386 STATE HORTICULTURAL SOCIETY, 1974

INDUCED INFESTATION OF FRUIT BY THE CARIBBEAN FRUBT FLY, ANASTREPHA SUSPENSA (LOEW)

A. K. Burditt, Jr., D. von Windeguth and mitis Blanco), kumquat (Fortunella crassifolia R. J. Knight, Jr. Swingle), Surinam cherry (Eugenia uniflora L.), rose apples (Syzygium jambos (L.) Alst.), Bar Subtropical Horticulture Research Unit bados cherry (Malpighia glabra L.), peach ARS, U.S.D.A. (Prunus persica (L.) Batsch), and other soft fruits. Swanson added loquat (Eriobotrya japonica (Thunb.) Lindl.) and tropical almond (Terminalia Abstract. Several cultivars or seedlings of caiappa L.) to the list of major hosts. He also , guava, grapefruit, murcott, and other presented information about the monthly infesta fruit were exposed in an outdoor cage containing tionof the major host species. These data were a large population of Caribbean fruit flies or by obtained by holding fruit in polyethylene contain injection of fruit fly eggs into the fruit. Varia ers and allowing the fruit fly larvae to emerge tionin susceptibility of species and varieties of from the fruit and drop to the bottom of the con fruit was determined. tainer where they pupated in vermiculite. Thus he Infestations in grapefruit ranged as high as could state that lychee (Litchi chinensis Sonn.), 10.6, 13.3, and 57.4 larvae/kg of fruit for natural, mango, and several types of citrus were occasion injected and cage infested fruit, respectively. ally infested and that only a few species of fruit Guavas, a natural host, supported infestations of were not, among them breadnut (Brosimum ali- 28.8 and 113 larvae/kg when the infestations castrum SW.), Indian jujube (Ziziphus mauriti- were natural and cage-induced. Temple and mur ana Lamb.), karanda (Carissa carandas L.), and cott oranges exposed to cage infestations aver Calophyllum inophyllum L. aged 2.5 and 21.0 larvae/kg, respectively. Likewise, von Windeguth et al. (5) examined Cage infestations of ranged to 163.9 the fluctuations in infestations of Caribbean fruit larvae/kg. Cultivars and selections of mangos fly larvae in the preferred hosts on the island of showed high variability; some were highly in Key West, which was to be the site of an attempt fested, and one remained uninfested. to suppress the fly population by using the sterile This research was undertaken toobtain in fly release method. They found that guava and formation needed for developing commodity treat tropical almond were the primary hosts of the ments for use by quarantine personnel in approv Caribbean fruit fly in the test area and that the ing shipment of fruit through quarantine barriers infestations in guavamight reach 395larvae/kg into areas where the Caribbean fruit fly does not of fruit. However, loquat, Surinam cherry, and occur. sapodilla (Achras zapota L.) also supported in festations in excess of 100 larvae/kg of fruit, and The most recent infestation of the Caribbean significant populations of larvae were found in fruit fly, Anastrepha suspensa (Loew), in Florida calamondin, Barbados cherry, Governor's Plum appears to have begun in April 1965. Since that (Flacourtia indica (Burm. f. Merr.), spondias time, the fly has spread as far north as Jackson (Spondias sp.), and kumquats. For these studies ville and up the west coast of Florida to Tampa. (5), fiberglass holding boxes were used for fruit There is still no indication that the present infesta and the larvae emerged and dropped into a layer tion will disappear as the first one did (it was de of sand on the bottom of the box. By this method tected in 1931 and disappeared in 1936). Indeed, they found that minor hosts on the island of Key such an outcome seems less likely than before. In West included egg fruit (Pouteria compechiana 1972, Swanson and Baranowski (4) reported that (H.B.K.) Baehni), peach, cocoplum (Chryso- 84 species of fruits in 23 famiiles were hosts of balanus icaco L.), satin leaf (Chrysophyllum the fly. In 1966, Weems (6) reported only 34 host oliviforme Lam.), lime (Citrus aurantifolia species and found thatthe Caribbean fruit fly was Swingle), mango, seagrape (Coccoloba uvifera), not a serious pestof commercial citrus, mangos date palm (Phoenix dactylifera L.), and sugar ( indica L.) or avocados (Persea amer- apple (Annona squamosa L.). An additional 17 icana Mill.) in Florida, though it did heavily infest species of fruit that were examined for fruit fly guavas (Psidium guajava L.), calamondin (Citrus larvae were negative. BURDITT, ET AL: INDUCED CARIBFLY INFESTATION 387

Research to develop commodity treatments such pared with 1.2 to 1.5% and 9.2 to 10.0%, respec as fumigation (2) for fruit infested with fruit tively, in uninfested fruit. flies requires that the investigator have available Similarly, in March and June, fruit obtained large numbers of fruit with moderate to heavy in from local cooperators were cage infested. The festation of larvae. However, in Florida, com mature Isle of Pine grapefruit supported an av mercial plantings of citrus, mangos, avocados and erage infestation of 3.4 larvae per kg. fruit in other fruit are generally not subject to heavy in March compared with 0.0 for similar fruit in Feb festations by the Caribbean fruit fly. Usually, ruary. Green fruit of this variety that had been when citrus were natural hosts the fruit was on injected did not support an infestation in June. backyard trees and had been left until they were Beginning in late June 1974, other grapefruit over-ripe (4). Even so, the incidence of larval were made available from fruit shippers in Ft. survival was low. Pierce, Vero Beach, and Tampa through the co operation of the Florida Fresh Citrus Fruit Ship Methods pers Association and their membership. These fruit and some locally grown grapefruit were either In our research therefore, the natural infesta cage infested or infested by injection. The results tion of larvae is being supplemented by using two (Table 1) showed levels ranging to an average of techniques, cage infestation or injection of eggs. 57 larvae per kg fruit for cage infested fruit com For cage infestation of fruit, the fruit are placed pared with 11 larvae per kg fruit for the naturally in a 12 x 12 x 9 feet high outdoor cage containing infested fruit. In this series of tests, varieties populations of adult fruit flies in excess of 30,000 showed considerable variation in susceptibility for 3-5 days. Generally one species of fruit is (Table 1). placed in the cage at a time though several va Finally, in early June 1974, we first placed rieties have frequently been infested at the same fruit from 28 mango seedlings and 7 cultivars time. For injection of eggs, eggs collected from (generally 25 from each tree) in our infestation oviposition cages are washed in water and sodium cage and held them for observation. (Four of these benzoate. Then, when the eggs are about 24 hours seedlings and a cultivar, , were derived old, ca. 200 are injected into each fruit by using a from an open pollinated Cambodiana tree.) The hypodermic syringe and needle. Infested fruit are infestation achieved by the exposure ranged from held in fiberglass containers at room temperature 8.9 to 132.3 larvae/kg fruit (Table 2). In another until the eggs hatch and larvae develop (5). test of fruit from seedlings of 13269, N 2187, and Larvae and pupae of the fruit fly are removed M 1007, (F-2 seedlings from Cambodiana) the in weekly from the containers and held in sand for festations averaged 7.2/kg; ranged from 0.4 to adult emergence. Simultaneous tests of total 163.9; and ranged from 0.0 to 13.5 respectively. In titratable acidity (expressed as citric acid) and of addition, fruit of 3 cultivars derived from soluble solids (expressed as sucrose) in a repre and 3 from other sources were cage infested. The sentative sample of infested fruit are analyzed by resultant infestations ranged from 5.9 to 64.9 standard methods (3). (Table 3).

Results Discussion Early in February 1974, we obtained 159 fruit representing 5 varieties of grapefruit from the Investigations have demonstrated that the USDA Horticulture Research Laboratory in Or Caribbean fruit fly has a wide potential range of lando. These fruit, 39 locally grown Isle of Pine hosts. Research is needed to determine the factors variety grapefruit, and 4 over-ripe grapefruit of involved in the susceptibility of fruit to egg de mixed sources were placed in the infestation cage. position, hatch and survival of the larvae. Such The results (Table 1) showed that only 6 Carib factors as terpene content (of mangos), maturity, bean fruit fly larvae survived in and pupated from acidity, peel thickness, all could have an influence. 236 fruit; 11 were obtained from the 4 over-ripe All of the mango seedlings examined, the re fruit. The 6 larvae that did survive came from sult of an open pollination, are highly heterogene fruit with both thick (14.3 mm) and thin rind ous in origin. Three parents (13269, N2187 and (5.3 mm). The analysis of the test fruit showed M1007) were selected because of outstanding horti citric acid ranging from 0.6 to 1.4% and sucrose cultural performance. Although all 3 derive orig ranging from 9.8 to 11.0% in infested fruit com inally from P.I. 11645, 'Cambodiana', all show 388 FLORIDA STATE HORTICULTURAL SOCIETY, 1974

Table 1, Infestation of Caribbean fruit fly larvae in fruit.

Fruit Infestation Data Time of No/kg. vear Kind Variety Number Technique fruit

February Grapefruit 37 cage 0.0 Temple x Nakon x

Duncan 38 cage 0.3 Pink seedless 44 cage 0.0 Isle of Pines

Rough 35 cage 0.0

Normal 4 cage 0.4

Marsh 40 cage 0.1 Mixed over

ripe 4 cage 6.9

March Grapefruit Isle of Pines 32 cage 3.4

Guava Common 60 cage 67.0

Orange Temple 25 cage 2.5

Murcott 25 cage 21.0

June Grapefruit red 24 cage 41.2 Isle of Pines 12 injected 0.0

Marsh 102 cage 57.4 Lime Persian 18 injected 2.3 Guava Common 40 injected 113.0 Common 20 natural 28.8 Grapefruit Pink seedless 34 natural 0.1 Marsh 23 natural 10.6 Marsh 13 injected 8.8 Marsh 13 injected 13.3

July Grapefruit Ruby red 86 injected 3.8 Marsh 125 injected 2.4 Marsh 242 injected 0.5

signs of a mixed background and two (M1007 and 10 of the 19 seedlings of N2187. M1007 itself did N2187) obviously carry genes of Indian origin: not fruit heavily this year and therefore could not M1007's fruit is blushed red and has a strong be included in the infestation test. turpentine-like "Indian" flavor, and N2187 bears The infestation of fruit in seedlings of N2187 an elongate, blushed fruit with a mild, sweet flavor ranged from 163.9 to 0.4 larvae/kg. Attractiveness resembling that of 'Ameeri' (an Indian import). to Anastrepha may depend on the inheritance of All 4 seedlings of M1007 were less susceptible to specific substances presently unknown. No obvious Caribbean fruit fly larvae than the samples from external character relates directly to a cultivar's BURDITT, ET AL: INDUCED CARIBFLY INFESTATION 389

Table 2. Infestation of mango Tahle 3. Infestation of fruit fruit by Caribbean fruit fly from mango cultivars by larvae resulting from cage Caribbean fruit fly larvae exposure. resulting from cage exposure.

Seedling Number identifi of Infestation/ Infestation/ cation Fruit kg.fruit Cultivar2 kg fruit

Cambodiana Iladen 5.9 N 2188 20 132.3 11.3 Florigon 25 63.0 Pope 38.7 N 2162 25 60.9 Ono 14.8 132692 25 47.4 Tyler Premier 64.9 132 692 25 26.2 Kensington N 2187 25 8.9 11.5

13269 z 25 fruit/cultivar WA40926 25 7.2 attractiveness to the fruit fly. N2188, 'Florigon',.' N 2187 13269, and 'Tyler Premier', among the more heavily infested, bear predominantly yellow fruit. N2187, WA31720 2 163.9 '', WA41347, and WA31926, with low or no WA31529 25 83.5 infestation, bear red-blushed fruit. However, WA31426 15 39.1 WA41231 (infestation 13.5/kg) has an unblushed WA31314 25 30.8 yellow fruit and Tope' (38.7) has a blushed deep WA31715 25 28.1 red fruit. Thus fruit fly attractiveness in the WA31723 25 23.9 mango cannot be related to color. WA31626 25 22.5 Grapefruit, like many species of fruit, are not WA31302 25 21.6 generally subject to attack by the Caribbean fruit WA31612 25 17.1 fly. However, some commercial grapefruit, do sup WA31324 25 15.7 port fly infestations. As a result, treatments such WA31428 21 10.9 as fumigation are needed to insure that fruit being WA41453 10 10.5 shipped are free of fruit fly larvae. WA31506 10.4 15 Over 35 years ago, Baker (1) developed what WA31712 5.2 25 is still the basis for commodity treatments to per- WA21704 24 5.2 mit shipment of fruit from areas where they are 1451 2.3 25 subject to fruit fly infestation. Recommendation of WA31726 2.0 25 a commodity treatment is dependent upon obtain- WA31304 0.7 25 ing 99.99683% mortality in a population of ca. WA41347 0.4 25 100,000 fruit fly larvae exposed to treatment, Probit 9 security, as the procedure is known, ' M 1007 would anticipate that only 32 of one million fruit;.! fly larvae infesting commercal fruit would survive f' WA41231 13.5 25 an acceptable treatment. V7A31923 25 10.8 The population of fruit fly larvae in a par WA32020 25 4.6 ticular species of fruit is dependent on many fac WA31926 25 0.0 tors including the maturity of the fruit and the general condition of the fruit as related to other factors such as injury from weather, disease, or 2 Two samples tested from 13269. cold. Therefore, our methods of supplementing the 390 FLORIDA STATE HORTICULTURAL SOCIETY, 1974 natural infestation of fruit by cage infestation or fruit required for such research. However, the injecting eggs directly in the fruit is an aid in de technique does not eliminate the need to investigate veloping commodity treatments for citrus and other natural infestations in fruit. fruit grown in Florida and subject to infestation by the Caribbean fruit fly. Literature Cited

Summary 1. Baker, A. C. 1939. The basis for treatment of products where fruit flies are involved as a condition for entry into the United States. U. S. Dept. Agric. Circu. 551, 7 p. Infestations of Caribbean fruit fly larvae in 2. Burditt, A. K., Jr., S. T. Seo and J. W. Balock. 1971. citrus and mango, though occuring at a low level, Basis for developing quarantine treatments for fruit flies, pp. 27-31. In Disinfestation of Fruit by Irradiation. Inter indicate the need for additional basic information national Atomic Energy Agency, Vienna, Austria. 3. Soule, J. W. Grierson, and J. G. Blair. 1967. Quality concerning the natural infestation present in fruit tests for citrus fruit. Florida Ext. Serv. Circ. 315. 28 p. and the potential susceptibility of fruit to infesta 4. Swanson, R. W. and R. M. Baranowski. 1972. Host range and infestation by the Caribbean fruit fly, Anastrepha tion by the Caribbean fruit fly. This research is suspense/, (Diptera:Tephritidae) in South Florida. Proc. Fla. State Hort. Soc. 85:271-274. time consuming and requires examination of large 5. von Windeguth, D. L., W. H. Pierce and L. F. Steiner. quantities fruit. Supplementation of natural in 1973. Infestations of Anastrepha suspensa in fruit on Key West, Florida and adjacent islands. Fla. Entomol. 56(2): 127- festations by cage infestations or injecting eggs 131. 6. Weems, H. V., Jr. 1966. The Caribbean fruit fly in into the fruit has reduced the time and amount of Florida. Proc. Fla. State Hort. Soc. 79:401-403.

THE WAMPEE, A FRUIT WELL ADAPTED TO SOUTHERN FLORIDA

Carl W. Campbell The genus Clausena contains some 30 species and many botanical varieties distributed through IF AS Agricultural Research and Education Center the Old World Tropics (6). Of these, the wampee Homestead has the largest and most desirable fruit for human consumption. The wampee is a relative newcomer Abstract The wampee, Clausena ..lansium to Florida, having been introduced from China as (Lour.) Skeels, was introduced relatively recently an undetermined species in 1908 (1). It is native to Florida, and therefore is not well known here. to southern China and Indochina. The fruit is well It is a small tree with dark green, glossy leaves known and highly esteemed in the Orient, but is and clusters of yellow, spherical to oval fruits. little known in the American Tropics, notwith Propagation is easy and may be done by seed, standing the efforts of horticulturists such as cuttings, air layers or grafting. Superior selec David (2). This is unfortunate because tions have been made in the Orient but have not the wampee grows well is southern Florida, yields been introduced to Florida because of restrictions a useful fruit, and is a beautiful ornamental tree. on importation of vegetative material of citrus and citrus relatives. Several selections of su Description perior types have been made in Florida, mainly based on productivity of the tree and sweetness The plant is a large shrub or small tree reach of the fruit. The wampee is well adapted to the ing a height of about 20 ft (6 m) at maturity. climate of southern Florida, and grows par Usually it branches near the ground and makes a ticularly well in the calcareous soils of the south multiple trunk unless specifically trained other eastern coastal region. It deserves to be more wise. The canopy is rounded and dense. widely grown for its useful fruit and for its ex The leaves are pinnately compound, with 5-12 cellent qualities as an ornamental plant. irregularly alternate leaflets 2-4 in (5-10 cm) in length. The leaflets are dark green and shiny with Florida Agricultural Experiment Stations Journal Series No. 5608. an undulate margin. branches and leaves