The Effects of Insecticide Treated Netting on Male-Female Interactions in Red Flour Beetles

Courtship behaviors take place before and after copulation for the purpose of stimulating the female (Evardsson & Arnqvist 2000). Females will mate with different males within minutes of the first copulation (Pai &Yan 2003), with males showing a preference for virgin females (Lewis & Iannini 1995). Red flour beetles (Tribolium castaneum) show a decrease in progeny output following exposure to insecticide treated netting (Scheff et al. in prep). To assess whether females exposed to insecticide treated netting had decreased courtship attempts, virgin females were placed with a single male to accurately determine the number of mating pair interactions. Courtship behavior and mating pair interactions were recorded to determine if the number of mating pair interactions will decrease after exposure to insecticide treated netting. Our results indicate no significant difference between the number of interactions between females exposed to control netting or insecticide treated netting. However, with females exposed to insecticide treated netting the duration of interactions increased and more interactions were initiated by males. These results suggest that the decline in progeny output may be due to reallocation of reproductive resources following exposure to insecticide treated netting and not due to decreased numbers of mating attempts

Some Observations on Insecticide Resistance

A model for development of resistance to an insecticide in an insect population is presented. The rate of development of resistance increased with increases in the proportion of the breeding population exposed to the insecticide and with increases in the survival from exposure to the insecticide. Restricting application of insecticides to an only if needed basis and, within limits, dosages that assure minimal survival of the exposed insects are suggested as means of impeding resistance to insecticides. The huge gene pools represented by the large populations of pest species are assumed to maintain insecticide resistance as a continuing problem in crop protection

Detection of Insecticide Resistance in Aedes Aegypti to Organophosphate in Pulogadung, East Jakarta

Dengue Hemorrhagic Fever (DHF) is a major public health problem in Indonesia. Jakarta is a capital city with the highest number of dengue patients. Among sporadic endemic areas in Jakarta, Pulogadung, a district of East Jakarta, is one of endemic areas of this disease. The primary strategy for the control of DHF is based on reducing population densities of the main mosquito vector Aedes aegypti. Organophosphate is an insecticide that has been used for more than 25 years in dengue vector control program. The long term used and sublethal dosage of this insecticide can induce resistance. This laboratory study used microplate test and ELISA reader to determine the increase of alfa- esterase activity in Aedes aegypti larvae for detecting the resistance to organophosphate. Resistance pattern of Ae aegypti to organophosphate insecticide in RW 01 Pulogadung was shown to be: 23% high resistant, 33% medium resistant and 44% sensitive. This result was highly related to local community behavior where we found that the use of insecticide spray by the people was very low (8.8% of the sample). We found that the people who used insecticide spray were only 8.8% of the sample. Therefore, organophosphate still can be used in this area to control the Dengue Hemorrhagic Fever in the future. Based on resistance pattern of Ae aegypti to organophosphate insecticide in RW 01 Pulogadung, we can conclude that organophosphate still can be used in this area to control the Dengue Hemorrhagic Fever in the future

Assessment of a national voucher scheme to deliver insecticide-treated mosquito nets to pregnant women.

BACKGROUND: The benefits of a health-related intervention may be compromised by the challenges of delivering the intervention on a large scale. We analyzed the process involved in the Tanzania National Voucher Scheme, a system for delivering insecticide-treated mosquito nets to pregnant women. We aimed to identify potential ways to equitably improve overall coverage of the intervention. METHODS: We defined five steps in the process. We collected data from a multistage cluster survey of nationally representative households conducted in 2007 across 21 districts in Tanzania. Using these data, we multiplied the rate of success of each step cumulatively to estimate the overall success of the system. RESULTS: The rate of coverage for use of insecticide-treated nets among pregnant women was 23% (95% confidence interval [CI] 19%-27%). We observed large differences in coverage by socio-economic status, from 7% (95% CI 4%-13%) among participants in the poorest households to 48% (95% CI 38%-59%) among those in the richest households. The rate of success of each step in the process was high (60%-98%). However, the cumulative rate of success for the process as a whole was low (30%). The largest and most inequitable reduction in coverage occurred in the step involving treatment of nets with insecticide. INTERPRETATION: The cumulative effect of modest attrition at several steps in the process substantially diminished the overall rate of coverage for all women, but most markedly among the poorest participants. Analysis of the process suggests that delivery of nets treated with long-lasting insecticide rather than untreated nets packaged with an insecticide-treatment kit could result in an improvement in coverage of 22 percentage points, from 30% to 52%

Comparison of Leafhopper Species Complexes in the Ground Cover of Sprayed and Unsprayed Peach Orchards in Michigan (Homoptera: Cicadellldae)

Two Michigan peach orchards were sampled for leafhoppers using a fixed-area ground sampling device attached to a D-vac®. Absolute abundance estimates indicated that routine tree insecticide applications greatly depressed leafhopper populations. This, and the fact that no resident, known vectors of the X-disease pathogen were detected, suggests that increasing insecticide applications to check the spread of the disease through vector control would be ineffective

ESTIMATING INSECTICIDE APPLICATION FREQUENCIES: A COMPARISON OF GEOMETRIC AND OTHER COUNT DATA MODELS

The number of insecticide applications made by an apple grower to control an insect infestation is modeled as a geometric random variable. Insecticide efficacy, rate per application, month of treatment, and method of application all have significant impacts on the expected number of applications. The number of applications to control a given insect population is dependent on the probability of achieving successful control with a given application. Results suggest that northeastern growers have the highest and mid-Atlantic growers the lowest probability of controlling an infestation with a given application. Results also indicate that scales require the least and moths the most number of applications. Growers are not responsive to per unit insecticide prices, but respond negatively to insecticide toxicity, supporting findings from previous pesticide demand analyses.Apples, Count data, Geometric, Insect control, Pesticides, Crop Production/Industries,

Assessing the long-distance repellency of long-lasting insecticide netting to a suite of post-harvest insects

Insects are our main competitors for food on the planet (1). In fact, growers lose 10-30% of crops during storage, processing, and marketing after harvest each year to stored product insects (2,3). Challenges to current management include increasing insecticide resistance to phosphine (4), which is the most common insect fumigant. Another challenge has been an increasing demand for organic or low insecticide-input products by consumers (5). To meet these challenges we came up with an alternative management approach, a long lasting insecticide netting (LLIN). Insecticide-treated nets have been widely used as a tool for malaria vector control in tropical regions since the early 1990s (6). These nets are typically treated with a pyrethroid insecticide, such as permethrin or deltamethrin, which repel, incapacitate, and kill mosquitoes that land on the nets. Researchers have recently begun exploring the use of LLINs for management of agricultural pests in high value specialty crops (7). More recently, work with LLINs in post-harvest settings has demonstrated that this tool can induce mortality, as well as significantly decrease the movement and dispersal capacity of post-harvest insects (8). Some possible uses for LLIN include being used to line windows, vents, eaves, or other openings into food facilities. However, anecdotal evidence from IPM practitioners has suggested that pyrethroids, which the LLIN contains, may be repellent to specific groups of insects. In order for LLIN to be an effective tool at intercepting and preventing infestation by stored product insects, we must demonstrate that the netting is not repellent to a range of post-harvest insects

IMPACT OF A MORE INTENSIVE INSECT PEST INFESTATION LEVEL ON COTTON PRODUCTION: TEXAS HIGH PLAINS

This study evaluated implications of increased bollworm problems in a 20-county area of the Texas High Plains relative to cotton yields and economic impact. Results did not indicate a serious effect of bollworms upon lint yield when insecticides were used for control. However, estimated annual reduction in farmer profit due to the bollworm for 1979-81 was over $30 million. Yields were estimated to decline about 300,000 bales without insecticide use and about 30,000 bales with insecticide use. This decline suggests potentially serious implications for the comparative economic position of cotton in this region if insecticide resistance were to develop among insect pests.Crop Production/Industries,

Complex genome evolution in Anopheles coluzzii associated with increased insecticide usage in Mali.

In certain cases, a species may have access to important genetic variation present in a related species via adaptive introgression. These novel alleles may interact with their new genetic background, resulting in unexpected phenotypes. In this study, we describe a selective sweep on standing variation on the X chromosome in the mosquito Anopheles coluzzii, a principal malaria vector in West Africa. This event may have been influenced by the recent adaptive introgression of the insecticide resistance gene known as kdr from the sister species Anopheles gambiae. Individuals carrying both kdr and a nearly fixed X-linked haplotype, encompassing at least four genes including the P450 gene CYP9K1 and the cuticular protein CPR125, have rapidly increased in relative frequency. In parallel, a reproductively isolated insecticide-susceptible A. gambiae population (Bamako form) has been driven to local extinction, likely due to strong selection from increased insecticide-treated bed net usage