The data set on vertical distribution pattern of Bemisia tabaci genn. (Homoptera: Aleyrodidae) in several vegetable crops

Bemisia tabaci is one of the main pests of vegetable crops in the tropics, including in Indonesia. The vertical distribution pattern of B. tabaci on investigated vegetable plants can be used to establish a sample observation unit in monitoring activities of pest control management. This data showed the vertical distribution pattern of B. tabaci on vegetable plants gathered from two different locations, namely from the high land of Ciwidey District, Bandung City (string bean, kidney bean, and tomato) and the low land of Sliyeg District, Indramayu City (eggplant, towel gourd, cucumber, and long beans). The data of B. tabaci nymph population were then analyzed to determine vertical distribution patterns.

Type of data Data tables. How data were acquired Data was acquired by observing the Bemisia Tabaci nymph population on vegetable plants originated from high and low land areas. Data were taken from 25 diagonal plant samples. In each planting area, data were taken from five plots, and in each plot, five plants were chosen randomly. Three-hundred leaf samples were taken per vegetable type: namely 100 young, 100 middle, and 100 old leaves. Data format Raw and Analyzed. Parameters for data collection Data were collected on the number of nymphs of B. tabaci in young, middle, and old leaves from seven vegetable crops. This data was used to calculate the distribution pattern, dispersion index value, χ 2 value, and grouping index.
Description of data collection The obtained data were analyzed using vertical distribution pattern analysis, one-way ANOVA, and Duncan's multiple range test (DMRT) at 5%. Data

Value of the data
• The data obtained here contribute to our understanding of the vertical distribution pattern of the Bemisia tabaci population on lowland and highland vegetable crops. • These data will likely be useful for practitioners and farmers when planning pest control measures. • The data can be used as basic data for reference in determining the best plant sample unit (leaf position) for the future experiment

Data description
The data report the vertical distribution patterns of Bemisia tabaci in seven vegetable crops originating from two locations: eggplant, towel gourd, cucumber, and long beans from high land of Ciwidey; and beans, kidney beans, and tomatoes from the low land of Silyeg. The vertical distribution pattern data of B. tabaci is important to determine on which leaves (young, middle, or old) the nymphs are clumped. This information can be used as a basis for taking leaf samples, where the nymphs cluster for integrated pest control. Several parameters related to the distribution of B. tabaci in various vegetable crops were analyzed. Data on the distribution pattern, dispersion index value, and χ2 value of seven vegetable crops are presented in Table 1 . Table 1 also shows the suitability of the distribution patterns test of the seven vegetable crops.
On the young leaves, the population of B. tabaci nymphs was evenly distributed (follows a positive binomial distribution), while B. tabaci nymphs were clumped on the towel gourd. On the middle leaves, the population of B. tabaci nymphs was random, clumped, and uniformly distributed. On the old leaves, the population of B. tabaci nymphs was mostly clumped or follow a negative binomial distribution. The distribution pattern of the B. tabaci nymph population was obtained from the dispersion index value and χ2 value. The calculated χ2 values were compared with χ2 tables at = 0.05 and 0.95 with n = 1 degrees of freedom. χ2 tables (0.95, df = N -1) < χ2 counts < χ2 tables (0.05, df = N -1) show a random distribution, χ2 counts < χ2 tables (0.95, df = N -1) shows the distribution was evenly distributed, and when χ2 count > χ2 table (0.05, df = N -1) the distribution was clumped. String beans and kidney beans were two commodities with high population density, but the nymph populations on shoots do not form aggregates, where the distribution followed the positive or Poisson distributed binomials. As for the middle and old leaves, the population spreads following a negative binomial distribution.   Table 3 . Based on our observations, the nymphs were mainly found on the middle leaves of the seven vegetable crops from the Indramayu and Ciwidey areas, followed by the bottom leaves. In eggplant plants, string beans, kidney beans, towel gourd, and cucumbers, there were fewer B. tabaci nymphs on the young leaves than on middle and old leaves. Whereas in long bean and tomato, the number of B. tabaci nymphs in young, middle, and old leaves was not significant.

Leaf sampling
Leaf samples were derived from plants that were attacked by B. tabaci , specifically eggplants, cucumbers, towel gourd, and long beans from the Sliyeg Subdistrict, Indramayu District, and kidney beans, string beans, and tomatoes from Ciwidey Subdistrict, Bandung District. Each plant was divided into three parts: young leaves, middle leaves, and old leaves. Four leaves were then taken per section. Samples were determined diagonally (consisting of five plots), plucked, put into plastic containers or jars that perforated for ventilation, and the total number of B. tabaci nymphs counted.

Observation of the B. tabaci nymph population
The number of B. tabaci nymphs was determined by counting all of the nymphs on a leaf sample. On each sample, all B. tabaci nymphs were counted.

Analysis of the distribution pattern, dispersion index, grouping index, and chi-square value
To determine the vertical distribution pattern of the population, the dispersion index ( I ) was calculated, and if the distribution was clustered, the grouping index (k) was also calculated. The vertical distribution pattern was tested using the Chi-square ( χ2) test for goodness of fit [1] . To analyze the vertical distribution pattern, the following steps were applied: Step 1: Calculating dispersion index and determining distribution pattern The dispersion index was obtained from the following equation: Note: s 2 = sample variant x = average population density values n = number of samples xi = value x from 1,2,3,..etc.
Mean value from the sample: x = n N Variant value: The distribution pattern can be determined from the value of I (i.e., I > 1 shows a clumped distribution pattern (negative binomial), I = 1 shows a random distribution pattern (Poisson), and I < 1 shows a uniform distribution pattern (positive binomial).
Step 2: The frequency distribution Fx The frequency distribution was summarized as the number of individual nymphs per sample unit, that is the number of sample unit with 0, 1, 2, …, r number of individual nymphs. The data are summarized in the following table.
x (number of nymphs per sample) F x (number of the same amount) Step 3: The negative binomial probabilities P (x) grouping index ( k ) Negative binomial probabilities P (x) were used to calculate the probability of finding x individual nymphs in a leaf sample unit, where x = 0, 1, 2, …., r individual nymph. P (x) was calculated using the following equation: If the result of I analysis from the distribution pattern suitability test is clumped (negative binomial), then proceed with calculating the value of the grouping index ( k ).
The k (rough) value is obtained from Eq. (1) The rough k value is substituted into Eq. (2) to obtain the fine k value.
Note: n = number of samples fo = number of samples with zero individuals x = average population value ˆ k = rough k value Step 4: The expected negative binomial frequencies, E x Ex represents the expected frequencies of x = 0, 1, 2, …., r individual nymphs as the following equation: Step 5: Goodness-of-fit test statistic, χ2 The chi-square χ2 test was used to ascertain how well the observed frequencies ( F x in step 2) compare to expected frequencies ( Ex in step 4). The chi-square χ 2 was calculated using the following equation: The calculated χ2 value was compared to the χ2 table at a 5% significant difference with n = 1 degree of freedom. If the calculated χ2 value was greater than the table value, then the distribution was considered clumped.

Statistical analysis of the effect of leaf age on the vertical distribution of B. tabaci nymphs
The numbers of B. tabaci nymph populations found on young, middle, and old leaves were analyzed by analysis of variance (ANOVA). Furthermore, to determine the age of leaves that have an effect, the ANOVA was supplemented with Duncan's multiple range test at 5% significance level.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article.