Brinjal Fruit and Shoot Borer, Leucinodes orbonalis (Pyraustidae : Lepidoptera)
Brinjal Fruit and Shoot Borer (BFSB) is a very dangerous pest of brinjal. It not only reduces the yield by making holes in shoots as well as in fruits but also reduces the aesthetic value of the fruits so loss get doubled. It is a monophagous pest feeds only on Brinjal. The normal control measures like spraying of pesticides does not solve the problem instead making the environment polluted, ecological disturbance and vegetable poisoning. But if we understand the nature and behaviour of each life stage of the cycle, it is easy to replace poisonous chemicals with knowledge, local resources and skills.
Larva is a internal feeder it immediately bore into the nearest tender shoot or flower or fruit just after hatching,. Soon after boring into shoots or fruits, they plug the entrance hole with excreta. As a result, the affected twigs, flower and fruits dries up and may drop off.
Larval feeding, inside shoots, result in wilting of the young shoot. Presence of wilted shoots in an eggplant field is the surest sign of damage by this pest. The damaged shoots ultimately wither and drop off. This reduces plant growth, which in turn, reduces fruit number and size. New shoots can arise but this delays crop maturity and the newly formed shoots are also subject to larval damage. Larval feeding in flowers results in failure to form fruit from damaged flowers. Larval feeding inside the fruit results in destruction of fruit tissue. The feeding tunnels are often clogged with frass. This makes even slightly damaged fruit unfit for marketing. The yield loss varies from season to season and from location to location.
- Crop rotation is beneficial as the insect survives only on brinjal.
- Intercropping brinjal with other crops like cowpea, maize, corainder which improve the natural habitat for natural enemies (like spiders, lace wings, ladybirds etc) against the pest.
- Collection, destruction of dried shoot tips and bored fruits on campaign basis in an area. This is an efficient method because the larvae tend to pupate (transform into pupa and takes rest) in the plant residues itself. Burning of the infested parts and composting the crop remains is useful in preventing the buildup of the moth populations in a given area
- Mass Trapping of adult male moths using pheromones in fields is very efficient method to control the pest besides monitoring its population. Pheromones can be used in low-cost water-trough traps @ 40-60 traps per acre is very efficient in avoiding the pest in the first place. The pheromones traps trap the adult male moths (and not female ones) which reduces the fertilizing the eggs of female moths consequently reduce the carryover of pest.
- Natural enemies against BFSB reported in India:
Campyloneura sp (a bug), Cheilomenes sexmaculata (a ladybird beetle), Coccinella septempunctata (seven spotted ladybird beetle), Brumoides suturalis (three striped ladybird)
Pseudoperichaeta sp, Phanerotoma sp, Itamoplex sp, Eriborus argenteopilosus, Diadegma apostata
Fungus (Bipolaris tetramera), Baculovirus, Nuclear polyhedrosis virus
Photo courtesy by Bapuji Arcot
Submitted by Rakesh Kumar Singh on Thu, 09/09/2010 - 15:55