Background: Agricultural pesticides may play a profound role in selection of resistance in field populations of mosquito vectors. The objective of this study is to investigate possible links between agricultural pesticides use and development of resistance to insecticides by the major malaria vector Anopheles gambiae from cotton field.
Method: Susceptibility to 4% DDT, 0.05% deltamethrin, 0.75% permethrin, 0.1% bendiocarb was assessed using the WHO standard procedures for adult mosquitoes from cotton field. Tests were carried out with two to three days-old, non-engorged female mosquitoes. The An. gambiae Kisumu strain was used as a reference. Knockdown effect was recorded every 5 min and mortality scored 24 h after exposure. Mosquitoes were identified to species and molecular form by PCR-RFLP and genotypes at the knock down resistance (kdr) and, acetylcholinesterase mutations were determined in surviving specimens.
Results: During this survey, full susceptibility to bendiocarb was recorded in all samples. WHO diagnostic tests showed high frequency of resistance in An. gambiae to permethrin (ranging from 3% to 4% mortality), deltamethrin (13% to 22%), DDT (1.01% to 2%) in the seven selected areas. The Kdr gene seemed the main target- site resistance mechanism detected at the rates ranging from ranging from 65 to 71%.
The frequency of ace-1R gene was found but at very low frequency (< 0.1).
Conclusion: This investigation of malaria vector susceptibility to insecticides revealed a strong resistance to pyrethroid insecticides (permethrin and deltamethrin).
This Pyrethroid resistance may seriously jeopardize the efficacy of of IRS and LLINs on which, most African countries including Benin, rely to reduce malaria transmission.
The current findings will help for decision making in the National Malaria control program particularly in the choice of insecticide to use during campaigns of Indoor residual spraying in this part of Benin.

Background: Aedes aegypti is present year round in several cities of the Republic of Benin. This study aims to assess the seasonal distribution of this mosquito at Dandji, in southern Benin.
Method: A cross seasonal entomological study on larvae and adults of Ae. aegypti was carried out from May 2013 to April 2014 in southern Benin (Dandji). The study was based on sampling Ae. aegypti immature stages (larvae/pupae) from domestic, peri-domestic and natural water sources and were reared to adults. The collections were made during the dry and rainy seasons. Addional Ae. aegypti were collected by Human Landing Catches (HLC), Indoor Pyrethrum Spray Catches (PSC), Biogents (BG) sentinel trap and Gravid traps (GT).
Results: During the year of study, a total number of 18,658 mosquitoes were collected where 15,204 were collected by HLC; 303 with BG trap, 3,038 with PSC, 48 with the GT. Among the 18, 593 of Ae. aegypti collected, the female populations (13,834) was significantly higher than the male populations (p<0.05). From the 13,834 females, 1,380 were blood-fed.
Adult's collection was high during the two rainy seasons (June to July and October to November) but declined in the two dry seasons (December to March and August to September).
At Dandji, the average of Human Biting Rates (HBR) obtained during the rainy seasons (79.6 bites/p/n) was significantly higher than those obtained during the dry seasons (58.62 bites/p/n) (p < 0.05).
Conclusion: These findings showed the presence of Aedes aegypti year round at Dandji in southern Benin. This presence is strengthening with the trade of second hand tires which are good breeding sites for the development of Ae. aegypti. Data on blood feeding patterns of Ae. aegypti collected during this study will certainly provide valuable information about potential Dengue virus (DENV) hosts others than humans and will help to get a greater understanding about DENV ecology in Benin. It is therefore crucial for health authorities of Benin to develop a program to fight against this mosquito in order to avoid an outbreak of DENV as it was the case in many sub Saharan Africa countries recently.

The effectiveness of the Long-Lasting Insecticide-treat Nets (LLINs) has been widely demonstrated in the last two decades as an effective means of vector control against malaria. To understand how the washing practices in the community affected the effectiveness of LLINs, a survey was conducted in three health areas (Cotonou, Parakou and Tangui

A fast development of urban agriculture has recently taken place in many areas of the Republic of Benin. This study was conducted from January to December 2013 in southern and northern Benin in three major vegetable farms. It aimed to assess the genesis and the rapid expansion of urban agriculture especially, its contribution to the improvement of living conditions to urban populations.
The protocol was based on the collection of sociological data by interviewing vegetable farmers regarding on the history of vegetable farming in Benin, the various agricultural practices, the types of pesticides used, the typology of vegetable farms, the advantages and disadvantages of this agriculture.
Results from this study showed that:
(1) The creation of the first vegetable farmer was the work of the Christian missionaries and this in the context of their dietary requirements, but nowadays, the rapid development of urban agriculture is mainly due to unemployment observed in major cities, rural exodus and the search for a balanced diet by urban populations and increases the farmers' household income and their living standard;
(2) Vegetable farming activity is still devotes to young people (21-40 years old) where 75% among them are permanents gardeners, against 10% working part time and 15% on a temporary basis.
(3) Farmers used various types of pesticides, which in many cases were not recommended for this activity.
This study confirmed an increase activity of the vegetable farming in urban areas of Benin.
It has led to the use of insecticide in an improper manner to control vegetable pests, thus causing the emergence of insecticide resistance in malaria vectors.