Pyrethroids and terrestrial non‐target organisms

Abstract

A B S T R A C TThe discovery and development of the pyrethroid insecticides represents u major advance in the techniques of crop protection and disease vector control. These compounds combine outstanding eficacy against a broad spectrum of noxious insects with low toxicity to birds and mammals. This paper considers the effects of pyrethroids on other components of the terrestriul non-target fauna, with particular reference to effects on 'beneficial' orgunisms, including natural pest-control agents, pollinators, and orgunisms responsible for the maintenance of soil structure and fertility. This paper uses laboratory und field data to identify which groups of organisms may be potentially ut risk from the use of pyrethroids, and draws on extensive field data to consider the signijcance of such hazards under conditions of normal use. Emphasis will be placed throughout on the evaluation of these compounds under pructical conditions, including both crop and non-crop usuges. Limitations to, and opportunities for, the use of pyrethroids ure discussed, und the potential for jiirther development is considered.

Evaluation of decreasing deltamethrin concentration in the treatment of olive logs: effects on the olive bark beetle and its associated parasitoids

“…In support of this hypothesis the number of emerged parasitoids in 2005 and 2006 was significantly correlated with the total host number (emerged plus parasitized); the correlation coefficient was 0.974. This result accords with the findings of Inglesfield (1990), regarding the effect of a-cypermethrin on entomophagous arthropods. Inglesfield concluded that changes in the host-searching behaviour of these animals could reflect the effect of the treatments on host availability, illustrating difficulties in distinguishing between direct effects of treatments on entomophagous arthropods and indirect effects resulting from decreased host availability.…”

Pyrethroid Insecticides: Use, Environmental Fate, and Ecotoxicology

“…Cypermethrin applied at levels sufficient to control aphids (25 g a.i./ha) also suppressed numbers of predaceous carabid beetle populations for 6 days post-spray. However, the pyrethroid had no effects on staphliniid beetles and only minor effects on predatory flies and parasitic wasps (Inglesfield, 1989). Applications of deltamethrin at 6.23 g a.i./ha similarly reduced ladybird beetle populations in wheat crops, but had no impact on fly or parasitic wasp species.…”

Assessing the exposure and toxicity of pesticides to bumblebees (Bombus sp.)

“…Bumblebees are important pollinators of some crops and many wildflowers and are considered 'beneficial' insects. Many pesticides in current use, such as pyrethroids, are known to be more toxic at lower temperatures (Inglesfield, 1989) and are applied in the early morning or late evening. Therefore these pesticides may be a greater threat to foraging bumblebees, which fly at lower temperatures than honeybees.…”