229 



Ser, A, iv, p. 523]. These trees therefore should not be planted near 

 each other. Cottonwoods are the winter hosts of the beet aphis 

 {Pemphif/us betae), though a percentage of these Aphids always spend 

 the winter in the ground. 



The green apple aphis {Aphis pomi), the black cherry aphis {Mi/zus 

 cemsi), the box elder aphis {Chaitophonis negmidinis) and the dandelion 

 aphis {Macrosiphum tumxicis), entirely lack this habit of alternating 

 the food-plants. 



The successful control of Aphids therefore depends largely upon 

 knowing the life-history of the species in question and the enemies 

 that are associated with it. 



Davidson (W. M.). The Cat-tail Rush, Typ\a latifolia, as a Summer 

 Host of Injurious Insects. — Mthhj. Bull. Cal. State Commiss. 

 Hortic, Sacramento, vi, no. 2, February 1917, pp. 64-65, 1 fig. 

 The mealy plum aphis {Hijalopterus arundinis, F.) is the chief insect 

 pest that feeds on the cat-tail rush {Tijpha latifolia). Spring migrants 

 to this plant begin to arrive from the winter hosts, plums and apricots, 

 at the end of April and continue to do so until the end of July. A 

 series of wingless generations ensues until the middle of October, 

 when the winged autimm migrants and the winged males appear. The 

 colonies continue forming as late as December, the autumn migration 

 lasting over a period of one and a half months. From four to ten 

 generations appear to occur on the rush, the Aphids being found 

 in colonies on both sides of the blades, usually near the tips. Other 

 Aphids that may be found on this rush during the summer are : the 

 reddish-brown plum aphis (Rhopalosiphum nymphaeae, L.), which also 

 uses other water-plants, such as Alisnui, Nymphaea and Potamogeton, 

 as summer hosts ; the grain aphis {MacrosipJiHm gra)mrium, Kirby) ; 

 the oat aphis {Aphis averuie, F.), which may be found on cat-tail in 

 summer and autumn, and in winter and spring in California on grains 

 and grasses, including maize. It normally hibernates in the egg-stage 

 on rosaceous plants including the apple. A small black aphis {Aph is 

 gossypii, Glov.) also occurs in small numbers on cat-tail during the 

 summer and autumn months. Eed spider mites {Tetranychus sp.) some- 

 tunes feed in abundance on this rush during the summer months. 



Maskew (F.). Quarantine Division. — Mthly. BuU. Cal. State Commiss. 

 Hortic, Sacramento, vi, no. 2, February 1917, pp. 66-67. 



The following pests were intercepted during the month of December, 

 1916 : — From Brazil : Lepidopterous larvae in orchids. From China : 

 Cylas Jormicarius in sweet potatoes and weevil larvae in beans. 

 From Hawaii : Pseudococcus bromeliae and Diaspis bromsliae on 

 pineapples. Coccus longulus on betel leaves, and Chrysomphaliis aonidum 

 and Parlatoria sp. on coconuts. From Holland : Lepidosaphes ulmi 

 on boxwood, Aspidiotus britannicus, A. hederae and Coccus hesperidum 

 on bay trees and holly. From Japan : Lepidopterous larvae in 

 chili peppers, Pseudaonidia duplex on camellias, Thyridopterix sp. on 

 daphne. From Mexico : Trypeta ludens in guavas, Howardia biclavis 

 on unidentified plants. From Papute : Coleopterous larvae in 

 sugar-cane, Lepidosaphes beckii on oranges and limes. From Belgium : 

 Ahurodes sp. on azaleas, Aspidiotus britannicus and Coccus hesperidum 

 on bay trees. From Florida : Lepidosaphes beckii on grape fruit. 



