Proceedmqs of the 7th Internaiumal Working Conference on Stored-product Protection - Volume 2

Assessment ontruncatus (Horn)province, China

prevention of( Coleoptera:

invasion of ProstephanusBostrichidae ) in Hainan

WeI XuI, Ye QIXlanI, Guan Lianghuar and Zhang Shengfang''

Abstract

Large gram borer (Prostephanus truncatus (Horn» IS amajor pest of farm-stored maize and dned cassava It ISlisted to be the quarantme pest of Cluna. Under the optimumcondition of temperature (27 - 32°C) and relative hurmdrty(70 - 80 % r h.), P. truncat'US has the potential to spreadstill further into Haman Island from abroad, for, bemg atropical region, Haman also produces maize and cassava.According to the outbreak conditions of this pest, we madean assessment on mvasion of this pest to Hainan Island andfound: It IS possible for the beetle to spread into HamanIsland and subsequently spread into the inland of China Ifquarantine measures would not be taken.

Introduction

Prostephanus truncatus (HORN) attacks before harvestand contmues to do so throughout storage (Qumtana et al. ,1960). It has pnncipally been recorded m Central Amencancountnes, but It has been found in Califorma, Texas and theDistnct of Columbia. In South America, It was recordedonly from Brazil. In Tanzania, farm-stored maize andcassava are subject to very severe rnfestatron by theintroduced large gram borer. Outside the Amencancontment, It has been observed attacking stored maize inChina, and was found in products of Chmese ongm at anexposition held m Pans (Lesne, 1898) But there IS noevidence to suggest that It has become an establIshed pest inChina (Back and Cotton, 1922; Kulash, 1954). Accordmgto the optimum condItion of temperature (27 - 32°C) andrelative humIdIty (r h 70 - 80%) and farm-stored gram(maIze and cassava) of thIS pest, we made an mvestIgationm Haman Island FIrstly, to determine whether the

1 Hanan Amma and Plant Quarantllle Servlce, Haman 570311, Chma

2 Tlanjm Arumal and Plant Quarantme Servtce, Tlanjm 300191,Chma

3 Laboratory of Entomology, Instltute of Plant Quarantme,Agnculture Mmlstry, Beljlng 100029, Chma

temperature and humidity m Haman are instrumental to thispest's distribution. Secondly, to assess the possibility of thispest's infestation m maize and cassava in Haman. Thirdly,to assess Its potential for becommg an established pest mHaman. Fourthly, to assess the potential of ItS subsequentlyfurther spread into the inland of China For these purposes,we concluded an assessment on prevention of mvasion of thebeetle

Investigation

Temperature and humidity

According to the local meteorological records, the averagetemperature is between 27 - 32'C in Apnl , May, June,July, August and the first half month of September mHaman Obviously, the temperature m Haman IS adaptive tothe survival and development penod of the beetle. As to therelative hurmdity, It IS recorded that the relative hurmdity,it IS recorded that the relative hunudrty annually IS betweenr.h 80-85%. Thus, It IS a httle lugher than the suitablerelative hurmdrty (r h 70 ~ 80%). As a hot humid tropicalarea, Haman province takes the nsk of being established bythis large gram borer Once tlus pest IS spread into the area,temperature/humidity conditions WIll help this pest'sdistnbution

Maize and cassava

Farm-stored maize and cassava in eastern Africa aresubject to very severe infestation by the introduced beetle in1984. Through It IS hot and dry m eastern Mnca, thetradItIOnal storage methods aSSIst m the establIshment of thISpest. In eastern Mnca, farmers store maIze cobs with huskmtact and keep them m the lofts of houses or on racks orplatforms m the sun. In Haman Island, maize ISmamly usedas breedmg and then transported mto the mland of northernChma. Even though a small quantity of maIze WIth huskintact IS kept m Haman, they are only young maize cobs soldas snacks, or small part of them are stored as feed. Theacreage of maIze m Haman IS about 260,000 mu, and ItSannual produced quantity IS 46,000 tons, and It is plantedmamly in Sanya, LingshUl, QIOngzhong and Ledong.Compared WIth maIze, cassava cultivated and stored IS very

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Proceedinqe of the 7th Internatwnal Workirlg Conference on Stored-product Protection - Volume 2

popular m Haman, and Its acreage IS 500,000 mu, and ItSannual produced quantity IS 485,000 tons. It is distributed mmost of the cities and counties, mainly m Tunchang andQlongshan. The produced cassava IS mamly used as forageand starch. Also, some cassava slices are Imported fromThailand since 1988 But the large gram borer has neverbeen intercepted by quarantme. There is no record that thebeetle has ever mfested cassava and maize m Haman Theinvestigation results presented here clearly demonstrate thatP. truncatus has not been spread mto Haman Island, butonce It IS spread mto this tropical area, the losses can not beestimated.

Discussion

Haman Island, which covers an area of 34,000 square kmand has a population of 6.6 million, became a provmce andwas designated as a special economic zone m 1988 Smcethen, It has been makmg efforts to Improve mfrastructurefacihties and mvestment environment to attract moreforeign busmessmen. Especially m Agnculture, over 200Taiwan entrepreneurs have invested in tropical and highefficacious agnculture. The products have been exported tomany countnes and also to mland of Chma. So, Import andexport quarantme IS very important. Three measures can betaken as follows: FIrstly, m the course of quarantme, paymore attention to the maize, nce , cassava, bean WhICh areImported from the South America, Central Amenca,countnes and Eastern Africa areas. And other woodenpackmg parts should also be strictly mspected. Secondly, toreduce the possibility of infestation by the large grain borerand other msects, fumigation treatment should be takenpnor to storage of the gram. Thirdly, as a southernbreedmg base of Chma , Haman plays an Important role mprovidmg the fine vaneties of plants mto other provmces,mumcipahties and autonomous regions. In order to preventthe possible invasion of the large gram borer from abroadmto Haman and subsequently mto the mland of Chma,passenger and cargo ShIpS and planes from Haman to mlandof Chma should be stnctly quarantmed. OtherWlse, once thelarge gram borer IS further spread through Haman mto themland of Chma, the damage to the Agncul ture of ourcountry Wlll be hardly estimated We also have theresponSIbIlIties not to make Haman 'The Bndge Tower' ofthe large gram borer to Chma

References

Cao JI, LI Xueshu, Guan Llanghua, and LI XIanyu (eds. ),

1988. Handbook for Plant Quarantme, SCIence Press, p147 -151.Guan Lianghua and Wang Zongwei, 1982 The Large GramBorer (in Chmese). Plant Quarantme, 5, 16 - 17Bell R. J. and Watters F I , 1982. Environmental Factorsinfluencing the development and rate of increase ofProstephanus trancatus (Horn) on stored maize. Journalof Stored Products Research 18, 131-142.Borgemeister C , 1994. The effect of maize can selectedthe Impact of field infestation on stored maize losses by thelarger gram borer and associated storage pests.Proceedmgs of the 6th International workmg Conferenceon Stored-product Protection, 2, 906 - 909Cowley R. 1. , Howard D. C and Smrth R. H., 1980 Theeffect of gram stability m damage caused by Prostephanustruncatus (Horn) and three other beetle pests of storedMaize. Journal of Stored Products Research. 16, 75 -78.Golob P. and Hodges R., 1982 Study of an outbreak ofProstephanus truncatus (Horn) in Tanzania TropicalProducts Institute.Hodges R.J. , Meik J. and Denton H. , 1985. Infestation ofdned cassava (Mamhot Esculenta Crantz ) byProstephanus Truncatus (Horn) Journal of StoredProducts Research 21, 2, 73 - 77Hodges R. J., 1986 The biology and control ofProstephanus truncatus (Horn) - A destructive storedpest WIth an increasmg range. Journal of Stored ProductsResearch 22 ,1, 1 - 14Hodges R J. and Meik, J. ,1984 Infestation of maize cobsby Prostephanus truncatus (Horn) - Aspects of biologand control. Journal of Stored Products Research 20, 4,205 - 213Shires S. W , 1977 Ability of Prostephanus truncatus(Horn) to damage and breed on severe stored foodcommodities Journal of Stored Products Research 13, 205-208.

Slures S W ,1979 Influence of temperature and humidityon survrval , development penod and adult sex ratio mProstephanus truncatus (Horn) Journal of StoredProducts Research 15, 5 -10.ShIres S. W., 1980 LIfe hIstory of Prostephanustruncatus (Horn) at optimum condItions of temperatureand humIdIty Journal of Stored Products Research 16.Valene F. Wnght and Theodore J. SpIlman, 1983 Ananotated bIblIography on Prostephanus truncatus(Horn): A pest of stored gram TropIcal Stored ProductsInformation, 46, 25 - 30

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