After trees were fully wilted for several weeks, nearly all active galleries, judged by presence of exuded frass
, were confined to the lower 30 cm of the trees.
It usually preferred diseased and stressed mango trees and bored tiny holes (1.9-2.0mm in diameter) in the main tree trunk from which frass
was emitted out.
Leaflets were replaced, filter paper was changed and frass
was removed as needed.
From this set, 480 were selected based on the presence of a frass
plug, an indicator of occupancy by D.
Arthur (1981) pointed out that host size, shape, movement and surface texture, the presence of kairomones associated with host larval frass
, body fat, and labial and mandibular glands, as well as haemolymph, may elicit host acceptance behaviors by female parasitoids.
, produced by the larvae by consuming the tissue ingested while extending the gallery, was moist and putrified over time.
Preliminary research provided no evidence of an aggregation pheromone and no strong attraction to its fungal symbiont, to its frass
, or to ethanol (a standard attractant for ambrosia beetles); suggesting that host tree volatiles are the primary attractants for dispersing females (Hanula et al.
In addition to larval frass
, other parts of the host larva such as hemolymph, alimentary canal, fat bodies, labial glands, and mandibular glands may be the source of 1 or more kairomones that stimulate oviposition movements in larval parasitoid species (Arthur 1981).
At approximately 3 weeks post-transfer the solid container lid was exchanged for one with a single 5-cm diameter screened vent to allow for moisture exchange and reduce the likelihood of mold development on the diet block or frass
. A new diet block was added at 4 weeks post-transfer and then weekly thereafter until no more pupae were formed.
subrobustus infestation consistent with buprestid larval feeding (i.e., compact frass
, winding galleries, D-shaped exit holes) on trunks and stems below 2 m on 6 trees surrounding the traps, but none were found.
1b) could be seen, occasionally with dried frass
. When the stem was split from the top, wavy tunnel could be seen with full of frass
and insect larvae (Figs.
You might also spot sawdust from the holes, known as frass
, on the floor.