摘要:

Larvae of the pyralid moth,Sameodes albiguttalis(Warren), caused heavy but, sporadic damage to waterhyacinth,Eichhornia crassipes(Mart.) Solms in Argentina. Females laid an avg of 300 eggs each, usually in injuries, on the plant leaves. The larvae fed inside the petioles and bud of the plant and pupated in white cocoons in the bulbous-type petioles. Eggs required 4 days to hatch, the 5 larval instars took a total of 21 days to pupate, and pupae took 7 days to emerge. In the laboratory, 95.6% of the eggs survived, 54.3% of the larvae, and 96% of the pupae. With optimum conditions in the laboratory, the population was calculated to increase 1.16 times/day, or 150 times/generation of 34 days, and to double each 4.7 days. Five generations/year occurred in the field, and maximum populations measured were 130 larvae and pupae/l00 plants. A braconid parasitoid heavily attacked larval populations and a pathogen,Nosema invadensor nr., infected all stages in the field in Argentina.Sameodes albiguttaliswould probably be an effective control agent if released in regions where it is not native. A synergistic effect between it and weevils of the genusNeochetinais predicted. The factors affecting its potential effectiveness are discussed.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.309

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Sameodes albiguttalis(Warren) is highly specific to the plant family Pontederiaceae. In laboratory tests, it laid 60.3% of 13,645 eggs on waterhyacinth, (Eichhornia crassipes(Mart.) Solms), and 33.3% on 3 other species of Pontederiaceae; a few eggs were laid on 12 other plants of the 46 species tested. Larvae completed their development and produced adults or pupae only on waterhyacinth or occasionally onEichhornia azurea(Swartz) Kunth andPontederia cordataL. in the laboratory. However, in the field, larvae and pupae ofS. albiguttaliswere collected only from waterhyacinth and occasionally fromE. azurea.Sameodes albiguttalishas never been reported in Argentina onP. cordataor as a pest of any beneficial plant, and it did not damage any beneficial plants tested (exceptP. cordatain the laboratory). It appears safe for introduction into the U.S. to control waterhyacinth.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.322

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

AlthoughArgentinorhynchus bruchi(Hustache) from northern Argentina and Paraguay is extremely rare, it has the potential to cause heavy damage to waterlettuce (Pistia stratiotesL.). In the laboratory, adults ate 1 cm2of leaf surface/day. Field-collected females laid an avg 1575 eggs each on the leaf surface after they were brought into the laboratory. The eggs hatched in 7.6 days. First instars fed within the spongy leaf tissue, and 2nd and 3rd instars fed in the crown. Larvae developed through the 3rd instar in 12 days. The 4th instars could not be reared; they always exited from the plant and drowned in the water of the container. Adults fed and oviposited only on waterlettuce (except for slight feeding onSpirodela) among 26 plant species tested. Larvae fed slightly on 6 species of plants, but all died within 7 days except those on waterlettuce. In the laboratory, 6, 8, or 10 larvae/plant killed waterlettuce within a month.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.329

出版商:Oxford University Press    

年代:1978

数据来源: OUP