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1995 Nursery Inspection Summary 



NHPGA members may not be aware that entomolo- 

 gists working in the Division of Plant Industry of 

 the New Hampshire Department of Agriculture 

 compile an annual summary of the insects and diseases 

 found during their inspections of nurseries and green- 

 houses throughout the state. 



There are three inspectors — Siegfried Thewke, State 

 Entomologist, and entomologists Tom Durkis and |ona- 

 than lanis. Each inspects a specific region. Thewke's terri- 

 tory is the Seacoast; lanis works in the southwestern and 

 south-central parts of the state; Durkis covers the area 

 north of Concord. Although the regions vary widely in 

 size, they are fairly evenly divided in terms of the num- 

 bers of businesses they contain. 



In the Southern region, Jonathan lanis noted that the 

 highest occurrences (of 81 types of pests observed) were 

 of spider mites (103) — this means not that mites were 

 seen 108 times, but that they were seen at 108 busi- 

 nesses, aphids (92), thrips (74), whiteflies (46), botrytis 

 (40), lapanese beetles (38), leaf spot (35), powdery mil- 

 dew (30), mealy bug (25), fungus gnats (22), stem rot (20), 

 and columbine leaf miner (18). 



He found several pests worth noting individually. (1) 

 Dodder is a parasitic plant that infects a host plant by 

 entering the plant's tissue. The parasitized plant then 

 produces dodder seeds which spread and infect other 

 plants. The parasitic dodder plant also infests other 

 plants by moving on the surface substrate. Dodder was 

 found at two businesses last year. One was infested 

 heavily and had to dispose of a large amount of material. 

 (2) Thrips, because of their large numbers and their abil- 

 ity to transmit disease, were his number-one pest of the 

 year. (3) Botrytis was found in several greenhouses. One 

 of these was of special note because the infestation was 

 so bad that the owner had to dispose of his entire crop 

 (begonias). 



Dr. Thewke, covering the Seacoast, noted aphids (18), 

 spider mites (15), thrips (11), whitefly (9), and lapanese 

 beetle, mealybug, and shoreflies (all 8) as the most seri- 

 ous pest problems — of 34 noted — in his region. 



Tom Durkis found the populations of the major pests 

 of previous years (gypsy moth, pear thrips, saddled 

 prominent moth, hemlock looper) were low; the only ac- 

 tive defoliator was bruce spanworm and even it caused 

 only 600 acres of light-to-moderate sugar maple and 

 beech defoliation. 



Insect problems in Christmas tree plantations were 



down, although fir-fern rust occurrences were much higher 

 than in previous years. 



"A new insect pest on Frasier fir was collected in sev- 

 eral Christmas tree plantations in northern New Hamp- 

 shire. The insect is a moth that was found boring into ei- 

 ther terminal or lateral shoots. By the time it was discov- 

 ered in September, almost all of the insects had aban- 

 doned the trees. Only three specimens were collected 

 and they have been sent out for identification..." 



Flower pests include an increase in tortoise beetles 

 (the "goldbug"). Peony blight caused by botrytis was also 

 common in spite of the hot, dry weather and resulted in 

 several bud abortion cases. 



In greenhouses, thrips were by far the worst insect 

 pests of the season. .."in general, verbena looked terrible. 

 Besides the normal mildew, aphid and mite problems as- 

 sociated with the plant, it seemed as if the plants them- 

 selves were of poor quality, suggesting possible seed 

 source problems. With more and more flowers being 

 grown, the demand for seeds has increased at a very 

 rapid rate. Poor stock quality is showing up more often 

 than in the past. Often the quality of the plant can be 

 directly attributed to the seed source or supplier. Vet- 

 eran growers are complaining and warning others that re- 

 liable seed sources are one of the most important — if not 

 the most important — aspects of their business." 



This is a brief — unfairly brief — overview. Complete 

 1995 summaries were available at the Winter Meeting. 

 More information can be obtained by contacting Thewke, 

 Durkis, or lanis at the Division of Plant Industry, State 

 Lab Building, Lab D, 6 Hazen Drive, Concord, NH 03301; 

 the phone number is 603-271-2561. (B.P.) 



Garden Center 



Consultations and Landscaping Designs 

 Greenhouses, Nursery, Craft, and Christmas Shop 



656 South Mammoth Road (Rte. 28A) 



Manchester, NH 03103 



(603) 625-8298 



APRIL ♦ MAY I 996 



