Insecticide resistance resulting from an absence of target-site gene product

Genetic changes in insects that lead to insecticide resistance include point mutations and up-regulation/amplification of detoxification genes. Here, we report a third mechanism, resistance caused by an absence of gene product. Mutations of the Methoprene-tolerant (Met) gene of Drosophila melanogaster result in resistance to both methoprene, a juvenile hormone (JH) agonist insecticide, and JH. Previous results have demonstrated a mechanism of resistance involving an intracellular JH binding protein that has reduced ligand affinity in Met flies. We show that a γ-ray induced allele, Met27, completely lacks Met transcript during the insecticide-sensitive period in development. Although Met27 homozygotes have reduced oogenesis, they are viable, demonstrating that Met is not a vital gene. Most target-site resistance genes encode vital proteins and thus have few mutational changes that permit both resistance and viability. In contrast, resistance genes such as Met that encode nonvital insecticide target proteins can have a variety of mutational changes that result in an absence of functional gene product and thus should show higher rates of resistance evolution.

Functional haplodiploidy: a mechanism for the spread of insecticide resistance in an important international insect pest.

The coffee berry borer, Hypothenemus hampei, is the most important insect pest of coffee worldwide and has an unusual life history that ensures a high degree of inbreeding. Individual females lay a predominantly female brood within individual coffee berries and because males are flightless there is almost entirely full sib mating. We investigated the genetics associated with this interesting life history after the important discovery of resistance to the cyclodiene type insecticide endosulfan. Both the inheritance of the resistance phenotype and the resistance-associated point mutation in the gamma-aminobutyric acid receptor gene Rdl were examined. Consistent with haplodiploidy, males failed to express and transmit paternally derived resistance alleles. Furthermore, while cytological examination revealed that males are diploid, one set of chromosomes was condensed, and probably nonfunctional, in the somatic cells of all males examined. Moreover, although two sets of chromosomes were present in primary spermatocytes, the chromosomes failed to pair before the single meiotic division, and only one set was packaged in sperm. Thus, the coffee berry borer is "functionally" haplodiploid. Its genetics and life history may therefore represent an interesting intermediate step in the evolution of true haplodiploidy. The influence of this breeding system on the spread of insecticide resistance is discussed.

Insecticide application equipment for the control of insects of public health importance /

Mode of access: Internet.

Evaluation of the Bell 205A-1 turbojet helicopter and spray system for forest application of insecticide /

"GPO 990-424"--P. [4] of cover.

Federal Insecticide, Fungicide, and Rodenticide Act [microform] : hearing before the Subcommittee on Department Operations, Research, and Foreign Agriculture of the Committee on Agriculture, House of Representatives, Ninety-seventh Congress, second session, on H.R. 5203.

"Serial no. 97-R."

Thimet diethione insecticide technical manual.

Cover title: Thimet insecticide technical manual.

Insecticide and raticide plants; analysis and summary of information on the crop possibilities of insecticide and raticide plants.

Mimeographed.

Notices of judgment under the Insecticide act.

No. 73-1100 issued in U. S. Insecticide and Fungicide Board, Service and regulatory announcements.

Organizational, direct, and general support, and depot maintenance repair parts and special tools list : sprayer, insecticide, skid mounted, gasoline driven, 40 gal per hour, fog (Curtis Automotive Devices model CFR-40000) FSN 3740-790-6188.

Includes index.

Some effects of insecticide spray accumulations in soil on crop plants /

Caption title.

Structure and toxicity of insecticide deposits for control of bark beetles /

Includes bibliographical references (p. 54-59).

Rôle des boucles interhélicales du domaine I dans la formation de pores transmembranaires par la toxine insecticide Cry1Aa du bacille de Thuringe

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Rôle des boucles interhélicales du domaine I dans la formation de pores transmembranaires par la toxine insecticide Cry1Aa du bacille de Thuringe

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.