41 



Fryer (J. C. F.). Insect Pests of Basket Willows.— JZ. Bd. Agric., 

 London, xxiv, uo. 8, November 1917, pp. 844-852, 9 figs. 



Few plants are more subject to the attacks of insects than willows 

 or osiers. The more destructive species occurring in Great Britain 

 include several Aphids, which are perhaps the most serious pests, as by 

 sucking the plant-juices they stunt both leaves and rods, as well as 

 coating the leaves with honey-dew and thus encouraging sooty mould. 

 Some of the common species, such as Siphocorijne capreae and 

 S. pastinaceae, have certain Umbelliferous weeds for alternate host- 

 plants, e.g., hemlock, wild parsnip, etc., these should therefore be 

 carefully eradicated. Aphis scilicet i and Pterocomina pilosa are also 

 abundant on the leaves and shoots, while Melanoxantherium salicis is 

 the most common species on the rods. 



Willow beetles include PhgUodecta vitellinae and P. vidgatissima, 

 which first appear in spring and early summer, when they attack the 

 developing shoots and leaves, causing great injury by eating into the 

 growing point of the rod. Eggs are laid on the under-surface of the 

 leaves, which the larvae devour until fully developed, when they drop 

 to the ground and pupate. There are two overlapping broods in a 

 year, the adults of the second generation hibernating in rubbish on the 

 ground or in crevices in pollard willows and attacking willows again in 

 the following spring. GaleniceUa lineola is similar in life-history and 

 • habits to Phyllodecta spp. , but hibernates in damper places. Cryptor- 

 rhgnchus lapathi (willow weevil) has been previously described [see 

 this Review, Ser. A, ii, p. 192]. It attacks alder as well as willow, and 

 in addition to the damage to the rods by adult beetles, the larvae 

 injure the stumps. Aromia 'moschata (musk beetle) is not a serious 

 pest, although a conspicuous insect ; it feeds in pollard willow trees 

 and in old willow stumps. 



Pteronus (Nematus) salicis and other sawflies are very occasionally 

 found damaging willow leaves in Great Britain. Pontania gcdlicola 

 and similar species are the cause of the red and green galls so often 

 found on willow leaves ; the larvae live in the gall and, when fully fed, 

 make their way out and pupate in the soil. The injury is seldom 

 serious. 



The caterpillars of several moths feed on willow, but few of these 

 are injurious to any extent. In Somerset, Hypermecia cruciana and 

 Depressaria conterminella do some damage, the larvae spinning nests 

 at the tips of the gro'^v^ing rods and feeding on the buds and leaves. 

 Some moths, such as Trochilium bembeciforme (willow hornet clear- 

 wing) and Aegeria (Sesia) formicaeformis (red-tipped clear^dng), in the 

 larval stage live mainly in the stumps, pupate in the burrows and 

 emerge as adults in June and July. 



Several species of midges produce galls in the terminal buds. There 

 are generally two generations in a year and it is believed that the 

 winter is spent in the larval stage within the galls. Rhabdophaga 

 {Cecidomyia) heterobia and R. (C.) rosaria are both gall-forming midges, 

 while R. (C.) saliciperda (willow wood midge) burrows in the rods, the 

 larvae pupating in the burrows. 



General control methods may be used against several of these pests. 

 Direct measures against beetles or caterpillars involve the use of some 

 kind of poison spray for the leaves. Lead arsenate has been tried, but 



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