The toxicity and repellency of the bioactive chemicals of clove (Syzygium aromaticum) powder, eugenol, eugenol acetate, and beta-caryophyllene were evaluated against workers of the red imported fire ant, Solenopsis invicta Buren. Clove powder applied at 3 and 12 mg/cm2 provided 100% ant mortality within 6 h, and repelled 99% within 3 h. Eugenol was the fastest acting compound against red imported fire ant compared with eugenol acetate, beta-caryophyllene, and clove oil. The LT50 values inclined exponentially with the increase in the application rate of the chemical compounds tested. However, repellency did not increase with the increase in the application rate of the chemical compounds tested, but did with the increase in exposure time. Eugenol, eugenol acetate, as well as beta-caryophyllene and clove oil may provide another tool for red imported fire ant integrated pest management, particularly in situations where conventional insecticides are inappropriate.

Based on its properties of remaining attractive to the fire ants when wetted, combined with its ant-killing abilities both in the laboratory and in the field, T-bait is an efficient fire ant bait, especially under moist conditions.

It was shown that B. bassiana is able to control S. invicta under both laboratory and field conditions and can be used as a biocontrol agent against RIFA in Taiwan.

The red imported fire ant, Solenopsis invicta, is an invasive species that has been introduced into the United States and more recently into several countries in the Asian-Pacific region. The foraging dynamics of this pest ant is important in understanding its interactions with native ant species and in devising the most effective toxic bait control methods. In this study the effect of worker density, size of the foraging area, the number of food lures, duration of experiments, and the effect of the queen on foraging activity were investigated under laboratory conditions. The results showed that of the four ant densities investigated (very small, small, medium and high) the medium ant density most consistently had more workers at the food lures than the other ant density situations. The percentage of worker ants at the food lures was negatively correlated with an increase in foraging territory size for all four worker ant densities. Significantly fewer foragers were observed in the foraging areas when a queen was present, then when the queen was absent. In addition, when number of food lures was increased from 1 to 12, the mean number of workers found at the lures was significantly higher when four food lures were present. Furthermore, the number of worker ants observed on the food lures increased for the first 2.5 h and then decreased with time. The study suggests that observations of foraging activity could be restricted to 2.5 h. These data lay the ground work for further studies in optimizing the effectiveness of fire ant bait toxicants.

Abstract. Fall Armyworm (FAW), Spodoptera frugiperda, is an invasive pest of maize including other cultivated crops such as rice, wheat, and many other vegetables. This invasive species was initially noticed in North-America and later reported in many countries of Africa in early 2016. In South Asia, this has been reported for the first time in India followed by Srilanka in 2018 and Bangladesh, China, Taiwan and Nepal in 2019. It is polyphagous in nature and damage has been reported in more than 80 plant species. The loss has to lead up to 50-80% in maize in severe situation. FAW is a distant flyer and can fly more than 100 km in a night and spread well in crop fields. As this pest is already invasive in many states of India and the likelihood of entry and spreading in Nepal is higher because of the open border between the countries and flexible government quarantine policy. The great socio-economic loss has been forecasted once this pest has received invasive status in Nepal. Recently, this crop has been confirmed by Nepal Agricultural Research Council (NARC) in Gaidakot area of Nawalpur district, Nepal and has been noticed in almost all parts of Nepal such as Sidhuli, Chitwan, Nawalparasi, Tanahun and Rupendehi districts. However, this information has not been endorsed by Nepal Plant Protection Office (NPPO), an official invasive species endorsing organization in Nepal. This species is spreading rapidly in maize growing areas and significant losses have been reported in maize crop by the farmers. The regular scouting, surveillance, and monitoring can be suggested to evaluate the pest status in the crop field. Habitat manipulation with the deployment of deterring crops ‘push’ such as desmodium (Desmodium uncinatum) and pest-attracting crop ‘pull’ such as Napier (Pennisetum purpureum) and Sudan grass (Sorghum vulgare sudanense) is suggested in a ‘push-pull strategy’, the most popular and successful method of FAW management in the maize field. Field sanitation, and conserving pest’s natural enemies are other integrated approaches. However, in a commercial maize field, a group of ‘soft’ and selective chemicals have been suggested for immediate control of this pest. This review compiled the recent informations available on FAW and is useful for farmers, researchers and policy makers to draw a roadmap for the future FAW management in Nepal.