Sources and mechanisms of resistance to sorghum head bug, Eurystylus immaculatus Odh. in West Africa

Abstract

Printed ~n Ken!,a. All rights resr.r\ed SOURCES AND MECHANISMS OF RESIS'I'AN('E: 'TO SOR(;HIIM HEAD RUG, EURYSTYLL'S I~%lhlAC~~I.ATL!S 0I)H. I N WKS.1' AFRICA Abstract-Sorghum i s one of the most in1port;lnt cereal crops in West Africi~, i~n d t11e heed 1)up. Burystylus intntac111urir.s Odh. (Hemiptera: 5liridac.) i s the ke) pest of gri~iri sorghuni in this region. range of sorghuni genotypes \\ere cv;~luated for resistance to sorgliurn he;ltl bug 111 Sotlrt~;~ (hlali and Karnboinse (Hurkina Faso). (;enotypcs ('Shl .388. IS 14.332. hiillisor 84-7. Sakl~iki~, S 29 ill111 Kamboinselocal were resistant to head bug+. boll1 ilnder n i~t u r i~l illid headcagrscrcc~iing. Ilc;~d hug resistant genotypes hat1 a lolver percentage of hcatl hug d;lniagetl grain. 'I'II(. food qtri~lity of heid hug damaged grain was very poor and unaccept;~hle. ('ultivar non-preference was identified as ; I co~i~ponent of resistance to head l)ugs. and ('SS1 .I88 was nonpreferred conipi~red to K-35-I. Panicleco~iipactness was po\iti\ely associated w ith hrrltl IIII~ numbers and grain damage. However, genotypes with loose p;~nicles were also s~r c~p t i l~l e to I~~rgs. Long glumes (>5 nini), days to glunie opening (>I0 (lays after anthesis). >SO% co\cring of the gri~in by the glunies, and grain hardness contribute towards re4stance to I~urysr~luc ininruculn~u.\. 'l'his inforniation will be useful for developing a programme to 1)rec.d for rpsi\tancr 11) (hi+ inscct in Wp\t Africa. Kc?\ l+'orttv: E'ro.!\/yllr.~ ~tntt~c~c~rtlot~r\. Mirid'ir.. \orpll~rn~. I~IP\I-~~~IIII rv\l\l;tncc, IIIC~~I;IIII\III~ 01 rc\l\t;lllc.c, head hug.; Kesum&Divers genotypes de sorgho ont c'tk ebalu6s pour la r6sist;lnce il la punaise des panicllles du sorgho. Eurystylus imrnacularrts Odh. h Sotuha (Mali) et a Ka~nhoinsi. (Iiurkina Faso). I.64 genotypes CSIM 388, IS 14332, Malisor 84-7, Sakoika, S 29 et Karnboinsc local Ptaient relati\enient resistantsaux punaisesen criblage nature1 ou en cage. 1,esgenotypes resistants h la p~~n a i w i~vaient un pour centage moins eleve de graines endommagees par les punaises. Ida qualit6 ulimentairc dr4 graines endommagees etait tres faihle et inacceptable. L, a non preference des cultivars etait idenlifike comme une cornposante de la resistance aux punaises. I,e CSM 388 etait non prefere par rapport au E 35-1. 1, a densite de la panicule etait positivement asswiee aver les nombres de punaises et les degits aux graines. ('cpendant, les genotypes aver des panicules laches etaient kgalernent susceptihles aux punaises. Ides glurnes tongues (>5 rnrn), le nornbre de jours a I'ouverture des glurnrs (>20 jours apres I'anthese), >SO%' de couverture de la graine par les glurnes, ainsi que la durete de la graine contribuent a la resistance a Eurystylus.

Combined on-farm effect of plot size and sorghum genotype on sorghum panicle-feeding bug infestation in Mali

“…Both years, five panicles at the grain maturing stage (3 weeks after half-anthesis) were randomly chosen from the first central row of each plot, and successively shaken in a polyethylene plastic bag so as to dislodge all insects present (Sharma et al 1994). The total number of Eurystylus bugs (adults and nymphs) was then determined.…”

“…However, data from Tioribougou in 1998 were not considered since the sampling was not conducted in time. In addition, five panicles randomly chosen from the second central row of each plot were visually scored for bug damage, using a 1-9 rating scale, where 1 = all grains fully developed with less than 10% showing a few bug feeding punctures, and 9 = more than 75% grains remaining undeveloped and barely visible outside the glumes (Sharma et al 1994;Ratnadass et al 2002).…”

Survival and life table parameters of soybean pod borer Maruca vitrata (Geyer) (Lepidoptera: Crambidae) on leguminous crop cultivars

“…, ; Smith ) such as grapevine phylloxera ( Phylloxera vitifoliae ) (Painter ), cotton jassid ( Amrasca biguttula ) (Sundramurthy & Chitra ), sorghum shoot fly ( Atherigona soccata ) (Sharma ), and sorghum head bug ( Eurystylus oldi ) (Sharma et al . ).…”

“…HPR to insect was a principal method of insect control before the chemical insecticide era. Previous studies have reported the deployment of insect-resistant varieties for the control of insect pests (Maxwell & Jennings 1980;Sharma et al 1999aSharma et al , 1999bSmith 1989) such as grapevine phylloxera (Phylloxera vitifoliae) (Painter 1951), cotton jassid (Amrasca biguttula) (Sundramurthy & Chitra 1992), sorghum shoot fly (Atherigona soccata) (Sharma 1993), and sorghum head bug (Eurystylus oldi) (Sharma et al 1994). In this study, some of the leguminous crop cultivars such as cowpea cultivar Jangchae and soybean cultivar Daewon exhibited a higher level of insect resistance.…”

Influence of panicle compactness and host plant resistance in sequential plantings on population increase of panicle‐feeding insects inSorghum bicolor(L.) Moench

“…However, loose-panicled genotypes are also badly damaged when head bug infestation is high (Sharma, 1985;Sharma et al, 1993a). On the other hand, midge damage has been reported to be low in compact-panicled genotypes (Murty and Subramaniam, 1978).…”