Research Article  Monitoring cotton bollworms through synthetic sex pheromone traps

AbstractThe female sex pheromone gland of Diparopsis castanea Hmps. consists of modified intersegmental tissue between the eighth and ninth abdominal segments. Glands contain an average of 12·73 ×10–3 μg of pheromone consisting of 80·4±2·0% trans-9, 11-dodecadien-l-yl acetate (range 72·7–86·7%) and 19·6±2·0% 11-dodecen-l-yl acetate (range 13·3–27·3%). Although no significant correlation exists between female body weight and pheromone content of the gland, the duration of sex pheromone release over the lifespan of a female is positively correlated with its weight on emergence. Six behavioural steps may be recognised in the precopulatory behaviour of females but the frequency and duration of sex pheromone release is strongly influenced by both temperature and light intensity. At 25°C females typically ‘call’ on two or more occasions for 41–50% of the night, calling commencing earlier at cool (13·4°C) temperatures than at moderate (19·4°C) or warm (25·0°C) temperatures. Calling by mated females increases considerably from four to five nights after mating but is typically of shorter duration than for virgins. The dispersal flight of Diparopsis males in cotton crops commences almost immediately after sunset and before the end of dusk, with peak male catches in sex pheromone traps occurring earlier in the cooler months of May and June (20.00–22.00 h) than in November (02.00–04.00 h). The Diparopsis synthetic sex pheromone, dicastalure, traps a greater proportion of males and females both earlier and later in the night than virgin females and this ‘timing advantage’ may be important in a pheromone control programme based on disruption of communication between the sexes.

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Design and placement of synthetic sex pheromone traps for cacao mirids in Ghana

International Journal of Tropical Insect Science ◽

10.1017/s1742758417000340 ◽

2018 ◽

Vol 38 (02) ◽

pp. 122-131 ◽

Cited By ~ 4

Author(s):

J.E. Sarfo ◽

C.A.M. Campbell ◽

D.R. Hall

Keyword(s):

Sex Pheromone ◽

Sticky Trap ◽

Mass Trapping ◽

Pheromone Traps ◽

Water Trap ◽

Sahlbergella Singularis ◽

Sex Pheromone Traps ◽

Pheromone Components ◽

Synthetic Sex Pheromone ◽

Large Water

AbstractCacao mirids (Sahlbergella singularis,Distantiella theobromaandBryocoropsis laticollis) were captured in pheromone traps releasing a 2:1 blend of the sex pheromone components of the two first named species in a series of five experiments on cacao (Theobroma cacao) plantations in Ghana. A total of 835 cacao mirids were caught, all male, 95% of which wereS. singularis, 3%D. theobromaand 2%B. laticollis.Two sticky trap and two water trap designs made from locally available materials were as effective for capturingS. singularisand total mirids as the best sticky trap from previously reported studies. Coating the outer surface of a large water trap with sticker increased the catch 4.4×, and 2.7× for a cylindrical sticky trap. Sticker on the outside of the water trap also increased the inside catch ofS. singularisby 76% and total mirids by 71%. The numbers ofS. singularisandD. theobromatrapped increased with increasing trap elevation and were highest around canopy level. Those traps caught an average 12× more mirids than traps at 1.8 m, the height recommended currently. Therefore, large water traps coated with sticker and aligned with the cacao canopy should raise the current capture rates of pheromone traps for cacao mirids about 50×, which may be sufficient for effective pest management by mass trapping without synthetic insecticides.

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