboratory male, though competitive in mating with laboratory-reared females, was still unable to obtain native ♀ mates. Subsequent experiments at Brownsville, TX, and Isabela, PR, indicated that the activity periods of the laboratory and native insects were out of synchrony by 2 h, thus possibly rendering the 2 populations incompatible.

ISSN:0046-225X    

DOI:10.1093/ee/5.1.195

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Red rubber sleeve stoppers used as substrates for the sex pheromone of the codling moth,Laspeyresia pomonella(L.), produced a 1st order loss curve (k = 1.09 × 10−3/h corresponding to a half-life of 26.5 days); rubber bands produced a complex loss curve; and polyethylene caps allowed extensive chemical degradation after a few days. In field trapping tests, a release rate of 1.25 μg/h produced the highest catches. Sleeve stoppers baited with 1.5 mg of attractant/stopper had virtually maximum attractiveness for a month and would be ideal for mass trapping during this period. Sleeve stoppers baited with 5 mg of attractant/stopper may be used for survey since the rate loss curve indicates they will be more attractive than the old survey bait of 10 ♀ after as much as 4.4 mo (5 half-lives).

ISSN:0046-225X    

DOI:10.1093/ee/5.1.199

出版商:Oxford University Press    

年代:1976

数据来源: OUP