Trap response of cutworm moths (Abagrotis orbis) to a sex-attractant lure in grape vineyards

Larvae of Abagrotis orbis (Grote) (Lepidoptera: Noctuidae) are climbing cutworms and can damage grapevines, Vitis vinifera L. (Vitaceae), in early spring by consuming expanding buds. A sex attractant would be useful for monitoring this insect in commercial vineyards. (Z)-7-Tetradecenyl acetate and (Z)-11-hexadecenyl acetate were found in extracts of female abdominal tips. In multiple field experiments, male A. orbis were captured in traps baited with a combination of these two chemicals but not in traps baited with either chemical alone. Males were trapped from mid-September to early October in south-central Washington and south-central British Columbia. Other noctuid moths (Mamestra configurata Walker, Xestia c-nigrum (L.), and Feltia jaculifera (Guenée)) were also captured in traps baited with the A. orbis pheromone and may complicate the use of this lure to monitor A. orbis. Abagrotis discoidalis (Grote) was captured in traps baited with (Z)-7-tetradecenyl acetate but not in traps baited with the two chemicals together.

Quantifying an anti-bat flight response by eared moths

Using near-infrared videotaping we measured the nocturnal flight times of six species of eared moths (Amphipyra pyramidoides Guenée, Caenurgina erechtea (Cramer), Feltia jaculifera (Guenée), Phlogophora periculosa Guenée, Lymantria dispar (Linné), and Ennomos magnaria Guenée) in cages in which they flew, under randomized conditions, for 3 h in the absence and 3 h in the presence of simulated bat-attack sounds. When exposed to the ultrasound, four of the six species exhibited significant reductions in total flight time ranging from 38 to 98%. We suggest that this quantified measurement of flight time will be useful for fundamental studies on the evolution and ecology of moth hearing as well as applied studies on acoustic methods of controlling moth pests.

Mitochondrial DNA sequence variation among pheromotypes of the dingy cutworm, Feltia jaculifera (Gn.) (Lepidoptera: Noctuidae)

The dingy cutworm, Feltia jaculifera, is a complex of at least four pheromonal races (pheromotypes). We examined mitochondrial DNA (mtDNA) sequence and restriction-site variation in the cytochrome oxidase subunit I and II genes. Among 74 specimens representing the four pheromotypes, we found three discrete mitochondrial lineages. The most divergent mtDNA within F. jaculifera, the γ lineage, was associated with pheromotype C. This result confirms an earlier allozyme survey, which also found that pheromotype C was the most genetically distinct race. Thus, pheromotype C probably represents a classic sibling species. Of the two most similar mitochondrial lineages, the α lineage was disproportionately associated with pheromotype A and the β lineage was disproportionately associated with pheromotypes B and D. Although the correspondence between mitochondrial lineages and pheromotypes was incomplete, mtDNA variation provides strong nonbehavioral evidence for genetic divergence between pheromotypes A and B + D. Allozymes revealed more minor differentiation among the A, B, and D races. For pheromotypes A and B, the presence of distinct mtDNA lineages within populations without perfect correspondence to pheromone polymorphism has several possible explanations. It may be due to retained ancestral mtDNA polymorphism, whether initial divergence of pheromone races occurred in allopatry or sympatry, or to divergence in isolation with introgression following secondary contact. The greater differences in allele frequencies of mtDNA than of allozymes may be due either to the susceptibility of mtDNA to bottleneck effects or to asymmetric selection against hybrid females.

Electrophoretic comparisons of pheromotypes of the dingy cutworm, Feltia jaculifera (Gn.) (Lepidoptera: Noctuidae)

Males of four "sibling species" of Feltia jaculifera, characterized by their mate-recognition system (pheromotype), were examined for electrophoretic variation. Arginine phosphokinase was monomorphic but 14 other enzymes and 1 protein were polymorphic in one or more populations. No locus was diagnostic for any pheromotype. Mean heterozygosity per locus varied from 21 ± 7.8% to 26.7 ± 6.7%, the effective number of alleles per locus varied from 2.19 ± 0.43 to 3.44 ± 0.59, and from 4 to 11 loci were polymorphic in each population. Phenograms indicate that pheromotypes A, B, and D are genetically similar, whilst pheromotype C is distinctly different. Allele frequencies, FST values, and the large percentage (34–43%) of private alleles in sympatric populations of the pheromotypes indicate a genetic substructuring of the nominal species. However, the level of genetic differentiation among pheromotypes A, B, and D is well below that characteristic of sibling species. Nm values suggest that there is sufficient interbreeding between sympatric populations of pheromotypes A and B to preclude genetic differentiation due to drift. The evidence indicates that discrete mate-recognition systems can be achieved without much allozymic differentiation and can be maintained in spite of significant gene flow.