Our goal is to elucidate parameters of the reproductive biology of mealybugs infesting vineyards, particularly those parameters that have implications for the use of pheromones for monitoring or control of mealybugs. Despite their pest status, little information is available about reproduction in mealybugs, such as whether males and females mate only once or multiple times and the frequency of mating events. Our initial target species were the obscure, longtailed, and grape mealybugs, but we have expanded the study to include vine mealybugs, based on comments received from the review panels last year. During the 2009 funding cycle, we made excellent progress in gaining a better understanding of reproduction in these insects, as follows: ? We showed that both sexes of obscure, longtailed, and vine mealybugs can mate multiple times on the same day. Male obscure mealybugs can also mate again on subsequent days, whereas male longtailed mealybugs that multiply mated on day 1 died by the following morning. Studies to determine whether male vine mealybugs mate on more than one day are in progress. For all three species, females could remate 1 or more days after the first mating. ? After emergence from the cocoon, males of longtailed and obscure mealybugs can live up to 5 days, whereas females live much longer, for several weeks to many months. ? Contrary to expectations, exposure to pheromone did not accelerate the development or emergence of male longtailed and obscure mealybugs, nor did it affect male longevity. ? Although females can and will mate multiple times, they only need to mate once in order to produce a full complement of offspring. ? We were not able to run the corresponding experiments with grape mealybug because of difficulties in establishing a stable colony of this species. Overall, these results have important implications for using pheromone for monitoring or control of mealybugs. For example, because males can mate multiple times over a period of days, a relatively small number of males can inseminate most of the available females. Thus, although males are more susceptible to insecticides than females, even if a relatively small percentage of males survived an insecticide treatment, it may still be sufficient to mate the female population. If pheromone-based mating disruption were attempted, the pheromone coverage must be very good, because males would have to be disrupted for their entire lifetimes of 4-5 days, and because males can mate multiple times. Thus, a method such as attract-and-kill, that takes males out of the population, might be a more effective strategy. In terms of using pheromone-based methods for detection and monitoring of populations, in the absence of pesticide treatments, pheromone-baited traps should provide a sensitive, reliable, and species-specific method of detection of mealybug infestations, and possibly an estimate of population sizes. However, in areas with frequent insecticide use, trap catches may be artificially low due to the greater sensitivity of male mealybugs to insecticides than females. In such cases, manual sampling for mealybugs can be used as a backup.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF2009-10-16 07:23:102017-10-16 07:23:51Reproductive biology of obscure, longtailed, and vine mealybugs and its possible effects on detection, sampling, and control of mealybugs