ARS | Publication request: Development of a rearing methodology for the dogwood borer (Lepidoptera: Sesiidae)

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 7, 2009
Publication Date: January 1, 2010
Citation: Frank, D., Leskey, T.C., Bergh, J. 2010. Development of a rearing methodology for the dogwood borer (Lepidoptera: Sesiidae). Annals of the Entomological Society of America. 103(1):50-56.

Interpretive Summary: Dogwood borer has become an important wood-boring pest of apple throughout eastern North America, and particularly, on apple cultivars planted on dwarfing rootstocks. We have developed methods to continuously rear dogwood borer in the laboratory to facilitate our ability to conduct experiments throughout the year. Males and females could be induced to mate in cages by reducing light intensity to mimic twilight conditions, the period when mating occurs in nature. Mated females deposited eggs on apple branches wrapped in cheesecloth, providing a source of fertile eggs. Larvae were reared successfully using small, immature apples as a food source. In order to maintain a continuous colony and induce larvae to pupate, dogwood borer must be held under long-day conditions. This method will enable us to conduct experiments with dogwood borer of known age and physiological status throughout the year in order to develop effective control strategies for this wood-boring pest.

Technical Abstract: A continuous rearing method for dogwood borer, Synanthedon scitula (Harris) (Lepidoptera: Sesiidae), was devised using standardized procedures at each developmental stage. The mating success of pairs of moths in 30 and 60 cm(3) cages and exposed to natural daylight or artificial light did not differ significantly. Under natural daylight and artificial light, the average time at which mating occurred was 19:50 h and 19:15 h, respectively, but mating could be triggered earlier in the day by gradually reducing the intensity of artificial light. Mated females held in waxed paper cups deposited significantly more eggs on 2-yr-old apple branches wrapped in cheesecloth than on cheesecloth alone or when no oviposition substrate was provided. Larvae fed on and pupated within small, immature apples, and their establishment on this rearing medium was significantly improved on fruit with small perforations compared with those without perforations. Larvae introduced to these apples monthly between August and November completed development and pupated if exposed to constant long-day conditions using artificial light but showed a significantly reduced incidence of pupation in September and a cessation of pupation by October if exposed to natural daylight and decreasing daylength. The "dark-eye" stage was established as a common point in pupal development that could be used to generate a cohort of pupae from which moths emerged over a period of 2-3 d.