Heliothis subflexa

VICKERS, N.J., Defining a synthetic pheromone blend attractive to male Heliothis subflexa under wind tunnel conditions. J. Chem. EcoL, 2002, 28, 1255-1267. 

Teal, RE.A., Heath, R.R., Tumlinson, J.H. McLaughlin, J.R. 1981. Identification of a sex pheromone of Heliothis subflexa (GN.)(Lepidoptera Noctuidae) and field trapping studies using different blends of components. J. Chem. Ecol 7 1011—1022. 

LaChance LE (1984) Hybrid sterility eupyrene sperm production and abnormalities in the backcross generations of interspecific hybrids between Heliothis subflexa and H, virescens (Lepidoptera Noctuidae). Ann Entomol Soc Am 77 93-101... 

Members of the Heliothis genus of noctuid moths have been the subjects of considerable study in our laboratory over the past 10 years not only because of their economic importance, but also because of the ability to hybridize two of the species, H. subflexa and H. virescens. Since members of this genus use variations of the same types of compounds for pheromone communication a commonality in the biosynthetic capability of these insects seems indicated (Table I). 

Recent research has shown that the pheromone mediated behavior of lepidopterous insects is very complex. The chemical components of the pheromones are usually simple molecules, but complex mixtures involving permutations of geometry, functionality, and chain length are often required to elicit the complicated behavioral repertoire that eventually culminates in mating. To elucidate the chemical and behavioral aspects of this communications system, we have used a combination of methods including collection of the volatiles emitted by the female, analysis by high resolution capillary gas chromatography (GC), and the sequential and temporal analysis of the male s behavioral response to the pheromone blend and components thereof. New liquid phases and state of the art techniques have been developed for capillary GC to separate all the components of a pheromone blend. With these methods the chemical communication systems of Heliothis virescens (F.) and H. subflexa (Gn.) have been analyzed and certain aspects have been elucidated. 

The differences in the glandular pheromone constituents between H. virescens and H. subflexa are distinct. H. subflexa contains acetates of 16-carbon alcohols not found in H. virescens and does not contain the 14-carbon aldehydes which appear to be unique to H. virescens among Heliothis species studied thus far. It will be interesting to see what blends the hybrids of these species produce and relate this to data from investigations of the genetics of this hybridization. 

Figure 2. Amounts of Z11-16 AL, the pheromone component present in greatest amount, present in extracts of pheromone glands of virgin females of Heliothis zea. H. virescens and H. subflexa obtained at different times after injection of 0.5 pmole of PBAN in 10 of water during the photophase (n-10 each data point), Extracts were analyzed by capillary GC using Supelcowax 10 and SPBl columns (30m X 0.25mm id).

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