Beetles weevils

Bark damaged leaves yellowish. Causes Beetles weevils pine bark adelgids. A wide variety of pests attack the bark of pines. Beetles and weevils make small holes in the trunk where they bore through the bark and tunnel underneath. Pine bark adelgids are small, cottony, white insects that congregate on the bark of the trunk and limbs. 

Conifer chemical ecology includes many other herbivores, predators and pathogens, aside from the bark beetles, weevils, sawflies, or budworms, and in these diverse interactions, terpenoid volatile emissions as well as accumulated oleoresin terpenes are likely to play many important roles in signaling and defense. 

Wheat flour beetle (Tribolium castaneum) Grey weevil (Myllocerus sp.)... 

Rodrigues, C. and Pratissoli, D. 1990. Pathogenicity of Beauveria brongniartii (Sacc. Petch) and Metarhizium anisopliae (Mots Sorok) and its effect on the com weevil and bean beetle. Ann. Soc. Entomol. Bras. 190, 301-306. 

In addition to the leafhoppers and Mexican bean beetle there are other insects which, when their damage is taken collectively, constitute an important loss in bean production. These insects are the apion pod weevils, Apion spp., Dmbrotica spp., white flies, Trioleurodes spp., and leaf miners, Chalepus signaticollis Baly. It has been found that when the proper insecticides are applied correctly to a good stand of beans the use of insecticides is profitable to the grower. 

Beetles pass a holometabolous development with several larval instars, pupae (often poorly known), and completely transformed adults. Larvae show biting mouth parts and often possess abdominal cerci-like structures which are absent in adults. The usually short heads of adults may be elongated to form a snout (as in weevils). Antennae and legs, especially the tarsomeres, may vary strongly with species and are taxonomically useful. 

Attempts to investigate boll weevil (Anthonomus grandis) pheromone biosynthesis have identified isomerization, dehydration, and oxidation of the pheromone alcohols, and anticipated allylic oxidation of myrcene and limonene, but no evidence for the cyclization of acyclic precursors. The aggregation pheromones of bark beetles have been reviewed. Ips calligraphus responds to ipsdienol only in the presence of the c/5-verbenol (32) large additional concentrations of the enantiomer (l/ ,4i ,5/ )-(32) reduce beetle response. 5-(-)-Ipsenol, the pheromone of Ips grandicollis, increases the response of /. avulsus to its own pheromone ipsdienol. ... 

Perez A. L., Gries R., Gries G. and Oehlschlager A. C. (1996) Transformation of presumptive precursors to frontalin and exo-brevicomin by bark beetles and the West Indian sugarcane weevil (Coleoptera). Bioorg. Med. Chem. 4, 445 -50. 

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