Webworms

Phenazine-l-carboxamide (137) is known as oxychlororaphine and has been isolated from cultures of Pseudomonas chlororaphisit has some limited inhibitory properties, but the inhibitory action of phenazines is generally disappointing. Some phenazine derivatives have insecticidal properties thus, phenazine itself has been found to be toxic to the clothes moth, the Hawaiian beet webworm, the rice weevil and larva of the codling moth, but under trial conditions its toxicity to plant material, as evidenced by severe burning of foliage, was found to be too high to make it of practical value. 

Carroll M. J. and Berenbaum M. R. (2002). Behavioral responses of the parsnip webworm to host plant volatiles. J Chem Ecol 28 2191-2201. 

Pheromone components of the female fall webworm Hyphantria cunea, which are (3Z,6Z,95,10i )-9,10-epoxy-3,6-henicosadiene and (3Z,6Z,95,10i )-9,10-epoxy-1,3)6-henicosatriene were synthesized. ... 

Responses of Alder and Willow to Attack by Tent Caterpillars and Webworms ... 

Malacosoma callfornlcum pluvlale Dyar Lasiocampldae) and fall webworms (Hyphantrla cunea Drury Arctiidae). 

Figure 3. Top normalized average relative growth rate of fall webworm larvae raised on leaves from test (A), nearby control (B), and far control (C and D) groups of Sitka willow trees. The test trees were loaded with webworms and unloaded on the indicated dates. Connected points represent growth rates of larvae fed detached-leaves in the laboratory. Unconnected points at the right represent growth rates in the field of larvae on the various groups of willow trees. Bottom density of webworm larvae attacking the test trees on various dates.

Higher growth rates of the larvae fed leaves from willows at the airport site than those fed leaves from willows at the Kent site, throughout the experiment, show that significant and fairly constant differences in leaf quality can exist between trees at different sites. Normalized relative growth rates of webworms fed detached leaves in the laboratory were similar to those obtained by growing webworms on the trees. 

The chemical basis for the observed differences in leaf food quality is unknown. Little differences were found in Folin-Denis total phenolic or proanthocyanidin extinction coefficients of 85% aqueous methanol leaf extracts from the various plant groups throughout the experiment. There were no indications of changes in leaf quality of control willows 60 m distant from willows attacked by fall webworm. 

Responses of alder and willow to attack by tent caterpillars and webworms evidence for pheromonal sensitivity of willows. In Plant Resistance to Insects, ed. 

El-Sayed, A.M., Gibb, A.R. and Suckling, D.M. (2005a). Chemistry of the sex pheromone gland of the fall webworm, Hyphantria cunea, discovered in New Zealand. N. Z. Plant Protection, 58, 31-36. 

Zhang, Q. H., Schlyter, F., Chu, D., Ma, X.Y. and Ninomiya, Y. (1998). Diurnal and seasonal flight activity of males and population dynamics of fall webworm moth, Hyphantria cunea (Drury) (Lep., Arctiidae) monitored by pheromone traps../. Appl. Entomol., 122, 523-532. 

Pepper, J.H. and Hastings, E., Age variations in exoskeletal composition of the sugar beet webworm and their possible effect on membrane permeability, /. Econ. EntomoL, 36, 633,1943. 

Carroll, M.J. and Berenbaum, M.R. (2006) Lutein sequestration and furanocoumarin metabolism in parsnip webworms under different ultraviolet light regimes in the montane west. /. Chem. Ecol., 32, 277-305. 

Nitao, J.K., Berhow, M., Duval, S.M., Weisleder, D., Vaughn, S.F., Zangerl, A. and Berenbaum M.R. (2003) Characterization of furanocoumarin metabolites in parsnip webworm, Depressaria pastinacella.. Chem. Ecol, 29, 671-82. 

Because of their insect and disease problems. mimosas are usually short-lived. Mimosa webworms. 1" long, brown caterpillars, bind leaves with webs and skeletonize foliage. Remove and destroy nests spray leaves with BTK. or with pyrethrin as a last resort. Mimosa wilt produces wilted leaves and dead branches. Remove and destrov infected trees. 

Leaves chewed branch tips with webbing. Cause Barberry webworms. These 1 A", black caterpillars tie together leaves and twigs, forming a web nest in midsummer as they feed on the leaves. If not too numerous, remove nests by hand. Control large infestations with 3 applications of BTK made 1 week apart, or spray with pyrethrin. 

Leaves skeletonized branches webbed. Cause Cotoneaster webworms. These A", yellowish green to brown caterpillars feed on leaves and spin silken webs around leaves and stems. Young plants may die older ones can be seriously weakened. Break up and remove the webs spray plants with BTK. 

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