Pear suckers

Deltamethrin is a crystalline powder, white or slightly beige in color. The formulations include emulsifiable concentrates, wettable powders, ultra-low volume and flowable formulations, and granules. There are no known incompatibilities with other common insecticides and fungicides. It is used as a contact poison to control apple and pear suckers, plum fruit moths, caterpillars on brassicas, pea moths, aphids (apples, plums, hops), winter moths (apples and plums), and codling and tortrix moths (apples). It also is used in control of aphids, mealybugs, scale insects, and whiteflies on glasshouse cucumbers, tomatoes, peppers, potted plants, and ornamentals.9-11... 

PEAR SUCKERS Psylla pyri Psylla pirisuga Psylla piricola... 

The pear sucker species overwinter both in and outside the orchard. On the first warm days in March they emerge from their hiding-places and mate. At the end of March they start to lay their oval, yellow eggs, first on the fruit spurs and later on the inflorescences and leaves. The first larvae appear before flowering and begin immediately to suck on leaves and blossoms. From the third larval stage onwards they start to secrete honeydew. Two or three generations develop. Particularly between the end of May and middle of June the pear sucker population can increase dramatically or else completely collapse because of natural factors (predators and/or weather). Newly hatched pear suckers are very sensitive to cool, damp weather. 

When the pears are so big that they point downwards rather than upwards, pear suckers like to get between two fruits and suck within this protected space. Sooty mould fungi, which blacken the fruit, shoots and leaves, grow on the honeydew that they secrete. 

ENEMIES. The most important enemy of the pear sucker is the anthocorid hug Anthocoris nemoralis. 

In recent years there has been natural regulation of pear suckers by hoverfly larvae in June. The hoverfly appears to develop better in cold, wet periods than the anthocorid bug. In knockdown tests and visual inspections, 80% of the predators were hoverflies. 

Fig. 5.63. Adult pear sucker. Fig. 5.64. Pear sucker larvae ...

The damage threshold has definitely been exceeded when pear sucker larvae are on the fruit. 

The pear sucker is a pest which attacks the tips of shoots. Any measures which can check the growth of pear trees have a positive effect on infestation by pear suckers in the second and third generation. 

DIRECT. The pear sucker is a pest which can very effectively be kept under control by organic control measures. In years with poor weather conditions in June and July, however, the development of anthocorid bugs may be too slow. There may then be an explosive increase in the pear sucker population. 

The following measures should be applied if pear suckers have got between the fruits or if inspections give the impression that the anthocorid bugs are no longer able to create a stable situation ... 

Soap or wetting agent formulations dissolve the honeydew and also have a limited toxic effect on the pear sucker larvae. Pyrethrum sprays also only have a limited effect on the larvae. Wait for rain or water the orchard before using a pyrethrum spray, so as to dissolve the honeydew. 

Areas of application Mode of action Remarks Aphids, pear suckers Direct insecticidal action is only moderate, dissolves honeydew Russeting can occur under dry weather conditions Spraying at apple blossom time has a thinning effect... 

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