The numbers of pink bollworm moths caught in pheromone traps in all fields are shown in Table 3. In the insecticide-treated control fields, more moths were caught, spermatophores per female were higher, and the percentage of mated females was greater than in pheromone-treated fields. Also, mating was significantly reduced in fields treated with gossyplure plus virelure compared with control fields; significantly more pink bollworm males were caught in all control fields than in all gossyplure-treated fields. and mating and average spermatophores per female were reduced 45 and 64%, respectively, in the treated fields.
Effect on Tobacco Budworm Male Moth Catches
Catches of tobacco budworm male moths were low throughout the season (Figure 4). Before the applications of pheromone, they ranged from 0.3 to 9 per trap in the experimental cotton fields and averaged 2.2 moths per trap over all fields. The first
applications of the pheromone combinations were made May 16. There were no significant differences in trap catches between any of the treatments and the insecticide- treated control until after July 19.
However, beginning on July 20, after the fifth set of treatments. male catches in vlrelure-gossyplure treated fields were lower on all but one sampling date than in control fields. and the difference was significant on 21 of the 30 sampling dates. The impact of the TF-gossyplure and Z9 TDF-gossyplure treatments on tobacco budworm moth catches ln baited traps was variable. but catches were reduced In treated flelds on 10 of 30 sampling dates. Learn more about pheromones at http://thongchaimedical.org/?p=176
Pheromone treatments had little effect on populations of eggs and larvae. Fewer Heliothis eggs were found in terminals in the fields treated with virelure-gossyplure on some sampling dates in August, but the differences were not significantly different (Table 4). Also, larval populations were less in pheromone-treated fields than in control fields on one sampling date (August 23). During the month of September, egg counts were similar in all treated and insecticide treated—control fields. However, on October 4 and 8, significantly higher numbers of eggs were found in control fields than in fields treated with TF-gossyplure, virelurgossyplure, or Z—9 TDF—gossyplure according to Attract-RX pheromone | Pheromones-Planet.com
Heliothis populations in the untreated check field developed slowly and never reached damaging numbers.
Egg hatch ranged from 13 to 100% (average 81%) for the eggs collected from all fields from August 14 to September 11 (66 samples). Pheromone treatments did not affect egg hatch. Of the eggs collected and reared to adult moths, 33 to 100% (average 98%) were tobacco budworm. Learn about sex pheromones influence.
The nocturnal collections showed peak populations of tobacco budworm and boll- worm present on August 23 when 4.9 moths per man—hour were captured (Table 5). More tobacco budworms (about two times) were captured than bollworms. The high female-to-male sex ratio (about 2.8:l) of the tobacco budworm population may be related to the removal of tobacco budworm males from the low-density population by the four pheromone traps that were present throughout the season in each treated field.