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 …
Panonychus ulmi Crop: Apple Why is it a problem? Prolonged, intense infestations weaken apple trees, seriously affecting the development of shoots, buds and fruit set in the following year. Where and when is it a problem? Mites can be a pest in most apple growing regions, but serious problems are …
Popillia species and Protaetia neglecta Crop: Apple Why is it a problem? The adults of six species of apple fruit beetles all feed on developing and developed apples, making them unmarketable. Although feeding damage can be conspicuous, the economic impact is not important unless beetles arrive in large numbers. Where …
Myllocerus sp. nr chloris Crops: Apple, peach Why is it a problem? Adults feed in groups on small apples, causing rot and making them unmarketable. They can arrive in large numbers. However, as they normally feed in groups total fruit loss is generally quite low and they can be relatively …
Microserica sp. Crop: Apple Why is it a problem? Large beetle numbers can defoliate trees. This is mainly a problem with young trees and newly established orchards where it can retard growth. Where and when is it a problem? Problems have been recorded in Thimphu and Paro valley from late …
Linda rubescens Crop: Apple Why is it a problem? Larvae bore into stems, causing twig dieback. This is most damaging in seedlings, where the main leading shoot can be destroyed. Where and when is it a problem? Outbreaks are quite localized and rare. They have been reported in apple orchards …
Eriosoma lanigerum Crop: Apple Why is it a problem? The woolly aphid is a very conspicuous pest on trees of all sizes, but it is mostly a problem on small trees, on which it can stunt growth. Galls can also cause splitting and secondary infections, and root galls can affect …
Diaspidiotus perniciosus Crop: Apple Why is it a problem? When feeding on apples this scale insect leaves red spots, and in severe cases distorts the fruit. This affects sale prices, especially for export. Complete coverage on twigs and branches can lead to dieback of affected parts and ultimately the decline …
Cleorina spp. Crops: Apples, walnut Why is it a problem? Cleorina leaf beetles are not normally a serious problem in apples, but can cause localised damage to developing apples and occasionally completely defoliate young trees. Where and when is it a problem? This beetle can be commonly found in all …
Argyresthia sp. Crop: Apple Why is it a problem? Larvae burrow into developing apples, resulting in early fruit drop. Dissection is generally needed to confirm that they are the cause of early fruit drop. This is rarely done, so losses due to this insect are probably underreported. Where and when …
