Relationship between the Number of Oecophylla smaragdina Fab. ant nests and the Intensity of Prays endocarpa Meyrick Attacks on Pamelo Citrus ( Citrus maxima Merr)

This research on the relationship between the number of O. smaragdina nests and the intensity of P. endocarpa attacks has been conducted at the Pamelo citrus plantation of Gelengge in Pangkep Regency. The observation sample trees were those which had the O. smaragdina nests for three weeks in the Pamelo citrus trees. The sample trees were grouped into four categories namely: A) 1-2 nests per tree, B) 3-4 nests per tree, C) 5-6 nests per tree, and D) without nests (control). The observed parameters were the attack intensity of P. endocarpa on fruits on trees and on fallen fruits found under Pamelo citrus trees. The observation of the attack intensity was carried out after the Pamelo citrus fruits reached six weeks old, or after the fruits reached 50 mm-60 mm in size. The results showed the intensity of P. endocarpa attack on the fruits in the lowest tree was 36% in the trees with about 5-6 O. smaragdina nests, and the highest in the trees without nests was 66%. The attack intensity on the lowest falling fruit was 41.5% on the trees with 5-6 nests per tree, and the highest was 60.3% the in trees without the O. smaragdina nests. The regression analysis showed a relationship between the number of O. smaragdina nests with the attack intensity with the regression coefficients, respectively were r = 0.94 and r = 0.98.


I. INTRODUCTION
One of predator mostly found in many agricultural commodities is the ant Oecophylla smaragdina Fab.[1,2].The O. smaragdina has been studied for their utilization as predators against pests in some plants [3, 4, 5, 6, 7, 8, 9; 10, 11] The abundance of Oecophylla ants in a planting area can be marked and measured based on the presence and number of nests [12].These nests are created by weaving the leaves on the trees they inhabit [11,5].The nest is a breeding ground or a place to coordinate in carrying out daily activities [11].The number of nests created per tree can vary depending on the needs and environmental suitability of the O. smaragdina ants [13,14].
One of the pests whose status Prays endocarpa Meyrick is the important pest of the Pamelo citrus (Citrus maxima Merr) is the [15,16,17,18].These pests attack pangelo citrus at a young fruits age and have the potential to cause large losses due to the fall of young fruits, and if those fruits grow until large, then they are abnormally shaped due to the appearance of lumps and the shape of thre are small holes around the surface of the fruits [15,19,20].
The presence of O. smaragdina in the Pamelo citrus plant can be used as predators against P. endocarpa.However, it is not yet known how effective O. smaragdina abundance can be reduce the P. endocarpa attacks.The research aims to determinate the relationship between the nests number is one of the abundance parameters of O. smaragdina that can be used to assess its relationship with and the P. endocarpa damage on pamelo citrus.The parameters observed in this study The attack intensity of P. endocarpa were observed in the fruits that were still in the tree, and in the fruits that had fallen under the tree.The attack intensity on the fruits in the canopy is observed with a square frameshaped (1 m x 1 m) auxiliary tool made of parallon pipe (Figure 1).by searching various plant parts, such as branches, twigs, fruit leaves, and flowers [24,25].The nest located on young leaves makes it easier for them (O.

II. METHODS AND MATERIAL
smaragdina) to find food and eat a sugar-rich ingredient, i.e., the nectar, and a number of insects by patrolling around various parts of the tree [24].
Predators (six) nests.This number is still less than 10 nests per tree, which is the recommended number of nests to be able to offer the necessary protection to plants [27].
In order to be able to P. endocarpa on the Pamelo citrus plants, it is recommended to increase the number of nests per tree.A management is needed to maintain a high and stable weaver ant population on field [28].Some techniques to increase ant populations such as feeding [29], moving the nests This research was conducted from September to November 2022 in the farmer's Pamelo citrus garden in Gellenge, Ma'rang District, Pangkajene Regency, South Sulawesi, Indonesia.The conducted research arranged in the period of flowering and small fruiting of citrus.At a one-hectare Pamelo citrus field, five plots were created diagonally.Each plot consisted of ten samples of Pamelo citrus trees.The total sample of Pamelo citrus trees were 50 trees.When the citrus plants' fruits grew with a size of 10 mm -15 mm, the tree was marked as a sample tree for the measurement of the P. endocarpa attack intensity on the Pamelo citrus fruits.The criteria for sample trees for the observation of attack intensity were those that had O. smaragdina nests for three weeks (21 days) in the Pamelo citrus trees.Determined the number of nests per tree by repeating each for four times, namely: A=1-2 O. smaragdina ant nests per tree for three weeks; B= 3-4 O. smaragdina ant nests per tree for three weeks; C= 5-6 O. smaragdina ant nests per tree for three weeks and D= Without O. smaragdina ant nest (control) for three weeks

Figure 1 .
Figure 1. 1 m x 1 m square parallon pipe frame (a), Measuring the P. endocarpa attack intensity on the pamelo citrus plant (b). b

Figure 2 .
Figure 2. Observation of the P. endocarpa attack intensity on the Pamelo Citrus Fruits which have fallen under the Trees.The P. endocarpa attack intensity on the fruits is calculated by this equation: Attack = Number of attacked fruits Number of observed fruits × 100

Figure 3 .Figure 5 Figure 6 .
Figure 3.The P. endocarpa attack intensity on the fruits in the canopy of citrus plants (C.maxima) with different numbers

[
30], and reducing the use of pesticides [23] can be applied based on the knowledge of the O. smaragdina ant abundance.IV.CONCLUSION The presence of O. smaragdina ants on Pamelo citrus plants can inhibit the P. endocarpa attack intensity on the citrus fruits; the presence of the Category-C nests (5 -6 nests) reduces the P. endocarpa attack rate on the citrus fruits on the canopy by 30.96 % with a coefficient correlation of r = -0.94**,and 18.77 % on the fallen fruits with the correlation coefficient of r = -0.98 **.