HANDBOOK OX IXSFXT ENEMIES OF FLOWERS AXD SHRUBS 75 



flower thrips breeds in various grasses, 



alfalfa, vetch, clover, and weeds. These 

 plants are the chief sources of infesta- 

 tion, since the winged thrips migrate 

 from these to roses, peonies, and many 

 other garden flowers. The adult flower 

 thrips is a tiny, slender, brownish- 

 yellow insect with featherlike wings 

 (fig. 123) and is extremely active. The 

 younger stages are lemon colored. If 

 an infested blossom is examined, the 

 tiny thrips may be seen scurrying for 

 shelter among crevices at the bases of 

 the petals. Several generations occur 

 during the summer, and in extremely 



Figure 122. — Spotting on petals of 

 carnation flower caused by thrips. 



Figure 123. — The Florida flower thrips 

 (Frankliniella triticibispinosa Morgan). 

 About 16 times natural size. (Wat- 

 son.) 



hot, dry weather they complete a life 

 cycle in less than 2 weeks. 



The onion thrips (Thrips tabaci 

 Lind.) and the tobacco thrips (Frank- 

 liniella fusca (Hinds)) may often be 

 found injuring roses and other flowers 

 along with the flower thrips. The 

 habits and appearance of all these 

 thrips are similar. 



Treatment. — Spray with tartar 

 emetic solution prepared as directed for 

 use against the gladiolus thrips (p. 45), 

 repeating the applications twice a week 

 until the insects are controlled. The 

 paris green formula (p. 96) may be used 

 if tartar emetic is not obtainable. Best 

 results follow if the control efforts are 

 community wide. 



Prevention. — Cut off and dispose of 

 all blooms that have reached their 

 prime, to reduce the population present 

 in a garden. Do not throw spent flow- 

 er- on the ground, because the insects 

 will quickly desert such blooms and 

 travel to unopened buds on nearby 

 plants. 



Aphids, or Plant Lice 



Several species of aphids injure the 

 young and tender growth of garden 

 roses by sucking the plant juices. The 

 potato aphid (Macrosiphum solanifolii 

 (Ashm.)) is particularly abundant on 

 roses early in the season. It is green or 

 pinkish and about %-inch long. The 

 young develop from overwintering eggs 

 laid chiefly on the stems of roses. 



The rose aphid (Macrosiphum rosae 

 (L.)) may occur on roses throughout 

 the season. It feeds on and injures the 

 tender leaves, stems, and buds (fig. 

 124). It is similar in general appear- 

 ance to the potato aphid. The winter 

 is spent in the egg stage on the twigs 

 and stems. 



Another similar species, the green 

 peach aphid (Myzus persicae (Sulz.)), 

 at times also attacks roses. 



The small green rose aphid (Capito- 

 phorus rosarum (Kalt.)) is a smaller 

 green or green-and-black species that 

 is found on the leaves as well as on the 

 bud-; and young shoots. 



Treat ment. — See treatment for 

 aphids (p. 9). 



Rose Chafer 



Although the rose chafer is one of the 

 most serious pests oi rose blo--.Mii-. it is 

 equally destructive to the Bowers of 

 peony and iris. This beetle is discussed 

 under Peony on page 66. 



