摘要:

In a properly functioning ecosystem, most species are subject to predation as a regulatory factor. Tabanidae are no exception. McAtee and Beal (1912), Beal et a1. (1927), and Martin and Uhler (1939) reported that various species of birds prey on immature Tabanidae. Jones and Anthony (1964) were unable to find tabanid larvae in the crops of some Florida birds. Balduf (1935) reported that tabanid larvae were fed on by other insects, while Schwardt (1936), and Jackson and Wilson (1965) stated that insect predators ate the eggs of tabanids.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1116

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

The patterns of occurrence and importance of insects change as the prevalence of their hosts change. Prior to land clearing in Illinois and the introduction of exotic trees, pine sawflies were probably rare due to the scarcity of hosts. Only 2 pine species were a part of the original forest. Short leaf pine,Pinus echinataMill., ranged N into the S tip of Illinois, and E white pine,Pinus strobusL., occupied a small acreage in the extreme NW part of the State. All other pine species have been introduced. Pines have been planted for landscape enhancement for many years, and within the last 40 years extensive areas have been planted for timber and Christmas tree production. These plantings now provide suitable environments for 6 sawfly species.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1117

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

The need for dependable control of environmental parameters in bio-ecological studies has long been recognized. Many custom-built laboratory environmental chambers have been reported in the literature, and some are commercially available. The custom-built chambers are usually modified refrigerators (White and DeBach 1960) or they are fabricated from plywood, sheet metal, or plastic (Flitters and Messinger 1956; MacPhee and Patterson 1958; Jackson 1961). Most chambers are designed to produce constant temperatures with supplemental humidity control, air circulation, and light control (MacPhee and Patterson 1958; Jackson 1961, Scott 1968). Some are capable of programmed temperature control (Flitters and Messinger 1956; White and DeBach 1960). Commercial chambers are usually less specialized in function and more elaborate in design than custom chambers. This apparently is an attempt to maximize the adaptability of the chamber to a wider range of research programs.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1118

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Populations of insect pests can be controlled by maintaining a continuous population that can support enough parasites to effect a desired level of control (Evans 1930, Knipling and McGuire 1968). For example, Parker et al. (1971) suppressed larval populations of the imported cabbageworm,Pieris rapae(L.), by releasing fertile adults; then the resulting eggs supported an effective population of the egg parasiteTrichogramma evanescens(Westwood). Also, Thewke and Puttler (1970) demonstrated that a population ofTrichogrammacan be maintained by applying lepidopteran eggs artificially in the field. In the present tests, several species of lepidopteran eggs were exposed toTrichogrammain the field to determine whether host characteristics affected rate of parasitism. Our findings may be of value for both monitoringTrichogrammaparasitization and determining what host egg may be best used for supporting and increasing a population ofTrichogrammain the field.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1121

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Field studies on the foraging activity and behavior ofHeterotermes aureus(Snyder) andGnathamitermes perplexus(Banks) have revealed that these termites occasionally work at temperatures close to 50°C. Temperature is probably the major factor regulating their activity in plant debris on the soil surface, with moisture also having a regulatory effect in upper soil levels. Their ability to work at such high temperatures led us to this brief investigation of their upper survival thresholds.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1122

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

The fall cankerworm,Alsophila pometaria(Harris), is a chronic pest of hardwood forests in the Appalachian, mountain region of Virginia and North Carolina. Outbreaks occur frequently and occasionally become severe, but most are of short duration and local occurrence. Egg parasitism appears to play a major part in preventing the cankerworm from maintaining epidemic populations, thus causing the collapse of outbreaks. The scelionidTelenomus alsophilaeViereck has been the only egg parasite previously reported for this host in the S Appalachians.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1123

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Much knowledge about the stable fly,Stomoxys calcitrans(L.), remains to be gathered before successful control of this pest can be achieved. For example, we need to know some of the habits of the adults, including the way their feeding behavior is affected by various climatological conditions. Simmons (1944) stated that in tests conducted in Sarasota, FL, stable fly adults fed more readily in the early morning and late afternoon than they did at midday. However, since time is only relative, we cannot attribute this varied biting rate to time of day, but instead to the environmental conditions that were prevalent during those hours.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1125

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Hardwood tar oil is a byproduct obtained in the manufacture of charcoal. Dusts impregnated with this oil have been used for more than a decade in some southern States to treat seeds before planting to repel birds after seeds are planted in the field. Also, treatment of seeds prior to storage was alleged to be of value in preventing rodent damage. Both kinds of vertebrate pests cause extensive damage which is diffcult to estimate accurately. Unfortunately, the apparent successful use of hardwood tar oil in practice has been based on “grower satisfaction” rather than on experimental data, so the future of this product for agricultural use may be uncertain. Yet, the potential for use of a natural product applied only once for protection of seeds against a wide range of agricultural pests offers interesting possibilities in developing a program for protection of seeds in storage and in the field after planting. This paper presents a summary of results obtained from laboratory tests made to determine effectiveness of hardwood tar oil in preventing 3 species of grain beetles from damaging wheat seed.

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1126

出版商:Oxford University Press    

年代:1973

数据来源: OUP

摘要:

Sterile-male releases show considerable promise of controlling the Indian meal moth,Plodia interpunctella(Hübner) (Ashrafi et al. 1972 a, b). However, in some sterile-insect-release programs it is desirable to exclude females and to release only irradiated males. For example, the dose of irradiation required to sterilizeP. interpunctellais different for the 2 sexes (Cogburn et al. 1966), and females are rendered sterile by doses that produce only partial sterility in males. Then if the object of a control program is to induce self-perpetuating partial sterility in a population, as proposed by Ashrafi et al. (l972b), release of sterile females would be disadvantageous. A quick reliable method of sexing large numbers ofP. interpunctellawas therefore needed before field tests of the sterile-male-release method were practicable. Such a method was developed by using a genetic marker that I described (Brower 1972). (Adult Lepidoptera can be sexed by examination of the genitalia for the presence of claspers in the male, but this method is laborious if large numbers are involved, and it requires more handling of the adult than is desirable.)

ISSN:0046-225X    

DOI:10.1093/ee/2.6.1128

出版商:Oxford University Press    

年代:1973

数据来源: OUP