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 …
Parasitic plant: Scurrula parasitica Crop: Citrus Why is it a problem? This parasitic plant can reduce growth and vigour of citrus trees. It is easily managed, and only causes serious problems in neglected orchards. Where and when is it a problem? It occurs in all citrus growing areas from …
Diaphorina citri Crop: Citrus Why is it a problem? The Asiatic citrus psyllid (ACP) is the primary vector of the devastating disease, huanglongbing (HLB). Management of the vector is important to slow the spread of the disease within and between orchards. At high densities direct feeding can also damage plants, …
Cacopsylla heterogena Crop: Citrus Why is it a problem? The green citrus psyllid causes direct damage to new growth of both young and adult citrus trees. This is expected to reduce growth rates and yield. It is not known to vector the HLB pathogen although adults can acquire the …
Rhynchocoris poseidon Crop: Citrus Why is it a problem? Feeding on the sap of young mandarins can cause a considerable early (“summer”) fruit drop, although compensatory development of the remaining fruit can lessen its economic importance. Damage can be severe, but management is generally not needed in most years and …
Phyllocnistis citrella Crop: Citrus Why is it a problem? The citrus leaf-miner is mainly a problem in young (seedling) trees, including in nurseries, where at high densities it retards growth and can result in secondary infections. Mature trees are better able to withstand the attack. Where and when is it …
Bactrocera minax Crop: Citrus Why is it a problem? The Chinese fruit fly is the most serious insect pest in citrus. Up to 70% of losses through late fruit drops have been reported. Where and when is it a problem? In eastern Bhutan, in higher orchards (over 1000 m altitude) and …
Anoplophora nr versteegi Crop: Citrus Why is it a problem? The Citrus trunk borer is the primary cause of tree decline in Bhutan. Most die-back affected trees are infested with trunk borer. It can cause tree decline, mostly by ring-barking younger trees. Pest populations are slow to build up and …
Candidatus Liberibacter asiaticus Crop: Citrus Why is it problem? Huanglongbing (HLB), is one of the most devastating citrus diseases globally. There is no known cure for the disease. It probably entered Bhutan in the 1960s and has become the most serious threat to citrus production. Huanglongbing infection results in reduced …
Oidium citri Crop: Citrus Why is it a problem? This fungus is mostly a problem in nurseries and young orchards where it prevents growth, although new growth in older orchards can also be affected. Severe infections kill branches. It can also attack young fruitlets causing distortion and premature fruit drop. …
