Infestation of Meliaceous Trees by the Mahogany Shoot Borer in Plantation Areas of the Peruvian Amazon

Transcription

1 J]RCAS Intenational Symposium Seies 1 : Infestation of Meliaceous Tees by the Mahogany Shoot Boe in Plantation Aeas of the Peuvian Amazon Toshiya IKEDA*, Akihiko TAKETANI** and Akihiko YOKOTA** Abstact A lage numbe of tee species planted on degaded foest lands in the topics ae pesently being theatened by many foest pests and diseases. Tee damage occus not only on monocultual but also on vaious types of plantations ove vast aeas. The mahogany shoot boe, Hypsipy/a gandella Zelle, is the most hamful insect pest against meliaceous species in South Ameica. Field suveys on tee damage conducted in the plantation aeas of the Peuvian Amazon evealed that both Spanish cede (Cedela odoata) and mahogany (Swietenia macophylla) wee heavily infested by H. gandel/a, paticulaly, in line planting and opened aeas within thee yeas afte planting_ Othe planting tials, such as mixed planting o planting unde the canopy of suounding tees, wee also unsuccessful in most cases. Tees unde low light intensity, including those in natual egeneation, have escaped fom initial attacks of the insect pest fo a elatively longe peiod of time, though the tee gowth was educed. Fequent spouting (3 to 5.5 times a yea) induced epeated attacks of the insect, esulting in egeneation failue of the tee. Howeve, since the insect density is educed in the dy season and that the adult moth seldom flies at a height of moe than 8 m above gound, the development of effective contol measues may become possible. Intoduction The genus, Hypsipyla, a mahogany shoot boe, is well known as the most seious insect pest against meliaceous tee species in the topical and subtopical egions of the wold. Among 1 species, Hypsipyla gandella and H. olmsta ae most destuctive in the New Wold (Cental and Latin Ameica) and the Old Wold (Asia and Afica), espectively (Fig. 1). H. gandella attacks all the Latin Ameican Meliaceae, paticulaly, the Cedela and Swietenia species (Table 1). Lavae boe into and hollow out banches, stems, cones and seeds. The damage leads mainly to the inteuption of gowth o banching off in all diections caused by the epeated attacks on the teminal shoots of the young tees. In the Peuvian Amazon aeas since a lage numbe of species of useful tees including Cedela and Swietenia have been lost fo decades due to selective logging and shifting cultivation, thee has been a fowning awaeness about the need fo pomoting the ehabilitation and sustainable use of such valuable tee esouces since the ealy 198s (Matsui, 1986; Kobayashi el al., 1986). Consequently, a eseach poject fo the development of affoestation techniques was initiated in 1982 by the National Institute of Foesty and Zoology, Peu and the Japan Intenational Coopeation Agency, Japan. Since then, Cedela odoata (Spanish ceda) and Swietenia macophyl/a (Mahogany) have been planted in lage numbes in vaious ways. Howeve, both species of tees have been heavily infested with H. gandella within two yeas afte planting. The objectives of this study ae to analyse the oveall aspects of H. gandella infestation in plantation Pesented at the Intenational Symposium on "the Rehabilitation of Degaded Foest Lands in the Topics"Technical Appoach, Tsukuba, Ibaaki, Japan, 17 Septembe 1992, held by Topical Agicultue Reseach Cente (T ARC)_ * Reseach Infomation Division, Topical Agicultue Reseach Cente, Tsukuba, Ibaaki 35, Japan * * Division of Foest Biology, Foesty and Foest Poducts Reseach Institute, Inashiki, Ibaaki 35, Japan

2 164 JIRCAS Intenational Symposium Seies No. 1 (1994) Fig. 1 Geogaphical distibution of Hypsipyla gandella (dotted) and H. obusta (oblique lines) Table 1 Host tee species of Hyposipyla gandella and H. obusta Tee species H. gandella Swietenia macophylla S. mahogani S. humilis Cedela odoata C..fissilis C. lilloi C. tubifloa C. pocea Toona cilia/a T. ciliata va. austalis T. seata * * Melia awdiacta Khaya anthotheca K. gandifoliola K. ivoensis K. nyasica K. senegalensis Guaea tichilioids G. guaa G. guianensis Lovoa tichilioides Chlooxylon swietenia Chukasia tabulais Entandophgagma angolene E. utile Cedelinga catenaefomis * Note 1. Note 2. : attacked, * : not o less attacked * : Only cones ae attacked. H. obusta *

3 IKEDA et al : Infestation of Meliaceous Tees by the Mahogany Shoot Boe in Plantation Aeas of the Peuvian Amazon 165 aeas and to develop measues of contol of this pest. Study site The study site was set up in the Von Humbolt National Foest (9 S), appoximately 8km west of Pucallupa which is located beside the ive Ucayali, the uppe steam of the Amazon. Affoestation aeas fo the poject in the National Foest coveed moe than 7 ha, in which entomological studies wee conducted mostly in the lineplanting o opened aeas. Aveage ainfall in the aea exceeded 4,mm/yea, and the mean annual tempeatue was 25 'C. Infestation levels and attack fequencies The numbes of tees with cuent o pevious Hypsipyla attacks wee vey lage in the entie study aea except fo seveal plots. The less damaged tees wee located in the natual egeneation aea, one of the two undeplanted C. odoata aeas and in two lineplanting aeas with S. macophylla (Table 2). Howeve, tee gowth was vey poo due to shading by the suounding vegetation. In an opened aea with C. odoata, 98.7% of the tees wee attacked once o moe within 16 months afte planting; the numbe of attacks vaied fom O to 1, aveaging 3.1 pe tee (Yamazaki et al., 1992). The life span of H. gandella eaed in the laboatoy was 3844 days encluding the peiod of mating, indicating that thee could be 7 geneations pe yea. In contast, phenological studies showed that spouting occued 3 to 5.5 times a yea, mostly in the ainy season, on both C. odoata and S. macophylla Table 1 H. gandella infestation on 3 meliaceous species planted in vaios ways. Tee species Aea 1 > No. of tees Yea 2 lof Pecentage of tees 3 > with code investigated plantation cuent attacks pevious attacks C. odoata LP1 ( 5m) LP2 ( 5m) LP3 ( 5m) LP4 (1m) SJ LP5 (1m) LP6 (3m) LP7 (3m) Natual '' UP UP Opened aea C. fissi/is LP1 ( 5m) Opened aea Opened aea S. macopyl/a LP1(5m) LP2 ( 5m) LP3 ( 5m) LP4 (1m) LP5 (1m) The investigation was conducted in Septembe o Octobe ) LP: line planting aea whee tees wee planted at a distance indicated by a numeal in paentheses, Natual : natual egeneation aea, UP : planting unde the canopy of suounding tees, Opened aea : opened aea less than I ha whee tees wee planted at 22.5 m spacing. 2) Tees wee tansplanted in Januay o Febuay. 3) The cuent attack was the attack ecognized cuently by beaking of banches o shoots, o exudation of oleoesin, wheeas the pevions attack was the one ecognized by the swellinglike knot associated with tissue egeneation fo healing of the aea peviously attacked on the main stem. 4) Tees wee 58 cm high at the time of investigation. 5) Not investigated.

4 166 JIRCAS Intenational Symposium Seies No. 1 (1994) (Yamazaki et al., 1992). These data suggest that the tees ae always exposed to Hypsipyla attacks wheneve they have spouted. In addition, even in the dy season, the adult moth which is attacted to the esin exuded fom the stem peviously attacked lays eggs neaby, esulting in the development of anothe geneation. Location of attack, on tees and developmental stages of insects Investigations have been conducted duing the season in which both insects and tees wee most active (Table 3). Among a total of 2,62 C. odoata tees inspected nine times duing the season, 362 (13.8 %) wee attacked. Young lavae (1st to 2nd instas) wee most fequently detected in the offshoots and thei numbe deceased fom the uppe to the lowe stem pats, wheeas olde lavae (3d to 4th instas) congegated on the uppe stem pat. The 5th insta lavae and pupae wee also most fequently found in the uppe stem pat but wee distibuted in othe locations to some extent. These esults indicate that hatched lavae feed on eithe newly developed shoots o fesh foliage, and then hollow out the stem mostly fom the uppe to the lowe pat as they develop. As thee wee vey few younge lavae on tees with old o without foliage, the spouting and development of young foliage ae vey impotant fo the establishment of H. gandella population. The numbe of insects on an infested tee with foliage at vaious stages anged fom 1 to 4, aveaging about 2. Seasonal changes in fequency of attacks Attack intensity stated to incease in Septembe (beginning of the ainy season), peaked in Octobe, gadually deceased towad the end of the ainy season and futhe declined in the dy season fom May to August (Fig. 2). The incease in the numbe of insect attacks was synchonous with ainfall, suggesting that the apid development of new foliage tiggeed by ainfall at the beginning of the ainy season caused a apid incease of the Hypsipyla population. Howeve, it emains to be detemined which factos Table 3 Location of attacks by H. gandella and developmental stages in elation to the foliage conditions of C. odoata tees in the season fom August 1988 to Mach No. insects No. of tees No. of tees Uppe pat Middle pot of Lowe pat Offshoot Total of stem detecles of stem investigated attacked A B C A B C A B C A B C A B Tees with new shoots Tees with fesh foliage 3 > Tees with old foliage 4 > Tees without foliage Total i C ) A: 1st to 2nd inste lavae, B : 3d to 4th insta lavae, C: 5th insta lavae and pupae. The main stem was divided into thee pats and each potion was designated as the uppe, the middle and the lowe stem. 2) Tee with new soft shoots, appoximately 2 cm long, and with o without fesh o old foliage. 3) Tee with fesh foliage and with o withou old foliage. 4) Tee with only old foliage.

5 IKEDA et al : Infestation of Meliaceous Tees by tbe Mahogany Shoot Boe in Plantation Aeas of the Peuvian Amazon 167.c: µ "' " "" 4,...; "' :, 'O 'O J;l <.) µ "' µ "',.. µ '"' bo µ "' "' OJ <.),.. Os I 3 I,_ 2 1 O 8 6 ( R ' Q, i I\. 4 V la lo 14..o!IC:: n JFMAMJJ ASONDJ FMAMJ JASONDJFMAMJJASOND f 1987 l f 1988! 4 2 E E C: "' 'c. 'ij "'.. Fig. 2 Seasonnal changes in H. gandella infestation on C. odoata () and S. macophlla(e). pevented tbe Hypsipyla population fom futhe inceasing in spite of the additional supply of new shoots o fesh foliage thoughout the ainy season and it could be assumed that natual enemies may have been involved in the contol of the population (Yamazaki et al., 199). Host tee pefeence As shown in Fig. 2, the annual mean in tbe pecentage of attacked tees was slightly geate in C. odoata (8.47%) than in S. macophylla (5.82%). In an opened ectangula aea whee 14 tees of each species wee planted altenatively, C. odoata was moe fequently attacked (23 tees o 16.4%) than S. macophylla (1 tee o.7%) thee months afte planting. Moeove, in the host pefeence expeiment caied out by placing 14 seedlings of S. macophylla and 4 of C. odoata witb young foliage on the same staight line, 3 out of 4 C. odoata tees wee attacked wheeas none of the S. macophylla tees (1 tee o.7%) wee attacked in a month. These esults indicate tbat H. gandella pefeed C. odoata to S. macophylla. Although C. odoata is moe fequently attacked than S. macophylla by H. gandella in Latin Ameica, C. odoata intoduced in othe egions of the wold is not o less attacked by H. obusta than native Meliaceae (Table 1, Gijpma 197). On tbe othe hand Toona cilia/a, T. cilia/a va austalis, T seata, Melia azadiacta and some othe Meliaceae which expeience sevee attacks of H. obusta in thei native counties ae esistant to the attack of H. gandella in Latin Ameica. It was shown that these host selections depend on the native Hypsipyla moth and ae based on tbe moth attaction to a specific odo of the host tee, paticulaly of young foliage (Gijpma and Gaa, 197). Howeve, S. macophylla which is native to Latin Ameica, is heavily attacked by H. obusta even in othe egions of the wold. Moth behavio The adult moth is noctunal. The emegence of the moth begins at aound 17:, eaches a peak at 19: 2: and ends a little afte 2:. Mating occus between 2: and 23: and tbe eggs ae laid between 21: and 24: afte copulation. The female moth showed a chaacteistic flight behavio.

6 168 JIRCAS Intenational Symposium Seies No. 1 (1994) When C. odoata seedlings with new foliage wee placed at vaious heights of the towe, they wee most fequently attacked by H. gandella at a height of 2 m above the gound, and the highe the elevation, the fewe the attacks (Table 4). Seedlings damaged wee concentated at an elevation below 6m above the gound and the damage was limited above that level, suggesting that the female moth flies close to the gound level to seach fo host tees. The female moth can easily move to fesh foliage of young and low host tees due to attactive odo as well as he flying patten. Tee gowth unde vaious soil and topogaphical conditions Tee gowth was vey poo in line planting, opened o natual egeneation aeas (Table 5, and Fig. 3 and 4) due to the epeated insect attacks. Howeve, even at such a low level of tee gowth, some significant diffeences wee found depending on the soil type in line planting aeas whee the light conditions wee simila (Table 5). It appeas that tee gowth on acisol (APO) was pooe than on gleysol (GPO) o cambisol (BVO), wheeas, thee was no significant diffeence in the tee gowth depending on the topogaphy in most aeas except that the gowth of tees eithe on a slope o top of a hill was vey poo. Table 4 Relationship between the fequency of attacks of H. gandella and hieght of C. odoata seedings. Height of No. of No. of attacks(%) seedlings seedlings (m) AugOct, 1987 NovDec, 1987 MaAug, (6. ) 28( 1.9) 71 (52. 5) (19. 2) 2(37.) 21(15.6) (17.6) 5 ( 9.3) 17(12.6) ( 4.3) 1( 1. 9) 13( 9.6) ( 4.3) (.) 6( 4.4) ( 3.5) (.) 7 ( 5. 2) Total (1) 54 (1) 135(1) Chemical contol Thee methods of chemical contol wee tested to educe the damage as follows: soil teatment, stem o oot injection and folia application of insecticides. Soil teatment with 7 systemic insecticides (1 o 5 g each of Baycid, Othene, Sancyde, Fadan, Advantage, Padan and Disiston) was not significantly effective in peventing the moth fom attacking both C. odoata and S. macophy//a duing the 12 day peiod afte the teatment. Stem o oot injection of Otheni o Baycid also was not effective, wheeas folia application of insecticides, paticulaly pyethoid, effectively deceased the damage of tees. In a peliminay tial, the spay of Sumithion (fenitothion, oganophosphate) at.1% concentation onto C. odoata foliage was effective against lavae and pevented the oviposition fo two weeks. Howeve, the effectiveness lasted fo less than one month afte the spay. Sumithidine (a pyethoid chemical) was moe effective than Sumithion and the mean pecentage of the tees attacked between the spays was 4.8% fo Sumithidine and 13.3% fo Sumithion. Among the pyethoid chemicals, such as Belmak (3% solution of fenvaleate), Sumithidine (2% fenvaleate) and Mikantop (3% fenpopathin), Belmak emained effective a little longe than the othes, although the pecentages of attacked tees wee low anging between % fo all the thee teatments (spaying was caied out thee times duing the suvey peiod fom Apil to Octobe). Field tials fo folia spaying of Belmak wee caied out in vaious aeas. The gowth ate of the tees teated with the chemicals was much highe (2 to 3 times) than that of the unteated tees (Fig. 3 and 4). When the tees (5md in Fig. 4), wee teated with the chemicals thee yeas afte planting, the gowth ates wee the same as those of the tees teated fom the beginning (5mc).

7 IKEDA et al: Infestation of Meliaceous Tees by the Mahogany Shoot Boe in Plantation Aeas of the Peuvian Amazon 169 Table 5 Tee gowth unde vaious soil and topogaphical conditions Gowth incement Peiod (days) APO'' GPO BVO ECO Plane Slope Cedela odoata 5m m m m m m Open Natual Swietenia macophylla 5m m lOm lOm lOm Open Natual ) APO: plinthic acisol, GPO: plinthic gleysol, BVO: vetic cambisol, ECO: chomic cambisol Hill top s.µ.<a bo.<a,.. E< Smb Fig. 3 Age of tee afte planting (days) Aveage height of C.odoata tees which suvived afte planting (D: aea spayed with chemicals). 25

8 17 JIRCAS Intenational Symposium Seies No. 1 (1994) me 8 µ..c:: bo (l)..c:: <I) <I)... E< t Age of tee afte planting (days) Fig. 4 Aveage height of S.macophylla tees which suvived afte planting (D : ou spayis aea spayed with chemicals). The main natual enemies identified in the study site included a paasitic nematode (Memithidae), Conclusion and ecommendations fo Hypsipyla management in a plantation two paasitic wasps (Bacon sp. and Tichogamma sp.), and a fungus (Beauveia sp.). The laval paasitism of both the nematode and the wasps eached o sometimes exceeded a value of 1%. Howeve, biological contol with such agents has not been attempted yet. Theefoe, the cuent measues fo the management of H. gandel/a in the plantations of C. odoata and 5. macophy/la ae limited, and none of them except fo the folia spaying of insecticides has been successful on a lage scale. Thus, planting tials with the combination of seveal measues will be necessay fo the development of integated pest management. Based on ou expeimental esults and some contol tials caied out on a small scale by othe investigatos, the measues cuently ecommended fo the plantation of meliaceous tees ae as follows: 1) To avoid an aea with acisol 2) To plant as fa apat fom emaining native foests, as possible 3) To keep neighboing gasses and bushes without cutting off as a female moth can not each the host tee at a level below the suounding gasses. 4) To povide enough space above the seedlings; both C. odoata and 5. macophyl/a equie light. 5) To avoid planting in a goup o along a line except when chemical teatment is available 6) To mix with insect epellent tees such as Azadiachta indica 7) To fence a plantation aea with tees with dense banches and leaves 56m above the gound such as Acacia mangium to pevent the moth fom flying into the plantation 8) To emove infested potions of host plants whee lavae o pupae inhabit by hand 34 times a yea; spouting fom the main stem occus within seveal weeks 9) To pune and keep only one top shoot 1) To spay insecticides (fenvaleate) 35 times a yea fo 5. macophy/la and moe than 6 times fo C. odoata

9 IKEDA et al : Infestation of Meliaceous Tees by the Mahogany Shoot Boe in Plantation Aeas of the Peuvian Amazon 171 Refeences 1) Gijpma, P. (197): Immunity of Toona ilia/a va. austalis and Khaya ivoensis to attacks of Hypsipyla gandella Zelle in Tuialba, Costa Rica. Tuialba 2, ) Gijpma, P. and Gaa, R. I. (197) : Studies on the shoot boe Hypsipyla gandella Zelle. 1. Host selection behavio. Tuialba, 2, ) Kobayashi, F., Yamazaki, S. and Ikeda,T. (1986): Hypsipyla gandella theatening Meiiaceae plantations in Peuvian Amazon. Poceedings of 18th IUFRO Wold Congess, Div. II ) Matsui, M. (1986): Regeneation tial in Peuvian Amazon. Topical Foesty, 6, 1418 [In Japanese]. 5) Yamazaki, S., Taketani, A., Fujita, K., Pacheco, C. V. and Ikeda, T., (199): Ecology of Hypsipyla gandella and its seasonal change in population density in Peuvian Amazon foest. JARQ 24, ) Yamazaki, S., lkeda,t., Taketani,A., Pacheco, C. V., and Sato,T., (1992): Attack by the mahogany shoot boe, Hypsipyla gandella Zelle(Lepidoptea: Pyalidae), on the meliaceous tees in the Peuvian Amazon. Appl. Entomoi. Zoo!. 27, 3138.