October 1 2010
INSECTS
October 1, 2010
Issue 24
Casey Sclar Plant Health Care Leader, Longwood Gardens BIGGER THAN BEDBUGS, MORE NUMEROUS THAN Harmonia lady beetles, it is the Brown Marmorated Stink Bug, Halymorpha halys, [BMSB] that wins the pest of 2010 award! From humble local beginnings (discovered in Allentown, PA in 1996), this insect has now spread to over 25 States. It was quite prevalent early this spring, and then the dry, hot weather must have helped propel it straight up the charts to #1. Reddish brown-black nymphs hatch from light-green eggs laid on either upper or lower leaf surfaces. After 5 nymphal stages, they become ¾” long shield-shaped brown adults with white markings on the hind end. What am I saying? Just look around the room if you want to know what an adult looks like, unless you live in a cave or something…! Seriously, one yearly generation was originally reported in PA. No fewer than two distinct egg hatches occurred this year which leads me to believe otherwise. Adults emit a pungent odor when crushed and managing them in homes is a tricky business. Don't spray them indoors. Instead, use an old shop vac and then put it in the garage. Plug up the nozzle to keep the stink down or vacuum up vanilla beans/coffee to mask the odor. Restricting BMSB entry by caulking/sealing exterior gaps also helps you “go green” by showing you where the heat will escape your home this winter. This year, “Cat-Facing” feeding damage from its sucking mouthparts has been noted on fruit trees and vegetable crops, affecting crop quality. Feeding on hundreds of hosts from Apples to Zelkova - the actual amount of damage caused by this feeding varies and the long-term effects of feeding on things like tree trunks is not well known and may be minimal. Monitor for damage to highly desirable, permanent plant tissues and treat with a pyrethroid only when absolutely necessary. Recent work at Rutgers has identified an attractant and researchers in Maryland will work with black light and other light traps to construct better traps for them. Rain, clouds, and the onset of cold temperatures will ultimately put an end to their fall flight.
DISEASES
What's Hot! As Casey decribes, Brown Marmorated Stink Bugs have reached epic proportions in Delaware and Southeastern Pennsylvania this past weekend. People have a hard time believing pesticides aren’t the answer. Don’t just spray an insecticide to make your customer happy. Explain that pesticides don’t really work and wouldn’t last more than a few days to a week. Homeowners should concentrate on caulking and replacing screens to make the house less penetrable. Or, just get used to these relatively harmless insects. It is true that when you crush a stink bug, they release a pheremone that attracts even more stink bugs. It is better to usher them back outdoors without squeezing them and getting more pheremone in the air. Are we going to have good fall color this year? Everyone asks landscape professionals to predict fall color at the start of fall. Sunny days and cool nights result in the best fall color. Dry weather can be good for fall color as long as all the leaves don’t turn brown and shrivel up before they have a chance to display their fall pigments. Black gums or Nyssas are starting to color and for the most part appear to have maintained most of their leaves. We may have received rain just in time to keep leaves on the trees just long enough to lose their chlorophyll and let those fall pigments shine! (Continued)
Fornfomromrae tion i
on pests & practices covered in this newsletter, call your County Extension Office Helpful numbers to know:
Bob Mulrooney Extension Plant Pathologist NEEDLE YELLOWING OF CONIFERS. The older, inner needles of many conifers (eastern white pine is most pronounced) will begin to yellow and drop during the weeks of autumn. This (Continued)
UNIVERSITY OF DELAWARE
Garden Line (for home gardeners only) New Castle County Extension Kent County Extension Sussex County Extension
831-8862 831-2506 730-4000 856-7303
View pictures at http://ornamental diagnostics.blogspot.com/
COOPERATIVE EXTENSION
Cooperative Extension Education in Agriculture and Home Economics, University of Delaware, Delaware State University and the United States Department of Agriculture cooperating. Janice A. Seitz, Director. Distributed in furtherance of Acts of Congress of March 8 and June 30, 1914. It is the policy of the Delaware Cooperative Extension System that no person shall be subjected to discrimination on the grounds of race, color, sex, disability, age, or national origin.
Diseases (Continued)
What’s Hot (Continued)
normal event may be magnified by the summer drought and is often a concern to unknowing homeowners.
Before the rains, aphids and spider mites hatched out to get one more feeding in. Scout plants and manage with soaps and oils as needed.
DISEASES FAVORED BY DROUGHT. Every dry summer and fall I predict an increase of certain diseases that are favored by drought. The big three or four in my experience in this area are Botyrosphaeria canker on many trees and shrubs, Cytospora canker on Colorado Blue and Norway spruces, Nectria and Hypoxylon cankers on oaks, and pinewilt caused by the pinewood nematode on Japanese black pine, Austrian pine and Scots pine. Be on the lookout for these diseases in the landscape. The fungi involved in these diseases are not virulent pathogens in their own right; they need a weakened host in order to infect them. Healthy trees are resistant to these diseases. All these diseases have a strong relationship with prolonged drought stress. Be familiar with the symptoms of these diseases, which we will be seeing this fall and into next season and maybe for a few more seasons after that.
Fall generation tobacco budworms are actively feeding, manage only as needed on desirable perennials.
Editor: Susan Barton Extension Horticulturist
Cooperative Extension Townsend Hall Newark, Delaware 19717
, 2010 ber 28 Septem AS OF
DEGREE
G GROWINDAYS
46) = 30 (’ 0 9 68 7 = 3 lege Col y, PA) 8 6) ore = 32 nt '09 rthm Cou e 00 ( Swa aware ous ) = 38 l wn y (D e enh geto 6) Gre Count eor her e r, G 9 = 34 1 Fisc Castl ente 0 w c. C 921 (' (Ne 3 Edu h & nty) = u earc Res sex Co ( Su s
October 1, 2010
Issue 24
Casey Sclar Plant Health Care Leader, Longwood Gardens BIGGER THAN BEDBUGS, MORE NUMEROUS THAN Harmonia lady beetles, it is the Brown Marmorated Stink Bug, Halymorpha halys, [BMSB] that wins the pest of 2010 award! From humble local beginnings (discovered in Allentown, PA in 1996), this insect has now spread to over 25 States. It was quite prevalent early this spring, and then the dry, hot weather must have helped propel it straight up the charts to #1. Reddish brown-black nymphs hatch from light-green eggs laid on either upper or lower leaf surfaces. After 5 nymphal stages, they become ¾” long shield-shaped brown adults with white markings on the hind end. What am I saying? Just look around the room if you want to know what an adult looks like, unless you live in a cave or something…! Seriously, one yearly generation was originally reported in PA. No fewer than two distinct egg hatches occurred this year which leads me to believe otherwise. Adults emit a pungent odor when crushed and managing them in homes is a tricky business. Don't spray them indoors. Instead, use an old shop vac and then put it in the garage. Plug up the nozzle to keep the stink down or vacuum up vanilla beans/coffee to mask the odor. Restricting BMSB entry by caulking/sealing exterior gaps also helps you “go green” by showing you where the heat will escape your home this winter. This year, “Cat-Facing” feeding damage from its sucking mouthparts has been noted on fruit trees and vegetable crops, affecting crop quality. Feeding on hundreds of hosts from Apples to Zelkova - the actual amount of damage caused by this feeding varies and the long-term effects of feeding on things like tree trunks is not well known and may be minimal. Monitor for damage to highly desirable, permanent plant tissues and treat with a pyrethroid only when absolutely necessary. Recent work at Rutgers has identified an attractant and researchers in Maryland will work with black light and other light traps to construct better traps for them. Rain, clouds, and the onset of cold temperatures will ultimately put an end to their fall flight.
DISEASES
What's Hot! As Casey decribes, Brown Marmorated Stink Bugs have reached epic proportions in Delaware and Southeastern Pennsylvania this past weekend. People have a hard time believing pesticides aren’t the answer. Don’t just spray an insecticide to make your customer happy. Explain that pesticides don’t really work and wouldn’t last more than a few days to a week. Homeowners should concentrate on caulking and replacing screens to make the house less penetrable. Or, just get used to these relatively harmless insects. It is true that when you crush a stink bug, they release a pheremone that attracts even more stink bugs. It is better to usher them back outdoors without squeezing them and getting more pheremone in the air. Are we going to have good fall color this year? Everyone asks landscape professionals to predict fall color at the start of fall. Sunny days and cool nights result in the best fall color. Dry weather can be good for fall color as long as all the leaves don’t turn brown and shrivel up before they have a chance to display their fall pigments. Black gums or Nyssas are starting to color and for the most part appear to have maintained most of their leaves. We may have received rain just in time to keep leaves on the trees just long enough to lose their chlorophyll and let those fall pigments shine! (Continued)
Fornfomromrae tion i
on pests & practices covered in this newsletter, call your County Extension Office Helpful numbers to know:
Bob Mulrooney Extension Plant Pathologist NEEDLE YELLOWING OF CONIFERS. The older, inner needles of many conifers (eastern white pine is most pronounced) will begin to yellow and drop during the weeks of autumn. This (Continued)
UNIVERSITY OF DELAWARE
Garden Line (for home gardeners only) New Castle County Extension Kent County Extension Sussex County Extension
831-8862 831-2506 730-4000 856-7303
View pictures at http://ornamental diagnostics.blogspot.com/
COOPERATIVE EXTENSION
Cooperative Extension Education in Agriculture and Home Economics, University of Delaware, Delaware State University and the United States Department of Agriculture cooperating. Janice A. Seitz, Director. Distributed in furtherance of Acts of Congress of March 8 and June 30, 1914. It is the policy of the Delaware Cooperative Extension System that no person shall be subjected to discrimination on the grounds of race, color, sex, disability, age, or national origin.
Diseases (Continued)
What’s Hot (Continued)
normal event may be magnified by the summer drought and is often a concern to unknowing homeowners.
Before the rains, aphids and spider mites hatched out to get one more feeding in. Scout plants and manage with soaps and oils as needed.
DISEASES FAVORED BY DROUGHT. Every dry summer and fall I predict an increase of certain diseases that are favored by drought. The big three or four in my experience in this area are Botyrosphaeria canker on many trees and shrubs, Cytospora canker on Colorado Blue and Norway spruces, Nectria and Hypoxylon cankers on oaks, and pinewilt caused by the pinewood nematode on Japanese black pine, Austrian pine and Scots pine. Be on the lookout for these diseases in the landscape. The fungi involved in these diseases are not virulent pathogens in their own right; they need a weakened host in order to infect them. Healthy trees are resistant to these diseases. All these diseases have a strong relationship with prolonged drought stress. Be familiar with the symptoms of these diseases, which we will be seeing this fall and into next season and maybe for a few more seasons after that.
Fall generation tobacco budworms are actively feeding, manage only as needed on desirable perennials.
Editor: Susan Barton Extension Horticulturist
Cooperative Extension Townsend Hall Newark, Delaware 19717
, 2010 ber 28 Septem AS OF
DEGREE
G GROWINDAYS
46) = 30 (’ 0 9 68 7 = 3 lege Col y, PA) 8 6) ore = 32 nt '09 rthm Cou e 00 ( Swa aware ous ) = 38 l wn y (D e enh geto 6) Gre Count eor her e r, G 9 = 34 1 Fisc Castl ente 0 w c. C 921 (' (Ne 3 Edu h & nty) = u earc Res sex Co ( Su s
