Proceedings of the Hawaiian Entomological Society (1995) 32, p. 131 (Schreiner)

Ilse H. Schreiner (1995)
Impact of Liriomyza trifolii (Diptera: Agromyzidae) and other pests on yields of yard-long beans
Proceedings of the Hawaiian Entomological Society 32, 131-131
Abstract: A series of 3 experimental yard-long bean plantings was made in successive dry seasons in Guam to determine insect impact on yield. Several different insecticides were used to manipulate insect numbers. In all experiments, Liriomyza trifolii numbers were more closely correlated with yield than any other pest measured. Yield was reduced even where the seasonal mean number of L. trifolii mines per leaf did not exceed four. Both cowpea aphid, Aphis craccivora, and bean pod borer, Maruca testulalis, were direct pests which disfigured bean pods making them unmarketable. However, neither insect reduced total yields at infestation levels measured. Pod borer infestation levels were fairly low, with pod borers attacking no more than 12% of pods in unsprayed plots in the most infested of the 3 experiments. Aphid infestation rates also did not exceed 15% in any experiment. After the seedling stage, bean flies, Ophiomyia phaseoli, infesting up to 50% of the petioles had no effect on yield. Spider mites, Tetranychus cinnabarinus averaging up to 300 per leaflet also did not affect yield in the one eiperiment where mites were abundant.

Research topic(s) for pests/diseases/weeds:
damage/losses/economics

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis craccivora	Beans (Phaseolus)	Guam
	Tetranychus cinnabarinus	Beans (Phaseolus)	Guam
	Liriomyza trifolii	Beans (Phaseolus)	Guam
	Maruca vitrata	Beans (Phaseolus)	Guam
	Ophiomyia phaseoli	Beans (Phaseolus)	Guam