TMITE simulates tracheal mite parasitism of honey bee colony populations. This computer module estimates mite population size and composition at time (t) based upon the initial number of bees infested by mites, the success rate of mites transferring to new hosts, the age and caste structure of newly infested hosts, and the phenology of mite reproduction, development times, sex ratios, and phoretic periods.

Our PC BEEPOP honey bee population dynamics model provides daily estimates of the number of potential hosts: i.e., bees of suitable age and caste. This model estimates bee population size, composition, and food stores based on the initial size and age structure of the bee population, the reproductive potential of the queen, forager activity patterns and longevity, as well as the influence of variables such as weather conditions, exposures of bees to toxic chemicals, hive space, and resource availability.

When linked, TMITE and PC BEEPOP provide a flexible and powerful tool capable of examining the complex interactions of mites and bees. The results of sensitivity analysis and the model's projection of yearly trends in mite population growth were compared to the actual population dynamics of mites in colonies of bees kept in Montana and Arizona.

A beta test version is available to reviewers who will use the module and fill out a survey form. User input is critical to further development of this research and bee management tool. The module is packaged as part of a C language version of PC BEEPOP. The software is designed for IBM-compatible PCs. We recommend a computer with a 486 or pentium processor.

Preliminary Results

TMITE's initial projections may have considerable relevance toward management of tracheal mites. According to the model, in northern climates fall application of a miticide may provide little long-term protection to the colony. If mite levels are high in the fall, treatment may be necessary to save the colony. However, the model indicates that the mite population would have to be nearly eradicated in order to prevent the mite population from rebounding before spring.

On the other hand, application of a miticide during the spring buildup of the colony, or during the rapid growth period of the summer may provide better mite control. The model predicts that at these times, reduction of mite levels by only 30% could provide protection! Because the model follows the growth dynamics of mites and the bee populations, it can identify periods in which the bee population dynamics can outpace those of the mites.

We intend to test these predictions, which at this time should be considered unverified. If correct, the model may explain why a relatively non-toxic miticide-treatment with grease pattiescan suppress mite populations. (see Dr. Sammataro's recent doctoral thesis for more information on the use of grease patties to control tracheal mites)