Proc. Fla. State Hort. Soc. 112:210-212. 1999.

SEASONALITY AND CONTROL OF ON CARAMBOLA CULTIVARS IN SOUTHERN

J. E. Pena and R. Duncan is dark reddish to brown. Wingless forms (apterous) are University of Florida about 2 mm long and by production of honey dew, sooty Tropical Research and Education Center mold fungi develops around the infested areas. Homestead, FL 33031 Fruit piercing , Gonodonta spp. (: Noc- tuidae), feed at night by piercing the skin of the ripe or rip Additional index words. Morganella longispina, Nezara, Gon ening fruit with their strong proboscis and sucking the juice. odonta, Toxoptera. Internal injury to the fruit resembles a honeycomb. Second ary rots develop at the puncture site and the fermented fruits

Abstract. Seasonally and levels of damage of aphids, mealy are frequently visited by other , such as sap beetles (Nit- bugs, stink bugs and scales were monitored on 14 carambola idulidae). The fruit piercing moths are dark brown, with or cultivars grown at TREC from 1997 through 1998. The cultivar ange-dark yellow color on their hind wings. B-10 had the highest infestation of the scale Morganella long The objectives of this studywere: 1) to evaluate the sea- ispina and aphids, while the cultivars Pasi, Wai Wei and Cheng sonality of pest species on different carambola cultivars and Hui had the highest number of punctures from stink bugs 2) to determine efficacy of insecticides against plumose scale. (Nezara sp.) and fruit piercing moths (Gonodonta sp.) than oth er cultivars. Peaks of Morganella longispina density were ob Materials and Methods served between November and March. Efficacy of the insecticides Knack, Fulfill and Provado was tested against Evaluation. A germplasm bank consisting of 14 these scales during 1998. carambola cultivars (Arkin, BIO, B17, Chengchui, Erlin, Fwang Teng, Kajang, Kary, Lara, Miss, Pasi, Sri Kembangen, The carambola, Averrhoa carambola L., is believed to be na Wai Wei, Wubentou) was evaluated to determine the pres tive of Asia or Indonesia, and has attained commercial status ence of different insects and mites from October 1997 in Florida only recently (Campbell et al., 1985). This develop through October 1998. The germplasm bank, consisting of ment has also increased the importance of pests affect 119 plants (ca. 4 plants per cultivar) was introduced from Asia ing this crop. The insects that have been recorded from and maintained at the Tropical Research and Education Cen carambola include, Morganella longispina (Morgan) (Hom- ter, Homestead, FL. optera: Diaspididae), Diaprepes abbreviatus, Nezara viridula, Ec- Monthly inspections consisted on walking around each pantheria scribonia (Lepidoptera: Arctiidae) feeding on leaves tree to determine the presence of pollinators, i.e., bees visiting and rostrana (Wlk) feeding on fruit. Plumose scale, flowers and by collecting 1 fruit per tree to determine pres Morganella longispina (Morgan) has been found in Florida ence of fruit feeders or damage symptoms from plant bugs or since 1980 (Hamon, 1981). The female armor of the scale is from fruit piercing moths. A cluster of flowers was collected circular to oval (1-1.5 mm x 1.0 mm) convex, dull black, with per tree and the presence of mealybugs, aphids, determined. a thick and opaque texture. The male armor is similar in col Sampling for scales consisted on inspecting approximate or, smaller, slightly convex, elongate. The scale is known from ly 30 cm of a lateral twig per tree, and by using lOx hand lens, Algeria, South Africa, China, India, Sri Lanka, Sandwich is counting the total number of scales per twigportion. lands, Tahiti, Hawaiian Islands, Mauritius and most of the Control ofPlumose scale. Plumose scale (oyster shaped, black Caribbean Islands (including Bahama, Barbados, Dominican shiny scale) is found on lateral buds of carambola. The trial Republic, Trinidad, Haiti, Jamaica, Puerto Rico and from was conducted in a 10 acre block of 10-year-old carambola Guyana and Brazil in South America, Hamon, 1981). Its trees located near Homestead, FL. One application of insect polyphagous habits include thefollowing host plants, , icides (Table 1) was made on 24 July, 1998 between 1 PM and Ligustrum, Nerium, Severinia, Averrhoa, Eucalyptus, Carica, Coffea, Ficus, Persea, Mangifera, Macadamia among others (Hamon, 1981). Table 1. Insecticides used against scales infesting carambola trees. The plant bugs, southern stink bug [Nezara viridula (L.)] and the leaf-footed bug, (Leptoglossus spp.), move from vege Treatment Dose tables planted during fall and winter to carambola orchards 1. Applaud 70WP Buprofezin 0.25 lbs ai/A to 0.38 lbs ai/A = 0.77 that have mature and ripe fruit. Adults and nymphs insert lb/A =0.771b/100 gall = 0.077 lb/10 gall water = 32 g /10 gall water their piercing-sucking mouthparts penetrating on the fruit, extracting fruit fluids and leave behind a small puncture. 2. Fulfill 50WP Pymetrozyne 0.178 lbs ai/A = 0.36 lbs/A = 0.36 lbs/ 100 gall water = 0.0178 lb/10 gall With time, the area around this puncture (or scar) becomes water = 8 g product/10 gall water soft and shows decay. 0.02 lbs ai/A to 0.11 lbs ai/A = 0.13 Black citrus aphid, Toxoptera aurantii (Boyer de Fonsco- 3. Knack 0.86EC Pyriproxifen gall/A = 0.13 gall/100 gall water = lombe) is found in large colonies on flowering terminals feed 0.013 gall/10 gall water = 13 ml prod ing on flower peduncles of carambola. The black citrus aphid uct/10 gall water

4. Admire 1.6F Imidachloprid 0.044 lbs ai/A = 0.028 gall/A = 0.028 gall/100 gall water = 0.0028 gall/10 Florida Agricultural Experiment Station Journal Series No. N-01824. No gall water = 2.8 ml/10 gall water endorsements or registration of chemicals implied herein.

210 Proc. Fla. State Hort. Soc. 112: 1999. O N D J M A M J J A S O O N D J M A M J J A S O 1997 1998 1997 1998

Figure 1. Seasonality of aphids on carambola flowers between October Figure 3. Seasonality of plumose scales on carambola between October 1997 and October 1998 in Homestead, FL. 1997 and October 1998 in Homestead, FL.

4:00 PM at a rate of 200 gal per acre with a hand-gun sprayer, months of June and July (Fig. 3). The cultivar with highest 350 PSI. Treatments were arranged in a completely random plumose scale infestation was B-10, followed by Kajang, Wai ized design of 8 trees per treatment. Scale infestation was de Wei, Cheng Chui, Meis and Kary (Fig. 4). termined by collecting two 15 cm branches, that regularly had 10 buds. The number of live scales per branch was evaluated by removing the armor of the scale and by noticing the color, dryness, and other characteristics. Scale counts were taken 1 70 week before spray, and 2, 4, and 12 weeks after treatment. 60

Results 50 * r

o Aphids. Black citrus aphids were most common during the 00 40 month of November, 1997, when most of the flowers were 30 present on carambola trees (Fig. 1). Other insects such as, Planococcus citri (Risso) (Homoptera: Pseudococcidae) and 20 Daghbertus spp., were observed on the inflorescence. Highest aphid infestation peaks were observed on B-10, followed by I Pasi, Wai Wei, Cheng Chui, Kary and Erlin (Fig. 2). 0 Plumose scale. The number of infested branches peaked Kajang WiiWei Cheng B-10 Meis Kary during November, 1997 and was reduced between the Chui

Figure 4. Frequency of mean number of plumose scales on different car ambola cultivars.

0.6

0.5

0.4

0.3

0.2 -

§ 0.1

0.0 ONDJFMAMJJASO 1997 1998

Figure 2. Frequency of mean number of aphids per inflorescence on dif Figure 5. Seasonality of stinkbugs per fruit between October 1997 and Oc ferent carambola cultivars. tober 1998.

Proc. Fla. State Hort. Soc. 112: 1999. 211 0.6

C

S 0.4 -

c: £ 0.3- o I 0.2

OS

0.0 ONDJFMAMJJASO ONDJFMAMJJASO

1997 1998 1997 1998

Figure 6. Mean insect punctures on carambola fruits between October Figure 8. Seasonality of mites per fruit on carambola cultivars between 1997 and October 1998 in Homestead, FL. October 1997 and October 1998.

Plant Bugs. Stinkbugs were only observed in February and Table 2. Efficacy of insecticides against plumose scale in carambola. October 1998 (Fig. 5). However, highest number of punctures Mean Plumose scales/branch per fruit were detected between January and February (Fig. 6).

Lesions to fruit were also observed during July, August and No Treatment 1DBT 14DAT 34DAT 57DAT 79DAT vember. The cultivar with the highest number of punctures Applaud 30.88 a 6.13 c 40.5 b 28.1b 195 be was Pasi, followed by Sri Kembangen and Cheng Chui (Fig. 7). Fulfill 108.75 a 19.94 be 21.8 b 336.3 ab 786.1 a Mites. Tenuipalpids, possibly Brevivalpus spp., were ob Knack 116.81a 28.81 18.3 b 649.6 a 59.6 c served between August and October, 1998 (Fig. 8). Admire 33.25 a 36.63 b 35.8 b 21.2 b 42.3 c Untreated 113.19 a 105.19 a 1332.3 a 789.5 a 582.2 ab

Numbers within columns followed by a different letter were significant (P < 0.05).

Control of Plumose scale. All products were effective in re ducing plumose scale density compared with the control (Table 2). Product efficacy was observed 14 and 34 days after treatment. The products, Fulfill and Knack showed a drastic reduction compared with the control during the first 34 days following treatment. However, the products Applaud and Admire had the lowest scale density at 57 days after applica tion. Knack and Admire continue to be effective 79 days after treatment.

Literature Cited

Campbell, C. W., R. J. Knight, Jr. and R. Olszack. 1985. Carambola produc tion in Florida. Proc. Fla. State Hort. Soc. 98:145-149. Hamon, A. B. 1981. Plumose scale, Morganella longispina (Morgan). Fla. Figure 7. Frequency of mean number of insect punctures on carambola Dept. Agric. and Consumer Services. Division of Plant Industry, Entomol fruits on different carambola cultivars. ogy Circular No. 226, p. 2.

212 Proc. Fla. State Hort. Soc. 112: 1999.