Ground-surface application of pheromones through a mini-dispenser for mating disruption of the white grub beetle Dasylepida ishigakiensis (Coleoptera: Scarabaeidae)

AbstractA serious sugarcane pest, Dasylepida ishigakiensis, remains in the soil during most of its life cycle except for a short period for mating. Mating disruption by an artificial release of the sex pheromone (R)-2-butanol (R2B), therefore, may be a feasible method to control this pest. We examined the effects of artificial release of R2B and its related compounds, (S)-2-butanol (S2B) and the racemic 2-butanol (rac-2B), on the mating success of this beetle both in the laboratory and in the field. In flight tunnel experiments, almost all males orientated towards a R2B-releasing source and 40% of them landed on the source. When the atmosphere was permeated with R2B, the frequency of males landing on the model was significantly reduced. Both rac-2B and S2B were less effective, but substantial reduction in landing success by males was achieved at higher rac-2B concentrations. R2B released from polyethylene dispensers in sugarcane plots greatly reduced not only the proportion of females mated with males but also the number of males caught by R2B-baited traps, indicating that male mate-searching behaviour was strongly affected by the released R2B. Similar inhibitory effects on male behaviour were also observed when tube- or rope-type dispensers released high rac-2B concentrations in the field. These results indicate that it would be highly possible to control D. ishigakiensis through the disruption of the sexual communication by releasing either synthetic R2B or rac-2B.

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Genetic divergence among populations of the white grub beetle, Dasylepida ishigakiensis (Coleoptera: Scarabaeidae), distributed in the southern part of the Ryukyu Islands of Japan, detected from mitochondrial DNA sequences

Applied Entomology and Zoology ◽

10.1303/aez.2008.287 ◽

2008 ◽

Vol 43 (2) ◽

pp. 287-292 ◽

Cited By ~ 6

Author(s):

Masahiko Muraji ◽

Yoshio Hirai ◽

Toshiharu Akino ◽

Sadao Wakamura ◽

Norio Arakaki

Keyword(s):

Mitochondrial Dna ◽

Dna Sequences ◽

Genetic Divergence ◽

Ryukyu Islands ◽

White Grub ◽

Dasylepida Ishigakiensis ◽

The Ryukyu Islands

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Male white grub beetles prefer the pheromone composition of young females in the field

Bulletin of Entomological Research ◽

10.1017/s0007485316000432 ◽

2016 ◽

Vol 106 (5) ◽

pp. 679-684 ◽

Cited By ~ 1

Author(s):

N. Fujiwara-Tsujii ◽

H. Yasui ◽

S. Wakamura ◽

A. Nagayama ◽

N. Arakaki

Keyword(s):

Sex Pheromones ◽

Flight Tunnel ◽

White Grub ◽

Young Males ◽

Young Females ◽

Dasylepida Ishigakiensis ◽

Female Pheromone ◽

Pheromone Composition ◽

Older Males ◽

Qualitative Changes

AbstractFemales of the white grub beetle, Dasylepida ishigakiensis, release both (R)- and (S)-2-butanol as sex pheromones, but the males are only attracted to (R)-2-butanol. In laboratory-reared females, the proportion of the (R)-isomer decreased significantly as their calling opportunities increased and as they aged. We examined whether such qualitative changes also occur in field populations. We collected virgin females from the field and then trapped and analysed the volatiles emitted during their first and second callings. The ratio of (R)- to (S)-2-butanol (R/S) was 78:22 at the first calling, but shifted to 39:61 at the second calling. While investigating the composition of the female pheromones, the question arose as to whether the male preferences change in response to the shift in female pheromone composition. To answer this question, we observed the behaviour of young and old males in response to various R/S ratios as lures in the laboratory and in the field. In the flight tunnel assay of laboratory-reared individuals, young males touched female models with a 9:1 R/S ratio lure less than those with pure (R)-2-butanol; however, older males touched the two groups with equivalent frequency. In the field trap test, older males were much more attracted to (R)-2-butanol-scented lures. When we tested using lures with the same amount of (R)-2-butanol but added different amounts of the (S)-isomer, we found that increased levels of (S)-2-butanol resulted in lower attractiveness to males. (S)-2-butanol was confirmed to have an inhibitive activity in the attractiveness of (R)-2-butanol.

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