แก่นเกษตรKHON KAEN 44 AGR. ฉบับพิเศษ J. 44 SUPPL. 1 : (2559). 1 : (2016). KHON KAEN AGR. J. 44 SUPPL. 1 : (2016).87 Scale insects (Hemiptera: Coccoidea) on mango in Laos Pheophanh Soysouvanh and Ki-Jeong Hong1* ABSTRACT: Adult females of scale insects were collected on branches, leaves, peduncles, petioles and fruits of mango, Mangifera indica L. in mango orchards in Central and Southern Laos in 2015. The survey found nine species in eight genera in four families: Icerya seychellarum (Westwood) belong to family Monophlebidae; Ceroplastes stellifer (Signoret) and Coccus hesperidum (Linnaeus) belong to family Coccidae; Aulacaspis tubercularis (Maxwell- Lefroy) belong to family Diaspididae; Dysmicoccus neobrevipes Beardsley, Ferrisia virgata (Cokerell), Pseudococcus jackbeardsleyi (Beardsley), Rastrococcus iceryoides (Green), Rastococcus spinosus (Robinson) belong to family Pseudococcidae. Among these are 4 species newly recorded in Laos. Keywords: Coccidae, Diaspididae, Pseudococcidae, Monophlebidae, Mangifera indica Introduction value of fruit and their export potential. Scale insects can also cause indirect damage by serv- The genus Mangifera L. is endemic to South- ing as vectors of plant diseases. Some species east Asia, with the common mango, Mangifera of scale insects excrete honeydew, which accu- indica L.likely to have originated in the area be- mulates on the upper leaf surfaces. Under damp tween eastern India and Myanmar (Bompard and conditions, this honeydew can be colonised by a Schnell, 1997; Mukherjee, 1997) Subsequently, black, non-parasitic fungus known as sooty mold many countries with a tropical and subtropical which decreases photosynthesis by the leaves. In climate have been interested in the introduction addition, because scale insects are often difficult and development of good, edible mangoes. to control and remove from produce such as fruits, Mango is cultivated in Laos as a major fruit tree they are of quarantine concern, requiring man- along with citrus and banana (Department of agement to prevent their spread through export Agriculture, 2013). of plant products (Miller et al. 2002; 2005). This Mangoes like many other fruit plants that have study aimed to be guide pest management in the problems with insect pests. The most important field and promote adoption of rational phytosani- insect pests of mango include fruit flies, mango tary practices in Laos. seed weevil, mango leafhopper and scale insects. Scale insects injure mangoes by feeding on the Material and Methods plant’s sap through leaves, branches and fruits. Direct damage by scale insects results in defolia- The general surveillance and detection sur- tion, drying up of young twigs, and poor blossom- vey method were adopted following McMaugh ing. Direct damage also affects the commercial (2005). The collections were conducted in Central 1 Department of Plant Medicine, Sunchon National University, Suncheon 540-950, Republic of Korea * Corresponding author: [email protected] 88 แก่นเกษตร 44 ฉบับพิเศษ 1 : (2559). and southern part of Laos in January (dry season) threads; immatures yellow. Slide-mounted body and July (wet season) 2015 in mango orchards. oval, with 3 pairs of abdominal spiracles; Adult females of scale insects were collected from large open center pores present around branches, leaves, peduncles, petioles and fruits body margin and in dorsomedial area of head and of mango and then placed in small tubes contain- thorax, with triangular projection on inner rim. ing 75% alcohol. Thesespecimens were trans- Thoracic and abdominal spiracles simple, without ferred to the entomology laboratory in Suncheon pores in atrium; anal opening simple with sclero- National University for slide mounting. tized rim internally. Slides specimens were prepared following Family: Coccidae or soft scales. Two species Malipatil et al. (2013) and Williams and Watson were found. (1988). Specimens were placed in 10% KOH and Ceroplastes stellifer (Signoret) or stellate heated at 80°C for 10 minutes to clear body con- scale was collected during January and July 2015 tents. Specimens were left in a stain made up of on leaves. Field character: body round; covered 3 drops of acid fuchsin, 3 drops of acid alcohol with slightly translucent wax; developed into 6 or and 6 drops of 95% ethanol for at least 30 minutes. 7 radiating arms giving the appearance of a star Scale insect specimens were transferred from fish, each arm with white conical tip; female pink stain to 95% ethanol for 10 minutes then moved or purplish red then becoming darker in older to 100% ethanol. Specimens then were moved to females. Slide-mounted body oval, margin with 4 clove oil for an hour, and finally mounted in Can- stigmatic setae; antenna with 6 segments; 19 ada balsam. Slides were dried in an incubator at long setae between antennae. Tibia and tar- 40°C for two weeks. All slide-mounted specimens sus fused, without sclerosis; area around anal were identified using the southern Asian key in region sclerotized, forming protuberance; (Williams, 2004; Scalenet, 2015). claw without denticle; claw digitules equal; pre- opercular pores inconspicuous, restricted to Results area anterior of anal plates. Coccus hesperidum (Linnaeus) or brown soft A total of nine species representing eight scale was collected in January 2015 on pedun- genera and four families were collected, as fol- cles and fruit. Field character: body broadly lows: brown, soft scale oval to round; flat to slightly Family: Monophlebidae or giant scales. One convex in lateral view; body yellow-green to yel- monophlebid species, Icerya seychellarum (West- low-brown, body turning brown with age. Slide- wood), commonly known as the ice plant scale as mounted body elongate; claw without small found. It was collected in January and July 2015 denticle; marginal setae slightly enlarged, usu- on leaves and peduncles of mango. Field char- ally weakly fimbriate, occasionally simple; anal acter: body orange, legs and antenna dark- plates with posterior margin longer than anteri- brown, covered with white or yellow wax; medi- or margin; each anal plate with 4 apical setae, an area with longitudinal series of without a subdiscal seta; stigmatic setae differen- tufts, marginal areas with fringe of wax processes tiated from other marginal setae, middle seta con- all about same length and with numerous silken spicuously longer than lateral setae. KHON KAEN AGR. J. 44 SUPPL. 1 : (2016). 89 Family: Diaspididae or armored scales. One Pseudococcus jackbeardsleyi Beardsley, or species, Aulacaspis tubercularis (Maxwell-Le- jack beardsley mealybug, was collected on froy) commonly known as white mango scale, was leaves of mangoes in January 2015 in central and collected in January and July 2015 in central and southern Laos. Body oval and slightly rounded southern parts of Laos on leaves. It is circular, flat, in lateral view; body contents crushed are reddish thin and wrinkled. Exuviae lie near the margin and brown; mealy wax covering body, not thick are yellowish-brown, with a median black ridge, enough to hide pink body color. Slide-mounted forming a dark distinct median line. Males are body broadly oval, cerarii numbering 17 pairs. small, white, with their sides nearly parallel and Anal lobe cerarii each containing 2 setae, head distinctly tricarinate. On slide-mount: with angular cerarii each bearing 3–5 conical setae, each prosoma; body widest at prominent lateral tuber- cerarii with 4– 5 auxiliary setae. Antennae with 8 cles, almost level with anterior spiracles; poste- segments, legs well developed, translucent pores rior spiracles usually associated with spiracular fairly numerous on hind femur and tibia, each eye pores; gland spines and macroducts absent from with adjacent sclerotized rims. thorax and head. Pygidium with median lobes Rastrococcus iceryoides (Green) was col- zygotic, without any setae or gland spines be- lected in July 2015 on peduncle of mango in tween bases. central Laos. The body of this species was oval Family: Pseudococcidae or mealybugs. Five to round; slightly rounded to convex in lateral view; species of mealybugs were found. light yellow; legs light yellow; mealy wax covering Dysmicoccus neobrevipes (Beardsley), com- thick, in median area forming medial longitudinal monly called the pineapple mealybug, was col- ridge on thorax and abdomen. Slide-mounted: lected in January 2015 on leaves of mangoes in body broadly oval, cerarii each situated on a large central Laos. Body oval or rotund; gray or gray- area. Antennae each with 9 segments, legs well orange; body covered by flocculent white mealy developed, claw with denticle, circulus almost wax, without bare areas on dorsum. Slide-mount- transversely rectangular rounded. Ostioles well ed; body oval; cerarii numbering 17 pairs, anten- developed represented on both anterior and nae with 8 segments, legs and anal ring normally posterior. well developed. Rastococcus spinosus (Robinson), or Philip- Ferrisia virgata (Cokerell), or striped mealy- pine mango mealybug, was collected in January bug, was found in January 2015 on leaves of and July 2015 on leaves of mangoes in central mangoes in central and southern Laos. Body and south Laos. Adult female pale greenish white, elongate oval; body dark gray; legs dark brown; covered with white wax except for a bare area on covered by white mealy wax, with 2 submedi- midline, filaments conspicuous and long. Slide- al longitudinal bare areas on dorsum. Slide- mounted: body oval, cerarian setae truncate; 17 mounted body is elongate oval,