|Urban Knowledge Master|
Xylocopa sonorina (Smith)
|Sonoran carpenter bee|
Julian R. Yates III
Extension Urban Entomologist
College of Tropical Agriculture and Human Resources
University of Hawaii at Manoa
Pollen, nectar; polylectic, visits a wide variety of flowers, especially those of the Papilionaceae.
Hawaiian Islands, Midway, Marianas Islands, China, Japan, Java, New Guinea, Philippines.
Females prefer dead softwoods such as redwood, pine, canec, and dead parts of trees. Wooden roof shingles, exposed roof rafters (under eaves), doors, window sills, garage canec ceilings, telephone poles, wooden fences, and picnic tables are also vulnerable.
Females will burrow into these items and create entrance holes and galleries approximately 9-15 mm in diameter and 5.5-20.5 cm in length. If abandoned galleries are reused, their length and complexity (four to five branching tunnels) can be substantially increased.
Having located a suitable piece of wood, the female bee begins to excavate a single tunnel in preparation for egg laying. Because of our tropical climate, egg laying by female carpenter bees occurs year-round although it may decline during the winter months, when the weather is worse. Before laying eggs, the female collects pollen and deposits it, in the form of a ball, in the tunnel at a point furthest from the entrance. She lays a single egg on the pollen ball and seals both in a chamber with wood shavings. She may lay several eggs, each on its own pollen ball and inside its own sealed chamber, in a series within the tunnel. The eggs hatch in two to three days.
The larvae develop in approximately two weeks.
The prepupal (nonfeeding larvae) and pupal stages take about three to four weeks to reach adulthood.
Teneral (adult shortly after emergence, when it is not entirely hardened or not of the mature color) females are fed by the mother. They are capable of buzzing in about a week, and of flight in approximately two to three weeks. A single female in a tunnel may be joined later by her offspring or other bees. Only one female will collect pollen, prepare cells, and lay eggs, however. Other females perform guard and nest-cleaning duties.
In general, the biology and ecology of X. sonoria conforms with that of other Xylocopa species. Some points in its biology may be noteworthy either because they are different than those of other species studied, or because they may shed some light upon the social relationships of the bees. X. sonorina starts to develop a nest as a single female, and later may be joined by additional females. The latter may be her progeny, or other bees that have come to reside with her. This phenomenon has also been observed with X. pubescens. Similarly, each nesting X. virginica (L.) female is often joined by a non nesting female who remains with her for the duration of the nesting period. However, in the latter case, we do not know if there is familial relationship between the two bees. Yet, in all known cases, only one female did the work of collecting, cell preparing, and ovipositing; whereas the other bees performed mainly guard, and nest cleaning duties.
Hierarchy of the bees within the nest, as studied in some Xylocopa species is such that the mother does all the outside work whereas one daughter usually guards the entrance and the others stay inside until they are ready to leave, mate, and establish their own nest. The latter is often near, or a continuation of, the mother's nest.
The finding of females that were unfertilized but had worn wings indicates that they did more than their normal share of outdoor activity. It is possible that they were active for an unusually long time out of doors, perhaps until providing food for other nest inhabitants. This extended period of activity while being unmated may have resulted from inability to find mates due to seasonal or topographical problems. It also might have been the consequence of pheromonal suppression of the mating capacity of these bees by others, possibly their sisters. The possibility of such pheromonal disruption of activity may be indicated by the fact that mating activity in some carpenter bee species was shown to be regulated by pheromones.
Painted wood has been reported to be far less susceptible to attack.
Control of this pest requires dusting the entrance holes with an Environmental Protection Agency-approved insecticide (consult your local insecticide retailer). The prescribed dust should be puffed into entrance holes and the bees should be allowed to pass freely over these treated areas; do not plug the holes. It is best to treat the entrance holes just before sunset, when female foraging is at a minimum. This type of application allows the adult bees to transport the pesticide dust further into the galleries. New emerging bees leaving these holes will also brush against the insecticide. Aerosol stream (as opposed to spray) applicators are commercially available for treating tunnel entrances that are not readily accessible. Consult the pesticide's label for application methods and safety precautions.
Ebeling, W. 1978. Urban entomology. Division of Agricultural Sciences, University of California, Berkeley.
Gerling, D. 1983. Nesting biology and flower relationships of Xylocopa sonorina Smith in Hawaii (Hymenoptera: Anthophoridae). Pan Pacific Entomologist 58(4):336-351.
Hurd, P. D., Jr. 1978. An annotated catalog of the carpenter bees (Genus Xylocopa Latreille) of the Western Hemisphere (Hymenoptera: Anthophoridae). Smithsonian Institution Press, Washington D.C.
Mallis, A. 1982. Handbook of pest control. Franzak & Forester Co., Cleveland, Ohio.