THE BIOLOGY oF CANADIAN WEEDS. 78. sorunum carolinense L. and S olanum rostratum Dunal

I. J. BASSETT and D. B. MUNRO Biosvstematics Research Centre, ottawa, ontario K I A 0C6. Received 25 oct. I9g5 . accepted 7 Apr. 1986.

Bnssprr, L J. aNo MuNno, D. B. 19g6. The biology of Canadian weeds. 7g. carolinense L. and s. rostratum Dunal. cin. J. sci. 66:977- 991.

symmary of biological information is provided on two species of prickly nighl -Ashade, solanum carolinense (horse-nettle) and solanum iostratum (buffitouur). Horse-nettle, a perennial, is a troublesome weed in southern ontario. It is also an tmportant host for insects and diseases of crop and is considered porsonous to sheep, cattle and humans. Buffalobur, an innual, is widely scattered across canada, and reported to be poisonous to livestock. Details ofrepioductive biology, response to insects and methods of control for both species are presented.

Key words: Horse-nettle, weed biology, Solanum spp., buffalobur

[Biologie des mauvaises herbes canadiennes. 78. solanum carolineuse L. et .so- lanum rostrataz Dunal.] Titre abr6g6: Solanum carolinense et S. rostratum. on donne un r6sum6 de la biologie de deux plantes, solanum carolinense (morelle de la Caroline) et S . rostratum. Solanum carolinense est une mauvaise herbe vivace qui cause des probldmes dans le sud de I'ontario. c'est un h6te important oour les insectes et Ies maladies qui ravagent les cultures; on la considdre toxique pour les ovins. les bovins et l'6tre humain. solanum rostrum. une plante annullle, est 16- pandue dans tout le canada; on a signal6 ses effets toxiques ihez le b6tail. on donne des d6tails sur la reproduction de ces deux plantes, leui r6action aux insectes et les m€thodes de lutte employ6es contre

For personal use only. elles.

Mots cl6s: solanum rostratum Dunal, biologie des mauvaises herbes, Solanum spp.

l. Name perennial, 3-12 dm high, erect, loosely I. Solanum carolinense L. horse-nettle: branched; stems armed with slender yel- morelle de la Caroline (Alex- et al. l9g0): lowish spines up to 5 mm long. stellate-pu- ball-nettle (Fernald 1950); bull-netrle, ap- bescent; roots both vertical and horizontal. ple-of-Sodom. wild tomato, sand bri-er capable of producing new shoots. Leaves (Muenscher 1955). ovate to oblong, irregularly wavy-toothed Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 II. Solanum rostratum Dunal buffa- or lobed, 4-14 cm long by 2-6 cm wide, lobur, morelle rostr6 (Alex et -al. 19g0); both surfaces stellate pubescent with vel- Kansas-thistle (Fernald 1950); beaked lowish hairs; petiol"r up to 20 mm long. nightshade, sandbur, Colorado bur, Texas in open cymose racemes on prickly thistle (Muenscher 1955). . pedicels, calyx lobes 6-7 mm long, spine- nightshade family. Solanacdes. less; corolla violet or occasionallv white. 5- lobed. about 3 cm in diamerer :nl: 2. Description ifig. and Account of Variation 5, anthers 6-9 mm long. Pollen tri- Solanum I. carolinense (Fig. lA,B) is a colporate, averaging 26 p"m in diameter. Can. J. Plant Sci. 66:977-991 (Oct. 1986) Mature globose (Fig. 38), l0-20 mm

977 9'78 CANADIAN JOURNAL OF PLANT SCIENCE

in diameter, pale orange or yellow, smooth obovate, flattened, granulose, yellow and glabrous; about 2 mm long, lightbrown (Fig' 3C)'

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Fig. l. Mature plant and seedling of horse-nettle. A, mature plant; B, seedling. BASSETT AND MUNRO SOLANUM CAROLINENSE L. AND S. ROSTRATUM DUNAL 979

The chromosome number of n : 12.2n 3. Economic Importance : 24 has been determined for plants of h) Detrimental Horse-nettle is a trou- horse-nettle in Canada (Munro, unpubl. blesome weed in-I. corn (Fig. 4), grain and data) and in the United States (D'Arcy tomato fields, pastures , waste areas and oc- 1969). casionally in gardens in southern Ontario Horse-nettle is sometimes confused with and the eastern United States. Horse-nettle another prickly perennial plant, Solanum is also an important alternate host for in- e le a gnifolium Gav. (silverleaf nightshade). sects and diseases of crop plants (Ilnicki et However, S. eleagnifuliun differs from al. 1962) including the tomato leafspot fun- horse-nettle in having a dense, canescent Evs, Septoria lycopersicl (Pritchard and tomentum of scurf-like, many-rayed hairs Porte 192 I ) . The weed is also host for mos- with smaller prickles and thicker, entire or aic viruses of and tomato (Muenscher shallowly sinuate leaves. Solanum eleag- 1955) and pepper maggot, an insect pest of nifolium is most cornmon in the southwest- peppers in southwestern Ontario and south- ern United States and Mexico. This species ward (Foott 1963). has not been recorded in Canada. Horse-nettle is considered poisonous due IL Solanum rostratum (Fig. 2A,B) is an an- to its solanine content which may be up to nual, 3-8 dm high, erect, much branched; 10 times higher in autumn than during other stems covered with many stout yellow seasons. Ingestion of dry of horse-net- spines, up to I cm long, all parts pubescent tle has caused death of cattle. Symptoms of with stellate hairs. Leaves 2-10 cm long by poisoning include impaired vision, fast and 1-8 cm wide, ovate-oval or ovate in out- weak heartbeat and nervous disorders rang- line, deeply lobed or pinnately parted with ing from hyperactivity to deep depression, 5-7 lobes. with irregular. sinuate margins. coma and death. Ruminants show symp- petioles to 5 cm long. Inflorescence a cyme toms such as trembling and unsteadiness of few to l0 flowers; calyx lobes about 5 which may be initially confused with ra- mm long, very prickly; corolla yellow, 2.0- bies. Calves poisoned by horse-nettle ber- 2.5 cm broad (Fig. 3D); stamens 5, une- ries, in severe cases, show edema, transu- qual, 6-9 mm long. Pollen tricolporate, dation and local ventral swellings. Rapid

For personal use only. about 26 pm in diameter. Berry dark brown emaciation may ensue. Large cows often or black, about l0 mm in diameter (Fig. get icterus and other signs of severe liver 3E); seeds black, finely and deeply pitted, destruction after ingestion of berries. These about 3 mm in diameter (Fig. 3F). symptoms are also applicable to buffalobur The chromosome number of n : 12 has (Case 1955). Horse-nettle has also caused been determined for plants of buffalobur in death in sheep and possibly deer. A 6-yr old Canada (Crompton and Bassett 1976), boy died in Pennsylvania after eating ber- Mexico (Whalen 1979a) and in the United ries that were probably from horse-nettle States (Hardin et al. 1972). (Kingsbury 1964). Buffalobur is morphologically similar to II. Buffalobur, an annual spiny weed, is Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 Solanum citruillifolium A.Br., but has sim- often found in disturbed sites of the Great ple, gland-tipped hairs mixed with stellate Plains in the United States, spreading ones and a violet or bluish corolla with ac- northward into Canada, where it is less uminate lobes. The latter species is frequent common. Buffalobur is a nuisance because along roadsides and waste places in the the sharp spines stick to skin, hair and mu- southern United States. There is no record cous membranes of livestock (Wallace et al. of it occurring in Canada. 1956). Foliage of buffalbour contains cho- A descriptive key for all weedy Solanum linesterase inhibitory substances (Orgell et taxa in Canada has recently been published al. 1958). Several piglets have been re- (Bassett and Munro 1985). ported poisoned eating buffalobur (Case 980 CANADIAN JOURNAL OF PLANT SCIENCE

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Fig. 2. Mature plant and seedling of buffalobur. A, mature plant; B, seedling. BASSETT AND MUNRO SOLANUM CAROI'NENSE L AND S. ROSTRA TUM 981 - DIJNAL 1955; Simic 1943). Buffalobur is the major (b) Beneficial I. There are no reports of native host plant of the Colorado potato bet- beneficial qualities- for horse-nettle. tle (Brues 1941). Buffalobur is the most II. Several species in the family Solana- troublesome annual weed in cotton fields in ceae, including buffalobur, produce a large Oklahoma (McCormick 1917'). number of oil-rich seeds which can be used For personal use only. Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11

Fig. 3. Flowers, and seeds. A-C horse-nettle: A, ; B, fruit; C, . D-F buffalobur: D, flower; E, fruit; F, seed. 982 CANADIAN JOURNAL OF PLANT SCIENCE

for technical and food purposes (Aslanov a noxious weed in 36 other states (Ilnicki et and Novruzov 1978). al.1962). II. Buffalobur is not listed as a noxious (c) Legislation l. Horse-nettle is listed weed in Canadian Federal or Provincial as a noxious weed- under the Seeds Act and Weed or Seeds Act. Buffalobur is declared Regulations administered by Agriculture a secondary noxious weed under the South Canada (1967). It is also listed in the nox- Dakota Certification Standards (Wallace et ious weed act of Manitoba (Anonymous al. 1956). 1970) but not by any other Canadian prov- ince. In the United States, horse-nettle is 4. Geographical Distribution listed as a "primary noxious" weed in New I. Horse-nettle, a native of the Gulf States, Jersey (Bradbury and Aldrich 1957) and as has spread northward to Ontario (Fig. 5A) For personal use only. Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11

Fig. 4. Habitat picture of horse-nettle encroaching into a corn field, near Ridgetown, Kent County, Ontario. BASSETT AND MUNRO SOLANUM CAROLINENSEL, AND S. ROSTRATUM DUNAL 983 - and westward as far as California. Horse- central Mexico northward across the Great nettle has been introduced into Japan (Tak- Plains and into Canada (Fig. 5B). Buffa- ematsu et al. 1979) and India (Zutshi and lobur has been disseminated through much Kaul 197 4). of the world including U.S.S.R. and Aus- II. Buffalobur, native of the neotropics and tralia (Whalen 1979b). An additional Ca- southwestern Unites States. extends from nadian plant specimen, not included in Fig.

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Fig. 5. Distribution maps from herbarium specimens (ALTA, CAN, DAO, MT, MTMG, SASK, TRT, WIN, UBC). A, horse-nettle; O, literature record (Cayouefte 1972); B, buffalobur. 984 CANADIAN JOURNAL OF PLANT SCIENCE

58, was collected recently on Lulu Island (c) Communities inwhich the species occur near Vancouver, British Columbia (DAO) I. Horse-nettle was noticed most fre- (herbarium designations after Holmgren et -quently in corn, other grain fields, followed al. (1981)). by pastures, alfalfa, potatoes, soybeans and tomatoes, also in waste places (Ilnicki et al. 5. Habitat 1962; Munro unpubl. data). (a) Climatic requirements L In Canada, II. Buffalobur is an occasional weed in open horse-nettle shoots seldom- emerge before disturbed sites such as roadsides and waste mid-May and the tops usually die following places, especially in western Canada. In the the first frost in the fall. The plant grows United States, it has been reported in ov- rapidly during hot weather (Ilnicki et al. ergrazed pastures in Kansas and Oklahoma. 1962). Horse-nettle was found to be very Buffalobur has been introduced as seed, drought resistant which was attributed to the contaminating garden and forage crops fleshy, deeply-penetrating roots which (herbarium specimens DAO). often reach the water table (Bradbury and - Aldrich 1957). 6. History Horse-nettle was tested for cold tolerance I. The earliest known collections of horse- by planting several l5-mm-long root cut- nettle in Ontario were made in 1891 from tings 6 cm deep in soil in 12-cm plastic pots. Williams East Twp. and Essex Centre All pots were given I wk at * 3'C and di- (DAO, CAN). The earliest known collec- vided into varying temperature regimes for tion in Quebec was made in 1960 from Mis- I mo ( - lO, -20, - 30'C, control + 3'C). tassini, Roberval County (Cayouette 1912). Pots were then given I wk at * 3'C and II. The first record ofbuffalobur in Canada placed in a greenhouse at normal growing appeared in Fletcher (1880) where it was temperatures. Only root cuttings in control included in his list of plants occurring pots (+3"C) produced new shoots. Roots within the vicinity of Ottawa. of horse-nettle appear to be susceptible to freezing temperatures and this may explain 7. Growth and Development why horse-nettle has a distribution limited (a) Morphology I. Horse-nettle forms For personal use only. to southern Ontario where deeply penetrat- root networks which- allow clonal expan- ing roots remain below the frostline all win- sion. Roots can survive severing and short ter (Munro, unpubl. data). periods of movement to other suitable hab- II. Buffalobur, an annual, occurs on open itats. Horse-nettle has spines on stems and and often disturbed sites and flowers midveins of leaves which discourage most throughout summer and into fall. Seeds ma- herbivores from eating plants. ture shortly after flowering (Whalen II. Spines are found on stems, leaves and 1979b). Buffalobur appears to be wide- fruit of buffalobur discouraging ingestion spread across Canada. by herbivores. (b) Substratum-I. Horse-nettle occurs on (b) P e r e nnation l. Horse-nettle overwin- Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 a wide range of soil types but generally ters by roots which- penetrate as deep as a I grows best on sandy or gravelly soils. m in southwestern Ontario, thus avoiding Horse-nettle has thrived in clay pan soils of winter freezing (Munro, pers. obs.). New Missouri and also inhabits clay soils in shoots emerge the following spring. Up to southwestern Ontario (Case 1955; Dr. S. 20 aerial stems m-2 have been counted in Weaver pers. commun.). clonal colonies of horse-nettle (Solomon II. Buffalobur occurs in virtually all soil and McNaughton 1979). types, but seems to prefer Mesic conditions II. Buffalobur is an annual and overwinters in alkaline loam or clay mixtures (herbar- only as seeds. ium soecimens. CAN. DAO). (c) data I. Takematsu et - Physiological - BASSETT AND MUNRO SOLANUM CAROLINENSE L. AND S. ROSTRATUM DUNAL 985 -

al. (19'79) found that horse-nettle grown at a host-specific moth, Frumenta nundinella I l8 000 lx developed normally as did plants Zeller (see also Sections 10 and 13). Moth grown at half that level of light. However, larvae were found to infest fruits of unpol- plants grown at 20 000 lx had under 4OVo linated plants. Experimental parthenocarpy fresh weight of control plants and did not was induced by flower style removal indi- bloom. cating that tissue destruction by larvae was Tisdell ( I 96 I ) noted that root reserves of probably responsible for fruit development. horse-nettle (expressed as percent starch) Solomon (1985) discovered that horse- reached a low of l3.4%o I mo after shoot nettle plants produced three flower types. emergence in spring. The overwintering Flowers near the inflorescence apex had level of 347o was restored 2 mo after shoot short styles and were morphological male emergence. flowers which did not set fruit following II. Root physiology of buffalobur was dis- pollination. All other flowers were mor- cussed by Aldrich ( 1984) . Root volume and phological hermaphrodites; however, lower distribution was found to affect the degree flowers were fruting hermaphrodites while of competition for moisture that a given flowers in intermediate positions did not set weed would cause in crops. Buffalobur fruit (functional males) . Proportion of male could extract over I .3 kg 30 cm-3 of mois- flowers increased in response to water ture from the top 30 cm of soil to a width stress, increased shade or increased levels of I m. The same moisture extraction could of fertilizer. occur down to I m of soil depth but only in II. Buffalobur flowers are bright yellow band 30 cm wide. Buffalobur roots had a and are borne on bractless racemes. Five deep vertical distribution and therefore united form a nearly regular blos- plants would have to grow close to row som. Four stamens are equal in size (7-8 crops to cause significant moisture com- mm long), yellow and stand essentially petition. erect from petals. The fifth is much (d) Phenology I. Horse-nettle reaches - longer (12-15 mm) and is mainly yellow anthesis by early July and flowering con- with a darker greenish incurved tip. This tinues throughout the remainder of growing larger stamen is curved downward and then For personal use only. season. Berries and seed begin to mature by out. No nectar is secreted by flowers, but a mid-September. strong, somewhat offensive odour is pro- II. Buffalobur flowers in late June to early duced for a few hours after flowers first July in southwestern Ontario with fruit rip- open. ening by mid-August. Flower and fruit ma- Bowers (1915) described flowers as en- turation begins a week or two later in the atiostylous, that is, the stigma projects prairie provinces. down and outwards from one side of the (e) Mycorrhiza for mycor- - No evidence flower. This slender stigma is 12-14 mm rhizal association was found in the litera- long and occurs about 70 degrees either left ture for either plant species. or right of the largest anther. This left and Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 8. Reproduction right-handedness changes on successive ra- (a) Floral biology I. Horse-nettle has ro- cemes. Numerous taxa of visited flow- tate, 5-lobed, white- or violet flowers which ers and a large taxomonic list is provided are 3.0 cm in diameter. There are five equal for bees collected on buffalobur in Okla- anthers and a single stigma which arches homa. Insects such as Anthophora spp., above the anthers. Horse-nettle is polli- Bombus spp., and Xylocopa spp. curl their nated by and carpenter bees bodies over smaller stamens and collect (Hardin et al. 1912). pollen. The larger stamen dusts pollen onto Solomon ( I 980) discovered parthenocar- bees' bodies under their wings while the pic induced fruits on horse-nettle caused by stigmatic surface touches the opposite side. 986 CANADIAN JOURNAL OF PLANT SCIENCE

These bees must visit flowers where the po- seed germination nor did a pre-emergence sition of the style and large anther are re- cold treatment. Imbition of a O.2Vo potas- versed to effectively transfer pollen. sium nitrate (KNO3) solution increased ger- Unequal stamens serve different func- mination as did alternating temperatures tions. The four smaller stamens primarily from 20 to 30'C. provide pollen as an attractant to insects Ilnicki et al. (1962) noted that seedlings while the larger anther deposits pollen on emerged from unbroken or broken berries insects. Bowers (1975) did not, however, located within 2.5 cm of soil surface. Seed- find any difference in pollen fertility be- ling emergence occurred more quickly from tween the two anther types. Reproductive broken berries. There was some dormancy studies showed that self-fertilization rarely of seeds collected during autumn which dis- occurred in the absence of insects because appeared after a period of dry storage. Sol- of displaced anthers and stigma. However, omon (1983) noted that horse-nettle seeds experimental self- and cross pollination remained viable for at least 7 yr when stored both produced 5l-667a fruit set. Open-pol- under laboratory conditions. linated flowers produced higher fruit set. II. Steinbauer et al. (1955) found that buf- (b) Seed production and dispersal l. falobur seeds germirrated best in the labo- Berries of horse-nettle contain 40-110- ratory under alternating temperatures of 20- seeds (Gunn and Gaffney 1974). A single 30'C with 16 h per day at the lower tem- plant may produce up to 5000 seeds (Sol- perature. Cooley and Smith (1973) deter- omon and McNaughton 1979). Berries ap- mined that mechanical scarification of parently are spread by mammal ingestion seedcoats of buffalobur resulted in 68Vo and excretion although no conclusive evi- germination within 4 d when planted under dence is given for the ability of seeds to sur- 2 cm or less of soil. vive digestion (Hansen 1921; Bellue 1939; Robbins et al. 1952). (d) Vegetative reproduction I. Ilnicki et II. Berries of buffalobur contain 50-120 al. (196D found that vertical -and horizontal seeds. Mature fruit are enclosed by tight- underground organs of horse-nettle are fitting, spiny calyces (Gunn and Gaffney roots and not rhizomes as mentioned by For personal use only. 1974). Buffalobur plants can break at the some authors. Horizontal roots can extend soil surface in autumn and will tumble in to I m before they turn and produce new wind thus scattering berries (Kinch 1960). shoots. Vertical roots, penetrating to over (c) Viability of seeds and germination I. 3 m deep, can also produce new plants from Brown and Porter (1942) found that seeds- small segments at varying depths. Furrer from mature horse-nettle berries had de- and Fertig (1960) obtained four plants for veloped stronger dormancy than seeds from every six root cuttings (15 cm long) when less mature berries. Little germination oc- planted at a soil depth of 45 cm. Emergence curred at temperatures below 20"C. After 3 decreased directly with depth of planting. yr of burial in soil, germination percentage Smith and Calvert (1980) successfully Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 of seeds at depths of 8- I 2 cm was still high , produced plants from root sections as short but nearly zero in seeds at depths of 4O-45 as 2 mm, and 58Vo of 5-mm-long roots pro- cm. duced plants when buried 20 cm deep in Furrer and Fertig (1960) studied effects vermiculite. Takematsu et al. (1979) found of various factors on seedling emergence of that root segments were an important source horse-nettle. Best seedling emergence was of localized propagation because even small at 20 mm soil depth (687o) with little or no root segments survived some short-term emergence from seeds planted below 100 movement and dessication. mm. Seedling emergence was better in II. Buffalobur is an annual and does not re- lisht-textured soils. Lisht did not affect produce vegetatively. AND MUNRO SOLANUM L. AND S. ROSTRATUM DUNAL 987 BASSETT - CAROLINENSE

9. Hybrids opment. Second generation larvae had a po- No natural hybrids have been reported for tentially high impact on horse-nettle repro- horse-nettle or buffalobur. Experimental duction because moth larvae ate all seeds in crossing of buffalobur and other species berries they infested. produced negative results (Hardin et al. II. No significant information was found on 1912). buffalobur population dynamics.

10. Population Dynamics 11. Response to Herbicides and Other I. Autoallelopathy in horse-nettle seed ger- Chemicals mination was studied by Solomon (1983). I. The Ontario Weed Committee (1986) list Germination was inhibited by stems, roots horse-nettle as resistant to applications of and leaves of horse-nettle plants incorpo- 2,4-D and intermediate (i.e., killed less rated into soil. Leaf tissue had the strongest rapidly but controlled, either by higher rates inhibiting effect with as little as 2 g of leaf or repeated applications) in response to di- per 100 g of soil preventing germination. camba. However, leaf materials had no inhibiting Dave Bilyea and John Konecny (pers. effect on already germinated horse-nettle commun.) found that foliar applications of seedlings. This inhibiting effect on germi- l.l-1.'75 L ha-l of Kil-mor (2,4-Dlmeco- nation decreased through time unless fresh prop/dicamba) followed by ploughing 5 d leaf material was added. The inhibitor was later has been successful near Ridgetown, leached from soil with water. In natural sit- Ontario in controlling horse-nettle. Gly- uations, germination of seeds was 20Vo phosate, a nonselective herbicide, was less greater in plots where horse-nettle had effective. grown for less than 1 yr. The process of Complete eradication of horse-nettle is inhibition and reversibility of inhibition of difficult. Gorrell et al. (1981) used pi- seed germination can result in density-de- cloram at 1. I kg ha I to reduce shoot pop- pendant regulation of population size in ulations by 93Vo the first year of spraying horse-nettle. and eliminated horse-nettle completely Solomon and McNaughton (1979) stud- when used the two subsequent years. How- For personal use only. ied horse-nettle in a three-level food chain ever, in Ontario, a permit is required to use involving a plant-insect herbivore-parasi- this herbicide (Ontario Weed Committee toid relationship in New York State. The l 986). major fruit and leaf predator on horse-nettle II. Schultz and Tichota (1981) effectively was a moth, Frumenta nundinella Zeller, controlled buffalobur with 100 g ha ' of which in turn was subject to a wasp parasite glyphosate plus 138 I ha- t of dicamba ap- (Scambus pterophori Ashmead; Hymenop- plied to actively growing plants at least 10 tera, Ichneumonidae). Moth population cm tall. The effectiveness of this formula- density was controlled by density-depen- tion was improved with surfactants. Buf- dant predation of moth larvae by the poly- falobur is resistant to 2,4-D formulations Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 phagous parasitoid. Horse-nettle reproduc- except during very early growth (Kinch tion was reduced whether moth larvae were l 960). parasitized or not. However, long-term de- cimation of horse-nettle was unlikely be- 12. Response to Other Human cause of parasitic wasp reduced high dens- Manipulations ities ofthe herbivore (see Section 13 forlife I. Takematsu et al. (1919) found that horse- cycle information on the moth). nettle re-emerged aggressively after mow- Bailey and Kok 1982) found that first ing during first half of the growing season generation larvae of Frumenta nundinella whereas plant regrowth decreased after later had reduced horse-nettle srowth and devel- mowing. Root fresh weight was greatest in 988 CANADIAN JOURNAL OF PLANT SCIENCE

control plants but total fresh weight was mid-October. This common parasrte ls only 9Vo of controls when plants were cut- widespread on a variety of hosts. back at monthly intervals. Furrer and Fertig Foott (1963) described horse-nettle as a ( I 960) studied effects of cutting horse-net- wild host of the pepper maggot, Zonose- tle roots and planting them at various mata electa (Say) (Diptera: Trypetidae), depths. The authors concluded that shallow which is an important pest of pepper plants and deep tillage practices could readily in- and occasionally eggplants in southern crease spread of a horse-nettle infestation. Ontario. Infestation occurred in late Au- Ilnicki et al. (1962) determined that gust. Pepper maggot larvae were recovered horse-nettle could survive weekly cutting from fruits collected in Middlesex County, oftop growth when cut 7 cm above ground. southwestern Ontario. The interior of the A rosette of large leaves developed which fruits had been ingested and abundant frass allowed plants to acquire enough food re- was present. (Mike Oldham, Dr. H. Tes- serves to overwinter. However, seed set key; see Acknowledgments). was almost entirely eliminated. Other economic insects on horse-nettle II. Kinch (1960) suggested that buffalobur include: tobacco flea beetle, Epitrix hirti- can be easily controlled on well-cultivated pennis (Melsheimer), Coleoptera: Chryso- soil or if mowed to prevent seed produc- melidae; Scaphytopius acutus (Say), Hom- tion. optera: Cicadellidae, a vector of peach X- disease in Connecticut; Leptinotarsa juncta 13. Responses to Parasites (Germaer), Coleoptera: Chrysomelidae (a) Insects and other nondomestic animals (Metcalf and Flint 1951; Parket l97l; I. Horse-nettle is infested by a host-spe- McClure 1980). -cific moth, Frumenta nundinella Zeller II. King (1966) listed buffalobur as a wild (Lepidoptera: Gelechiidae) through most of host for the following nematodes Heter- its range including southwestern Ontario. odera rostochiensis, golden nematode, on Two generations of larvae occur each year. Long Island, New York and Heterodera ta- First generation larvae glue together two baccum, tobacco cyst nematode, in Con- leaves at the apex to form a capsule. Second necticut. Buffalobur is the native wild host For personal use only. generation larvae bore into berries, one lar- plant of the (Leptin' vae per berry, and eat the seed. Larvae de- otarsa decemlineata (Say), Coleoptera: velop through five instars before pupation. Chrysomelidae). This bettle was originally Each larva bores an escape hole in the fruit neotropical and moved northwards as buf- or leaves before pupating, leaving a thin falobur extended its range into North Amer- membrane about 2 mm in diameter. Moths ica. The beetle was described in 1824 as overwinter as adults in the eastern United being restricted to its native host plants. By States (Solomon 1980; Bailey and Kok I 874, cultivated potato plants were infested 1982). For information on moth effects on by the Colorado potato beetle from the horse-nettle see Section 10. Rocky Mountains to the Atlantic Coast Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 In southwestern Ontario, Foott (1967) (Brues 1947). Horse-nettle is also an alter- found Frumenta nundinellalarvae in many nate host for this beetle (Metcalf and Flint fruits during August but never observed 19s l). adult moths. Pupation was first observed (b) Microorganisms and viruses I. The between 30 Aug. and 4 Sept. Adults following fungal pathogens are -listed on emerged 2 to 4 wk later. A hymenopterous horse-nettle by the United States Depart- parasite, Bracon mellitor Say., was found ment of Agriculture (1960) from the north- in early September living on larvae. The ern states. HYPHOMYCETES: Alternaria parasite pupated within a cocoon inside ber- solani (EII. & G. Martin) Sor. in Wiscon- ries and emerged from mid-September to sin, Verticillium albo'atrum Reinke & BASSETT AND MUNRO SOLANUM CAROLINENSE L. AND S, ROSTRATUM DUNAL 989 - Berth. in New Jersey, New York; COE- aceae. Chem. Nat. Compd. [English translation LOMYCETES: Ascochyta lycopersici of Khim. Prir. Soedin.l 14: 678-679. Brun. in Delaware, Phyllosticta dulca- Bailey, T. E. and Kok, L. T. 1982. Biology of nundinella (Lepidoptera: Gelechi- marae Sacc. in Indiana, Septoria lycoper- Frumenta idae) on horse-nettle in Virginia. Can. Entomol. slcl Speg. in Delaware, Maryland; ERSI- ll4: 139-144. in PHALES: Erysiphe cichoracearwz DC. Bassett, I. J. and Munro, D. B. 1985. The bi- Iowa, Maryland, Pennsylvania, Micros- ology of Canadian Weeds. 67. Solanum ptycan- phaera spp. in Illinois. thumDun., S. nigrum L. and S. sarrachoides The following viruses have been found Sendt. Can. J. Plant Sci. 65: 4ol4l4. on horse-nettle: tobacco etch virus, Illinois Bellue, M. K. 1939. Carolina horse-nettle, So- (Weinbaum and Milbrath 1916); peach ro- Ianum carolinense L., and other weedy Solan- sette mosaic virus, Michigan (Ramsdell and ums in California. Calif. Dep. Agric. Bull. 28: Myers 1918); tobacco mosaic virus, Indi- 4',7t478. 1975. The pollination ecol- ana (United States Department of Agricul- Bowers, K. A. W. ogy of Solanum rostratum; Solanaceae. Am. J. ture 1960), and peach X-disease, Connect- (McClure Bot. 62:633-638. icut 1980). Bradbury, H. E. and Aldrich, R. J. 1957. II. The following fungal pathogen is re- Survey reveals extent of horse-nettle infestation. ported on buffalobur by the United States N.J. Agric. 39(0: a-7. Department of Agriculture (1960) from Brown, E. O. and Porter, R. H. 1942. The New York state. HYPHOMYCETES: Ver- viability and germination of seeds of Convol- ticillium albo-atrum Reinke & Berth. vulus arvenisL. and otherperennial weeds. Iowa (c) Higher plant parasites No higher Agric. Exp. Sta. Res. Btll. 294: 491494. plants have been found which- parasitize Brues, C. "I. 1947.Insects and human welfare. either horse-nettle or buffalobur. Rev. ed. Harvard University Press, Cambridge, Mass. 154 pp. Case, A. A. 1955. Nightshade poisoning. ACKNOWLEDGMENTS Southwest. Vet. 9: 140-143. We would like to thank the following people in Cayouette, R. 1972. Additions to the adventi- Ontario for assistance in acquiring specimens tious flora of Quebec. Nat. Can. 99: 135-136. and providing information concerning one of the Cooley, A. E. and Smith' D. T. 1973. Ger- For personal use only. plants; Dr. Susan Weaver, Canada Research mination and emergence of buffalobur, morn- Station, Harrow; Mike Oldham, Essex Regional ing-glory and cocklebur. Tex. Agric. Exp. Sta. Conservation Authority, Essex County; Dave Briefs. PR-3200: 5. Bilyea and John Konecny, Ridgetown Agricul- Crompton, C. W. and Bassett, l. J. 1976. In tural College; Robert Mailloux, Bob-A-Lou A. L

history studies of horse-nettle (Solanum caroli' Orgell, W. H., Vaidya, K. A. and Dahm' P. nense). Proc. N.E. WeedControlConf. 14: 336- A. 1958. Inhibition of human plasma cholines- 342. terase in vitro by extracts of Solanceous plants. Gorrell, R. M., Bingham, S. W. and Foy' C. Science 13 1136-1137. L. 1981. Control of horse-nettle (Solanum car' Parker, R. 197f . A comparison of haemolymph olinense) fleshy roots in pastures. Weed Sci. 29: proteins in two species of Leptinotarsc beetles. 586-589. J. Insect Physiol. 17: 1689-1698' Gunn, G. R. and Gaffney, F. B. 1974. Seed Pritchard, R. F. and Porte, W. S. 1921. Re- characteristics of 42 economically important lation to horse-nettle (Solanum caroLinense) to species of Solanaceae in the United States. U. leafspot (Septoria lycopersici). J. Agric. Res' S. Dep. Agric. Tech. Bull. 1471. 33 pp. 2l: 501-506. Hansen, A. A. 1921. Horse-nettle. Penn. Agric. Ramsdell, D. C. and Myers, R. L. f978. Ep- Exp. Sta. Weed Leaf. 6: 4 pp. idemiology ol peach rosette mosaic virus in a Hardin, J, W., Doerksen, G.r Herndonr D., concord grape vineyard. Phytopathology 68: Hobson, M. and Thomas, F.1972. Pollination 447450. ecology and floral biology of four weedy genera Robbins, W. W., Crafts, A. S. and Raynor, in southern Oklahoma. Southwest. Nat. 16: 403- R. N. 1952. Weed control. 2nd ed. McGraw- 412. Hill Book Co., New York. Holmgren, P. K., Keuken, W. and Schofield, Schultz, G. E. and Tichota, J. M. 1981. Fac- E. K. 1981. Index herbariorum. Part I. The her- tors influencing efficacy of low rates of gly- baria of the world. 7th ed. Dr. W. Junk B.V. phosate plus dicamba in reduced tillage systems. Publishers, The Hague/Boston. 452 pp. in Proc. North Central Weed Control Conf. 6: Ilnicki, R. D., Tisdell, T.F., Fertig' S. N' and 56 (Abstr.). Furrer' A. H., J.. 1962.Life history studies as Simic, W. J. lg43.Solaninepoisoning in swine. related to weed control in the Northeast. 3. Vet. Med. 38: 353. Horse-nettle. Univ. R. I. Agric. Exp. Sta. Bull. Smith, A. E. and Calvert, G. V. f980. Factors 368: 54 pp. influencing the control of horse-nettle in per- Kinch, R. C. 1960. Nebraska weeds. Nebr' ennial pastures. University of Georgia Agric' Dep. Agric. Inspection, Lincoln, Nebr. Bull. Exp. Sta. Res. Bull. 225. 15 PP. 101. Rev. 339 pp. Soiomon, B. P. 1980. Frumenta nundinella King, L. J. f966. Weeds of the world. Biology (Lepidoptera: Gelechiidae): Life history and in- N. Polunin ed. Plant science duciion of host parthenocarpy. Environ. Ento- For personal use only. and control. In monographs. Interscience Pub. Inc., New York. mol. 9: 821-825. 562 pp. Solomon, B. P. 1983. Autoallelopathy in So- delayed ger- Kingsbury, J. M. 1964. Poisonous plants of the Ianum carolinense - reversible United States and Canada. Prentice-Hall Inc., mination. Am. Midland Nat. 110: 412418. Englewood Cliffs, N.J. 626 pP. Solomon, B. P. 1985. Environmentally influ- McClure, S. M. 1980. Role of wild host plants enced changes in sex expression in an andro- plant. Ecology 66 1321-1332. in the feeding, oviposition and dispersal of 'Sca- monoecious phytopius acutus (Homoptera: Cicadellidae)' a Solomon, B. P. and McNaughton, S. J. 1979. vector of peach X-disease. Environ. Entomol. Numerical and temporal relationships in a three 9:283-292. level food chain. Oecologia (Berl.) 42: 4'7-56' weed Steinbauer, G. P., Grigsby, 8., Correa, L. Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11 McCormick, L. L. 1977. Category I for survey southern states. South. Weed Sci.- Soc. and Frank, P. 1955. A study of methods Res. Rep.- 30: 184-215. obtaining laboratory germination of certain weed Metcalf, C. L. and Flint, W. P. 1951. Destruc- seeds. Proc. Assoc. Official Seed Anal. 45: 48- tive and useful insects. Revised by R' L. Met- 52. Y. calf. 3rd ed. McGraw-Hill Book Co. Inc'' To- Takematsu. T., Konnai, M., Takeuchi, ronto, Ont. l07l pp. and lchizen, N. 1979. Study on the ecological Muenscher, W. C. 1955. Weeds. 2nd ed. The properties and control of perennial weed horse- Daigaku Nogakubu Gaku- Macmillan Co., New York. 560 PP' nettle. Utsunomiya Ontario Weed Committee. 1986. Guide to jutsu Hokoku. l0 93-102' chemical weed control. Ont. Dep. Agric. Food Tisdell, T. F. 1961. A life cycle study of horse- (Solanum Ph.D' Thesis, Publ. 75. AGDEX 641. 184 PP. nettle carolinense)' BASSETT AND MUNRO CAROLINENSEL. AND S, ROSTRATUM DUNAL 991 -SOLANUM

Rutgers University. University Microfilms In- and weeds in southern Illinois. Plant Dis. Rep. ternational, Ann Arbor, Mich. 92 pp. 60:469471. United States Department of Agriculture. Whafen, M. D. l979a.ln A.Love, ed. IOPB 1960. Index of plant diseases in the United chromosome number reports. LXIII. Taxon 28: States. Agric. Res. Serv., Washington, D.C. 265-2'79. Agric. Handbook 165. 531 pp. Whalen, M. D. 1979b. of Solanum Wallace, K., Kinch, R. C. and Sanderson, E, sectronAndroceras. Gentes Herb. 11: 359426. E. 1956. South Dakota weeds. S.D. Agric. Ext. Zutshi. U. and Kaul. B. L.1974. Meiotic stud- Serv. Rev. 367 pp. ies in some exotic nontuberous species of So- Weinbaum, Z. and Milbrath, G. M. l976.The lanum. Cytologia (Tokyo) 39 : 225-232. isolation of tobacco etch virus from bell peppers For personal use only. Can. J. Plant Sci. Downloaded from pubs.aic.ca by Entomology on 09/16/11