INSECTS IN RELATION
ENTOMOLOGY AND PLANT QUARANTINE
INSECTS IN RELATION
Circular 6 Powder-Post beetles
Table of Contents
Types of Products Likely to be Infested............ 3
Symptoms of Infestation............................ 4
Description of the Lyctus Beetles and Their Habits. 4 Measures for Preventing Lyctus Infestation......... 5
Careful Selection and Grading of Stock........... 5
Frequent Inspections............................. 6
Chemical Treatments to Act as Repellents......... 8
(1) Borax (2) Sulphur
(3) Pentachlorophenol (4) Linseed oil
Period of Protection............................. 9
Measures for Controlling Lyctus and Other PowderPost Beetle Infestations......................... 10
Chemical Treatments 10
Che ica Tr atm nt ..............................@1
Precautions to Take in Handling Chemicals...... 10
Surface Applications......................... 11
(1) Urthodichlorobenzene.................. 11
(2) Turpentine and Kerosene Mixture........ 11
(1)j Pentachlorophenol...................... 11
(2) Light ine Oils........................ 11
(3) Kerosene............................... 12
Heat Treatments.................................. 12
Dry Heat....................................... 12
Moist Heat..................................... 12
List of Companies Handling Chemicals and the Trade
Names of the Latter.............................. 14
List of Publications on Powder-rost Beetles and
Their Control.................................... 15
... 9 ...
Circular 6 -Powder-Post Beetles 2
Buildings and stored wooden products used in connection with the National Defense Program are subject to the attack of powder-post beetles. The most
important of these are the Lyctus beetles (fig. 1)0
Lyctus beetles attack only the sapwood portion of openpored hardwoods such as ash, oak,
walnut, pecan and hickory. Many other kinds of wood, however, are susceptible to infestation. The extent of infestation and subsequent damage is in proportion to the starch content of the wood, as this substance is attractive
to them (fig. 6b). Heartwood is practically free of starch and is immune to infestation (fig. 6a). Under certain conditions, damage to the finest quality stock representing a loss of 10 to 50 percent of the product is not unusual. Figure 1 -Winged adult (figs. 3 and 7). beetle of Lyctus
planicollis, Lec., the Other beetles attack seasoned
southern Lyctus. softwoods and differ from the above
Enlarged. species in that they infest both
sapwood and heartwood. Inasmuch as they attack mainly the woodwork of buildings, such as
the sills, joists, subflooring, rafters, etc,, the extent of damage caused by them is generally much less than that
of the Lyctus beetles which attack large stores of finished
products. Because of the relative unimportance, of the
species- which infest softwoods, the following-discussion
is applicable particularly to the Lyctus beetles, with
the exception of that portion of the control measures
which relates to chemical treatment.
Circular 6 Powder-Post Bectles 3
TYPES OF PRODUCTS LIKELY TO BE TJF212TZD
All classes of crude and finished frrdiood products stored at quartermaster depots by the Army and Navy are subject to attack by Lyctus beetles. Gun stock
Figure 2 Walnut gun stock blank pulverized by Lyctus planicollis
blanks (fig. 2), implement handles (fig. 6b), and wooden wheels in particular have to be watched closely. In addition the bins, floors and structural timbers made of hardwoods are subject to infestation. At administrative quarters and in officers' dwellings, such articles as furniture, filing cabinets, and floors may be damaged by
these insects (fig. 3).
Firure 3 Surface of
wood removed to reveal
t ightly packed powder
or frass made by the
larvae or grubs; also
a few emergence holes
through surface made
__ __ by the adult beetles
. of Lyctus planicollis (about natural size)
Circular 6 Powder-Post Beetles 4
SYLIPO14S OF INFESTATION
During the first year of infestation the powder comes from exceedingly minute holes in the stored sapwood material of hickory, ash, oak and other seasoned hardwood products, but after the second year the small holes from which the beetles have emerged are more or less conspicuous (fig. 3). From these, flour-like powder falls and forms in piles and is readily seen when the infested material is moved or jarred (fig. 7). When the wood is cut or split the interior is often found to have been converted into a mass of closely packed powdery material which has
been held together by an outer thin shell and intervening fibers of sound wood (fig. 3). The grubs, burrowing through the solid wood in all directions, have pulverized the wood fiber and have packed their burrows with this powdered wood (fig. 4). The injury done by larvae of Lyctus beetles is always confined to the white wood Figure 4 Larva, or sapivood, although rarely the heart"grub" or "worm" wood is penetrated when the matured of Lyctus plani- beetles are emerging from the wood.
DESCRIPTION OF THE LYCTUS BEETLES AND THEIR HABITS
The winged adult Lyctus beetles are srall, slender, somewhat flattened, reddish brown to nearly black, and about three-sixteenths inch in length (fig. 1). They lay their eggs (fig. 5) in the pores of the wood, and the
Figure 5 Eggs of Lyctus planicollis inserted in pore
in wood. Enlarged about 50x.
Circular Powder-Post Beetles 5
larvae or grubs (fig. 4) which hatch from them burrow through the wood and reduce the fiber to a flour-like powder (figs* 2s 3 and 7). The different kinds of Lyotus beetles vary somewhat in their habits and seasonal history, but there is a general similarity. Under outdoor conditions they pass the winter as larvae in the wood, change to pupae (the resting stage) in early spring, and in late spring and early summer the adult beetles emerge from the wood and fly about* In storehouses, or other buildings that are kept warm and dry the development is hastened and the adult beetles may emerge during the latter part of the winter or early in the spring. In the extreme south, one species may have more than a single generation a year.
ME~ASURES FOR PREVENTIING LYCTUS INFESTATION
Careful Selection and Grading of Stock
Of prime importance in protecting stores of rouch hardwood products in the process of seasoning and of the more valuable manlufactured articles from Lyctus injury, is the selection of stock which is naturally immune or at least somewhat resistant to attack. The likelihood of infestation is mainly in direct proportion to the quantity of sapwood present in the product and the amount of starch it contains
Inasmuch as heartwood is immune to infestation
(fig. 6a) it is desirable to obtain all heartwood material where possible* Heartwood has not been readily accepted by the trade at large because of the deep color. It is just as serviceable, however, as the sapwood (fig. 6b and is free from losses due to Lyctus attack. The Forest Products Laboratory of the Forest Service has conducted exhaustive strength tests and has found that the heaviest and consequently the strongest hickory averages more than 10 growth rings per inch; also that weight for weight red hickory (heartwood) is as strong as white hickory Isapwood)o
Circular 6 -Powder-Post Beetles 6
It is recognized that in many cases it will be impossible to obtain all neartwood, and therefore, in order to simplify the periodic inspections which should be made, the stock should be graded and stored by type of material, such as (1) heartwood, (2) pure sapwood and (3) part sapwood.
Figure 6 -Two finished
a. Red heartwood,
b. White sapwood,
by Lyatus pLani
The material should also be piled according to age, since the longer the stock is exposed to infestation, the greater is the probability of damage. If the above system is followed, the heartwood pile never need be disturbed. If not so classified, all of the stored product has to be h ndled each time an inspection is made.
Another means of keeping losses at a minimum, is
to make frequent inspections, especially during the spring and early summer. The discovery of small piles of powderlike dust coming from tiny holes (fig. 7) indicates that infestation has taken place and that action should be
Circular 6 -Powder-Post Beetles 7
taken immediately to separate the stock containing live "worms" from the uniinfested stock. This will prevent spread of the infestation. In the case of heated buildings, it is important to make at least one mid-winter
Figure 7 Ash sapwood (airplane stock) destroyed by larvae of
Lyetus planicollis. Note telltale piles of powder pushed to
surface of wood; also holes in surface (greatly reduced).
inspection, because under such conditions the small black beetles (fig. 1) begin to emerge any time after the middle of February. Once emergence has taken place, all of the sapwood stock which has not been chemically treated is liable to attack.
Inasmuch as it is difficult at times to detect
early stages of infestation and often impractical to make periodic inspections, -it may be desirable to insure protection and avoid inspections by treating chemically all of the sapwood stock*
Circular 6 Powder-Post Beetles
Chemical Treatments to Act as Repellents
As the result of recent research, a number of
chemical treatments have been developed for use in protecting rough and green as well as seasoned finished products against Lyctus attack. These are surface treatments and in the case of rough products that are later to be converted into finished articles, retreatment is advisable following such conversion. These materials have been tested on a commercial scale and found to be practical for use where the necessary facilities for handling are available. A simple way to treat lumber and other bulky products is to provide a vat or other suitable container in which to immerse the wood for a given period,
When preparing large quantities of the chemical
it is often convenient to run a one-half inch steam line jet into the container in order to heat the solution and agitate it sufficiently to hasten getting the chemical into the solution. In addition a steam coil of sufficient size should be laid at the bottom of the container to hold the temperature of'the solution at about 1800F, This procedures particularly desirable in the use of borax and sulphur, since these chemicals are suitable for treating green lumber and other rough products,
(1) Borax: When borax is to be used, a 5 percent concentration is readily mixed by dissolving 22 pounds of borax in 50 gallons of water. When the temperature of the solution is held at 1800F. the green wood should be immersed for a period of 10 seconds. Borax is cheap, readily available and free from health hazards.
(2) Sulphur. Another promising dip recently discovered is sulphur, Lyctus beetles avoid sulphur treated wood when non-treated material is available. If they do crawl over treated wood, the sulphur causes the females' oviDositors to become distended and paralyzed, thereby preventing egg laying and larval attack.
A 1 to 2 percent concentration is prepared by mixing to 8 pounds of "sulfocide" or other finely divided
Circular 6 -Powder-Post Beetles 9
sulphur, such as microfine sulphur or dry lime sulphur, with 50 gallons of water. A satisfactory treatment for green wood consists of a 10 second immersion in the mrixture at a temperature of 190uF. This treatment is less Costly (5 to 8 cents per thousand board feet) than that of borax (181 cents per thousand board feet) and has the advantage of giving somewhat greater protection against Lyctus attack. Sulphur has not been as thoroughly tested on a commercial scale as has borax as its discovery for such use is so recent. Present results, however, are most encouraging.
(3) Pentachlorophenol:, This is one of the most
effective chemicals for use in preventing Lyctus beetles from attacking seasoned wood. The most desirable carrier appears to be a light fuel oil of the kerosene type, At ordinary temperatures of around 680F., about 3 percent of crystalline pentachlorophenol by weight will dissolve in the oil, Heat increases its solubility and agitation hastens the process. When difficulty is experienced in obtaining quick solubility, the addition of 5 percent of a more active solvent, such as pine oil will be found quite helpful. These solutions may be obtained already prepared under trade names. It has been determined that seasoned lumber and other products i-mmersed for a period of 10 seconds in a 3 percent solution of pentachlorophenol was effectively protected against Lyctus attack. oil treatments are limited to seasoned wood.
(4) Linseed oil: For treating more expensive
seasoned finised products, it may be advantageous to use boiled linseed oil which is readily available locally. Boiled linseed oil should be applied hot to be most effective; two applications should be made if a brush is used. Where a large quantity of stock is involved, it may be more practical to immerse the material in a tank containing the oil. A little kerosene added to the hot oil, aids rapid penetration. Linseed oil stains the wood slightly yellow.
Period of Protection
As indicated above, the chemical treatments recommended, with the exception of linseed oil, are the result
Circular 6 Powder-Post Beetles 10
of recent experimental work and consequently the period of protection offered beyond 1 or 2 years is unknown.
MEASURES FOR CONTROLLING LYCTUS AND OTHER
POWDER-POST BEETLE INFESTATIONS
once infestations have been discovered and the attacked material has been separated from the remainder of the stock, it should be destroyed by burning if sufficient ly damaged* If it is only lightly attacked and still serviceable, the infested portion should be triimned off and burned or treated with a penetrating chemical. In addition all refuse stock which might be harboring beetles should be removed and destroyed,
Infested serviceable material can be treated chemically either by surface applications or by immersing the product in a vat for a certain period. The method used depends upon the quantity of material involved and the facilities available for treatment,
Precautions Necessary in Handling Chemicals
Reasonable care should be taken in connection with handling the chemicals that are suggested for use in treating infested wood. Some of these chemicals, as orthodichlorobenzene, pentachlorophenol and creosote, will cause irritation of the skin of certain people. It is therefore advisable to wear chemically resistant (rubberized fabric or neoprene treated) gloves and aprons. The eyes should be protected by goggles, especially if the chemical is to be applied to overhead timbers. Rooms where treatment is being applied should be well ventilated so as to avoid headache or nausea. When possible, equip the room where considerable treating is to be done, with a fan or blower adequate to remove fumes. Also follow the directions furnished by the companies marketing the chemicals for safe use and antidotes. These mixtures should not be heated over a direct fire. Where possible dip the wood in vats of these mixtures which are heated by coils of steam
Circular 6 Powder-Post Beetles ii
High grade seasoned products, especially finished manufactured articles like furniture or floors of buildings are best treated by surface applications with suitable penetrating toxic substances.
(1) Orthodichlorobenzene: This is one of the most penetrating and effective liquids for killing all stages of powder-post beetles in infested wood. The wood should be liberally saturated with it or dilutions of it with cottonseed or light petroleum oil up to 50 percent. Where the borers are deeply imbedded, more than one application may be necessary to reach all of the active forms. Treated material should be kept under observation in a warm room for several days to determine the full effectiveness of the chemical. It is quite likely that the finish on the surface of the wood will be marred; however, the surface can be refinished subsequently.
(2) Turpentine and Kerosene Mixture: Where there is danger of marring the finish on the wood, a mixture composed of 9 parts turpentine to 1 part kerosene may be used, although this mixture is not as effective as is orthodichlorobenzene.
There are several chemicals and mixtures which are suitable for treating wooden products in vats. 71here facilities are available, such applications are more likely to insure successful treatments than is possible by surface applications.
(1) Pentachlorophenol: Another material which is
about as penetrating as orthodichlorobenzene is pentachlorophenol. It is very effective in killing Lyctus in all stages present in seasoned stock up to 4 inches thick when submerged in a 5 percent solution in a light fuel oil for a period of at least 5 minutes. Larger stock will require longer periods of immersion.
(2) Light Pine Oils: These oils have been used effectively in treating infested wood and also do not mar the finish.
Circular 6 Powder-Post Beetles 12
(3) Kerosene: Another readily available material is kerosene. It Fas a fire hazard and slightly raises the grain andit is difficult to stain kerosene-treated sapwood so as to match the rest when articles need to be finished or refinished
In some instances as at aircraft factories and shipyards, facilities may be available for killing Lyctus beetles in various stages of development in infested stock by means of heat treatments, For this purpose a kiln or other suitable chamber in which temperatures and humidities can be regulated is necessary. Such treatments are practical when large stores of infested lumber or other wood products
Where dry heat is used, a kiln treatment Which
will raise the temperature throughout the wood to at least 1200F. will be effective in killing powder-post beetles
Another method of effectively treatIng infested stock is to place it in a kiln which is supplied with live steam and then gradually raise the temperature to the degree necessary to produce mortality. After all parts of the product have reached the designated kiln temperature, such temperature is maintained for the required period to kill all stages of the beetles, Inasmuch as wood is a poor conductor of heat, its temperature rises slowly. The time required for wood to acquire the kiln temperature is called the "lag" period. This varies according to the thickness of the wood*
In Table No. 1 it will be noted that an additional short safety period is allowed even after the designated lethal period has expired to make certain of an effective treatment. Thus, to successfully treat infested stock such as ash sapwood one inch thick when exposed to-a kiln temperature of 1300F. under conditions of a saturated atmosphere, it requires 1/2 hour for the "lag" time, 1-1/2'hours for the treatment at the constant temperature and 1/2 hour additional safety period, or a total of 2-1/2 hours*, 1,ower temperatures and humidities in the kiln lengthen the period of exposure for material of the same thickness. Heavier dimension stock also greatly increases the period required for successful treatment*
Circular 6 Powder-Post Bet
Table 1. ftShedule for treating wood to cheek
damg by Dder-Post beetles,
:Lohao*Time ro- :Addi- :Time :Total period
t~-: :quired to :tion- :then :of exposure
Relative :pera-: Thicek- : overcom lag :-. al : bld at : af ter kil has humidity :twro : noe :after kiln has:& of elethal : attained
(percent): re- : of finedd lethal--safe- :t4)r: required
:quired: timber :temeratux'e ty :,ature condi t ionrs
Or Inches : Hours :Hours :Hours : Hours
0 ~ 100 *0 130
~ : ( 2 3+
: ~0:( Bj
:( :1 6 :8
:(** * : t 2 1 6
:( : 30 :38
:( 2 2 I :0 39
:( 1 : 1 : 4 :0
:( 2 :2 : 1 :4 :
:(~:( aj :1 :4
:( : : 1 :4
:( 3 4 2 :7 11
:( 1 :: 9 : 38
:( 2 :2 : ~ 36 :
n ( 3 : j 9:36 A N!A
Circular 6 -Powder-Post Beetles 14
LIST OF COMPANIES HANDLING CHEMICALS AD THE
TRADE NAMES OF THE LATTER
E. I. duont deNemours & Co., Inc., Wilmington, Del. Los Angeles Chemical Co., 1960 Santa Fe Ave., Los
Mallinckrodt Chemical Works, 3600 No. Second St.,
St. Louis, Missouri
Pacific Coast Borax Co., 51 Madison Ave., New York City
Coal-tar Creosote Oil: (Grade 1, Federal or American Wood lPreservers' Specifications) Barrett Company, 40 Rector St., iNew York City Bermuth Lembcke Co., 420 Lexington Ave., New York City Creosote Sales Corp., Lexington Bldg., Baltimore, Md. James Good, Inc., Susquehanna Ave. and Martha St.,
Koppers Company, Tar and Chemical Division, Pittsburgh,
Los Angeles Chemical Co., 1960 Santa Fe Ave., tos Angeles,
Monsanto Chemical Works, 1700 So. Second St., St. Louis,
Orthodichlorobenzene: (Orthene or U. D. B.)
Capitol Chemical Co., 1050 30th St., N.W., Washington,
Dow Chemical Co., M, idland, Michigan E. I. duFont deNemours & Co., Inc., vilmington, Del. James Good, Inc., Susquehanna Ave. and Martha St.,
Hooker Electrochemical Co., 60 East 42nd St., New York
Hughes ChemicalKCo., 1424 Philpot St., Baltimore, 1Md. allinckrodt Chemical Works, 3600 No. Second St.,
St. Louis, miSsouri
Monsanto Chemical Works, 1700 So. Second St., St. Louis,
Solvay Sales Corp., 40 Rector St., New York City
entachlorophenol: (Dowicide G, Permasan or Permatol A, iermaseal, eermatox and Wood-tox.) Dow Chemical Company, Midland, Michigan Monsanto Chemical Works, 1700 So. Second St., St. Louis,
Circular 6 Powder-Post Beetles 15
Micro fine Suphr
Acme White Lead & Color Works, Detroit, Michigan American Cyanamid & Chemical Corp., 30 Rockefeller
~Plaza, New York City
Freeport Sulphur Co., 122 East 42nd St., New York City
B. G. Pratt, 50 Church St., New York City California Spray Chemical Corp., Richmond, Calif. E. I. duPont deNemours & Co., Inc., Wilmington, Del. Freeport Sulphur Co., 122 East 42nd St., New York City
Neoprene Treated Gloves:
American Anode, Inc., 60 Cherry St., Akron, Ohio
The above list of concerns and their products is included for the information of the users of this circular, without given or inferred guarantee of the reliability of the firms or endorsement of their individual products. No attempt has been made to make the list fully complete and no discrimination is intended or implied against firms whose names or products are not listed.
LIST OF PUBLICATIONS ON POW9DER-POST
BEETLES AND THEIR CONTROL
Christian, M, B. -- 1939 -- Chemical dip tests against Lytu powder-post beetles.
ii-hrn Lumberman 159(20) 105-109, Dec. 15.
-1940 -- yetus powder-post beetles and their control. "Pests" 8(6): 8-9 and 10, figs. 4, June,
Kansas City, Mo.
-1940 -- yctus beetle damage prevention.
Southern Lumberman 160 (2021): 47-9, 3 figs., June 15. St. George, R. A.-- 1929 -- protection of log cabins, rustic work, and unseasoned wood from injurious insects. Farmers' Bull. 1582, p. 19, figs. 23.
Circular 6 Powder-Post Beetlea 16
Snyder, T.E. ----- 1916 -- Egg and manner of oviposition of Lyctus planicollis. Jour. of Agr. Research, Vol. VI, No. 7, Dept. of Agr., Washington, D. C., May 15.
-- 1923 -- High temperatures as a remedy for Lytus powder-post beetles. Jour. For. v. 21, No. 8, pp. 810-814. Snyder, T. E. and St. George, R. A.-- 1924 -- Determination of temperatures fatal to the powder-post beetle, Lyctus planicollis LeConte, y steaming infested ash and oak lumber in
a kiln. Jour. Agr. Research, v. 28, no. 10, pp.-1033-38, illus.
Snyder, T.E. ----- 1926 --Preventing damage by Lctus powder-post beetles. U.S.D.A. Farmers' Bull. No. 1477. March (revised Sept. 1936, Feb. 1938)
-- 1927 -- Defects in timber caused by insects. Dept. Bull. 1490, U.S.D.A., pp. 46, figs. 45, July.
--1935-- An introduced Anobiid beetle
destructive to houses in the Southern States. Proc. Biol. Soc. Wash., Vol. 48, pp. 5960, Pl. III, May 3.
-- 1938-- The present status of the Lyctus problem. Yearbook National Hardwood Lbr. Ass'n., pp. 84-90, fig. 1, October, Chicago, Ill.
UNIVERSITY OF FLORIDA
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