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Environment & Ecology 33 (1B) : 416—420, January—March 2015 Website: environmentandecology.com ISSN 0970-0420

Pest Complex and Population Dynamic of Shoot and Fruit Borer (Leucinodes orbonalis Guen.) of Brinjal in Medium Altitude Hill of Meghalaya Pukhram Bhumita, Rajendra D. Solanki, D. Kumar

Received 15 May 2014 ; Accepted 28 June 2014 ; Published online 21 July 2014

Abstract The experiment was conducted to study the pest complex and incidence pattern of shoot and fruit borer of brinjal. A local variety of brinjal was transplanted and raised with recommended management practices. Observations were recorded on weekly basis from randomly selected thirty tagged plants from entire field during early hours starting from seedling to till maturity of the crop. The brinjal crop was found to be infested by eight insect pests belonging to five orders viz. Diptera, Hemiptera, Thysanoptera, Coleoptera and Lepidoptera and one non-insect such as red spider mite. Majority of recorded insect pests were as minor except brinjal shoot and fruit borer. Highest shoot and fruit damage were recorded by shoot and fruit borer on 6th July with 20.43 and 32.76%, respectively. Relative humidity had significantly positive correlation on population build up of brinjal shoot and fruit borer during study period. Spiders’ population was found to be natural regulators for controlling small insect pests.

P. Bhumita* Department of Agricultural Entomology, BCKV, Mohanpur 741252, Nadia, WB, India R. D. Solanki, D. Kumar Division of Entomology, ICAR, RC-NEH Region, Lamphelpat 795004, Imphal, Manipur, India e-mail: [email protected] *Correspondence

Keywords Brinjal, Pest complex, Leucinodes orbonalis, Population dynamic, Meghalaya.

Introduction Brinjal (Solanum melongena L.) is an important vegetable crop grown all over the country. It is an important dietary vegetable crop in Indian dish. Under sustainable farming brinjal provides regular daily income to meet the day to day expenditure. In Meghalaya 0.56% area is under brinjal cultivation with productivity of only 11.82 tons/ha as compared to the national average productivity (16.0 tons/ha) [1]. The crop is subjected to high degree of instability in production from year to year, mainly on account of losses caused by different insect pests like sucking pest, defoliators and fruit and shoot borer at different stages of the crop. Out of total damage by pest complex, nearly 25.82 to 92.50% fruit damage is attributed due to brinjal shoot and fruit borer. As Meghalaya state is highly weather dynamics which are most conducive for development of different insect species and their natural enemies. Though, pest complex of brinjal has been studied by different workers in different part of the country as well as for this region and reported a variable number of pests on brinjal at different time but pest spectrum of a particular crop is always changing under changing climate scenario. Recently it has been observed that minor pests are becoming major in some commercial crops. Therefore, periodical surveillance on pest complex for each crop may help to recognize the relative economic importance of differ-

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Table 1. Pest complex of brinjal under the agro-climatic condition of Umiam, Meghalaya during 2010. Sl. No.

Common name

Scientific name

Order

Family

Crop stage

Status

Diptera

Agromyzidae

Seedling Vegetative to maturity

Minor

Hemiptera

Aphididae

Hemiptera

Cicadellidae

-do-

Minor

Hemiptera Thysanoptera Coleoptera

Aleurodidae

-do-

Minor

-do-

Minor

-do-

Minor

Coleoptera

Thripidae Chrysomelidae Chrysomelidae

Minor

Lepidoptera

Pyralidae

-doFlowering to maturity

Tetranychus urticae Koch

Acharina

Tetranychidae

Seedling to vegetative

Minor

–

–

–

All stages

–

A. Insect pest 1.

Leaf miner

2.

Aphid

3.

Jassid

4.

White fly

5.

Thrips

6.

Brinjal leaf beetle

Liriomyza trifolii (Burgess) Aphis gossypii Glover Amrascabiguttula biguttula Ishida Bemisia tabaci Lindeman Thrips tabaci Lindeman Phylliodes balyi

7.

White spotted flea beetle Fruit and shoot borer

Monoleptasignata Oliv Leucinodes orbonalis Guen

8.

Minor

Major

B. Non-insect pest 1.

Red spider mite

C. Natural enemies 1.

Spiders

ent pests on that crop. Furthermore, assessment of population fluctuation of major pests is a pre-requisite for the implementation of effective control measures against them. Keeping this view in mind, the present study was carried out to record the pest complex of brinjal as well as population dynamic of shoot and fruit borer. (The authors are grateful to the Director, ICAR Research Complex for NEH Region and Head, Division of Crop Improvement for providing required facilities to carry out the study. The authors are also thankful to the Research Associate and Research Fellows under Insect Bio-systematic Project, Entomology, Division of Crop Improvement, Umiam, Meghalaya to help for proper identification of insect species). Materials and Methods The experiment was conducted during pre-kharif

season, 2010 at Entomology Farm, ICAR Research Complex for NEH Region, Umiam, Meghalaya to study the pest complex occurred on brinjal. Experimental site located at an altitude of 1000 msl with geographical location of 25°30´ N latitude and 91°51´ E longitude. A local variety of brinjal was transplanted on 5 April, 2010 in plot size of 200 m2 with 50 cm × 50 cm spacing. Crop was raised with all recommended management practices except plant protection. Observations were recorded weekly basis from randomly selected thirty tagged plants from entire field during early hours starting from seedling to till maturity of the crop. Thus, altogether thirty plants were observed by following Plant Inspection Method (PIM). Shoot and fruit borer was recorded in shoot by counting the drooped shoots and total number of shoot and in fruits by counting the damaged fruits and total number of fruits after harvesting and subsequently converted into per cent infestation. Sucking pests and leaf feeding insects were recorded from three leaves (upper, middle, lower) / plant. Recorded insect pests

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presented in Table 1. The brinjal crop was found to be infested by eight insect pests belonging to five orders viz. Diptera, Hemiptera, Thysanoptera, Coleoptera and Lepidoptera and one non-insect pest which was under the order-Acarina. Out of these, some insects infested the crop continuously after their first appearance in considerable numbers were designated as major pests and insect species which appeared occasionally or in small number were designated as minor pests. The pests were associated with brinjal plant infesting leaf, shoot, stem, flower, fruit and roots. The pests recorded during study period were aphid (Aphis gossypii Glover), jassid (Amrascabiguttula biguttula Ishida), brinjal leaf beetle (Phylliodes balyi Jacoby), white spotted flea beetle (Monolepta signata Oliv), thrips (Thrips tabaci Lind.), whitefly (Bemisia tabaci Lind.), leaf miner (Liriomyzatrifolii Meigan), shoot and fruit borer (Leucinode sorbonalis Guen.) and red spider mite (Tetranychus urticae Koch). The natural enemy recorded was only spiders. Among the recorded pest, leaf miner appeared first in the field only at seedling stage with very short period. At very early growth stage of the crop thrips incidence was observed and its infestation continued up to the maturity of the crop. Other sucking pests such as jassids, aphids and white fly were present throughout the cropping season starting from vegetative stage with minimum to moderate numbers. Among leaf feeding insects, brinjal leaf beetle, Phylliodes balyi Jacoby and white spotted flea beetle, Monolepta signata Oliv. were

Fig. 1. Trend of brinjal shoot and fruit borer incidence.

were identified at Division of Entomology, ICAR Research Complex for NEH Region, Umiam, Meghalaya. Insect pests were categorized as major and minor pests according to their incidence level during study period. Meteorological parameters viz. temperature, relative humidity, rainfall and sunshine hours were collected from the Division of Agricultural Engineering, ICAR RC for NEH region, Barapani and correlated with recorded insects’ population. Correlation coefficients (r) were calculated. Results and Discussion Pest complex Insect pests recorded in brinjal during experiment are

Table 2. Meteorological data at Umiam, Meghalaya during crop season. Date of observation

Temperature (0C) Maximum Minimum

Relative humidity (%) Morning Evening

Rainfall (mm)

Sunshine (h)

07.04.2010 14.04.2010 21.04.2010 28.04.2010 05.05.2010 12.05.2010 19.05.2010 26.05.2010 02.06.2010 09.06.2010 16.06.2010 23.06.2010 30.06.2010 06.07.2010

32.5 30.4 29 23.4 29.2 32 28.8 28.2 29.3 28.6 29 26.7 24.4 28.3

52 60 76 85 72 52 89 85 95 90 91 91 90 90

0 4.6 4 7.8 3.8 0 31.1 3.8 2.9 0.3 20.3 3.8 10 3.8

8.3 8.7 7.7 7.8 5.7 9.3 4.2 4.4 2.8 5.1 3.1 2.8 1.4 4.4

21.3 14.5 18 13.6 17.4 22 17.2 18 19.7 20.2 19 20.2 19 20.7

40 57 52 65 66 54 72 74 67 71 67 74 77 72

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Table 3. Correlation coefficients (r) between population of brinjal shoot and fruit borer and weather factors during crop season. *Significant at 5% ; SFB = Shoot and fruit borer.

Insects SFB in shoots SFB in fruits

Temperature (0C) Maximum Minimum

Relative humidity (%) Morning Evening

Rainfall (mm)

Sunshine (h)

– 0.38

0.45

0.65*

0.69*

0.08

– 0.79*

– 0.38

0.42

0.67*

0.64*

0.02

– 0.79*

also present from vegetative to maturity stage of the crop without causing noticeable damage to the crop [2]. Incidence of brinjal shoot and fruit borer was started from advanced vegetative stage and persists till maturity of the crop. The shoot and fruit borer was considered as the major pest which caused major losses to brinjal fruits. Non-insect pest, red spider mite appeared from seedling to vegetative stage and incidence level indicated its minor status. The present investigation on pest complex is similar with the finding reported earlier on brinjal from this region. Less number of insect pests was found on brinjal during study period that may be due to variety, weather factors and crop phenology. Present investigations revealed that L. orbonalis is the major and most destructive pest of brinjal in this region [2, 3]. The natural enemy recorded was spider (Oxyopes javanus Thorell) which predates on the insect pests of brinjal and was found throughout the crop season [4].

on July 6 with 32.76% fruit damage [5—7]. Weather parameters viz., maximum and minimum temperatures, relative humidity, rainfall and sunshine hours (Table 2) were correlated with the population of brinjal shoot and fruit borer and depicted in Table 3. The correlation between pest population and both morning and evening humidity had significantly positive influence while sunshine hours had significantly negative influence on the population build up of brinjal shoot and fruit borer. Minimum temperature and rainfall showed non-significant positive correlation whereas maximum temperature had negative correlation on population build up of the pest but it was not statistically significant [8, 9]. References 1.

2.

Population dynamics of shoot and fruit borer (Leucinodes orbonalis Guen.) 3.

Shoot and fruit borer infestation was found absent during early growth stages of the crop (Fig. 1). The population was found in the field at the advanced vegetative growth stage of the crop and gradually increases with increasing rate till the harvest of the crop. Shoots infestation was observed from the first week of May till the first week of July. The highest shoot infestation was recorded on July 6 (20.43% infestation). Fruits infestation was noticed in the last week of May immediately after fruiting started and continued till the first week of July i.e. last harvesting of fruits. The highest fruit infestation was observed

4.

5.

6.

7.

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bonalis Guenee. Ann Pl Prot Sci 17 : 319—321. Acharya MF, Vyas HJ, Gedia MV, Patel PV (2008) Biometrical analysis of Helicoverpa armigera on different hosts. Ann Pl Prot Sci 16 : 360—362.

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Naik V, China Babu, Arjuna Rao P, Krishnayya PV, Srinivasarao V (2008) Seasonal incidence and management of Leucinodes orbonalis on brinjal. Ann Pl Protec Sci 16 : 329—332.