Positioning Unbailed Pyramid Traps 

 to Capture Plum Curculios 



Ronald Prokopy and Starker Wright 



Department of Entomology, University of Massachusetts 



In the 1996 Winter issue of Fruit Notes, we 

 reported results of our 1995 research on plum 

 curculio responses to unbaited "Tedders" traps. 

 These traps are pjrramidal in shape, dark in 

 color, and are placed on the ground. They 

 capture curculios that arrive on the trap 

 surface and subsequently crawl upward to the 

 tip, where they enter an inverted screen funnel 

 (a cotton boll weevil trap top) placed over the 

 tip, from which they cannot escape. 



All reported tests to date using Tedders 

 traps (hereafter referred to as pyramid traps) 

 for capturing plum curculios have involved 

 deploying unbaited traps between canopies of 

 apple trees within rows. In 1996, we evaluated 

 unbaited pyramid traps at four different 

 positions on the ground in a small commercial 

 apple orchard (Prokopy orchard) in Conway, 

 MA. In addition, we compared curculio 

 captures by pyramid traps with captures by 

 unbaited cotton boll weevil trap tops placed in 

 tree canopies. For each position or type of trap, 

 we compared daily trap captures with daily 

 incidence of orchard fruit scarring by plum 

 curculios. 



Materials & Methods 



Each pyramid trap was black and measured 

 40 inches in vertical height, 22 inches in base 

 width, and 2 inches in top width. Each was 

 staked to the ground to prevent toppling by 

 wind. All traps were constructed from plywood 

 in our laboratory, but beginning in 1997, traps 

 of essentially identical type can be purchased 

 from Gemplers Inc., Mt. Horeb, WI (only known 

 supplier). 



The orchard consisted of ten rows of five 

 trees per row. Tree trunks were 20 feet apart 

 between rows and 13 feet apart within rows. 



Trees were about 12 feet tall and about 10 feet 

 in canopy diameter. Soil beneath tree canopies 

 was treated with glyphosate in April and was 

 devoid of vegetation throughout our study. The 

 remainder of the orchard floor was covered with 

 grass, which was maintained at a height of 2 to 

 4 inches. Dense woods, which we considered to 

 be prime overwintering habitat for plum 

 curculios, lay about 25 feet north of the end tree 

 of each row, and a large open field of grass lay 

 immediately south. 



At the pink stage of bud development, 

 pyramid traps were placed in association with 

 each of the trees in the second through ninth 

 rows (Figure 1). One trap was placed 10 feet 

 north of the trunk of the northernmost tree (15 

 feet from the woods), one trap 10 feet south of 

 the trunk of the southernmost tree of a row (at 

 the edge of the open field), one trap mid-way 

 between the canopies of the northernmost and 

 next northernmost tree of a row, and one trap 1 

 foot from the trunk of the center tree of a row. 

 At the same time, a boll weevil trap top was 

 placed on the cut end of a 4-inch upright twig in 

 the upper part of northernmost trees in the 

 second through ninth rows. 



Traps were examined daily at 7 AM from 

 time of installation (May 14) until four weeks 

 after petal fall (June 27). In addition to 

 recording numbers of curculios captured each 

 day, we also recorded daily (from full bloom on 

 May 23 until June 15) the number of fruit 

 receiving a curculio feeding or oviposition scar 

 in samples of five fruit per tree per day (200 

 fruit per day among 40 trees). 



Orchard trees received no insecticide before 

 bloom but were treated with phosmet on May 

 28 (80% petal fall) and on June 15. All traps 

 were removed during treatment, which was 

 applied by a motorized back pack sprayer to the 



Fruit Notes, Volume 62 (Number 1), Fall, 1997 



