Evaluation of the synthetic sex pheromone of the obscure mealybug, Pseudococcus viburni, as an attractant to conspecific males, and to females of the parasitoid Acerophagus maculipennis

Abstract

The obscure mealybug, Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae), is a cosmopolitan pest. In New Zealand, recently introduced management tools include the host‐specific parasitoid Acerophagus maculipennis (Mercet) (Hymenoptera: Encyrtidae) established in 2001, and pheromone‐baited monitoring traps available since 2005. Red delta traps baited with rubber septum lures impregnated with 4.0 μg of the mealybug synthetic sex pheromone, placed in apple orchards in Hawke's Bay and Nelson, trapped both male P. viburni and female A. maculipennis. Two generations of both species per year were discernible, but numbers were low in spring and parasitoids were not trapped during winter (June to September). Male P. viburni catches reached a plateau at a pheromone dose of ca. 1.0 μg per lure but numbers of A. maculipennis per trap increased up to 100 μg per lure, the maximum dose tested. A mathematical model showed that the lures had a half‐life of about 7.4 days and were most attractive to P. viburni with a dose of 0.19 μg, and that the trap effectiveness decreased rapidly once the release rate dropped below the optimum. The model also predicted that the initial pheromone dose should be increased from 0.19 to 5.41 μg per lure as the desired period of deployment increased from 0 to 9 weeks. A dose of 4.0 μg had an initial relative effectiveness of about 55%, reached peak effectiveness after about 5 weeks, and fell to 55% relative effectiveness again after about 8.3 weeks. We conclude that an initial pheromone load of 4.0 μg is appropriate for practical monitoring of P. viburni during the New Zealand summer. Future applications of the sex pheromone for managing the pest and parasitoid are discussed.

Efficacy of Kairomone Lures to Attract Parasitoids of Halyomorpha halys

“…The lures used in the field study contained a load rate of 10 mg per lure, high in comparison to standard pheromone lures (1 mg), in the hopes of ensuring the attraction of parasitoids (Trécé, Inc., Adair, OK, USA); however, this relatively high load rate may have been counterproductive to our objective. In studies of pheromone lure load rates, it has been found that attraction often plateaus and can even become repellent to the insect at high release rates [ 23 , 24 , 25 ]. In addition, our lures were placed directly adjacent to the H. halys egg masses ( Figure 1 ), which may deter parasitoid attraction as the host female stink bug does not typically remain near the eggs following oviposition.…”

“…Traditionally, rubber septa are a standard chemical release device used in pest management (e.g., pheromone lures) [ 23 , 24 , 25 ]. Septa can be loaded with kairomone compounds to attract beneficial parasitoids and enhance target pest parasitism [ 26 , 27 ].…”

Integrative taxonomy methods reveal high mealybug (Hemiptera: Pseudococcidae) diversity in southern Brazilian fruit crops

“…In other countries, including Argentina, Italy, New Zealand and South Africa, Ps . viburni is considered the most economically important species found infesting apple and pears 30 – 33 . This species was also the dominant species in strawberry fields (>than 99% of the specimens collected).…”

Parasitoids (Hymenoptera) of Mealybug Pests (Hemiptera: Pseudococcidae) from Southern Brazil: Molecular and Morphological Characterization

“…Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) are important pests worldwide, infesting fruit plants such as apples, persimmon, strawberry, and grapevines (Charles et al 2015;Pacheco da Silva et al 2017). Nymphs and adult females damage crops by secreting honeydew, which facilitates the development of sooty mold, and by transmission of toxins and viruses, which may eventually kill the plant (Golino et al 2002;Franco et al 2009;Daane et al 2012).…”