

the chemical was placed on the bark of a tree (method 

 B), high kills were maintained through the eighth week. 

 The bark application covered with plastic (method C) 

 was no more effective than the uncovered application 

 (method B), table 5. 



Bagworms introduced into the cages in any week 

 after the first were larger than those used the previous 

 week. Exposing the bagworms to the chemical for more 

 than 1 week probably would have resulted in higher 

 kills than those shown in the table. 



Mimosa Webworm on Honey Locust. — At irregular 

 intervals after application of SD-3562 to honey locust 

 trees in groups A, B, C, and D, table 6, nests con- 

 taining larvae of the mimosa webworm, Homadaula 

 albizziae Clarke, were confined in cages on the trees. 

 In the first two tests, in the sixth and tenth weeks 

 after the trees were treated, each caged branch was 

 clipped from the tree at the end of 7 days, and branch 

 and bag were taken to the laboratory for examination. 

 Although the number of larvae recovered in cages on 

 treated trees was low (small dead larvae are very 

 difficult to find in leaf debris), the results showed 

 rather conclusively that SD-3562 applied by each of 

 the four methods was highly effective during the sixth 

 week after treatment, table 6. A drop in kill during the 

 tenth week was noted on some of the trees; subse- 

 quently the cages were left on the trees for 2-week 

 periods. The longer exposure resulted in complete 

 kills of larvae on most trees through the period of the 

 experiment, table 6. On trees treated by method B, 

 bark application, complete kills were recorded for all 

 periods of observation. 



Mite on Honey Locust. - On August 4, 8 weeks 

 after the application of SD-3562 to honey locust trees 

 in the experiment for control of bagworms, table 5, 

 honey locust leaves infested with the honey locust 

 mite, Eotetranychus multidigituli (Ewing), were taped 

 to leaves on the trees in group A. Counts made 2 

 weeks later indicated a complete kill of mites on all 

 the treated trees in this group. 



Fall Webworm and Walnut Caterpillar on Honey 

 Locust. — Larvae of the fall webworm, Hvphantria 

 cunea (Drury), and the walnut caterpillar, Datana inte- 

 gerrima Grote & Robinson, were caged on honey locust 

 trees in group A during the tenth week after the appli- 

 cation of SD-3562. The chemical was highly effective 

 against the larvae of the fall webworm. Results of the 

 test involving the walnut caterpillar were inconclusive. 



ADDITIONAL TESTS FOR CONTROL 

 OF MIMOSA WEBWORM 



SD-3562 was applied on July 25, 1961, to the 

 uninjured bark of a honey locust tree, 30 feet tall and 

 6 inches dbh, at the rate of 2 ml per inch of trunk dbh, 

 fig. 1. After treatment, the treated area was covered 

 with a hardware cloth cylinder and heavy kraft paper 

 as a safety measure and to reduce weathering, figs. 5 

 and 6. The application of SD-3562 was effective 



within a week after treatment and provided excellent 

 protection for about 5 weeks. The tree was treated 

 again on September 6, when some of its new growth 

 was found to be infested. This tree was virtually free 

 of any sign of webworm damage at the end of the 

 growing season. 



Fig. 5 (left). — Hardware cloth around the trunk of a 

 honey locust tree treated with SD-3562. This is a safety 

 measure used on trees in residential areas to keep human 

 beings and pets from coming in contact with the chemical. 

 The hardware cloth was removed 2 weeks after the tree had 

 been treated. 



Fig. 6 (right). — The tree shown in fig. 5. Paper cover- 

 ing has been added over the hardware cloth to give further 

 protection to human beings and pets and to reduce weather- 

 ing of the chemical. The paper was removed 1 week after 

 the tree had been treated. 



