Beneficial insects contribute to agriculture by controlling plant pests and pollination. Beneficial insects can be divided into two groups: predators and parasitoids. Predators consume more than one prey and are usually larger than their prey. Furthermore, predators are generalists and may be omnivorous. On the contrary, parasitoids are smaller than …
Aceria litchi Crop: Litchi Why is it a problem? Lychee erinose mite destroys leaves, flowers, and fruits. Heavy infestations prevent flower and fruit setting and reduce the photosynthetic ability of leaves. Overall, LEM weakens the tree. Where and when is it a problem? It is commonly observed in Sarpang and …
Spodoptera frugiperda Crops: Maize Why is it a problem? The fall armyworm (FAW) is a polyphagous pest that damages more than 350 plant species belonging to 76 plant families (Montezano et al., 2018). The higher damage is found in maize and sorghum, which are their primary hosts (Casmuz & Juárez, …
Why is it a problem? Rice is the staple diet of the Bhutanese people. Weeds are one of the constraints to rice production. In a weed survey conducted in the rice growing areas of western Bhutan, at least 19 different species were found infesting transplanted rice (Dorji et al., 2013). …
Crop: Apple Why is it a problem? Tree lichens are common in all apple orchards. They are only a problem if allowed to cover branches and young shoots. In severe cases they cause drying of branches and reduce growth and fruiting. This normally only occurs in poorly managed orchards and …
Tuta absoluta Crop: Tomato Why is it a threat? Although not yet detected in Bhutan, the tomato leaf miner is a devastating pest of tomato. Tomato plants are attacked in all the growth stages in both open fields and greenhouses. Although using pesticides is now thought to be an effective …
Why is it a problem? Maize is the second most important cereal crop in Bhutan. Weeds in maize are a serious constraint to increased production and accounts for about 50% of the input costs. Maize is often inter-cropped with other crops, making weed management more difficult; whether hand weeding or …
Why is it a problem? Potato is one of the main cash crops in Bhutan. Weeds are a severe constraint in potato production, and require considerable resources to manage. Investigations comparing three weed management treatments across a wide range of locations reported average yields of 6.7, 10.7 and 11.6 MT/ha …
Sus scrofa Crops: All crops, but especially maize, rice and potato Why is it a problem? Wild boar are the main vertebrate pests of agricultural crops in Bhutan. Crop losses due to wild boar are one of the main constraints to alleviating poverty and increasing food security in the country. …
Potamogeton distinctus Crop: Rice Why is it a problem? Potamogeton distinctus, locally called shochum, is one of the most serious weeds in transplanted rice in Bhutan. It is an aquatic plant so grows together with the rice. Yield reductions of up to 37% have been reported, even when farmers …
