The distribution and importance of stem-borer species of sorghum in Kenya, viz. Chilo partellus Swinhoe, C. orichalcociliellus Strand, Busseola fusca Fuller, Eldana saccharina Walker and Sesamia calamistis Hampson were studied and discussed. The incidence and period of activity of the stem-borer complex on sorghum indicated that C. partellus, which is a major pest, infested the crop early, while E. saccharina and S. calamistis infested late and persisted in the crop till it was harvested. Preliminary studies on the carryover of stem-borer showed that the larvae of C. partellus and S. calamistis were able to enter diapause in dry sorghum stalks for several months at the end of long and short rain seasons. Some new alternative host plants and parasites and predators affecting different life stages of stem-borers were identified. Preliminary screening of several sorghum lines was carried out for identification and confirmation of resistance to C. partellus and B. fusca, and some sources of resistance were reported.

Intensive field studies conducted in the banana growing areas in western Kenya have lead to the identification of 12 predators of eggs, larvae and pupae of the banana weevil, Cosmopolites sordidus. None of the predators attacked the adult weevils and also no parasitoids were recorded. The paper briefly describes the prevalence and distribution of the predators in banana plantations.

Chilo partellus (Swinhoe) abdominal tip extracts were examined by gas-liquid chromatography (GLC) combined with simultaneous electroantennographic (EAG) recording from the male moth. Two olfactory stimulants were detected and identified as (Z)-ll-hexadecenal (I) and (Z)-I 1-hexadecen-l-ol (II) by their GLC behavior, microchemical reactions, and comparison with synthetic materials. Both compounds were detected in volatiles emitted by the "calling" female moth. Synthetic (Z)-9-tetradecenyl formate, a structural analog of aldehyde (I), also elicited a significant EAG response from the male moth. Field trials carried out in India using synthetic (I) and (II) as bait in water traps showed that compound (I) was highly attractive to male C. partellus; compound (II) was not attractive, and its addition to (I) significantly reduced trap catches.

Intmat~ond Crop Reuuch lnsulute lor the Semi-Arid Tropn (ICRISAT) Patancheru. PO.. 542 324 A P. India A*mct-Thu p a w d m b n the results ofeatennve runng of shoolHy s p c~n of the genera 4rher1-OM and 4cr1rorhana from cult~valcd and w~ld Grrnuneae ln Andhra Pradnh. lnd~a N~nctun lly specla werc recorded from 41 gramlnrcmw s p c l n ~nclud~ng cult~vated sorghum 4rhrngena nxcors an Important pest of sorghums in the Old World troptcl. w u reared from ! ? host plants Only culuvated and wtld spma of wrghum were Imponant u hosts of tha pest spates It was observed that altemat~ve host Gramlneu were of nunor Importance In the 'carryover' of lrhrrtyonu wco~n through the o U~u o n but the trr~gated sorghum grown for fodder wuld be an lmportanl wurce of Hm In general. shootlltn 01 a pnneuiar spcc~n usually favored one gram~narcuu host r b t e others The numer~ully dom~nnnt fly reared from wlld Grnm~neu was Alhrr~yonafdl~rlo. wh~rh u n recorded on 17 hosts. lncludtng wrgnum Other common spcoa In Gram~neae were 4rhrr1yonu pullo 41hrr1yona or):ar. Arhsr~qo~ puncrorn and Arhmgona orr~palp~s, all of wh~ch werc also reared In verv low numbers from sorghum F~vc new spntn of 4thrngona werc reared thru of thnc w~l l h dn~r~bcd bhorrly

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Records of Arhengona spp, bred from cultlvdted cereals. mtnor m~llets and wild grass hosts ere glven. A Iota1 01 19 plant hosts of Arherrgona specter IS Ilrted. A. soccata, sorghum shootfly, was by far the commonest spocles present on sorghum and ~t was alw r~orded from malze, pearl m~llet, Echinochloa colonurn. Errochlos procera, Cyrnbopogon sp, and Paspalurn scrobicularum. Numbers of A. roccara bred from grasses were very low. Data showed that specles of Arhe~gona were In general highly specific In choice of plant host A. lalcafa wds the commonest qrass l~vlng species, but tended to favour Echinochlm colonurn and E. crusgsll~. The dom~nant specter on pearl millet was A. appmximara, on Panicum ps~lopodium, A. pulla and on Digiraria adscendens, A. oryzae. An lnlerertlng dnd important record was the recovery of A. eriochloae from both sorghum and Er~ochloa procara. Th~s rprclcs was prev~ously only known from the peratype descr~bed In 1926. Other specles were bred from a range of host grasses.