ABSTRACT
The annona fruit borer wasp Bephratelloides cubensis Ashmead was recorded for the first time damaging "ilama" fruits Annona diversifolia (Anonaceae) in Coatlan del rio, Morelos, Cacahuamilpa and El Ocotillo, Guerrero, Mexico. Geographical distribution, hosts and damage are mentioned.
Subject(s)
Animals , Homing Behavior , Hymenoptera , Demography , Hymenoptera/anatomy & histology , MexicoABSTRACT
The annona fruit borer wasp Bephratelloides cubensis Ashmead was recorded for the first time damaging "ilama" fruits Annona diversifolia (Anonaceae) in Coatlan del rio, Morelos, Cacahuamilpa and El Ocotillo, Guerrero, Mexico. Geographical distribution, hosts and damage are mentioned.
Subject(s)
Homing Behavior , Hymenoptera , Animals , Demography , Hymenoptera/anatomy & histology , MexicoABSTRACT
Scyphophorus acupuncatus Gyllenhal is considered to be the most significant pest of cultivated agaves in the world. Recent studies on the chemical ecology of this weevil have shown that males release a pheromone that attracts both sexes. In this study, we investigated the effect of feeding, aging, photoperiod, and time of day on pheromone release by S. acupuncatus males under laboratory conditions. The pheromone released by individual males was sampled using solid-phase microextraction and analyzed by gas chromatography-coupled mass spectrometry. Our results show that food is an important factor because weevils deprived of plant material did not release any pheromone. In addition, we found that males fed with apple, a nonhost plant, released less pheromone than weevils fed with agave. Host odor does not seem to be important in stimulating pheromone release. We found that males as young as 1 mo were able to release pheromone, although the numbers of individuals releasing pheromone increased with age. Older males released more pheromone than younger males. We found that S. acupuncatus males released pheromone during the photophase and scotophase; there was, however, no significant peak in pheromone release. Also, the pheromone released by S. acupunctatus was not affected by the length of the photoperiod.
Subject(s)
Pheromones/chemistry , Weevils/physiology , Agave , Animals , Feeding Behavior , Female , Gas Chromatography-Mass Spectrometry , Male , Malus , Photoperiod , Solid Phase Microextraction , Time Factors , Weevils/chemistryABSTRACT
Olfactory response of male and female Scyphophorus acupunctatus Gyllenhal (Coleoptera: Curculionidae) to volatiles released from the same or opposite conspecifics alone, or combined with host plant volatiles, was evaluated in the laboratory and field. We also evaluated the response to synthetic Rhynchophorinae pheromones in the laboratory. In laboratory tests, attraction of males and females in Y-tube olfactometer to conspecific males was greater than to females and clean air. Males and females preferred the combination males + agave over agave alone. Both sexes were significantly attracted to 2-methyl-4-heptanol and 2-methyl-4-octanol compared with hexane control. In field trials, weevils were successfully caught in the traps baited with conspecifics and plant material. These field results support those of the laboratory bioassays, showing that males attracted conspecific males and females and addition of plant material enhanced the attraction. These results further suggest that S. acupunctatus produces an aggregation pheromone.
