The First Recording of Blue Pea Butterfly, Lampides boeticus L. on Ziziphus Spina-christi Trees in Nineveh Governorate

The larvae of the blue pea butterfly, Lampedies boeticus L., were observed for the first time feeding on Ziziphus spina-christi leaves in 2020 in the gardens of Mosul University / Nineveh Governorate. The larvae feed on the lower surface layer of the leaves, leaving the feeding places in the form of transparent linear spots. The leaf may be stripped of its green area when the infection intensifies and eventually leads to its fall. The rate and severity of leaf injury varied during the months of the year and reached its peak in November with an average of 61.42% and 20.06 linear/leaf spots, respectively, while the injury rate of leaf and severity were the lowest in May with an average of 2.47%, 0, 61 linear spots/leaf. The results also showed that the southern and eastern directions of the tree were the most preferred for the insect, as the average rates of leaf infestation were 22,84, 22.12%, respectively. The mid-site leaves on the stem were the most affected by the feeding of butterfly larvae, with a severity of 7.08 linear spot/leaf.


Introduction
Ziziphus spina-christi trees are one of the evergreen trees grown in tropical, subtropical and warm temperate regions [1].Its cultivation is spread in many regions of the world, especially arid and semiarid regions such as India and Pakistan [2].These trees have a great ability to withstand harsh environmental conditions of high temperatures and low temperatures up to -2 ºC [1].The Ziziphus spina-christi tree is multi-purpose, its fruits contain a high percentage of vitamin C, in addition to sugars, proteins, organic and amino acids, fats and mineral salts, and its leaves and bark have medicinal properties.Ziziphus spina-christi cultivation is widespread in the central and southern regions of Iraq, especially in Basra Governorate / Iraq [3].However, neglect and poor service increased the disease and insect problems of these trees.Ziziphus spina-christi trees in Iraq are infested with many insect pests that affect the quantity and quality of fruits, including scale insects, types of mites and mealybugs [4], the buckthorn worm, the buckthorn leaf borer [5], the fruit fly Ceratitus capetata and the buckthorn fruit fly [6].These trees planted in gardens and central islands inside the University of Mosul -Nineveh Governorate suffer from severe whiteflies [7], in addition to the presence of signs of leaf chewing .Linear spots of different lengths with transparent appearance and different densities were observed.The severe infestation led to erosion of leaves from their vegetative area, and then to their yellowing and falling.Therefore, the study aimed at diagnosing the insect type that caused the infestation, in addition to determining the rates and severity of infestation in an attempt to assess the levels of seasonal infestation of this pest on Ziziphus spina-christi trees.

Infestation Diagnosis
Random samples were collected from Ziziphus spina-christi leaves with signs of leaf rodent infestation at different times of the growing season, and brought to the laboratory where the larvae and pupae were extracted from the leaves and placed in dishes inside the incubator until the adults came out.The samples were then sent to the Natural History Museum / Baghdad for the purpose of diagnosis and identification of the insect species.

Seasonal Damage and the Effect of Direction and Location of the Leaf on the Stem on the Rate and Severity of Injury
A field survey was conducted for Ziziphus spina-christi trees inside the University of Mosul, where weekly random samples were taken for a whole year, starting from October 2020 and ending in September of the year 2021 to follow up the insect's damage during the different growing seasons (except for the months of February and March, no readings were taken due to leaf fall during that period).The sample was represented by four stems with a length of 75 cm representing the four directions of each tree (three trees) randomly, so that the sample size became 12 stems, brought to the laboratory where each stem is divided into three regions (terminal, middle and basal).The number of healthy and infected leaves is calculated in each part and in each direction to calculate the percentage of leaf injury, and the number of tunnels (linear spots) for each leaf in each section and direction is calculated to calculate the severity of the injury.

Leaf injury rate = number of injury leaves in the sample / number of sample leaves×100
Severity of injury = number of linear spots leaves in the sample \ number of injury leaves in the sample

Infestation Diagnosis
The results of the diagnosis from the Natural History Museum / Baghdad showed that the insect causing the injury is Lampedies boeticus.L belonging to the Lycaenidae family and the order of Lepidoptera, according to the book no. 8 dated 01/31/2022.This is the first record of the butterfly larvae feeding on the leaves of Ziziphus spina-christi trees where it was not previously recorded on such leaves in the literature of scientific research.The blue pea butterfly spreads in open fields in India and infects herbaceous plants and causes various damages to plants.[8], mentioned that the larvae of the blue cowpea butterfly L. boeticus.L feed on different species of the families Leguminosae, Cruciferae and Polygonaceae, including Colana and soybeans, in addition to cowpeas.Broad beans (Vicia Faba) and peas (Pisum Sativum) are among the preferred host plants for the insect.As reported by Chang, 1989, the blue pea butterfly infects mainly beans, peas and hyacinth beans in Taiwan.[9] reported that insect feeding on Vigna Unguiculata and Lupinus Albus resulted in higher insect fecundity, shorter virgin duration and greater longevity of adult compared to feeding on Glycine Max or Phaseolus Vulgaris.The larvae were seen feeding on the surface layer of the leaf consuming the green layer, leaving the infestation in the form of linear spot areas with a transparent appearance.Usually there is more than one linear spot in the plant leaf.In case of severe damage, the plant leaf appears stripped of its green area and eventually leads to its fall.

Percentage and Severity of Infestation Leaves
The rate and severity of leaf injury varied during the months of the year, due to the varying environmental conditions.The injury rate ranged between 2.47 -61.42%.The month of November recorded the highest rate leaf injury, with an average of 61.42%, followed by September with an average of 30.25%.The injury was the lowest in the month of May with an average of 2.47%, while the leaves were free of any infection during the month of April (the infection rate is zero).Also, the results in Table No.
(1) showed that the injury severity was the highest during the month of November, with an average of 20.06 linear spots/leaf, then followed by September with an average of 8.78 linear spots/leaf, while the lowest average recorded during a month May, and it reached 0.61 linear spot / leaf.It seems that the plant's vital condition and environmental conditions were suitable for the development of the butterfly larval community to cause the greatest damage to the leaves during the autumn months, in general and November, in particular.It also seems that the availability of adult food, nectar, during this period affects the increase in the process of laying eggs, and thus the development of the butterfly community, as [10] mentioned.This species is more dependent on nectar resources obtained by adults for laying eggs and that reduced availability of nectar sources constrains fertility.No leaf Injury rates were recorded during the months of February and March, due to the falling leaves and their absence during that period.The results agreed with what [11] mentioned in a study conducted in Iraq that the number of eggs and larvae of the blue peasles butterfly reached its peak on cowpea plants during the autumn months (September, October and November), where the Injury rates were 27,33, 38,33 and 29,47%, respective.

Distribution of Infestation on Plant Stems
The distribution of leaf Injury on the stem gives an indication of the insect's preference for leaf type, as the terminal leaves are often juicy with light colors, and as the leaf advances in age, it becomes less juicy and its color becomes mostly dark.Here it can be said that the color of the leaf and the nature of its texture are important factors in attracting adults to lay eggs.The results showed that the median leaves on the stem were the most affected by the criterion of injury rate and severity, where the averages reached 22.22% and 7.08 linear spot / leaf, respectively.The statistical analysis showed that there were significant differences between the mean severity of injury at the probability level of 0.05, Table (1).The reason may be that the infestation begins in the tender leaves that are at the tip of the site and are preferred by the insect.With the passage of time and with the age of the leaf, the accumulated infection in the intermediate leaves becomes high, and with the age of the leaf more, the intermediate leaves turn into deteriorating basal leaves, most of which fall off as a result of the high infection.

The Distribution of the Infection in the Four Directions of the Tree
Knowing the distribution of the infestation and the insect density on the four directions of the tree is useful in the control process, and in directing the spraying of the pesticide more accurately in the direction in which the numerical density is represented.The results in Table (2) showed that the incidence and severity of leaves were highest in the southern and eastern directions of the tree, where it reached 22,84, 22.12%, respectively; while the lowest percentage of leaf injury was in the western direction of the tree.The reason may be the effect of heat resulting from direct sunlight in the southern direction, which corresponds to the arc of the sun, where warm conditions are available for the activity of the insect.Likewise with the severity of the injury , the leaves were found in the southern and eastern directions that were most affected by the feeding of the insect larvae, and the severity of the injury was 7.42 and 6.73 linear spots/leaf, respectively.While the leaves in the northern direction recorded the lowest injury severity of 4.05 linear spot/leaf, and clear significant differences were recorded between the averages at the probability level of 0.05 according to the Lsd test.

Figure 1 .
Figure 1.The larvae feeding on the surface layer of the leaf consuming the green layer.

Table 1 .
Effect of date , leaf location on Rate and Severity of Injury of blue pea Butterfly Lampedies boeticus L.

Table 2 .
Effect of date, direction on Rate and Severity of Injury of blue pea Butterfly Lampedies boeticus L.