TECHNICAL BULLETIN No. 24 OCTOBER 1954 FEEDING HABITS OF THE TOMATO BUG, CYRTOPELTIS (ENGYTATUS) MODESTUS (DISTANT) WITH SPECIAL REFERENCE TO THE FEEDING LESION ON TOMATO Y. TANADA F. G. HOLDAWAY HAWAII AGRICULTURAL EXPERIMENT STATION, UNIVERSITY OF HAWAII FEEDING HABITS OF THE TOMATO BUG, CYRT OPELTIS (ENGYTAT US) MODESTUS (DISTANT), \VITH SPECIAL REFERENCE TO THE FEEDING LESION ON TOMATO Y . TANADA F. G. HOLDAWAY UNIVERSITY OF HA WA Il COL LEGE OF AG RICULTURE H AWA II AGRICULTURAL EX PERIMENT STATION HONOLULU, HAWAII O CTOBER, 195-1 T ECHNICAL BULLETIN No . 24 THE AUTHORS Dr. Y. Tanada is Assistant Entomologi st at the Haw aii Agr icultural Experiment Station. He received the degree of Master of Scienc e from th e University of Hawaii in J une 1945. The subject matter of this bulletin is from his th esis, which was submitted in partial fulfillment of the requirements for that degree. D r. Tanada received the degree of Doctor of Philosophy at the University of California in Feb ruary 1953. Dr. F. G . Holdaway is Entomologist at the University Farm , Un iversity of M innesota. ACKNOWLEDGMENTS Grateful appreciation is expressed to the late Dr. C. J. Engard for his advi ce on plant anatomy and botanical microtech niq ue; to the departments of plant physiol­ ogy, and soi ls and ag ricult ural chemistry of the College of Agriculture of th e University of Hawaii for the use of their facilities; to D r. R. L. Usinger of the Un iversity of California at Berkel ey for his suggestions on the taxonomic status of the tomato bug; and to D r. A. A. Granovsky of th e University of Minnesota, D r. W . Carter of the Pineapple Research Institute, D r. H . A. Bess, Dr. D . E. Hardy, Dr. M . Sherman , D r. K . Sho ji, and D r. L. D. Tuthill of the Uni versity of Haw aii for thei r reading of the manuscript. CONTENTS PAGE INTR ODUCTI O N 5 Ta xon omi c status 5 Hisror y and imp ortance of the tom ato bug in Hawaii 6 Distribution and feeding habits menti on ed in literature 6 THE F EEDING L ESION 7 Proudure . 7 External characteristics 9 Internal characteristics 12 FEED ING ON VASCULAR TISSUES 18 Observations in cages and in the field 18 Ingestion of dyes from th e xylem tissue 19 F ORMATI ON OF F EEDING L ESIONS BY NYMPHS . 20 R ET URN O FB UGS TOF EEDING LE SIONS 20 Cage observatio ns 20 Field observatio ns 21 Feeding on fresh injury 22 MICRO CH EMI CAL A N ALYSIS OF T HE L ESIO NS 23 DISTRIBUTI ON OF B UGS ON T OM AT O PL AN T PARTS IN THE FI ELD 24 Proced ure . 24 Resul ts 24 DISTRIBUTI ON O FB UGS O N PLANTS GROWN AT DIFFERENT NITROGEN L EVELS 27 Procedure . 27 Results 28 DISCUSSION 32 S UMMARY . 35 LITERATUR E CIT ED 36 FEEDING HABITS O FTHE TOMATO BUG, CYRTOPELTlS (ENGYTATUS) MODESTUS (DISTANT) , WITH SPECIAL REFERENCE TO THE FEEDING LESION ON TOMATO Y. TANADA F. G. HOLDAWAY INTR ODUCT IO N The present study concerns the feeding habits of the tomato bug, Cyrtopeltis (EngytattiS) modestus (Distant), and the unusual feeding lesions produced on tomato plants (fig. 1). Existing informatio n on the feeding habits and rhe taxon omic status of this insect have been incorporared in this bulletin. During rhe five-year period of this study, 1940-1945, rhe tomato bug was a serious pesr of tomato in Hawaii and was difficult to control with the insecticides available at that rime. At present it is effectively controlled by DDT. FIG. 1. A t o m at o bu g, Cyrtopeltis (Bngy/(t/IIs) modestus (D istant ), feed ing at site of you ng lesion on to mato stem. Taxonomic States There has been much confusion in con necrion wirh the scientific name of rhe tomato bug. It was firsr described by Reuter (65) in 1875 as Engytatus genicula ts«. In 1909, however, he placed ir in the genus Cyrtopeltis, which he believed to be synonymous with Engytattls (46, 18). According to Knight (46) and China (18), however, the epithet genimlattiS Reuter cou ld no r be used because it is preoccupied 6 HAWAII AGRICULTURAL EXPE RIME NT STATION in Cvrtopeltis by geniculat« Fieber. Since Uhler (S7) had stated that Neoproba uarians Distant was a syno nym of Bngytatus genimlatus Reuter, varians D istant was th e next available name for th e species. Th e pro blem became further involved when Reut er in 1910 reversed his viewpoint of 1909. Knight (46), after a careful comparison of Cyrtopeltis genimlata Fieber and Bngytatm genimlatus Reuter, concluded that Cyrtopeltis and Engytatus were congeneric. In 1946 Usinger (SS), in his study of the insects of Guam, came to the conclusion that Cyrtopeltis (type : genimlata Fieber) and Bngytatus (type: genimlatus Reuter) were distinct genera. However, Carvalho (15, 16) in 1947 and 1952 placed Engyteu«: as a synonym of Cyrtopeltis in his pub­ lications on the classification of the Miridae. Recently China and Carvalh o (19) conducted a thorough study of the genitalia of this group and concluded that the genital characters would necessitate establish ­ ing a number of new genera. They decided to include all very closely related groups other than Dicypbus and Macrolophus as subgenera und er Cyrtopeltis Fieber. Further­ more, after examining th e typ e specimen, they found that Distant's species, varians, is quite distinct from "genimlatus." On this basis, they gave Cyrtopeltis (Engytatus) laridus (G ibson) as the name of the tomato bug. However, du e to a curious lapsus, China and Carvalho placed N eosilia modesto Distant , 1893, in synonymy under luridus G ibso n, 1917, on page 160. Usin ger (in litt.) reports that he called this inconsistency to the atte ntion of Dr. China in conversatio ns in London in 1953 and that Dr. China ag reed that Cyrtopeltis (Bngytatus) modestus (D istant ) is th e correct nam e. Cyrtopeltis (Engytatus) modestus (D istant) is commonly known in Puerto Rico as the large tobacco suck-fly (51), in Californi a as the tomato suck-fly (23), and in Hawaii as the tomato bug (30, 33, 34) . History and Importance ofthe Tomato Bug in Hawaii In 1924 Swezey (76) first reported the presence of C. modestus on tomato in Manoa Valley , Oahu , and in 1925 report ed it from widely scattered regions on Oahu (77, 7S). Between 1927 and 1935, th e tom ato bug was collected from Kaua i (SO ), M olok ai (S3), Maui (79), Hawa ii (s1), and Rabbit Island (10). Holdaway and Look (33, 34) reported the tomato bu g abundant in hot, dry regions but not in coo l, moist regions. From 1937 to 1947, the tomato bug became increasingly more important to tomato production in Hawaii. It reached its peak of importance soon after 1941 when the Hawaii Agricultural Experiment Station (75) introduced a tomato variety which was found suitable for production at low elevations and high temperature (31). Wh en DDT became commercially available in 1947, this insecti cide was found to be highly to xic to th e to mato bug, and the extensive use of DDT has practically eliminated the tomato bug from tom ato plantings (32). Distribution and Feeding Habits Mentioned in the Literature C. modestus has been reported also as a pest of tomato from Cuba (8, 9), Puerto Rico (22), southern Californ ia (23), South Caro lina (66), Delaware (52), Arizona and Texas (44) , and Georgia and Mississippi (47). It is a pest on tobacco in Brazil (56), Puerto Rico (51, S), and Cuba (8,9). Th e to mato bug has been reported on many plant s in addi tion to tomato and tobacco : Jatropha gossypifolia L. (22) ; squash vines (40, 33, 91) ; Heterotbeca grandi­ flora Nutt.(S2); potatoes and eggplant (30,33); ornamental geraniums and a species of ornamental Plumbago (33, 91) ; watermelon , dishcloth go urd, and th e hairy morning-glory (Merremia aegyptia (L.) Urban = Ipomoea pentaphylla (L.)) (34); garden bean (35); Lagenaria sp. (gourd) (91); Gynandropsis pentaphylla (L.) D e FEEDING H AIlI TS OF T HE TOM ATO DUG 7 Candolle (48); Bougainuillae« sp ., So lantau sisymbrifolill1lJ Lam., a type of marigo ld (Calm dula sp .), and pumpkin leaf.* Accord ing to Uhler (87), the tomato bug in the West Indies lives on vario us kinds of weeds growing on roadsides and in neglected gardens. Th e tomato bug attacks chiefly the you nge r growing parts of tomato plants (44, 66), and its feeding results in a type of injury report ed by vario us workers as girdles (44), feeding scars (33), and feed ing rings or red rings (41, 66, 23). Apparently these workers are referring to th e same type of injury or lesion , which is desc ribed most appropriately by the term "feeding ring." Th e ste m or petiole is weakened at th e site of the feeding injury, and when bent breaks readily. Later the injured portion beco mes swo llen and quite resistant to breakage (44, 41, 66). The bug produces feeding rings also on the morning-glory, dis hclo th go urd (34), an d to bacco (85). Accordin g to Illingworth (37, 38, 39), the feeding of th e tomato bug on to ma­ to blossoms results in blossom drop . Fullaway (28) observed that feedin g on flower stems causes shedding of blossom s. Reynard (66), however, reported that in South Caro lina the tomato bug attac ks only the stems and leaves of tomato and nor the flowers.