CROP PROTECTION 21 APPROACHES AND PRACTICES IN PEST MANAGEMENT - ENTOMOLOGY CABBAGE WORMS (Crocidolomiapavonana)Jimae Faith B. MagnayeTTH; 1:00 – 2:00
I. Introduction Cabbage is one of the mass produced horticultural crops in the world. Not only that it is very palatable yet the availability of the market makes the production profitable. However, like any crops, growing cabbages also have problems. One particular problem of the cabbage industry is the occurrence of Cabbage Worm infestation. Scientifically known as of Crocidolomiapavonana, cabbage worm is classified taxonomically as: Phylum: Arthropoda Class: Insecta Order: Lepidoptera Family: Crambidae Subfamily: Evergestinae Genus: Crocidolomia Species: pavonana (Source:http://www.lepbarcoding.org/australia/species.php?region=1&id=7 1690) In other countries, Crocidolomiapavonanais more commonly known as cabbage cluster worm or leaf webber. Other information regarding Crocidolomiapavonanawill be based upon information labelled with the common name cabbage cluster worm or leaf webber.
Studying the life cycle, damage caused and its casualties, vectors and control methods is important especially since cabbage is a crop that is has high economic yield yet highly susceptible, too.II. REVIEW OF RELATED LITERATURE A. Life cycle of Crocidolomiapavonanaand Damage Eggs are laid in clusters of 40-300 on the underside of the leaves. Hatching time takes a week while the completion of the life cycle comes in 3-4 weeks’ time. After which, the larva will turn into the cabbage moth(http://www.pestsandcrops.com, 2012). Figure 1: Crocidolomiapavonanain aggregate (Source: http://www.pestsandcrops.com, 2012)
Figure 2: Crocidolomiapavonanain mature stage (Source: http://www.pestsandcrops.com, 2012) The larval stage occurs after hatching where thelarvae became consume the leaves by groups. They werecalled cabbage cluster worms due to this feeding behaviour. Young leaves, shoots and became the initial food ofthe Crocidolomiapavonana. After which, they consume theolder leaves (ICAR, 2012). This trend led to unpleasingphysical appearance of the crop. Although considered minor causal agent of decreasein the physical yield, the damage made byCrocidolomiapavonanais more on the quality side of thecrop. After leaf infestation, the physical form of the produceis full of holes and at times, only the net are the only onesbeing left.
Moreover, since the affected family of crop has the economic value on the leaves, this problem must be addressed.B. Methods of Control Since Crocidolomiapavonanais considered as a minor pest, only a few control methods were formulated to protect the crop it attacks. Moreover, some of these methods where adopted from the control methods of diamond-backed moth also known as Plutellaxylostella. Both species came from the same family which is the reason for the same or applicable control. a. Cultural In terms of cultural method, the land preparation is the process where the control method is incorporated. The land preparation for the crops affected with this pest requires thorough ploughing in which the plant residues from the previous cropping should be mixed with the soil. The method allows the end of the life cycle of the Crocidolomiapavonanasince there’s no available crop during the laying period.
b. Biological Utilization of biological controls for Crocidolomiapavonanais not practiced since the damage caused by the pest is minimal compared to others. However, the studies show that Bacillus thurigiensisand Trichogrammachilonisis applicable for its control (Saucke, et al.,2010). Older studies indicated that the utilization of Pteromaruspuparum or commonly known as chalcis fly is also proven beneficial to the crop by functioning as Crocidolomiapavonana’sparasite. On the other hand, another biological control for the mature stage of Crocidolomiapavonanais the Phymatawolffi or the ambush bug. The ambush bug devours on the mature cabbage moth which prevents further lying of eggs. (Chittenden,1912).c. Mechanical & Physical The only mechanical control made before was via hand picking which became laborious as well as less productive due to the size and the number of the pest (Chittenden,1912).
d. Behavioural No behavioural control was yet established for Crocidolomiapavonana.e. Chemical and Biotic pesticide There is no established chemical or biotic pesticide that could control Crocidolomiapavonanayet studies and practices show that there are certain substances being tested and used in order to control the pest. According to the results of the study of Dadang and Djoko (2011), botanical insecticides derived from Piper retrofractum, Annonasquamosa and Aglaiaodorota are relatively more effective than delamethrin, a synthetic chemical and as effective as B. thurigiensis. The parameter for this result is the number of larvae present as well as the reproduction rate of the said pest. In terms of synthetic chemicals, arsenicals are commonly used. Yet this practice is not common since the application should be at least five times in order to visibly control the pest. One established chemical control is the Durivo™ by Syngenta. It is a broad spectrum insecticide which controls
the insect pest of leafy vegetables where the family of Brassica is included. The active ingredients present in this chemical control are thiametoxam and chlorantranilipole (Durivo Label, 2012). f. Others Usage of genetically modified organism such as the Bt cabbage was a suggested mode of control to decrease the larval population of the Crocidolomiapavonana. Yet, the availability and cost of this type of cabbage are the constraints that cause the less utilization of this practice (Saucke, et al.,2010).C. Disease Crocidolomiapavonanais not a vector of pathogenic disease. However, the existence of this pest allows the susceptibility or the easy entrance of another pest. The insect pest that follows after the existence or completion of the life cycle of Crocidolomiapavonana is the Plutellaxylostella. The attack of the Crocidolomiapavonanaduring the larval stage destroys the inner buds and the outer leaves while the attack of
Plutellaxylostellaat its mature stage is a combination that cabbage producers dread. This can cause losses up to 100% of the economic yield. Harvests can be made yet the collected crops have low value in the market due to its damagedphysical appearance. D. Crop In terms of scope of infection, the Brassica family of crops are commonly affected. Not only are the cabbages being affected but also its relatives such as lettuce, broccoli and cauliflower.III. OTHER INFORMATION: i. Foraging behaviour and its effect on behaviour One study conducted showed the different feeding behaviour of Crocidolomiapavonanaupon its location. If the larval stage will be placed in the internals buds, the leaf tips are consumed first and the base of the leaf was not consumed where as in the case of the older leaf location, the base of the leaves were consumed first, leaving the tips of the leaves uneaten (Takeuchi, et al. 2009). In relation to this, the larvae found in the older, external leaves were found to cause less damage than the ones found in the inner buds.
IV. References: Chittenden, H. (1912) Cabbage Worms. Farmers’ Bulletin (766). Retrieved on September 25, 2012 from http://naldc.nal.usda.gov/download/ORC00000200/PDF Dadang, E. D. F. &Djoko, P. (2012). Field efficacy of two botanical insecticide formulations against cabbage insect pests, Crocidolomiapavonana (Lep.,Pyralidae) and Plutellaxylostella (Lep., Yponomeutidae). J.ISSAAS 17: 2, 38-47. Durivo Label (2012). Durivo Information Label.Syngenta Product Information Database. Retrieved on September 25, 2012 from www.syngenta.com Fabricius (1974) Crocidolomiapavonana.Insect Information Database. Retrieved on September 25, 2012 from http://22.214.171.124/NABG/pestrecdis.php?keyword=Oilseeds%20Mustard&pna me=Crocidolomia%20pavonana Saucke, H., F. Dori, & H. Schmutterer (2010). Biological and integrated control of Plutellaxylostella (Lep., Yponomeutidae) and Crocidolomiapavonana (Lep., Pyralidae) in Brassica Crop in Papua New Guinea. Biocontrol Science and Technology 10: 5, 595-600. Retrieved on September 25, 2012 from http://www.wiz.uni- kassel.de/phytomed/Saucke%20et%20al%202000_DBM%20biocontr ol.pdf
Tackeuchi, H., Zalucki, M. P. & Furlong, M.J. (2009).Crocidolomiapavonanalarval foraging: behaviour and feeding site preferences in cabbage, Brassica oleracea. EntomologiaExperimetalis et Applicata:10.1111/j.1570- 7458.2009.00918.Unknown (2012).Greater Cabbage Moth.Pests of Field Crops in South Africa.Retrived on September 24, 2012 from http://www.pestsandcrops.com