摘要:

Mixtures ofMetaseiulus occidentalis(Nesbitt) andTyphlodromus pyriScheuten inoculated into apple trees gave as good or better biological control of European red mitePanonychus ulmiKoch and twospotted spider miteTetranychus urticae(Koch) than did similarly sized populations of either predatory mite alone. In mixes,M. occidentalisincreased more rapidly and achieved higher densities at midseason when prey were abundant than didT. pyri,which persisted longer and provided more predation at the end of the growing season. Both species alone gave near equal control ofP. ulmi. Control of twospotted mite byM. occidentaliswas always excellent. Sometimes,T. pyridid not controlT. urticaebefore it reached damaging levels. These mites appear to be complementary biological control agents. Their management in mixed populations is discussed.

ISSN:1754-5692    

DOI:10.1093/ee/21.1.202

出版商:Oxford University Press    

年代:1992

数据来源: OUP

摘要:

When polyhedral inclusion bodies (PIB) of the singly embedded nucleopolyhedrosis virus ofHeliothis, Baculovirus heliothis(HzSNPV), were exposed in water to simulated sunlight, there was about a 90% loss of its original viral activity, and the PIB were ≍3 times more sensitive than dry PIB. The pH (at 3,6, or 9) of the suspension had no significant effect on the extent of inactivation of PIB by simulated sunlight. Temperature of exposure (10, 22, 35, or 50%C) also had no effect on sensitivity of PIB exposed to simulated sunlight. Normally encountered field temperatures or pH, or both, coupled with exposure to sunlight, should not adversely affect the stability of PIB of HzSNPV. Presence of free water, however, can significantly increase the extent of PIB inactivation by sunlight.

ISSN:1754-5692    

DOI:10.1093/ee/21.1.210

出版商:Oxford University Press    

年代:1992

数据来源: OUP

摘要:

Larval weights for fall armyworm,Spodoptera frugiperda(J.E. Smith), were not significantly affected at two constant temperature regimes (24 and 27%C) when larvae parasitized byCotesia marginiventris(Cresson) were reared on resistant versus susceptible corn genotypes. Results indicated that the third trophic level was not adversely affected by fall armyworm feeding on pinto bean diet containing resistant versus susceptible corn genotypes. Developmental times forC. marginiventriswere shorter when the parasitoids were maintained at the higher temperature. Time from egg to cocoon formation at 24%C was Significantly less when hosts were fed diet containing foliage from the susceptible genotype ‘Cacahuacintle X’. Parasitoid longevity was increased at the higher temperature regime and was not affected by the corn genotype.

ISSN:1754-5692    

DOI:10.1093/ee/21.1.214

出版商:Oxford University Press    

年代:1992

数据来源: OUP