WHITEFLY DIVERSITY (HEMIPTERA: ALEYRODIDAE) AND ITS PARASITOIDS IN LOWLAND IN WEST SUMATERA

Whitefly is an important pest in various fruit plants. This study aimed to study the diversity of whitefly in fruit plants in the lowlands of West Sumatra. Fruit plants samplings were guava, sweet orange and lime. Sampling locations were at Padang Timur District, Padang, Pauh 1 District, Padang, Pauh 2 District Padang. The method used is methode survey and sample determination is done by Purposive Random Sampling method. The taking of nymph was conducted by searching the parasitic nymphs on each plant found throughout the location determined as the location of the study. Based on the identification results, there were 2 whitefly species found in fruit plants in the lowland, Aleurocanthus woglumi and Bemisia tabaci . The diversity of whitefly in the lowlands was 1, 065 and the uniformity index was 0, to metapleuron; membranous mesocoxa of of acropleuron; mesosternum dorsoapical tibial mesotibia with of pegs anteroapical elongate commonly with tarsomeres; pegs in various along or anteroventral surfaces of tarsomeres; metasoma with cercus advanced anteriorly, triangular or U-shaped and/or more terga M-like and around cerci.

Whitefly pest control still uses insecticides. There is no single control method that gives optimal results in controlling whitefly both using chemical insecticides, biology, and technical culture. The use of pesticides can have a negative impact on the environment including causing pest resistance, resurgence of pests, leaving residues on products and hazards for consumers [8]. One effort to overcome the negative impact of the use of pesticides is by environmentally friendly controls by utilizing parasitoid. Information on whitefly on fruit trees at site altitude ie lowlands needs to be reported as basic information about the diversity of whitefly. The study of diversity in fruit trees in the lowlands of West Sumatra has not been reported yet. The objectives of this study are: (1) Determining the type of whitefly, (2) Determining the type of parasitoid, (3) diversity analyse.

Implementation of Research
The survey methode was used in this reserach and the determination of the sample was conducted by Purposive Random Sampling method. The geographical position and height of the sampling location was done using GPS (Global Positioning System). The sampling method was carried out by taking plant leaves directly with two parasitic nymphs in one plant. Sampling was carried out in three locations, Padang Timur District, Padang (7 m asl), Pauh 1 District, Padang (119 m asl), Pauh 2 District, Padang (140 m asl). Samples that taken from the field were carried out to the laboratory and the parasitic whitefly nymphs were separated according to the type of whitefly. The whitefly that after separated was put in petridish and then closed and labeled. Adult of whitefly was identified based on Martin's identification key (1987) [9] and parasitoid was identified using the identification book   [10].

Observations a. Type Whitefly
Observation of whitefly species was carried out by identifying based on Martin's identification key (1987) and by matching previous research drawings [9] [7].

b. Number of Whitefly
Whitefly nymphs were counted by the number of nymphs in the leaves in each type of whitefly. Each type of whitefly was separated by one nymph on one petridish. This observation was conducted to determine the number of individual nymphs on guava, sweet orange and lime.

c. Parasitoid type
The parasitoid that came out of the parasitic nymphs in the petridish was collected by taking a parasitoid from the petridish using a brush and inserted into the testub which contained 96% alcohol. This observation aimed to determine the type of parasitoid that parasites whitefly.

Data Analysis a. Diversity Index
The whitefly diversity index was determined using the Shannon-Wienner diversity index formula [11]. The criteria for species diversity index according to Fachrul (2007) [12]

. Evenness Index
Species evenness was the proportion of each species in a community. The evenness index of whitefly was determined using the Simpsons Equity Index formula [11]. The criteria for species evenness index according (Krebs, 2000) were 3, namely: if E < 0.4 meant evenness is low, if E = 0.4 -0.6 classified as moderate and if E > 0.6 then classified as high [11]. Evenness of whitefly species could be calculated using Simpson's evenness index [11]. The Simpson's evenness index equation is as follows:  According to the morphology, the nymphs of whitefly A. woglumi and B. tabaci had the following characteristics ( Figure 2). Nymph A. woglumi had the characteristics by having a shiny black body color with stiff black shiny thorns. There were 11 pairs of taper spines on the dorsal, a pair of spines in the posterior size longer than the other spines that resemble a tail [9] [5] (Figure 2a). Other studies also found nymph of A. woglumi in citrus plants with the same characteristics in this study [7]. B. tabaci nymph had the characteristics of a pear-shaped body and red eyes. The B. tabaci nymph had characteristics such as an elliptical puparium, one pair of caudal setaer which was located at the same size of puparium, there was a vasiform orifice on the triangular posterior puparium area with a size longer than a round groove (cudal furrow). Another feature was the operculum (operculum) which covered the vasiform orifice [9] (Figure 2b). Another study also found B. tabaci nymph on cassava leaves, cotton leaves, potato leaves and tobacco with the same characteristics in this study.

Number of nymphs Whitefly
The number of whitefly nymphs in each species found in leaves varied.

Types of parasitoids
The results of identification of whitefly parasitoid found in fruit plants in the lowlands of West Sumatra were 4 species, namely Encarsia (Aphelinidae), Encyrtidae, Platygastridae 01 and Platygastridae 02. The morphology of the parasitoid species has the following characteristics.

Encarsia (Aphelinidae)
Body 2 mm in length or less, relatively lightly sclerotized, often dark but at most with obscure metalic luster; antenna usually with at most 6 distinct flagellomeres (rarely with 7-9 flagellomeres including obscure ring-like basal flagellomeres); females with at most 4 distinct flagellomeres between pedicel and club; males without distinct club; pronotum usually distinctly shorter than half length of mesoscutum and often linear in dorsal view; mesoscutum with notauli more or less straight, complete and widely separated at transscutal articulation near anteromedial angels of axillae; axillae relatively small, with anteromedial angels widely separated, usually partly advanced anterior to scutellum; prepectus flat posterior to pronotum, with anterodorsal point of articulation anterior to (E) or posterior to (some A) insertion of pl₂ -t₂ c muscle, sometimes also with internal prepectal strut between ventral angle of prepectus and mesoscutum (some A); individual usually fully winged but some females subapterous; fore wing with marginal vein relatively long; stigmal vein short and postmarginal vein either absent or not extending beyond point in line with apex of stigmal vein (A), oe stigmal and postmarginal veins both long but then parastigma (curved apical part of submarginal vein) usually extending spike-like onto membrane behind submarginal vein and with 1 or 2 conspicuously long bristles (E); mesopleuron usually with distinct mesepisternum and mesepimeron separated by fine groove and than with or without small subalar acropleuron, but acropleuron sometimes enlarged and very rarely comprising entire mesopleuron; mesothorax in ventral view without membranous area anterior to mesocoxa (except Coccobius); mesotrochantinal plate and metasternum abutting (requires removal of mesocoxae to observe) and either with metasternum extending anteriorly and ventrally to mesotrochantinal plate (then metasternal pit widely separated from anterior margin of metasternum) (A) or mesotrochantinal plate extending dorsally to transverse margin of metasternum (then metasternal pit very near anterior margin of metasternum) (E); protibia with relatively long, curved apical spur; mesotibia dorsoapically, and mesotarsus ventrally, without pegs (except some Eutrichosomella); mesotibial spur relatively long, often robust; metatibia sometimes with long and conspicuous bristles (most E); tarsi usually with 5, less commonly with 4, tarsomeres; propodeum almost always conspicuously transverse, with metasoma widely attached to mesosoma; cercus not conspicuously advanced anteriorly. a b 515 Species are primary endoparasitoids or ectoparasitoids, or hyperparasitoids, mostly of Aleyrodoidae, Aphidoidae, Auchenorrhyncha, Psylloidae and especially Coccoidae (Homoptera), but also of the eggs of Lepidoptera amd Orthoptera, the eggs, larvae, and pupae of Diptera and the larvae of other Chalcidoids and Dryinidae. The family is renowed for its often complicated modes of differential development and parasitism of the sexes. In some species the females are endoparasitoids and the males ectoparasitoids of the same host species, whereas in others the males are hyperparasitoids of females of their own species (obligate adelphoparasitism or autoparasitism), of other aphelinid species (facultative adelphoparasitism), or of other primary parasitoid [

Encyrtidae
Body with pronotum usually visible and most often transverse in dorsal view; mesoscutum usually without notauli but if present then linear and more or less sinuately V-shaped; mesocutum articulated to scutellar-axillar complex only laterally, with very slender membranous area and/or depressed anterior margin of scutellar-axillar complex visible between sclerites if mesonotum arched; axillae almost always transverse-triangular, usually with contiguous anteromedial angels (sometimes appearing separate because of overhanging posteromedial curvature of mesoscutum); prepectus flat posterior to pronotum but internally with prepectal strut between ventral angel of prepectus and mesocutum; individuals fully winged to wingless; fully winged specimens with marginal, stigmal, and postmarginal veins relatively short, the marginal vein usually very short to punctiform; acropleuron convexly enlarged to metapleuron; mesothorax in ventral view with or without membranous area anterior to each mesocoxa but mesocoxa unable to rotate completely out of fossa; mesocoxa inserted at or anterior to midline of acropleuron; mesosternum transverse; protibia without dorsoapical spicules, with relatively long, curved tibial spur; mesotibia with row of pegs along anteroapical margin, with robust, usually elongate spur; tarsi usually with 5, less commonly with 4, tarsomeres; mesotarsus usually with pegs in various patterns along ventral or anteroventral surfaces of tarsomeres; metasoma with cercus advanced anteriorly, usually distinctly so, and then apical tergum large, triangular or U-shaped and/or with one or more terga M-like between and around cerci.
Encyrtidae is one of the most important Chalcidoid families for biological control. Species are endoparasitoids, mostly of Coccoidae (Homoptera), but also of the eggs or larvae of Coleoptera, Diptera, Lepidoptera, Hymenoptera, Neuroptera, Orthoptera, Hemiptera and Arachnida. One tribe, Copidosomatini, whose members are primary parasitoids of Lepidoptera, has an unusual process of multiplication of specimens from one egg within the host larva. The egg in this polyembryonic type of development divides into an irregularly branched chain of cells, each of which becomes a separate embryo. The resulting endoparasitic larvae consume the host larva and pupate within its swollen and distorted skin, with the emerging adults being all of one sex, unless more than one egg was deposited initially [ Figure 4. Encyrtidae; has a body size of 2 mm, yellow, has two pairs of wings, antenna type Agre

Platygastridae
The body length is generally 1-2 mm to 4 mm, usually slender, usually black, rarely yellowish, without metallic colors. Antenna strongly elbowed, usually with 8 flagellomeres, rarely with fewer (5-7); male flagellomere 2 (rarely 1) modified; fore wing usually veinless or if submarginal vein developed then only very rarely reaching anterior margin of wing, the stigmal and postmarginal veins absent; hind wing at most with short stub of submarginal vein; metasomal segment 2 always the longest and widest; female almost always with only 6 apparent tergits, exceptionally fewer; metasomal tergum 7 (apical tergum) internal, considerably reduced and depigmented, without cerci or sensory plates, hidden under tergum 6 and not extruded with ovipositor.
Some Platygastidae are primarily solitary parasitoids in eggs of various insects (Coleoptera, Homoptera) or they parasitize egg-like hosts such as young larvae of Coccoidae or Aleyrodidae (Homoptera); the entire development is completed in one stage of the hosts (idiobionts). However, most Platygastridae are koinobionts, parasitizing the host egg (usually gall-forming Cecidomyiidae) but developing only after the host is nearly full grown (prepupa or pupa). Some of these species are polyembryonic with two or more individuals developing from one fertilized egg [

Diversity Index
The results of the analysis of the diversity index of whitefly in the lowlands of West Sumatra according to Shannon Winner were classified as low, ie 1, 065 in the lowlands. It due to by the small number of whitefly species (2 species) found. The height of the place at a location affected the temperature that was suitable for the development of certain whitefly. Another study reported that the diversity of insects at an altitude of 1100 m above sea level was lower than the diversity of insects on plains less than 1000 m asl [46]. The evenness index of whitefly species in the lowlands of West Sumatra was relatively high (0, 969, close to 1) which was thought to have relatively more stable environmental conditions, meaning that no species dominated at each location. It due to each location had a different environmental condition that affected the stability of the environment and population. Another study reported that high and low evenness was correlated to the stability of environmental and population factors. There was an association between diversity index and evenness of whitefly in each location, where if diversity was high then evenness was high [47].

Conclusions and Suggestions:-
The results showed that there were 2 species Aluerocanthus woglumi and Bemisia tabaci found in fruit plants in the lowlands of West Sumatra. (2) There were 4 species of whitefly parasitoid found in the lowlands of West Sumatra, Encarsi (Aphelinidae), Encyrtidae, Platygastridae. (3) Diversity index of whitefly in the lowlands of West Sumatra was 1, 065 and its evenness index 0, 969. Further research is reqiured to analyse thr effectiveness the parasitoid biology as a biological agent as an environmentally friendly control in West Sumatra.