Cuticular Hydrocarbons of the Host-Specific Ectoparasitoid Cephalonomia stephanoderis (Hymenoptera: Bethylidae) and Its Host the Coffee Berry Borer (Coleoptera: Scolytidae)

Abstract

Cuticular hydrocarbons have been identified from larvae and adults of the bethylid wasp Cephalonomia stephanoderis Betrem and larval, prepupal, pupal, and adult stages of its host, the scolytid beetle Hypothenemus hampei (Ferrari). Larval, male and female wasps have the same cuticular hydrocarbons, but in different relative abundances. The major components of adults are n-alkanes (C21−C33), monomethyl alkanes (3-, 5-, 7-, 9-, 10-, 11-, 12-, 13-, 14-, 15-, 16-, and 17-methyl), and Z-(10)-monomethyl alkenes (with the methyl branch at C14−C19). Minor components include a series of 3,X-; 4,X-; 5,X-; 6,X-; 7,X-, and 8,X- dimethyl alkanes (with X at C14−C19) and a series of 3,9,13- and 3,11,15-trimethyl alkanes. Male C. stephanoderis are characterized by high proportions of n-alkanes and lower proportions of the monomethyl alkanes and methylbranched alkenes. Female wasps are characterized by lower proportions of n-alkanes and higher proportions of the monomethyl alkanes and methylbranched alkenes. Larval C. stephanoderis are characterized by high proportions of the methylbranched components and lower proportions of the n-alkanes and the n- and methylbranched alkenes. Host scolytid beetle cuticular hydrocarbons are totally saturated. Major components of all stages and sexes include n-alkanes (C22 − C31), monomethyl alkanes (3-, 4-, 5-, 13-, 14-, 15-, 16- and 17-methyl), a series of dimethyl alkanes (3,7-; 3,9-; 3,15-; 3,17-; and 3,19-), and a series of trimethyl alkanes (3,7,13-; 3,9,13-; and 3,11,15-). Minor components are a series of 4,14- and 4,16-dimethyl alkanes and 5,17- and 5,19-dimethyl alkanes. All immature beetle stages had similar hydrocarbon compositions, which differed moderately from those of the adults. As with the adult wasps, relative compositions of male and female beetles differed. Males were characterized by a greater proportion of n-alkanes and lesser proportions of monomethyl alkanes and trimethyl alkanes. Females had lesser proportions of n-alkanes and greater proportions of monomethyl alkanes and trimethyl alkanes. The cuticular profiles of the parasitoid and host are compared and discussed in terms of both intraspecific and interspecific semiochemical interactions.